# Somender singhs groove theory on an vw 8v



## ny_fam (Apr 3, 2004)

Anyone trying this on their projects?
http://somender-singh.com/content/view/7/49/
I put 2 groves per cylinder this last fall and have seen favorable results. You can see the grooves in a picture on the scientific rabbit. 
Now that my car is all put back together and the weather is not 100 degrees, I'll be putting miles on it.
Few specs of my setup:
Stock JH Block 1.8
ported solid lifter big valve head
A1 ported intake manifold
decked head to 9.5:1 
2 head Grooves per cylinder
Kent Gs2 cam
Cam gear set at +1 degree
Dual outlet exhaust mani
TT dual down pipe
Autotech 2" cat back with dynomax

Running on cheap pump gas








Cheers


_Modified by ny_fam at 5:07 PM 8-6-2006_


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

yup, just finishedmy motor last night:
GX block= 9to1 comp
big vlv head w/ 2 grooves
G grind
tt dp w/ 2" nocat exh and quiet muffler
point dist w/ msd box
I also am curious as to the mpg I'll get. I was happy to have the 9to1 comp as I didn't want to have to run higher octane fuel or resort to a knock sensor ign. 
This just replaced the 1.7l that was in the car.


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (ps2375)*

Cool- would be interested in your milage results and also where you end up setting the timing. Technically we should get the best power at 6 BTDC or even closter to TDC.
Any pictures of your grooves ?
Here's a few good pictures of my motor: 
http://somender-singh.com/content/view/66/37/
Did you CC the head before you installed it? 
If so did you calculate your CR ? or estimate ?
Cheers



_Modified by ny_fam at 7:20 PM 8-6-2006_


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## CaptEditor (Feb 23, 2004)

I'm building an 8v for economy and have been looking into doing this to my head. Any tips for putting the grooves in?

-Kevin


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## vwpoorboy (Jul 11, 2005)

This is an interesting concept. Does anyone have comparable results?
Or even an explantation on why this works?


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## ny_fam (Apr 3, 2004)

*Re: (CaptEditor)*

Here's some good references:
Guy from the inventors website was on here helping out.
http://forums.vwvortex.com/zer...37447
The inventor's web page; on the theory.
The rabbit GTI on the Inventors web site is mine.. http://****************.com/smile/emthup.gif 
http://somender-singh.com/content/view/7/49/ 
Cheers
ny_fam


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## ps2375 (Aug 13, 2003)

*Re: (ny_fam)*

I thought I took some pics of the head with the grooves, but I guess not. I used the head gasket to scribe the outside of the cylinder then I used a triangle shaped file to make the grooves. with the centerline of groove pointed at spark plug and the land between valves. I put a groove on both sides of the combution chamber. The car runs very nice, and seems to get alittle stronger as it breaks in. It is only a 9to1 comp as per VW specs. I did not cc the head or anything to calc the actual ratio.
Looking the pics of your head, that is exactly how mine looks. http://****************.com/smile/emthup.gif 


_Modified by ps2375 at 9:13 PM 8-7-2006_


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## ps2375 (Aug 13, 2003)

*Re: (ny_fam)*

Well, first tank of gas and 31.4mpg. Much better than I anticipated on breakin of the motor and for the heavy foot on the gas. It accecelerates so easily with part throttle. Appairently the 1.7 was very tired. I just put my K&N panel filter in this morning (I had to clean it). http://****************.com/smile/emthup.gif


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## snowfox (Apr 4, 2002)

*Re: (ps2375)*

That whole concept is pretty interesting and makes some sense. I'll be curious to hear how your mileage goes as you continue to break the motor in.
I am currently getting 30-32 in combined city/freeway commute, but I wouldn't mind picking up a little more MPG, if you can dig it. For reference, my set up is:
2.0 ABA bottom end (10:1 CR)
Big valve c-flow hydro head
Hydro "G" factory cam
Big throttle body
Dual outlet exh. manifold (Dasher)
TT dual DP/hi-flow cat/2" cat back
CIS-E (K-Jetronic)
All pushing a Fox wagon around. It's nothing screaming fast, but definitely has more poop than your average Fox.








I have 150k miles on the motor/head now, so a top-end rebuild can't be too far in the future. These grooves could be something for me to consider when the time comes. Keep the reports coming! http://****************.com/smile/emthup.gif


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## 84_GLI_coupe (Apr 3, 2001)

*Re: (snowfox)*

I've been wanting to try it out on my head the next time I blow my engine up, but I'm not so sure that I'd want to stay with a 1.8 8v for much longer. 144whp on the first blown bottom end, more power now. 16L/100km (~16mpg) city driving nicely.








It's a great idea. The BMW racing folks have apparently been grooving their heads for a long time.
I guess if I had a bunch of spare time, I could get my spare 10:1 1.8 8v on our engine dyno, tune the Megasquirt properly, get numbers, groove the chambers, and retune, it'd be about the best comparison. I wish I had the time...


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## ny_fam (Apr 3, 2004)

*Re: (84_GLI_coupe)*

See mention of Grooves on BMW racing engines. Is there any think on the net to read about the success of the BMW grooves? OR is it like any other good racing tech, secret.. secret secret..
Cheers


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## 84_GLI_coupe (Apr 3, 2001)

*Re: (ny_fam)*

Occasional word of mouth thing.


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## S4mig (Sep 18, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

Very interesting, but essentially its just creating more swirl in the combustion chamber. Alot of aftermarket heads use heart shaped chambers which do mainly the same thing. The only real drawback I can see is the slight reduction in compression and the posibilty of carbon forming in the grooves or hot spotting if the groove isn't smoothed out.


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## 84_GLI_coupe (Apr 3, 2001)

*Re: Somender singhs groove theory on an vw 8v (S4mig)*

Hot spots are definitely a concern. Carbon deposits shouldn't be an issue as long as you're not running overly rich, you've got good spark, and you're using a catch can for the oil breather.


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## vwpoorboy (Jul 11, 2005)

*Re: Somender singhs groove theory on an vw 8v (S4mig)*

Carbon build up is supposed to diminish because of a more complete burn. 
more efficiency= more complete burn= less carbon build-up http://****************.com/smile/emthup.gif


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (vwpoorboy)*


_Quote, originally posted by *vwpoorboy* »_Carbon build up is supposed to diminish because of a more complete burn. 
more efficiency= more complete burn= less carbon build-up http://****************.com/smile/emthup.gif 

And one more important point = more power !


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## vwpoorboy (Jul 11, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

"And one more important point = more power !"
well yes in theory, but because in reality you are loweringt the compression ratio by increasing the combustion chamber size, not much happens.
I'd like to see someone mill the head to match the cc's before& after, to see how much it helps when the CR is the same


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (vwpoorboy)*

I upped the CR then grooved. and CC'ed after the grooves but the CR was 9.5:1 when done.
Yea I wonder if you get more power from the grooves or from the increased compression?
OR
the Grooves allow you to run crazy CR without expensive gas ?
Why would BMW racing use them ?


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

WOW, the 2nd tank was 36.8 mpg!! I don't know how much the grooves have to do with the improvement,. I'm guessing the fresh motor has alot to do with the improvement. But every little thing helps to make a motor as efficient as possible. http://****************.com/smile/emthup.gif


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## blitz_bunny (May 22, 2006)

desi rabbit pride yar ! this is neato, im gunna look into it for a future build....


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## Cyrus #1 (Sep 29, 2005)

*Re: (blitz_bunny)*

I'm in the process of rebuilding a head right now and am interested in doing this. Do any of you have pictures of what the grooves look like on a VW head?


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## ps2375 (Aug 13, 2003)

*Re: (Cyrus #1)*

check the link in the first post in this thread. My head looks the same as his does.


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## Cyrus #1 (Sep 29, 2005)

*Re: (ps2375)*

I did check the link but the pictures aren't showing up. All I get is the little animations.


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## ps2375 (Aug 13, 2003)

*Re: (blitz_bunny)*

no diesel here.


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## ps2375 (Aug 13, 2003)

*Re: (Cyrus #1)*

try his website. you'll see the GTI with a pic of the head in there.


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## ny_fam (Apr 3, 2004)

*Re: (ps2375)*

Here's what your looking for:
http://somender-singh.com/content/view/66/37/
FYI thats my car ..






















Also more of the same at scientific rabbit.com
http://scientificrabbit.com/in...mid=1
A note I got from the inventor about the grooves:
My Question:
How close does the groove come to the gasket sealing area?
Somender's answer:
It should end 1.5 mm from the gasket surface. Cut the groove all the way into the combustion chamber cavity. Try to direct the squish flow between the valves.
My Question:
How wide is the groove at the large end?
Somender's answer:
The groove outlet should be 3 mm wide
My Question:
Are flat top pistons required to make the most of this technique ? My motor has dished pistons.
Somender's answer:
Stick with the dish pistons, Somender has convinced me that they work with the grooves. My grooved Suburban has dished pistons. 
Cheers
Derek


_Modified by ny_fam at 10:32 PM 8-17-2006_


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## Cyrus #1 (Sep 29, 2005)

*Re: (ny_fam)*

Good information. Thanks guys.


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## ny_fam (Apr 3, 2004)

*Re: (Cyrus #1)*


_Quote, originally posted by *Cyrus #1* »_I'm in the process of rebuilding a head right now and am interested in doing this. Do any of you have pictures of what the grooves look like on a VW head?

Are you planning on any other upgrades at the same time ?
Few questions we'd like to get the answers to when you make the mod.
Take pictures of the head before (as it came off the block) burn patterns are interesting.
Take pictures of the grooves just before the head gets installed.
Also nice to CC the chambers after the grooves.
Have any gas milage and performance data from before?
Will you be milling the head to get 10:1 CR ?
Then performance and milage data after its running again.
An What timing advance are You running with the grooves. Technically you shouldn't need as much advance to get max power. And on Cheap Gas.
Cheers
Derek


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## Cyrus #1 (Sep 29, 2005)

*Re: (ny_fam)*


_Quote, originally posted by *ny_fam* »_Are you planning on any other upgrades at the same time ?

I've got a cam, a TT 266 that will be going in. I'll also be swapping to a dual outlet manifold, most likely getting a new exhaust, and doing a mild port and polish.

_Quote, originally posted by *ny_fam* »_Have any gas milage and performance data from before?

This will be hard to compare. My O2 sensor is basically shot and I don't have a cat right now. When I put on the head a new O2 sensor and a new cat will be going on.

_Quote, originally posted by *ny_fam* »_Will you be milling the head to get 10:1 CR?

I've already milled the head, it should be right around 10:1. Do you know approximately how much the grooves increase the chamber size?
Thanks for your help,
Cody


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

Hi All,
I am very pleased to see the excitement sounding the grooved cylinder head modification.
For a little background on myself, I have been modifying engines for performance and racing for nearly 30 years. Most of my work is with the SBC engine for drag race cars. After reading the article about Somender Singh and his work nearly two years ago, I contacted him and he was kind enough to direct me to assure success. Over the last two years I have modified dozens of engines, all have produced positive results. In addition over the internet I have been following numerous projects around the globe.
Anyone interested is some interesting reading I suggest turbo brick’s forum. Be prepared for a long read, these people have much to say about the groove modification and the effects it has on their Volvo engines. I especially like the post describing how Les uses his modified engine to clean his old used spark plugs!

http://forums.turbobricks.com/...singh
Cheers
AB


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

AB,
After reading about the advancements and various groove configuration the Volvo guys have been cutting, is there any additional configurations you would recommend for the vw 8v motor? Other than or in-addition to the 2 grooves per chamber?

Also another point you mentioned on the Turbobricks forum about Air/fuel ratios. Where you mentioned that an engine with the grooves may not make its best power with fuel at the rich setting.(but make more power with more air) Does this normally hold true? or only with specific engines / configurations? 
Also would this be a reasonable way to find the right(optimum) mixture & timing procedure?

_Quote »_
http://forums.turbobricks.com/...68313
The approach I take is first set initial air/fuel slightly richer than I want to run. I then advance the ignition timing until I observe slight detonation. This is done to see if the engine is octane/detonation limited. If I obtain significant advance with no detonation it means my compression ratio is to low for the fuel.
By this time I have an idea of where I am in regards to detonation and how the engine responds to ignition timing. I test a couple of ignition advance settings for drivability and economy. With the timing set I like to lean it out slowly.
I like to test settings on the road at temperature under normal loads.

Stock Timing for the JH motor I run is 6 degrees BTDC, best or better performance is usually found between 8 and 12 degrees BTDC. I'd susspect that with the grooves best performance would be found somewhere between 6 and 10 degrees ?
I hope that we can get some dyno tuning done with these grooves. The Stock CIS fuel system found on the MK1 cars traditionaly leans out to much between 5.5k and 6.5k rpms . And thus performance suffers in the upper rpms. I wonder how the engine fueling with respond under dyno watching power at upper rpms?
Given that less timing advance is required, is recurving the distributor something worth looking at ?
I guess those with an ion sensing ignition have the advantage here..









Cheers
Derek


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (ps2375)*

Hey ps2375 ,
Have you tried driving around in 5th at 30 mph yet? Low end power is great with the grooves http://****************.com/smile/emthup.gif 
Cheers


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

I have, but I have the wide ratio 4sp(4th the same as 5th). No signs of knock, but the extra I'm feeling I think is more the new motor than the grooves. But it is all good. http://****************.com/smile/emthup.gif


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (ps2375)*

Do you have an idea what advance your timing is at?
with 9.0:1 and cheap gas you shouldn't hit ping. 
I've got mine at about 9.5:1 with 8 - 10 degrees advance. 
Cheers


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

not really sure. I'll have to get my brothers lite, it has the advance dial on it.


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (ps2375)*

Oh and watch the color of your oil.
























It won't get all black between oil changes. http://****************.com/smile/emthup.gif


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

better not, I've got new rings on that baby, and they better seal real good!!







And also a Trasko oil filter that is essentially a spin-on bypass type filter.Ckeck it out at http://www.trasko-usa.com/ , it looks and is billet style. http://****************.com/smile/emthup.gif 

_Modified by ps2375 at 9:34 PM 8-23-2006_ 


_Modified by ps2375 at 10:52 AM 8-24-2006_


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (ps2375)*

Nice filter http://****************.com/smile/emthup.gif 
But $75 for a filter http://****************.com/smile/emthdown.gif 
How often are you planning on changing your oil now ?


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## ps2375 (Aug 13, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

I've been running this for about the last 2-3 yrs. I did oil changes at 5-6k mi, now with the fresh motor and syn oil, depending on how it looks around 10k mi. I drive enough that I'm not worried about short trips and sludge. So, I'll see how it does.


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*


_Quote, originally posted by *ny_fam* »_AB,
After reading about the advancements and various groove configuration the Volvo guys have been cutting, is there any additional configurations you would recommend for the vw 8v motor? Other than or in-addition to the 2 grooves per chamber?

Also another point you mentioned on the Turbobricks forum about Air/fuel ratios. Where you mentioned that an engine with the grooves may not make its best power with fuel at the rich setting.(but make more power with more air) Does this normally hold true? or only with specific engines / configurations? 
Also would this be a reasonable way to find the right(optimum) mixture & timing procedure?

Stock Timing for the JH motor I run is 6 degrees BTDC, best or better performance is usually found between 8 and 12 degrees BTDC. I'd susspect that with the grooves best performance would be found somewhere between 6 and 10 degrees ?
I hope that we can get some dyno tuning done with these grooves. The Stock CIS fuel system found on the MK1 cars traditionaly leans out to much between 5.5k and 6.5k rpms . And thus performance suffers in the upper rpms. I wonder how the engine fueling with respond under dyno watching power at upper rpms?
Given that less timing advance is required, is recurving the distributor something worth looking at ?
I guess those with an ion sensing ignition have the advantage here..









Cheers
Derek



With your engine the squish pad is rather small, extra grooves should generate additional mixture movement to excite the charge. With your cylinder head I recommend three grooves in each squish pad, cut the groove inlet deep to direct the squish flow into the chamber roof. 
One of the reasons for running rich fuel mixtures in the internal combustion engine is because of mixture stratification. This is when the air/fuel mixtures varies in the chamber. Excessively lean areas can be so lean that they will not support combustion. Mixture movement generates a more homogenous mixture eliminating lean areas therefore leaner mixtures can be run with out flame out in areas of the chamber. 
Engines with several modifications will have different ignition advance requirements. My recommendation is to find what works best in normal driving conditions.. This could me very different from factory settings. 
_Modified by automotivebreath at 10:05 AM 8-25-2006_


_Modified by automotivebreath at 10:06 AM 8-25-2006_


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

AB are you suggesting 6 grooves per cylinder? since their are two squish pads per cylinder. And I know I need to extend the exiting grooves closer to the gasket surface.
Each pointing to the spark plug ?
Do you have any pictures of a head with 6 grooves per cylinder?
With additional grooves how high could I safely increase the compression?
Cheers


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

Here's a picture from Les in Wales. Two things I like a lot about the layout are a groove close to the sparkplug to promote early turbulent flame development and multiple grooves in the far squish area. 
Notice how he decided not to point all of the grooves at the plug.


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

Here's what Im thinking for the next set of grooves.
Either the blue setup or the red


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## RaraK69 (Jan 16, 2001)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

wow surprised this is on here. been watching the website for more info on this. very cool a few guys are running this


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*


_Quote, originally posted by *ny_fam* »_Here's what Im thinking for the next set of grooves.
Either the blue setup or the red










Blue. 
Something to think about, flame travels quickly in the hot area surrounding the exhaust valve. Perhaps addition benefit can be found by enhancing turbulence in the colder region surrounding the intake valve.


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## vwpoorboy (Jul 11, 2005)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

here's mine...
3mm wide... 1.5mm from the edge








sorry for the blur...it looked a lot better when it was a tiny pic...the other pictures made this one big
i'll post results as soon as i get it running http://****************.com/smile/emthup.gif 


_Modified by vwpoorboy at 7:20 PM 9-4-2006_


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (vwpoorboy)*

Did you get the head milled to bump the compression ratio? 
Nice grooves! 
Whats the rest of your setup?


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## VDUBIN (Jun 28, 2001)

I wonder how this mod would work on a turbo motor.


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## chickenfriend (Jan 31, 2005)

*Re: Somender singhs groove theory on an vw 8v (VDUBIN)*

Since the modification is reportedly supposed to cause a more complete combustion of the fuel, has anyone compared the modification to an unmodified head in terms of unburnt hydrocarbon emmisions at the tailpipe?
Seems that would be a relatively easy way to test one purported benefit of the modification.


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (chickenfriend)*

Yea thats a good idea, but it would require a before and after test. Its just $ and time.


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## chickenfriend (Jan 31, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*


_Quote, originally posted by *ny_fam* »_Yea thats a good idea, but it would require a before and after test. Its just $ and time.









Yeah. I know. True.


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (VDUBIN)*


_Quote, originally posted by *VDUBIN* »_I wonder how this mod would work on a turbo motor.


_Quote, originally posted by *Morten http://www.turbobricks.com* »_
And after 40 km this is my impression.
The engine is mutch smoother.
The turbo spools 500 rpm sooner.
I had to reduce my fuel 3-10 %
Strait a-b test i modified the old head.
Engine Modefied B23 et
Megasquirt running the ekstra code WB lambda controller.
After 2 weeks of driving with the groves.
This is my results.
I'm able to use the same boost pressure on regular, as i had with premium petrol before.
220 kpa with the same timing.
Fuel consumption.
Before 28 Mpg Imp. Best.
After 32 Mpg Imp and i'm still tuning.
AFR before at cruise 16-1
After at cruise 17.5-1 and nothing strange drivability problems.
I'm going to try 18-1 next week if i can burn it.
So far i’m very happy 
Morten


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## vwpoorboy (Jul 11, 2005)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

i guess i should have given more background.
it's a JH head (cis) on top a freshly rebuilt ABA, balanced and polished rotating assembly, more mods to follow but in need this running asap.
previously with the 1.8 JH i was occasionally getting 30mpg. i'm hoping to get 30+mpg. but that's a hope and we'll see reality before long. just having tranny difficulties right now








if any of you are so inclined to help it happen faster help would be appreciated http://forums.vwvortex.com/zerothread?id=2805308


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## snowfox (Apr 4, 2002)

*Re: Somender singhs groove theory on an vw 8v (vwpoorboy)*


_Quote, originally posted by *vwpoorboy* »_previously with the 1.8 JH i was occasionally getting 30mpg. i'm hoping to get 30+mpg. but that's a hope and we'll see reality before long.

Depending on how you're cammed and how drive, you should hit this easily, even without grooves. I have an ME head / Hyro "G" cam / big TB on an ABA in a Fox wagon that averages 31 in commute traffic - 35 or 36 in Freeway cruising.


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## VWinA (Oct 20, 1999)

*Re: Somender singhs groove theory on an vw 8v (snowfox)*

I find all this very interesting but I'm still not ready to grove my ported and polished head on my ABA running motronic.
I wonder how Bosch Motronic will react and if it would be beneficial to a heavilly moded engine running at high rpms.


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (VWinA)*


_Quote, originally posted by *VWinA* »_I find all this very interesting but I'm still not ready to grove my ported and polished head on my ABA running motronic.
I wonder how Bosch Motronic will react and if it would be beneficial to a heavilly moded engine running at high rpms.

With high compression SBC engines we run to 8000 RPM. We find the groove extends the RPM range slightly and maximum power is realized with a leaner A/F ratio.










_Modified by automotivebreath at 5:48 PM 9-7-2006_


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## 88GL_Wagon (Apr 17, 2003)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

Bringing this back from the dead.
Seems these Grooves may help me reach my goal of running 11.6:1 on CA pump gas (91 oct)
Everyone that has done this, did you do the grooves yourself or have a machine shop do it? Singh's himself seems to favor 1 groove, has anyone tried 1, and then 2 to see the difference between the number of grooves?
Now that some of you have used this "groove theory" can you give us real world numbers, increased performance, how much of an increase did you see in fuel economy? Is the tune for a grooved head much different than a non-grooved motor? 
What kind of base timing are you running, and how much total timing?


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (88GL_Wagon)*

Any progress reports ?
Did 88GL_Wagon groove your vw head ?
Cheers


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## benzboyracer (Aug 5, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

Just to stir this up a bit- anyone know where to get a triangular file? Can't find one at the local big-box ships.. (Home Despot, bLowes, etc). I've got an extra x-flow head to play with.

Muwahaha.



_Modified by benzboyracer at 7:11 PM 2-12-2007_


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## wclark (Mar 28, 2001)

*Re: Somender singhs groove theory on an vw 8v (benzboyracer)*

Now that (as you aptly put it) Home Despot and bLowes have put almost all the local hardware stores and lumber yards out of business around here, I do a lot of my shopping on the web...especially for slightly "uncommon" tools - the ones hardware stores used to carry but the home improvement centers dont.
By the way, I decided against grooving my heads this time around. After inspecting my chambers with my fiberscope I decided against removing the head. I needed to do some port matching for the new intake and header but that was easily done with the head in place and the drivetrain on my dolly.
Also, like some others, when I looked at most of the reported test data I saw some problems (with the data). Many before/after reports changed more than one thing between tests making the data suspect and the one I saw that seemed to do only the groove was a lawnmower engine (low RPM compared to an auto engine) that showed what I would call insignificant changes in torque. I am not saying the groove doesnt work, just that the test data so far doesnt seem to demonstrate that it does.


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## snowjedi (Nov 16, 2005)

*Re: Somender singhs groove theory on an vw 8v (wclark)*

i was very skeptical about doing this, and i did tons of research. my buddy has a 90 cabbu that needed a hg done, so i helped him out, and i grooved his head while it was off. we put it all back together and the car pulls noticeably harder now(obvously harder than it used to because it had a bad hg, but harder than any other stock 1.8 cabb i've driven!) i coulden't beleive the difference. it has more grunt everywhere in the rpms. I, FOR ONE, AM A BELEIVER!!


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (snowjedi)*

Some new groove placement ideas.
The Green lines are the new idea lines. AB - suggests that the intake valve area needs more assistance. Thought two different grooves would help the intake area, on the intake side of the squish zone. 








I think these new lines will allow me to up the CR a bit. If things work out I'll be running 10.5:1 CR, with my new pistons.
snowjedi - see your running high CR - do you have grooves in on the JH head too?



_Modified by ny_fam at 3:13 PM 2-17-2007_


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## polskipolak (Aug 22, 2003)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

I am also considering doing this on my rebuild. My setup will be exactly as the one described on the website that the OP posted. 
I unfortunately didnt get a chance to drive this car in stock form so I wont have any kind of comparison to make to help anyone out. 
So the green lines seem to be the best way to groove? What if I only wanted 4 grooves per cylinder, just so I dont lower the compression as much, what would the best combo be then? or should I just stick to the 2 per cylinder?


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (polskipolak)*

The benefit of having more grooves is to run a CR 10:1 or a bit higher, on cheap gas.
If you run just 2 grooves stay under 10:1 CR unless you've done other work to limit detonation and or a knock sensor.
Cheers


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## CaptEditor (Feb 23, 2004)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

Back from the dead!
Any updates on these grooved engines?
I am preparing to perform this modification and I read somewhere that a tighter squish zone makes the groves more effective and that the 8v VWs have a relatively large clearance in the squish zone. I was thinking about running the Group A headgasket to bup the CR up by .4 and tighten the squish zone a little.
Any thoughts?

-Kevin


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## B4S (Apr 16, 2003)

*Re: Somender singhs groove theory on an vw 8v (CaptEditor)*

I'd like to know more too, I'm in the middle of prepping a head for the engine I'll be using this summer. I'm going to do it anyway, but it'd be nice to see some rolling updates







.


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## ny_fam (Apr 3, 2004)

*Re: Somender singhs groove theory on an vw 8v (B4S)*

Here is what I've learned from race engine builders, perhaps this will lend some more info when and where to use these grooves.
A tight squish zone is very important to: 
fuel atomization inside the chamber. 
a great mixture lead to making more power
Best way the flam front expands
less octane needed for a given CR.
Faster burn, less heat
The sweet squish zone for these engines seem to be between .05" and .03"
Now the Grooves are designed to help accomplish the same above goals that can be achieved with a tight squish zone when you don't have a tight squish zone to work with.
These 8v engines have a very poor squish zone. In fact is has two difference clearance. On the spark plug side of the chamber the clearance is .14" on the other side of the chamber in the small section where the piston has a small step the clearance is .07"
Now the inventors site for the grooves states the grooves works best when the clearance is at least .07".
My use of the grooves worked OK, however I ended up finding out that I was able to run high compression with lower octane could have been due to a warn block. I didn't find this out till I was about to rebuild the block. Each cylinder was at 130 psi or so. So you can't really go on my results.
If your looking for the same effects do one of the two things:
Get new pistons that are taller and protrude above the bock. Both the RV and JH pistons don't even come up to the top of the block.(.07" from the top in fact)
And or get the top of the block milled a bit.
You'll still need to run dished pistons to control the CR.
These recommendation are the same for NA and boosted engines.
At this point I don't recommend Grooves for the VW counter flow 8V heads. We live and learn - it was a good experiment to run, I learned alot! Some time we learn what works, but most of the time we learn what doesn't








Cheers
ny_fam


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## CaptEditor (Feb 23, 2004)

Would a better alternative (keepig stock pistons) be simply shaving the block down .02-.04"?
-Kevin


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## ny_fam (Apr 3, 2004)

*Re: (CaptEditor)*

Yea could work,
If your only going down .02 .04 it may be easier to get a thinner head gasket.


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## CaptEditor (Feb 23, 2004)

*Re: (ny_fam)*

True, I think I will get the thinner headgasket. How about polishing the combustion chambers? How much would that help reduce detonation and what methods should be used to do it?

-Kevin


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## ny_fam (Apr 3, 2004)

*Re: (CaptEditor)*

polishing is a known method to asist in heading off detonation. Also google de-edging. I've seen that around too. Both ways to reduce hot spots.
Did you find a source for a thinner head gasket?
Cheers
ny_fam


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## B4S (Apr 16, 2003)

*Re: (ny_fam)*

Bildon sells the Group A gasket, it's thinner than the stocker.


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## 4ePikanini (Aug 29, 2007)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*


_Quote, originally posted by *automotivebreath* »_
Blue. 
Something to think about, flame travels quickly in the hot area surrounding the exhaust valve. Perhaps addition benefit can be found by enhancing turbulence in the colder region surrounding the intake valve.









Did anybody notice that there is no spark plug hole in this pic


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## BellCityDubber (Jun 13, 2007)

*Re: Somender singhs groove theory on an vw 8v (fourie_marius)*


_Quote, originally posted by *fourie_marius* »_
Did anybody notice that there is no spark plug hole in this pic









I did when I was doing some research, and it's gotta be a diesel... that's the only explainiation I can come up with...

Anyways, I tried putting in some somender-singh grooves in a head and I'm not sure if it's the grooves or not, but once I got it together I seem to have a major hesitation down in the low rpms.... 
I've tried looking for vac leaks, checked cam and ignition timing, checked fueling, EVERYTHING.. and I just can't seem to get `er to run properly.
so I'm going to put a different head on and see what I come up with.


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## 4ePikanini (Aug 29, 2007)

*Re: Somender singhs groove theory on an vw 8v (BellCityDubber)*

i think doing this on a diesel is a bad idea cus you lose the necessary compression
also i dont think that those grooves really work
imagine this :
take two blocks of wood and flap em together : you get a nice uniform woosh of air coming out
cut a groove and you get a directional flow of air that that will assist mixture in that single portion
if it was that good an idea, all manufacturers would dit cus it is easy to incorporate it into the manufacturing process.
i always agree not mess with a good researched stock design thats got a big budget design behind it. look at formula1 design if you are looking for aftermarket performance increase.


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (fourie_marius)*

The cylinder head is from my 68 Camaro, AFR 190 cc intake runner 350ci
SBC. Drag race application 1/4 mile 10.7 at 124 best times to date. 
These pictures were taken about three years ago. The engine has been 
rebuilt but still running with these heads. 
The plug is under the bottom squish pad, the picture angle hides it.
The grooves work as claimed. 
Here's a better picture:












_Modified by automotivebreath at 4:43 PM 6-4-2008_


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## BellCityDubber (Jun 13, 2007)

*Re: Somender singhs groove theory on an vw 8v (fourie_marius)*


_Quote, originally posted by *fourie_marius* »_i think doing this on a diesel is a bad idea cus you lose the necessary compression


woah woah woah, now... I drive diesels... I lovem... and really in a vw diesel, you dont NEED the 22.5:1 compression, you can get away with an effective compression ratio of about 15:1, even when most TD guys do the 1.9 head on the 1.6 block, it drops the CR down to 18:1 from 22.5
and after calculating the 2cc / cyl you're only loosing MAYBE... MAYBE 8cc
and seeing as how the flame propagation in a diesel is typically slower than that of it's gasoline counterparts, I would presume it would improve a nice clean uniform burn.

BUT.. I'm still in the testing phase of running a grooved head, so I'm really not for, nor against the idea at the moment, we'll have to see how this new head plays out for me.


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## 4ePikanini (Aug 29, 2007)

*Re: Somender singhs groove theory on an vw 8v (BellCityDubber)*

im a sceptic by nature so ill only be convinced if i see a before, and after dyno/logsheet combo


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## automotivebreath (Dec 28, 2005)

*Re: Somender singhs groove theory on an vw 8v (fourie_marius)*

"im a sceptic by nature so ill only be convinced if i see a before, 
and after dyno/logsheet combo" 
I'm a skeptic by nature also; when I see dyno log sheets I question the
validity.


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## BellCityDubber (Jun 13, 2007)

*Re: Somender singhs groove theory on an vw 8v (automotivebreath)*

well.... I finally managed to swap heads, and diagnosed a faulty CIS injector.
Things are now running smooth on my 86 GTI...
Real smooth infact.
..... almost too smooth for the installed 268 cam.. it was much lumpier at idle before... 
I get what somender-singh was saying about "direct drive".....
When I pull into our laneway/parking lot at work, it's got a rather steep incline (my jetta hates it)... but with the grooves in the GTI head, I can kinda crawl up it in a taller gear without having to downshift or give it the pedal... it kinda helps with the low end it feels.
as far as running cooler or being more efficient, I'm still on the fence. I've just put a half a tank of 94 (yeah yeah, well... it is a decked head on a 10:1 GTI bottom end... and I drag it)... on top of that I have a "stuck open" thermostat... so I cant quite tell if it's running cooler either.
and to make results even MORE skewed... 
yes, it's a decked head, with a different cam, portmached intake and exhaust ports... and an exhaust header...
so, yea... I'm not a very good comparison, but it does feel more like "direct drive" so to speak.
it can pull nice down low in taller gears.... I'll find out how my fuel economy is in the next little while. I'll see about a time slip from the track and maybe put my 272 back in











_Modified by BellCityDubber at 2:28 PM 6-6-2008_


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## BellCityDubber (Jun 13, 2007)

*Re: Somender singhs groove theory on an vw 8v (BellCityDubber)*

well.. after driving it for a while... 
from what I've witnessed, I'm begining to think it's the real deal!
So far, since putting a whack of upgrades on the car, I figured I should have had higher fuel consumption. 
Before - in stock form I was seeing about 500 (and change, approx 550 from filler cap to bone dry) to a tank of gas (55L tank in a mk2)
After putting small grooves (mine weren't PERFECT, but there are noticeable grooves cut) and putting it back together with a decked head at 0.080" and a 272 cam with portmatched intake and exhaust with a tri-y header, I figured I would be going thru fuel like crazy
Not to mention I took out my cat (the car is an 86 - emmissions exempt here in ontario, as it's over 20 years old) and am testing with 87 octane fuel

Now - I've been driving around here and there... spirited driving (yeah, I'm bagging on it here and there) and take it to the track and such... So far from filling up, at 3/4s tank, I've driven 175km... we'll say... 170 because I'm just on the low side of the 3/4s line.
so 550 / 5 = 110 (20%, like most of the Somender Singh articles claim for fuel savings) 550 + 110 = 660.... if I can hit anywhere over 620.. I'll be quite happy! and this would be on 87 octane fuel!!! that's like... saving an extra $15cnd in fuel!!! http://****************.com/smile/emthup.gif http://****************.com/smile/emthup.gif 
now, if fuel consumption keeps going the way it's going, I should see a tank of fuel lasting me at least 680kms!!!








my idle with my 272 camshaft after doing the work now sounds like my idle with my 268 camshaft BEFORE the grooves... lumpy... but not as lumpy as it SHOULD/COULD be....
And I can't tell about running any "colder" because of the shorter amount of time the pistons are exposed to combustion... Because I still havent fixed my thermostat







but I'm going to be refitting the whole cooling system sometime over the summer... new pump, new pulley, new hoses, new thermostat, proper G11 coolant, and some Redline waterwetter. 
so I'll have some more results in the way of cooling in the next little while
I'll keep people posted.










_Modified by BellCityDubber at 1:54 PM 6-10-2008_


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## magics5rip (Mar 17, 2004)

*Re: Somender singhs groove theory on an vw 8v (BellCityDubber)*

Just started to read about these grooves and I am happy to see that there are dubbers experimenting with this! I may have to cut some grooves myself the next time my head has to come out. 
Keep the updates coming! http://****************.com/smile/emthup.gif


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## BellCityDubber (Jun 13, 2007)

*FV-QR*

^ yeah dude! experiment!!
I mean, all I did was get a lightly ported and decked head from a buddy of mine.... he said "do whatever with it" and I only decided to do it because I remembered it and I blew my headgasket








so far things are looking promising.. and all it cost me was time, some $ for the head gasket, and a mini-hacksaw blade/handle..
it's really easy, and worth the little amount of effort! I haven't noticed any ill effects to date


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## automotivebreath (Dec 28, 2005)

*Re: FV-QR (BellCityDubber)*

This is some thing I use on a regular basis to improve combustion. Here's 
a picture of a set I have in the shop now, 23 degree SBC heads for a
maximum power street strip car.


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## brobs is back (Jan 22, 2008)

*Re: FV-QR (automotivebreath)*

any updates on this?
i have a p+p big valve carb head to put on my 1.5..
should i do this?
how do i know where/how deep to put the grooves??


_Modified by brobs is back at 5:00 PM 2-12-2009_


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## ny_fam (Apr 3, 2004)

*Re: FV-QR (brobs is back)*

Here is what I've learned about this.
Tighter squish zone is better .050" is great! No grooves needed then.
The grooves work best at .070" when you can't get .050" or better. I think the VW engine would need multiple grooves.
The vw engine uses a .14" squish zone on one side. I'd get a .040" MLS gasket over the grooves any day. Or deck the block or better pistons.


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## tacurong (Jul 13, 2009)

*Re: Somender singhs groove theory on an vw 8v (ny_fam)*

bunch of crap if it was so good the germans would of had it years ago


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