AFR lean spikes going into boost (bad or ugly?)

[turbobaja]

Spot on at 350F, regardless of load or ambient temps? My experience tells me your cht gauge is dash ornament, nothing more.

Oil temp tells you nothing about your combustion chamber temps and exhaust temps FYI.

[madmike]

Yes check that CHT gauge My gauge goes up when climbing hills as shoud yours

[Buggsy]

Perfect situation for a Bosch distributor with a single vacuum can and also centrifugal advance. Most of these engines running 8 to 1 compression have terrible combustion chambers. Extremely slow burn, so they can use a ton of initial advance, even up to 20 btdc. I'd start by buying one of these for $10-20 at a swap meet and limiting centrifugal advance to about 5 degrees using mechanical stops. Run a vacuum line from the can of the distributor to ported vacuum on your carb. Ported vacuum will be 0 at idle, several inches at light throttle and 0 at wide open throttle, so don't confuse it with manifold vacuum. This will give you another 10 degrees advance at light throttle openings, but no vacuum advance during boost. Start with about 12 degrees initial advance and keep bumping it up a couple degrees at a time until you hear it ping on your test drive, then back it down a couple degrees. Unless your running some huge cam, you will have decent drivability, decent mileage, and will end up with the 22 to 25 degrees under boost that you are seeking. And you can't beat the price. You will want to put a Pertronix unit in the distributor also. Draw through carbs will never run as nice as EFI, but can be made to run pretty nice with the right stuff.

[seabeebuggy]

I have the same lean spots when shifting. Nothing big there. any time you open the throttle it will lean but for a second.

[63fiberbuggy]

Update - changed venturis from 36 to 32 & air corrections from 175 to 215; huge difference in drivability! No studder/popping, and pulls strong on throttle "punch".

I added a 3 Bar Map Sensor today; and datalogged a couple 45 minute each runs on my LM-2. I just downloaded to PC & can't seem to figure out how to "covert" the volt data to vacuum/boost display. Anyone with inside scoop?

[madmike]

good job
I was going to do 34's in my 40dcoe for my 2276 for more topend ,but now I want to try a 4 barrel holly