964 Plastic Intake on 3.2 heads?

[911-32]

I am wondering if anyone has been through the exercise of putting a 964 plastic intake onto 3.2 heads? I am aware of one engine in the UK that has this set-up. It was done by 9M and I have some correspondence from Colin Belton that is pretty helpful. He used the bottom sections of the 3.2 intake mated to the upper sections of the 964 intake, so a hybrid if you like with fabbed up supports for 964 fuel rails. He basically replaced the plastic stacks in the 964 intake with stacks made from two sacrificed 3.2 intakes. Yes, 2 intakes because you use only the LHS as no 4 runner is swan necked to clear the A/C pump. Cost is 10 hours labour to do it this way plus sacrificing two 3.2 intakes - so probably GBP1,000+ - ouch! I am also aware of adapters that SRP sells for this same purpose and that was my preferred route, however, Colin thinks the injectors will not line up with the cut-outs in the 3.2 heads. Hence a dilemma and possibly creating an equally difficult/expensive problem. Obviously I will be asking SRP if their adapters "work" - so to speak, but perhaps the brain trust has been there, done that? I seem to recall a 993 v-ram intake fitted to a 3.2 at some point in the past, so maybe that had the same issues.

In addition, I have found out that -

- the resonance flap is at 5500rpm open/close (memory told me 5200rpm, so that is good to know) - so an MSD rpm activated switch is fine to control that
- 3.2 high impedance injectors flow more than 964 low impedance injectors but I can use the 964 fuel pressure (3.8 bar vs 2.5 bar) regulator to get extra fuel if necessary

Anyhow, I would welcome any thoughts while I am at the planning stage. I guess the obvious question is why do this at all? The 964 plastic intake has proven to be very efficient, much better than the 3.2 intake and the engine I have seen (3.5 litre based on 3.2) has shown a circa 25hp gain on the dyno.

I hope this post is well received here as I debated putting it in the general Technical forum. I thought answers here would be more related to actual experience.

Thanks

[MBEngineering]

HI 911-32
Have a look hear;

http://www.smartracingproducts.com/pdfcat/srp2008_engine_fuel.pdf

bottom of page 27

regards mike

[911-32]

Mike,

Thanks for the pointer to SRP. I am aware of the adapters they have but wary of the problems 9M allude to. I spoke with Rich at Jerry Woods yesterday (very helpful ) and he will send me some better pictures I hope.

I understand the problem a little better after looking at things more closely and engaging my brain. The 964 injectors fire into the 964 plastic stacks whereas the 3.2 uses cut-outs in the head to let the injectors fire into the head (imprecise description). So, if you use the 964 stacks, rails and injectors, you are left with unused cut-outs in the heads. Perhaps the SRP adapters cover the cutout, perhaps the cut-outs need to be filled.

I am not a mechanic - I just try to plan the project and then write the cheques ! If anyone has insites, I am all ears. I need to try to hunt out a photo of the cutouts in the 3.2 heads if Rich doesn't come back with something.

Thanks,
RB

[MBEngineering]

HI 911-32
some photos for you to look at/compare;

3.2 head with cut out for injector


3.2 head with spacer/heat sink


964 head


964 head on top of the 3.2 to compare


the heads can be welded up to get rid of the injector slot or a spacer/heat sink can be made to cover it,

this one is for a SC head


with a 3.2 manifold gasket on top


regards mike

[930gt-40r]

I think there is a guy on the turbo forum that is blowing through a 3.6 plenum into a 3.4 motor- Ill ask him next time I talk to him.

[juicersr]

Originally Posted by 930gt-40r

I think there is a guy on the turbo forum that is blowing through a 3.6 plenum into a 3.4 motor- Ill ask him next time I talk to him.

Is that 'Aspemo'? His looks like an aluminum 964 plenum.



looks like he used some sort of spacer

[930gt-40r]

Juice- your good- I wasnt even thinking of him.
I was thinking GT2EVOGUY- but yea- aspemo is doing what 911-32 is talking about (Option #2 with the adapters) as well.

[911-32]

Originally Posted by MBEngineering

HI 911-32
some photos for you to look at/compare;

- photos snipped -

regards mike

Mike - that is very useful. Thank you for taking the time and effort to put up the pics

I picked up my intake on Sunday. All things being equal, I will start disassembly and then assembly in late Dec. I think the SRP adapters look like they will cover the 3.2 cutout. I am beginning to wonder why Colin thought there was a problem with the SRP adapters, but he is nobody's fool - so I will see.

RB