No low end torque after switching from 2 bbl to 4bbl.

kcludtke · 2023-09-05 04:35:43

https://cimg9.ibsrv.net/gimg/classicoldsmobile.com-vbulletin/1242x941/img_4619_original_07eda7d8cf2ec90f9d7d6c8d2d576c7591019146.jpeg Nuff? said.

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September 14th, 2023, 02:05 PM

#41

matt69olds

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Join Date: Jan 2010

Location: central Indiana

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Nuff’ said.

September 14th, 2023, 06:37 PM

#42

Donaldbabineau

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Join Date: Nov 2020

Location: Washington State

Posts: 421

Quote:

Originally Posted by DR_DAN

I bet you set the timing to 1966 specs correct? If so it’s about 12-14* retarded. HEI distributors have to have 18-22* initial timing. Then check your total timing WITHOUT the vacuum advance hooked up. You need to know what rpm it comes in and how much. If it’s over 36* total most likely some welding of the slots is needed. Same thing with the vacuum advance or buy an adjustable. 12-* of vacuum advance, manifold vacuum only.
this is where you need to start

The original GM HEI from the late 70s early 80s have about 20 or 21 degrees of mechanical advance. If you are shooting for 34 degrees which is where most stock GM V8s are happiest, the initial timing without vacuum advance should be about 14 degrees. 18 degrees on my 9.5ish:1 compression 455 was way too much timing.