# 2.0 8v head on a 1.8 8v will it work?



## gen1jetta (Jul 6, 2014)

Hey guys just spit balling a few weeks ago and got the idea to convert my 1.8 from counterflow to 2.0 crossflow head while still being an 8v so it will be cheaper to build. 

What would it do to the compression?
Does the 2.0 8v head even fit on a 1.8 8v? (How much would I have to machine? )


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## ps2375 (Aug 13, 2003)

Does nothing to compression. One or both dowel pins will need to be removed and the large oil return hole is in a slightly different position. I was doing this when my car was hit and totaled, so I sold it all off. (BTW, I still have a ported mkIV intake mani swap f/s). I was looking to make 2.0 power with a 1.8 block.

No machining needed.


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## gen1jetta (Jul 6, 2014)

That good to hear I don't have to get it machined. But I will not be able to mess with anything until I gethome. I'll be in Alaska for another month . Miss my mk1.

What's the difference of a mkIV intake compared to a mkIII intake


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## rommeldawg (May 25, 2009)

mk4 intake has better flow.... go to scientificrabbit.com for more info.


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## ps2375 (Aug 13, 2003)

rommeldawg said:


> mk4 intake has better flow.... go to scientificrabbit.com for more info.


That is who ported mine. It all would've been great fun, as I was already making about 94whp with a bolt-on low CR motor on MS. The new motor was a stock 10:1cr block. I had pictures of how the HG fit, but not sure if I still have them. There was about 1/8" of the oil return that needed fixed.


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## rommeldawg (May 25, 2009)

i did one better having gotten one from him... port matched every thing... whats kind of strange is the upper plenum gasket and intake bores match perfectly from factory... head and lower do not... i have ported head with oversized valves and have ported all openings to the gaskets used. but porting aside the intake from the mk4 just flows better then the mk3s intake, mk3 and early mk4 aeg exhaust manifolds how ever flow better then the later avh azg bev bbw manifolds. but like legos you can pretty much mix and match many things vw to get it right


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## ps2375 (Aug 13, 2003)

I had a Raceland header on my counterflow that was also going to go on the crossflow setup, seemed to work well. I do still have a pic of that on the head and block mocked up. And not shown is the heat shield that also braces the rear of the manifold.



I was really pleased with how well it fit and was on the car for almost a year and performed very well.


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## rommeldawg (May 25, 2009)

yeah i noticed tt started offering a header for later model mk4 would be interesting to see what difference it made


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## G60 Carat (May 14, 2004)

Last year I built a 1.8 with a 2.0 crossflow head. The dowel circled in red (missing from photo) had to be removed as it doesn't line up with anything. I just gently tapped it down with a hammer and it will fall out the backside of the motor. The locating hole in headgasket circled in blue (this is a 2.0 ABA headgasket) had to be reamed out to fit over the dowel pin. Then it all goes together. 

There is no machine work. I run this combo at 18psi and 50hp nitrous jetting, nothing leaks. :thumbup:


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## UroTuning (Jul 18, 2012)

The raceland header i had on my mk3 was good. Sounded nice and i got it slightly used for 90 dollars!


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