# 12v vs 24v crank advise due to spun bearings



## adaptorman (Dec 12, 2007)

hi all as some know ive been have trouble with 24v engine crank failure ,(spun bearings ) 
as the 12vr6 turbo seems to hold up very well , im going to use a mk3 vr6 crank in to a 24v engine along with upratted conrod bearings and arp bolts and oil pump,
first did a few mock up pics
r32 crank mk4 , shiny one
mk3 vr6( oily one) 
first both cranks








note im useing the 2.8 mk3 crank as it going into a mk4 2.8/not a r32 engine








also did a few mocks up and fitted the r32 crank in the mk3 block fits a treat shame about the pistons just standing proud
















next checked the mk3/4 oil oils odd thing they look idenical yet the mk4 has a deeper sump
















ps can anyone explain what the crank numbers/letters mean as ill add them for each crank
mk3 2.8 vr6 (1996) DE23/021L/L2 
MK4 2.8 BDE (2002) DE55/021L/UE
mk4 r32 bub (2003) DE18/021F/DK any idea what they mean











_Modified by adaptorman at 6:16 PM 2-4-2010_


----------



## EL DRIFTO (Jul 11, 2004)

*Re: 12v vs 24v crank advise due to spun bearings (adaptorman)*

& i would think twice the lifters take more oil http://****************.com/smile/emthup.gif 
r the oil holes larger in the mk3 crank ?
you'd think the mk4 would use a shallower sump being lower cars on the street


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

The 24v lifters are really small.


----------



## mcdub (Jun 19, 2005)

Holly F that block has seen better days.
Quick browse over both cranks,imo the 12v looks stronger and thicker on the counter weights.
Maybe its just me.


----------



## adaptorman (Dec 12, 2007)

*Re: (mcdub)*

lol i was just mocking up while i had the engine stripped to see if a r32 crank fits in a 12v block with stock rods and pistons as i then skimed the old pistons down and cleaned the bores , and i think it would work as nothing catchers and plenty of conrod clearance on the bottom piston walls ,, heres the end pic , (no more dodgy looking block lol)








id like to know what these numbers mean any idea...
ps can anyone explain what the crank numbers/letters mean as ill add them for each crank
mk3 2.8 vr6 (1996) DE23/021L/L2 
MK4 2.8 BDE (2002) DE55/021L/UE
mk4 r32 bub (2003) DE18/021F/DK any idea what they mean 


_Modified by adaptorman at 8:09 PM 2-4-2010_


----------



## Issam Abed (Feb 12, 2004)

*Re: 12v vs 24v crank advise due to spun bearings (adaptorman)*

6 of one
half of a dozen of the other....
The AAA 12V VR6 crank is what we used on the TA motor.


----------



## adaptorman (Dec 12, 2007)

*Re: 12v vs 24v crank advise due to spun bearings (Issam Abed)*

hi what a ta motor (is it a us term ) im tempterd to build a r32 12v motor just to see what hapernds







unless anyone outthere has one , what would i exspect from it regards a stock 12v 2.8 (id like to turbo but reckon the compression maybe too high and a nice thick head spacer would be needed


----------



## nuts4boosting (Jun 30, 2006)

think he is talking about the time attack motor in the audi. 1000 crank i believe


----------



## adaptorman (Dec 12, 2007)

*Re: (nuts4boosting)*

ant a clue tbh ,


----------



## S3.2 (Sep 19, 2009)

*Re: 12v vs 24v crank advise due to spun bearings (adaptorman)*


_Quote, originally posted by *adaptorman* »_
lol i was just mocking up while i had the engine stripped to see if a r32 crank fits in a 12v block with stock rods and pistons as i then skimed the old pistons down and cleaned the bores , and i think it would work as nothing catchers and plenty of conrod clearance on the bottom piston walls ,, heres the end pic 
im tempterd to build a r32 12v motor just to see what hapernds







unless anyone outthere has one , what would i exspect from it regards a stock 12v 2.8 (id like to turbo but reckon the compression maybe too high and a nice thick head spacer would be needed









How can that be?
Won't the pistons go out of the block 6mm when TDC? (the diff. of strokes)
Surely you didn't skim 6mm off the piston tops...


----------



## adaptorman (Dec 12, 2007)

yes it works and u dont need to skim 6mm off the pistons , as if u look at the pic were the 12v piston pertrudes out of the bore , i skimed it down leval (as these were scrap pistons , as i was just seeing if it would work tbh , , so i timed the engine and checked compression its shows 14.1 instead of the stock 10.1 fairly high but works and clears , i do reckon it would run ,, how well i carnt tell you tbh , just thought id try the idea tbh


----------



## need_a_VR6 (May 19, 1999)

*FV-QR*

You'd need to deck the pistons half the stroke difference. Nice to not see the top ring come out of the bore


----------



## adaptorman (Dec 12, 2007)

luckly it dosent.....but 6mm would be too mutch ,, more like 4mm ,,as u see they sit nice


----------



## adaptorman (Dec 12, 2007)

heres a pic


----------



## 05JettaGLXVR6 (Jan 25, 2006)

*Re: (adaptorman)*

Why are you blaming the 24v crank for you spinning bearings? Noone else seem so be having a problem...as i recall your not making some crazy power.


----------



## S3.2 (Sep 19, 2009)

*Re: FV-QR (need_a_VR6)*


_Quote, originally posted by *need_a_VR6* »_You'd need to deck the pistons half the stroke difference. Nice to not see the top ring come out of the bore









Eeerr, yes sorry I meant 3mm...


----------



## adaptorman (Dec 12, 2007)

*Re: (05JettaGLXVR6)*

its advise and possible faults tbh , as if u can tell me why 3 differnert engines runing 25/27psi all had spun bearing , and all have had differnert engine oils , after others here pm regards they have had same problems ,among theres have had this has to be another reason, hernce why im just going to try a mk3 vr6 crank just to see ,thought a try either way


----------



## MarcoVR6SC (May 3, 2003)

*Re: (adaptorman)*

Before you try this setup, check the valve clearance.
Another thing to considder is the piston weight, you'll probaly need to balance the R32 crank with the (shaved or not) 12V pistons.


----------



## adaptorman (Dec 12, 2007)

hi pal , valve clearance wouldnt be a prob as i bolted the head down and spun the crank over to check compression ,which is high compaired to stock compression ,but i would have a 5mm headspacer fitted for turbo use, regards the crank its a balanced item to start with , ? as is a conrod, so unsure on that one tbh as i said this was only a mock up idea due to the pistons were buggard due to water damage


_Modified by adaptorman at 8:44 PM 2-5-2010_


----------



## DannyLo (Aug 2, 2006)

*Re: (adaptorman)*

so eff it, try and start it


----------



## adaptorman (Dec 12, 2007)

*Re: (Lieutenant Dan)*

no point as its a scrap engine , i.e knackerd pistons etc , ill do a proper one with better pistons and rebuild one just to see how it runs etc


----------



## Snitches Get Stitches (Jul 21, 2007)

So you spun bearings on a junkyard motor w/ just a spacer? Your boost levels were 25-29psi? Most of the folks on here using a spacer typically do not exceed 20psi. What turbo were you using on these junkyard motors? How about the exhaust mani? Any upgrades to hardware anywhere on the motors(stock rod bolts, etc..)??
Any chance you had a wideband on either of these motors to see what your engine was doing? I read you were using megasquirt> did you do the tuning? What size injectors>?
Spun bearings seems odd still though... I would expect you to go lean and detonate or lift the head before spinning those bearings.
Good luck with your next build!!


----------



## adaptorman (Dec 12, 2007)

*Re: (Snitches Get Stitches)*

2 engines were totaly stock apart from a headspacer 8.5.1 
injectors 560cc stubby low inpedance/turbo hx40 holset
invovate lc-1 wideband , megasquirt ms2 standalone , custom twin scroll manifold , with r32 clyinder head/ tunie was from my mates vr6 t which has never had a problem ,, with 180,000 on the clock
3 engine was upratted but ended in the same fault , 
hernce why im fiting the 12v crank /upratted bearing in the 24v engine to see if it helps//worth a try i reckon ...


_Modified by adaptorman at 9:31 PM 2-7-2010_


----------

