# can I use mk4 VR6 block along with MK3 head and transmission? my mk3 block is shot



## zero666cool (Apr 17, 2004)

Hi guys, my block on my mk3 motor is shot and I came across a mk4 block from a 12V 2001 vr6, I was wondering if this block would bolt right up to my head and transmission or not? and would the mk4 block have the places for mounting and sensors and everything else from the mk3 or would I need more mk4 parts to make it work? Also, how would the compression be? would it be the same or different?
Thanks in advance


----------



## zero666cool (Apr 17, 2004)

*Re: can I use mk4 VR6 block along with MK3 head and transmission? my mk3 block is shot (zero666cool)*

anyone?


----------



## ibuiltdarrinsgolf (Dec 30, 2009)

*Re: can I use mk4 VR6 block along with MK3 head and transmission? my mk3 block is shot (zero666cool)*

is the head a vr6 12v head? and is the trans from a 12v vr6?


----------



## zero666cool (Apr 17, 2004)

*Re: can I use mk4 VR6 block along with MK3 head and transm ... (ibuiltdarrinsgolf)*

Yes the head and everything else is from a mk3 12V VR6. thanks


----------



## bonesaw (Aug 8, 2004)

*Re: can I use mk4 VR6 block along with MK3 head and transm ... (zero666cool)*

yes will work. if you use mk4 HG its 10.5:1


----------



## ibuiltdarrinsgolf (Dec 30, 2009)

*Re: can I use mk4 VR6 block along with MK3 head and transm ... (zero666cool)*

i mean thoeretically it should work if the bolts fit use them


----------



## VortechVeedub (Nov 27, 2005)

*Re: can I use mk4 VR6 block along with MK3 head and transmission? my mk3 block is shot (zero666cool)*

Yes, with the 12 valve motors you can.
I built the VR in my 95 GTI using a block from an 01 and a head from 98. The blocks are the same except the mk4 block has extra mounting holes on the passenger side for the MK4 engine mount.
The Mk3 o2a/o2j transmission will bolt right up. 
The compression should be the same as long as you use the stock MK3 head gasket. I believe the mk4 gasket is slightly thinner and produces a 10.5 to 1 ratio as opposed to 10 to 1 on the mk3 motors. 
I don't know if the mk4 wiring is the same for the crank angle sensor and the knock sensors or if they can connect right up to the mk3 harness but you can definitely swap over your original sensors from you blown motor and your good to go..



_Modified by VortechVeedub at 12:30 AM 1-2-2010_


----------



## zero666cool (Apr 17, 2004)

*Re: can I use mk4 VR6 block along with MK3 head and transmissi ... (VortechVeedub)*

Thanks for the info, the mk4 headgasket is indeed thiner and would bump the compression by .5 points. So I heard from another guy that even the head would work too and I can use my mk3 manifold and sensors on it, but is this true or was he just telling me this to sell his engine? I can use the mk3 crank angle sensor if the positions are at the same spot. so if I swap all the sensors and wiring and everything else it should work? how about the stuff on the head?
Thanks,


----------



## VortechVeedub (Nov 27, 2005)

*Re: can I use mk4 VR6 block along with MK3 head and transmissi ... (zero666cool)*

I believe the heads are the same but the mk4 12v head uses a different type of magnet on the cam sprocket with more teeth than the MK3. I don't think the mk4 sensor output could be interpreted by the MK3 ECU. 
The upper timing chain cover is different and you wouldn't be able to use the mk3 sensor because it would be too long. 
You would need to swap the magnet on the cam sprocket and put the mk3 one on the mk4 head and use your original hall sensor with your original mk3 upper timing chain cover. 




_Modified by VortechVeedub at 2:44 AM 1-12-2010_


----------



## zero666cool (Apr 17, 2004)

*Re: can I use mk4 VR6 block along with MK3 head and transmissi ... (VortechVeedub)*

that makes sense, thank you http://****************.com/smile/emthup.gif


----------



## zero. (Aug 14, 2001)

I know this is an old thread, but I'm in the process of starting a rebuild for a similar swap. My AAA block is cracked. It had a dual chain setup. I pulled an AFP block and didn't take the head/gears, so I can't swap for a single chain setup. Are there any differences with the intermediate shaft/gear and do I need to swap it from my cracked AAA block or is the only difference with the timing chain related stuff the upper guide rail? I know the hall sender is different, but I plan on using all AAA stuff except for the block.


----------



## need_a_VR6 (May 19, 1999)

Swap the outer double row int shaft gear from the aaa and you are gold.


----------

