PMO 46mm Carburetor Installation on 3.2L

[lindy 911]

Yes, velocity stacks are needed.

[KTL]

Agreed. They are similar to the chokes inside the carb throats in that they tune the airflow into the carbs. They are basically like the main chokes/venturis in that they allow the air to be gathered and accelerated into the throat. The air is accelerated by the diameter transition. Going from large to smaller is the venturi effect which accelerates the flow.

[JJ 911SC]

https://www.google.ca/#q=venturi+effect

And since I like the look of them I went from:



to this;



to this; and



finally finish with that

[/QUOTE]

[PMNorris]

Very nice. I think i'll try and try and get my engine to work before blinging it up more.

[JJ 911SC]

Originally Posted by PMNorris

Very nice. I think i'll try and try and get my engine to work before blinging it up more.

Most definitely.

When I sent the first picture around I got a few, but is it working!!!

[lindy 911]

I think from a pure air flow perspective, the rain hat option or the K&N will flow much more air. The stacks with the little filters in each look very restrictive to me. Consider the total surface area of the K&N, then compare it to the total surface area of the three little filters. Also, make sure whatever choice you use that there is ample room between the top of the stack and the bottom of the air cleaner. The setups you show have been known to be too close and restrict air flow.

[KTL]

I think the best choice for a dry environment is the ITG filter setup. Plenty of flow AND filtration.

ITG air filter kit for PMO [9312-41] - $279.00 : Clewett Engineering, The complete solution for ignition & fuel injection

The K&N is a nice fit and quite common. But the filters are know to allow too much dirt to pass the filter.

[Gordo2]

I set up the throttle / accelerator linkage as good as possible using the original CIS linkage, however I think it's still too long even though I've adjusted / shortened every rod from the pedal to the intake manifold linkage pivot / bell crank.

I've read that the top of the the bell crank / pivot should be nearly parallel to the deck - mine is significantly angled down toward the rear of the vehicle:



I think it will work for start up but based on my research, the current set up may result in uneven throttle response.

I searched for a used transmission mounted bell crank made for carburetors but didn't turn any up; same for the early linkage rod that goes from the trans to the intake manifold - as such I think I need to shorten one of the linkage rods.

Steve W recommends removing ~ 1" from the rod that goes from the trans to the intake manifold. Anyone ever do this, and if so, did you just cut the end off and re-thread the rod?

Thanks,

Gordo

[toddu]

Gordo
You sure that's not an inch off the rod from the peddle to the tranny bellcrank?

Post a WTB. Within a day I was able to source a bellcrank and an early rod from tranny to manifold. Still need a slight adjustment, but smooth operation and WOT is achievable.

Todd

[JJ 911SC]

Originally Posted by Gordo2

... Steve W recommends removing ~ 1" from the rod that goes from the trans to the intake manifold. Anyone ever do this, and if so, did you just cut the end off and re-thread the rod?

I had to do that. The hardest thing was to removed to ball end. In was "weld" in there but soaking and heat did the trick.

In my kit the pivot plate supply by PMO had 2 place to mount the ball, one place for high throttle and one for low one. As luck would have it, I pick the wrong hole when I first assemble it.

[sithot]

Originally Posted by Gordo2

Thanks Henry - I will be installing the engine tin this weekend, will check to confirm that the bell crank ball lines up with the cutout for the throttle linkage coming from the transmission.

I've read that I will probably need to replace the bell crank mounted on the transmission with an earlier carb style bell crank to get the correct throw - otherwise I may find inconsistent pedal travel / throttle movement (touchy as you apply throttle).


PMO install and throttle linkage

The Clewett mount is pretty slick. I liked the idea that it will allow me to keep some separation between the fuel pressure reg/lines (which will be mounted to the firewall) and the coils. Wish I could claim credit for such a clean looking / functional design.

Once again, thanks for the input folks.

Gordo

Where did you stash the electronics? Thanks.

[Gordo2]

Originally Posted by sithot

Where did you stash the electronics? Thanks.

I don't know if I have any photos - but I mounted the XDi controller under the passenger seat.

The link has info on how I wired it in: Engine Harness / Multi-pin Connector for Carb Conversion '83 SC

Good luck, Gordo

[sithot]

Thanks, Gordo. Good links on your link too!

If you ever get lost in the Shenandoah Valley, look me up.

[JackMan]

subscribed

[The Watson]

Can someone tell me which early bellcrank to use at the transmission? There is one version from 1965-1969 and another from 1969-1972. Thanks!

[Mark Henry]

Jealous...this would be the perfect upgrade for my 3.0 twinplug with 40's.
But then I'd have to upgrade my headers, etc, plus I'm from Canada so balls in it would cost around $10K.
I guess I could get a couple large for the fresh 40's.

[911 SLANT]

I just purchased a pair 46mm PMOs from Rothsport. Cant wait to get them. Just rebuilt motor 2.8 with J&E Pistons 9:5.1, MOD S cams, ported heads 41/35, Rarelyl8 headers 1.5 OD and M&K GT3 sport muffler. 7:31 gear ratio.

[toddu]

Interested to hear how you make out with the headers. I had them for a hot second but was told the primaries were too short for carbs. Have mixed feelings about my current headers.

Todd

[911 SLANT]

Brian makes his headers custom to your motor specs. I will let you know.