3.2 heads, crazy project.....

[Porschekid962]

Does anyone have any 3.2 heads laying around? For starters I am looking for one or two non useable heads for some r&d work. On top of that I will be in the market at some point in the next 6 months for a set of good 3.2 heads.

Are you guys as shocked as I am at the cost of aftermarket ITB setups for our Porsche cars? A lot of my friends are old american muscle junkies and flipping through their catalogs shocked me. Complete efi/itb setups for unker 5k, turnkey with harnesses? I know we are a limited market but should the Porsche market really be as sever as it is? Who am I to talk though, I spent about 3k of my money on a set of Jenvey's for a recent build.

Anyways I am embarking on this project for fun and self satisfaction. Once it is all done and if things work well I will make my drawings available to anyone who wants them just because I think this forum is awesome and has so much to offer. I in no way intend to take money or business away from companies that sell their own kits. I really dont think I will because the amount of time involved would scare most people away.

Just to let you all in on the basics. I currently have a hot rod 3.3 short stroke motor with itb's in a car. I like the throttle bodies but would like to change certain things and make other aspects easier to deal with.

Current gripes with aftermarket itbs:
Weight, while sometimes lighter than stock they can still weigh in at over 15 pounds.

Ease of assembly: Not bad but still not easy. Balancing of throttles from one clyinder to another takes time unless they share a common throttle shaft, not many do.

Adjustability: Custom trumpets and spacer lengths are available from most companies but they are as always rather expensive and sometimes are still not in the dimensions that you want.

Maintanence: Not needed on most except for checking of throttle plate balance, once you have setup a set of Jenvey's adjusting them is simple. Rebuilding them is another story. Send them back or dyi and wait for parts to show up and then see if you can do a decent job.

Asthetics: Like anything we do with our cars we want it to look good. Most itb setups look great to start with but after looking at racecar setups they leave something to be desired. They can be bulky and sometimes look like carbs. The filtration setups are also a bit ungainly and fuel hose routing is interesting to say the least.

Price: Most systems reatil for about 3k. You get manifold in some cases, throttle bodies, trumpets, fuel rails, filter basebplate and filters. Most come with a throttle crossbar but its up to you do figure out how to hook it up to the stock Porsche linkage. I know we shell out for a set of cylinders or pistons, hot cams, headers, the list is endless. Should they really cost 3k+ though?

My idea.....

A rather short throttle body housing that mounts directly to the intake port on the head. One common throttle shaft for each bank, eliminates balancing between cylinders. Lightweight runners in different lengths for different apps. Lightweight trumpets and a sealed airbox for each bank. Still contemplating one single airbox for both banks to aid in scavenging but for now I want to keep it simple.

As for the injectors, that is why I want to get a trashed 3.2 head or two. My third iteration of my current motor calls for 3.2 heads so that is what I will be working with. My idea will adapt to other heads if needed. The basics are to machine a hole into the base of the intake runner port and press fit or weld an adaptor into it that will accept an electronic fuel injector. The fuel rail will mount to the throttle bodies.

Basically I wanted to move the throttle plate as close to the head as possible. Make assembly simple and straightforward and adjustability almost non existent. The throttle linkage will be an adaptation of the 993 RS race car setup and will take a cable mounted on the trans from the bellcrank directly or a throttle cable directly from the GO pedal. Return spring duties will be carried out by a spring on the throttle linkage instead of a spring on each shaft or each clyinder as some setups have them. Bearing will be either oil impregnated bronze bushing or sealed ball bearings, still up in the air at this point. There will be a MAP port on each TB just because I want one. Dont think they way I am designing this would work well with forced induction though.

So any comments are welcome, anyone that has some trashed 3.2 heads that they want to unload let me know and anyone that has a full set of good ones keep me in mind for the future.

Have a great night all, cheers

[rvanderpyl]

Hey you want cheap, try looking at EFI setup for Volkswagon motors, throttle bodys at $500.00 and complete setups for < $2000.00 inlcuding the controllers. One of the reasons I am rolling my own as well. Although I'm not going as far as to try to make my own throttle bodys.

[cnavarro]

You have to realize the even with the VW systems, there are great variations in what you get vs. what you pay for.

I just did an ITB with TWM throttle bodies, SDS, coil packs and drivers, with a huge bosch pump and huge siemens injectors, and that alone was nearly $3500, not including manifolds, air cleaners, linkage, crank position sensor/bracket, fuel lines....

It is not uncommon to see parts alone for a four cylinder FI conversion go for $5-7k plus labor for fabrication and installation I have seen go for another $5-10k in a race prep shop. The great savings are in the DIY, but still you have to fork over big $$$ for the best parts.

Still worth it over carbs IMHO, but I'm not so sure about huge benefits for most already equipped with some sort of fuel injection and the cost to modify the stock injection to suit your needs.

[jpnovak]

I have a 78 SC head that you could use to mock-up. I realize the intake section is taller but the port size is nearly identical and the intake spacing is the same. It has some "issues" with the combustion chamber and is otherwise trash.

You can have it. PM me an address.