I am looking for timing specs for a 78 350 motor
I have a 74 Vet but it has a 78 motor with no polution stuff on it.
Thanks in advance,
Schoon

 

Hi SCHOON, there's good info on timing at www.corvetteforums.com/m_50943/tm.htm PG.

 

Doesn't directly address specific specs but interesting discussion on the topic: http://www.lbfun.com/Corvette/Tech/vettetech.html Go down to bottom and click on timing.

In general, pre-FI SBCs like 35-39 degrees total (initial + mechanical). Smog motors may be different tho.

 

Lars wrote the papers on timing and I cannot come close to his advise so follow it 100%.
The original question was whats the timing for a 78 350 motor, it's someware between 8 and 10 BTDC but if you want to get the most HP out of your motor you have to make some modifacations.
Since I never know if this forum will cut us off in the middle of an answer I said look at my old post.
To get the most HP you have to advance the initial timing to about 18*.
The stock springs will not give you total centrifugal advance untill about 4500 to 5ooo rpm so those must be changed to bring in the total advance to 36*at about 2800 to 3000 rpm. So if you have 18* initial plus 18 centrifugal that equals 36*. You may get more centrifugal from lighter springs and in that case you will have to lower your initial advance.
It takes a little trial and error. You also have to consider how much you vacuum can brings in at idle and cruise. You dont want to go over 52* max, hope this explains it a little better, PG.

 

pg found a good system, and there are aftermarket companies that sell the "mechanical advance weight and spring kit" where you simply install the kit and disconnect the vacuum line.
With a small block Chevy having no smogdevices, advance the distributor "just" to the point where the motor cranks slow-this will be due to the timing being too far advanced-and then retard (go back) just a crack, to the point where it cranks regularly, tighten the distributor and leave it there. I know, I know, it sounds crazy, but it works great everytime. The engine will perform perfectly, gas mileage the best, etc. etc.. This works great w/no smog devices. Ofcourse you can use a vacuum gauge, the most accurate wayon an engine that has mileage on it, but going about it the way I've explained is a "sure shot." And no, there's no chance of damage in the long run or anything of the sort. I've been doing this since early '83 and haven't had a problem. Try it, it works.

 

I will give it a try.
Thanks!