Benefits of a PICT 34-3 with 37mm throttle body?

[bigbore]

oh and my P/C are forged are 90.5 cima/mahle and a set of AAs
rocker shafts are restored stock with swivel adjusters.
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where its cold and snowy

[bigbore]

[ccowx]

Here is my combination that I am putting together over the winter for a 1970 Westy:

-74mm by 92mm thick wall
-Eagle 2232 cam
-37x32 heads
-1.1 exhaust rockers, 1.25 intake
-Ported end castings and modified center section
-34-3 carb with 37mm throttle body and 30mm venturi
-8.3 compression
-1-3/8" header with functional pre-heat
-Gutted air cleaner with shortened snorkel
-Solex SVDA with Winterburn CDI ignition

I am hopeful of achieving around 100 hp and 140 pounds of torque. Wherever the numbers fall, it should make for a nice bus engine.

Chris

[Rob Combs]

Hello all,

For those working on getting ported vacuum back after boring the carb body to 37, short of changing to programmable ignition, could one place an EGR solenoid inline between manifold vacuum and the vacuum canister, then control the EGR solenoid with a well-adjusted closed throttle microswitch?

Set it to apply vacuum just as the throttle leaves the closed position and close off vacuum as the throttle returns to fully closed and you should get a similar effect to having ported vacuum at the carb. Make sure you get the solenoid hoses routed correctly and it will vent the canister to atmosphere when not applying vacuum, allowing the timing plate to return to its nominal position.

I'm planning out something similar with my dual carb setup and I think I have ~ $25 total in a bag of 10 microswitches, a bag of 100 tiny screws to mount the switch, and a generic EGR solenoid. The only things you 'd need to create are a bracket to hold the CTP switch, perhaps another to mount the solenoid, and a wiring harness to control the solenoid.

Rob

[Alstrup]

[ccowx]

Alstrup,

I think my mis-translation from European specs to North American is to blame!

Chris

As for the ported vacuum on a bored out throttle bore on a 34-3, I believe that you can plug the existing port and if you are careful, re-drill it in a slightly different spot. The issue is that when you widen the bore it moves the location of the hole slightly so it no longer sits in the right spot in relation to the throttle plate. If you pull out the plug in the back of the carb and are careful, it could be re-drilled.

Chris