# help me max out the 8v head.



## rob ap (Oct 3, 2003)

im considering a nice project. the only problem is im researching what is availiable and possible with whats out there. the engine package im looking for requires EXTENSIVE modification however with the right parts it could be done right.
so here goes:
assuming i had the ability to make power this high...what would it take to make the 8v head live decently well at 10k rpm







i wouldnt worry about the crank, rods, pistons...those will all need to be race parts anyway for any possible longevity and those parts ill get, but i'll need at least 10k rpm from the head. This is not a drag racing head....its road racing...it will spend its life 30 minutes at a time at 7.5 to 10k rpm. titanium valves and retainers + the other lightweight parts, 13+:1 compression. (just so you know...if i used a 16v, i would have to SERIOUSLY destroke it way beyond reasonable ammounts for the rules.)
so would the masters of science-fiction engine building please step forward and take a crack at this one. (any takers?) just what RPM can you get from the 8v.
is the vw 8v able to do this at all? or am i beter off going to a different manufacturer.
thanks for the help everyone.
-rob ap


----------



## switch_900 (Aug 29, 2001)

*Re: help me max out the 8v head. (rob ap)*

well Bell Helicopters makes 1.8L 8v's that fly helicopters at 25,000 rpms so I'd say that's a start at how high you could rev it. How much you wanna spend to get it there?


----------



## 2slo2go (Aug 17, 2002)

*Re: help me max out the 8v head. (switch_900)*

well... I'm pretty sure you either going to need carbs or individual throttlebodies if your going to make power in that rpm range. Personally I'd go with throttlebodies. I'm assuming the block is going to be completely forged balanced and blue printed, the head (solid lifter) would have to be extensively ported polished and a five angle valve job performed. I'd have the valves ceramic treated. Crane or Shrick valve springs are a must (no TT), and a really really big cam... like 300 or something. That's really just a start. A 10k rpm road racing 8v sounds expensive.


_Modified by 2slo2go at 2:20 PM 10-4-2003_


----------



## rob ap (Oct 3, 2003)

it will be relatively expensive....but worth it if the answers i find are good and warrant the project. the class is DSR in the scca. relatively unlimited in modifications...just limits on displacement and # of valves and 4 cyl max. i'm limited to 1300cc for an 8v head. the newest 1300cc tech used in the class is very old late 60's early 70's stuff...datsun A12 and 13 or the honda EB series....ancient soch.
the thing is, the classification limits for the engine will be 1300cc for the 8v head.....much much less if i go 16v...and the cost goes up if i go even smaller. so of course forged balanced and properly prepped internals. This is not a drag engine...its a road race engine. 30 minute sessions at a time, but to be competitive withthe 1300 i need at least 10k rpm. ill be sticking it onto a hewland transaxle. one of the best things going for the VW is the cam directly acts on the valve...no followers and rockers like on a honda or something.
lightweight parts would make it happen....but im trying to find out if anyones turning 10k already on the strip or street and what theyve done to do that....also who would be the one to go to to find the parts i need...(any european companies i havent heard of yet?)
Ti valves, forged knifed chro-steel crank, your usual race forged internals.
oh, and Bell Textron uses gas turbine turboshaft engines. (small jet attached to a transmission) they havent used a piston since the model 47 days of MASH....i fly for a living....ive flown behind the gas turbine. it goes 4000 hours between overhaul.

_Modified by rob ap at 8:28 PM 10-4-2003_


_Modified by rob ap at 8:28 PM 10-4-2003_


----------



## 2slo2go (Aug 17, 2002)

*Re: (rob ap)*

Based on the information you've provided, I would definitely say you should go to another manufacturer. A 1.3l 8v engine at 10,000 rpm is an explosion. I can't even imagine reducing the displacement on a 1.6, which is what I assume your starting with? Thats a go-kart engine. I say get a mini cooper. and put a yamaha or honda engine in it.










_Modified by 2slo2go at 7:10 PM 10-4-2003_


----------



## rob ap (Oct 3, 2003)

okay...
the competition using the datsun/nissan A series is spinning 10k making 150hp at the wheels. and thats at 1300cc. was hoping VW could do that....perhaps i was too optimistic about VW


----------



## 84_GLI_coupe (Apr 3, 2001)

*Re: (rob ap)*

Look in the April 2003 copy of Performance VW for a MK2 with a 1300 that revs to 10800RPM.
1300cc 8v 4-cyl with twin 40 DCOE carbs, electric fuel pump, P&P big valve head (1300 head, not our 1800 head), Sorg Motorsport valve cover, Schrick 296 cam and adjustable pulley, knife-edged crank, Mahle pistons, lightened and balanced flywheel, Sachs Power Clutch, Rennsport Group A 4-branch manifold and straight through system with Supersprint twin tailpipe muffler.
Makes 102PS (= 102 hp?). Gorgeous work of art! http://****************.com/smile/emthup.gif


----------



## 2slo2go (Aug 17, 2002)

*Re: (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_Look in the April 2003 copy of Performance VW for a MK2 with a 1300 that revs to 10800RPM.
1300cc 8v 4-cyl with twin 40 DCOE carbs, electric fuel pump, P&P big valve head (1300 head, not our 1800 head), Sorg Motorsport valve cover, Schrick 296 cam and adjustable pulley, knife-edged crank, Mahle pistons, lightened and balanced flywheel, Sachs Power Clutch, Rennsport Group A 4-branch manifold and straight through system with Supersprint twin tailpipe muffler.
Makes 102PS (= 102 hp?). Gorgeous work of art! http://****************.com/smile/emthup.gif 

That sounds like the right amount of hp you would see! All that work for 102 hp? Hmm... I'm thinking unless you're going forced induction or 16v your not going to make a greaat deal of hp regardless of the rpm with a 1300cc 8v due to flow restriction. A 1.6 block reduced to 1.3 with a 1.8 16v head and ITB's? THAT might work and give you 150 at the wheels. It'd try that first if its even possible I don't know... I doubt it. If it were me I'd go to 2L class











_Modified by 2slo2go at 11:54 AM 10-5-2003_


----------



## rob ap (Oct 3, 2003)

well, remember its an unlimited in modifications class...stepped tube headers, minimal muffler, as much headwork as you can stand doing and as wild a cam youd ever want to go. it shouldnt be streetable when youre done. just drivable on the track. regarding the rules...its 1300cc for an 8v....if i go to a 16v head....i gotta go to 1005cc. and then spin at least 12k to get what i want. the guys using the 1005 are harvesting the yamaha R1 form the salvage yard....170hp thats fine....but they havve NO torque...the 1300 formula keeps up with them just fine. (proven by tyhe nissan A12/13 combo engines) whered that guy get his head and crank? (is it just a built euro 1.3 engine or something?)
the 2L cars cant hold a candle to the DSR laptimes....theyre very close to the formula atlantic cars. DSR class is very lightweight and gets alot of freedom in design. the sports 2000 (2L) class dosent get that much....and its heavier.


_Modified by rob ap at 6:26 PM 10-5-2003_


----------



## SuBsOnIc_DuB (Sep 15, 2003)

*Re: (84_GLI_coupe)*


_Quote, originally posted by *84_GLI_coupe* »_
Makes 102PS (= 102 hp?). Gorgeous work of art! http://****************.com/smile/emthup.gif 

ps is a japanese horse power rating i dont know exactly how the conversion works but i think it would be about 150 hp +/- 10 hp


----------



## vwman53 (Mar 6, 2003)

*Re: help me max out the 8v head. (rob ap)*

Ever concider an aircooled vw engine instead? The 66 engines were 1300 cc. Earlier motors were even less, the common 40hp was 1200 cc, and i guess those are the motors they use in formula vee. I bet with a little work, a set of dual port heads could be made to fit a 1300, and there is a plethora of parts out there for the classic aircooled. Other than that, good luck with your project, keep us posted on how it turns out.


----------



## 84_GLI_coupe (Apr 3, 2001)

*Re: help me max out the 8v head. (vwman53)*

The 1.3 in PVW used the original VW 1.3, which is fairly plentiful over there.
And Formula Vee engines are required to be 40hp spec engines ONLY. They can blueprint the hell out of them, but they can't go beyond the blueprints. The cars are light, so that makes up for it.
Our FSAE car weighs very little (can be picked up by a few guys) and has a 600cc Gixxer engine in it that puts out ~85hp with the tiny air restrictor in the intake. It gets up to 60mph in about 3 seconds. http://****************.com/smile/emthup.gif


----------



## Dumitru (Dec 23, 2002)

*Re: (rob ap)*

So you're a pilot, eh rob? I hope you're doing better than I am these days. By the sounds of what you're cooking, you are







. Anyway, I love "building" fantasy engines that I'd like to build if I had the cash, so I'll give it a shot here:
(you're pretty much going to have to go to all custom parts)
Block:
You'll need 84mm pistons and a 58.5mm crank. This gives 1296cc's. If you get a set of 161mm rods, this would give you a piston with very close to the same compression height as a 2L 16v and much nicer geometry to boot. You'll need some dummy plastic pistons made up to check valve-to-piston clearances before you order the actual pistons. BTW, for this engine, the piston speed at 10,800 rpm's are the same as a 1.8 at 7300, Piston G's will be about 30% greater tho. Still, engine life shouldn't be too short (at least the bottom end, anyway)
Head: I'd definitely go with full face shim under bucket lifters. For a lot of reasons, these are just better than the stock shim over. I'm told converted hydraulics are the way to go, I plan to machine a set on my lathe and try them in my Rabbit. For a cam that would take advantage of these lifters go to Webcams, part number 00-352 (http://www.webcamshafts.com/volkswagen-auto.html) (btw, Shrick also makes really nice cams for this purpose) What I'd do is download Web-Cams work sheet, give them your engine specs, head flow data and they'll be able to help you
I wouldn't go to the 37mm oversize lifters, you definitely want to keep the weight down, and with such a short stroke more lift may not be necessary, but more weight is definitely a no-no. For valves, Schrick makes valves with 41X6mmx139mm and 34X5mmX124mm (these need to be cut to length, custom guides, etc).
Hmm, what else, obviously a TT race 4-1 1.75" header, excellent exhaust, ITB's and standalone, top notch headwork is a must. 
VW Motorsport got 180 HP out of a 1.8 at 7200 RPM's, if everything is done right you should be able to get about that, albeit at a much higher RPM. 180 hp 1,3L 10,800RPM anyone?
Proper gears for this beast would be a whole new chapter in itself...
Have fun! Feel free to contact me if you want to discuss this at more length [email protected]
D



_Modified by Dumitru at 6:43 AM 10-7-2003_


----------



## dohc (Sep 28, 2001)

*Re: (2slo2go)*


_Quote, originally posted by *2slo2go* »_
That sounds like the right amount of hp you would see! All that work for 102 hp? Hmm... I'm thinking unless you're going forced induction or 16v your not going to make a greaat deal of hp regardless of the rpm with a 1300cc 8v due to flow restriction. A 1.6 block reduced to 1.3 with a 1.8 16v head and ITB's? THAT might work and give you 150 at the wheels. It'd try that first if its even possible I don't know... I doubt it. If it were me I'd go to 2L class








_Modified by 2slo2go at 11:54 AM 10-5-2003_

Ya, but that was with the really small valve head. If he were to destroke the 1.6, and use an ABA head with 42.5mm intake & 35.5mm ex., he would probably be making 150whp, but would need to use a bigger cam then a 296.


----------



## bigthump (May 27, 2003)

*Re: (rob ap)*

well,
I would recommend the hyabusa motocycle engine for your application. Makes 185hp from 1.23L at 12000rpm.
The rascal track car uses this engine.


----------



## dohc (Sep 28, 2001)

*Re: (bigthump)*


_Quote, originally posted by *bigthump* »_well,
I would recommend the hyabusa motocycle engine for your application. Makes 185hp from 1.23L at 12000rpm.
The rascal track car uses this engine.

Good idea, but he said that he has to go smaller if he uses a 16V motor.
Also, you might not have to destroke, apparently VW makes a 1.3L crank, it's a 75mm stroke. But I don't know if it will fit into the same blocks that we use here in NA. If so grab that crank and a 1.6 block, and grab a block that has a 74mm bore







....I guess I just answered my own question, can't use our blocks, but you could always sleeve it :crazy:


_Modified by dohc at 10:48 PM 10-7-2003_


----------



## J. Daniel (Dec 3, 1999)

*Re: (dohc)*

If my 2.0 8V makes 155 HP at the flywheel at 6200 RPM in streetable trim then a 1300 cc version would need to have a power peak at ~9800 RPM.
i.e. the total airflow thru a 2.0 at 6200 RPM is the same a 1.3 at 9800, so the ports and valve sizes sound like they are big enough to make the power you want.
As suggested above I'd go with a bore big enough to let you use minimum 40/34 valve sizes and get a custom crank made for the really short stroke. Deck the block as much as possible to save weight and get custom rods.
Then it's just a question of building a head that will run at those revs.
BTW how big are the valves in the competition's engines? That's a pretty good indication of whether the VW will be competitive.
One last note: crossflow head! you can do alot more with the ports and manifolding.


----------



## mrkrad (Nov 9, 2000)

*Re: (J. Daniel)*

why not just buy a vtec motor and be done with it? at least you can drive the vtec home, a 8v head that flowed to 9K rpm would be hardly streetable and idle at over 2000rpm,lol.
why reinvent the wheel?


----------



## J. Daniel (Dec 3, 1999)

*Re: (mrkrad)*

You need to go back and reread his stated requirements.
It's a racing engine!
A 16V for the class he wants to race in is 1005cc while an 8V is 1300cc. The 8V's are competitive in the class and he wants to know if the VW is a competitive 8V.
I'm betting it is while acknowledging getting the head to run at that speed is the major part of the challenge.
BTW, call Techtonics. I bet Colin was running his drag 8V to at least 8K if not more, so he'd be able to give you some useful data.


----------



## dohc (Sep 28, 2001)

*Re: (J. Daniel)*


_Quote, originally posted by *J. Daniel* »_If my 2.0 8V makes 155 HP at the flywheel at 6200 RPM in streetable trim then a 1300 cc version would need to have a power peak at ~9800 RPM.
i.e. the total airflow thru a 2.0 at 6200 RPM is the same a 1.3 at 9800, so the ports and valve sizes sound like they are big enough to make the power you want.
As suggested above I'd go with a bore big enough to let you use minimum 40/34 valve sizes and get a custom crank made for the really short stroke. Deck the block as much as possible to save weight and get custom rods.
Then it's just a question of building a head that will run at those revs.
BTW how big are the valves in the competition's engines? That's a pretty good indication of whether the VW will be competitive.
One last note: crossflow head! you can do alot more with the ports and manifolding.

Oh ya, that's right!! The valves, even the stock 40,33 would be too big for a 74mm bore. Well if you wanted to use the stock big valve head, you'd need an 81mm bore at least, and a 63mm stroke







With stock pistons, your rod ratio would be 2.43:1.00, so it definitely would be a revver.
I've seen 8V's revving to 9000rpm and still making power, but never any as small as the one you want to build, maybe you should just grab an R1, or GSX-R1000 motor and save your money for suspension. There are advantages to bigger dispacement, 2v heads, like wicked mid range, but it doesn't seem VW makes anything as small as you need.


----------



## J. Daniel (Dec 3, 1999)

*Re: (dohc)*

I like this idea so much, I thought I'd add some more.
Remember the last Super Vee's. 1600cc and 190 HP @~9000.
They were getting so powerful the rules put restrictions on cam profiles!
Anyway, that's 118 HP/L and if you could maintain that power level with the smaller displacement that would work out to 154 HP!
What would it take to get 10-11K RPM? Probably titanium valves and retainers, maybe titanium buckets. (Del West Engineering)
The Nissan A12 doesn't look too impressive from what I could find. Maybe I'm finding the wrong engine, but 73 bore, so the stroke is 77? 37mm intakes, 30mm exhausts and PUSHROD valvetrain??? Tell me I've found the wrong engine!
If you're up for the cost of all the custom parts, the VW seems like alot better solution than the Nissan.


----------



## dohc (Sep 28, 2001)

*Re: (J. Daniel)*


_Quote, originally posted by *J. Daniel* »_I like this idea so much, I thought I'd add some more.
Remember the last Super Vee's. 1600cc and 190 HP @~9000.
They were getting so powerful the rules put restrictions on cam profiles!
Anyway, that's 118 HP/L and if you could maintain that power level with the smaller displacement that would work out to 154 HP!
What would it take to get 10-11K RPM? Probably titanium valves and retainers, maybe titanium buckets. (Del West Engineering)
The Nissan A12 doesn't look too impressive from what I could find. Maybe I'm finding the wrong engine, but 73 bore, so the stroke is 77? 37mm intakes, 30mm exhausts and PUSHROD valvetrain??? Tell me I've found the wrong engine!
If you're up for the cost of all the custom parts, the VW seems like alot better solution than the Nissan.

I don't think he would have to get such expensive parts. The difference in weight between titanium and stainless valves is negliable at best. I looked at all my options when I was designing my 16V. Not worth it. In a VW valve train the heaviest parts are the lifters, valve, and retainer, in that order. If you have some custom shim under bucket lifters made, and get titanium or aluminum retainers from autotech, or Catcams (they also make light weight lifters), your valve train weight is halfed. Also if you do get custom valves, then get them made with 5.5-6mm stems, that should save some weight too and allow the head to flow better.
If you really want to destroke a 1.6, use (first try and find







) a heron head, and then destroke the 1.6 crank. Either that, or use an ABA head, with a 1.8 block, with a majorly destroked 1.6 crank...which will incindentaly give you a motorcycle like rod to stroke ratio with a stock rod (which is plenty strong for 10000rpm when shot peen with stonger bolts).


----------

