Carb and MPFI heads valvetrain

[Probz]

I am doing a research before buying parts for custom project.

I plan on building custom intakes for dual carb setup (independent carb for each head), i was thinking about getting MPFI heads for better flow but the heads that are available to me have no valvetrain, i was wondering if carb single intake port heads valvetrain(cam, lifters...) fit on MPFI dual port heads?

MPFI heads compression ratio comes from different pistons not head clearence? I was wondering how much can i shave down the head without running into clereance issues.

[Crazyeights]

One bank of your 1.8L is about 900cc. Maybe you could use a matched pair of VW carbs or a pair from a motorcycle. You are also going to have to find or make some good quality throttle linkage. It needs to be adjustable too so that you can sync the carbs. As far as the heads go my thoughts are to stick with the single port version. Your exhaust port on the output side of the head is only a single port. The MPFI heads aren't worth the added trouble and expense.

Do it right and you'll make good power for what it is. It'll look cool too if you are detail oriented. Please keep thread updated and post pictures.

Edited April 18, 2021 by Crazyeights

[el_freddo]

Agreed with @Crazyeights on the single port (carb) heads. Easier to make a manifold for and probably no real gains in the MPFI heads. 

But to answer your question, all interchangeable. Cam profiles changed between turbo and carb EA82s, but I’m not sure about how similar the NA MPFI cam profile is to the Carb units - or whether they’re actually the same (highly likely!). 

All the best with it. Do your research on intake runner length as this has lots to do with where your power will be made etc  

Typically, short runners for a revvy engine, not much torque down low. Long runners are good for low down torque but not so good for top end high rev work. That’s the basics on it, I’m sure there’s more detailed science to it.

Cheers 

Bennie

[Probz]

Thank you all for quality information! I am currently in progress of stripping down my car, taking out the drivetrain and cutting up the body to scrap (its super rusted and ive broken rear end 3 times so far, always wanted to build a tube chassis car). I got to finish up another project and then i can start working on the tube chassis and suspension, engine mods won't probably happen until winter time, but i will be making a new build thread once ive made some progress.