My 3.0L Weber conversion notes (long)

[si2t3m]

Hi all,

Just wanted to pass along all the info i collected while doing the 3.0L transplant in my 914-6 conversion. Had a couple of pitfalls and just want to make life easier to other. HTH

My setup:
79 3.0L engine
40IDT Webers with Watershields and air breather setup.
2.0L intake manifolds ported to 38mm
PMO Insulator
MSD6A box
MSD High vibration coil
Magnecor wires


First when installing the MSD box, i wired it to spec. Problem encountered when connection to the green wire from the magnetic pickup on the distributor. MSD instructions says that reverse polarity will cause advance. You bet! I had figured that the green (internal wire in the green wire from the dizzy is positive) and the sheilding cable (again in the green wire) is negative. So connected the MSD purple wire to the green wire and MSD green wire to shield. Wrong. In a WAG I reverse them and reindexed the dizzy to get it working properly.

Second. Idle circuits was blocked in 2 barrels on one of the carbs. A simple test to find out any blockage is to remove the top cover and the idle jets and carriers. Spray carb cleaner in the idle jet port. Carb cleaner should spit out of the emulsion tube wells.

Third. Use the gaskets provided with the insulators from PMO. For some stupid reason i had used the 3.0L intake manifold gaskets between the head and the insulators because i had a hard time getting the ones provided with the insulator to slide under the shroud. After removing the 3.0L intake manifold gaskets and insulators i could see a gap. Air was entering between the gasket and insulator at the 'egg head' shape of the inner hole of the gasket. Replace with the gaskets provided with the insulators and the hissing noise when away. Ajusting the carbs was a breeze afterwards.

Last thing. I had been told that the 2.0L intake manifolds wouldn't seal properly on the heads. Without the insulators I can now understand. But with the insulators this is not an issue.

I missed the saturday sessions of the DE in my area. After finding the gasket issue saturday afternoon. Ajusted the carbs and took off early sunday morning to catch up. Had a blast all day.

HTH

Marc-Andre Morin
70 914-6 conversion 3.0L Webers

[epbrown]

How's the gas mileage? I've always heard that you give up a lot of mileage for the throttle response of Webers, but a PMO rep at a tech session I attended (Tweeks - couple of years ago) said it shouldn't be that bad if the carbs are properly set-up.

Emanuel

[si2t3m]

Well,

It sucks gas!!!

Sunday morning it took me 2 hours to go to the race track. It's around 140 miles from my place. Ok i was driving a wee bit fast 80-85 (3600-3800 rpm in 5th gear speedo might be off). filled her up just before the race track and filled it for 20$ (around 27 liters).

A little calculation makes it around 18-19mpg.

When the 1.7 was in the 914 i probably could of done the full trip and the five 20 minutes session on the same tank. But it's more fun with the 3.0L setup.

I didn't even mind about the gas mileage when at WOT on the track with the engine roaring just a couple of inches in back of me


Marc-Andre Morin
70 914-6 conversion 3.0L Webers