head swap from 4.2 v8?

[dubvinci]

ive recently heard of folks using the passenger head from a non fsi 4.2 v8 on a 4cyl bottom end for the larger ports and cams along with the infinite ablity for adjustment of the t-belt sprocket on the cam. i currently have one at my fingertips thats still bolted on a v8. ive counted the teeth on the cam gear and its double my crank pulley. also the intake and exhaust bolt patterns and angles look to perfectly match a regular 20v head. also the valve cover is shorter and flatter that any regualar 20v. just wondering if anyone on here has physically done this and any small things i need to know before i do this...also curious as to what compression ratio is on a 2.0 bottom end...

[1999.5GTIVR6]

Hmmm interesting, I haven't heard of that....
Bump for more info. Where did u first hear of this? Any links?

[jettred3]

someone made it work.

IIRC, only a 3.6L head can work (4.2 cyl. offset poses a challenge) and even then, the block needs to be bored out. This type of combo is the best for a 16v...if you got the money. You'll need a min. of a 2.1L for these heads to work.

They both use the same cast. The valve placement is different on the V8 head (due to the 84.5mm pistons), the coolant holes would need to be welded also but the base cast is identical to our 16v heads.

I was looking into this awhile back but there are no real benefits to using the head other then the wow factor.

I think Breadfan was building one.

The Big boys overseas don't **** with that ****. It's an Audi STW head most likely. The Head is canted to aid the 90degree exhaust valve angle and has different port work like huge ovaled exhaust ports.

[MikkiJayne]

There's a great thread on the ClubGTI forum about the SuperTouring 16V motors which used the 3.6 V8 16V head. 305HP from a normally aspirated 2.0 16V!

Never seen it done with a 20V head though.

[dubvinci]

awesome info guys! i can get the head for free if it works out so imma take it off the start doin some comparing to a 1.8t head as far as head gasket and holes for passages and such....and hey if i can make it work it will end up cheaper than anything else cuz free is king!! i have a spare aeg bottom end that i can do some mock up with a t-belt and see how tight clearances are....

[DWI_gti]

There's a great thread on the ClubGTI forum about the SuperTouring 16V motors which used the 3.6 V8 16V head. 305HP from a normally aspirated 2.0 16V!

Never seen it done with a 20V head though.

post that link!

EDIT: Found the link
http://www.clubgti.com/showthread.ph...-an-N-A-valver