[vegasjones]

So I've been trying to tackle a lack of cooling issue with the 396 I just out in my 65. After a lot of trial and error I believe it's coming down to timing. Today I bought a new distributor, an MSD Pro Billet with vacuum advance.

Here's my dilemma. A good friend of mine, who I really do trust and is a good mechanic, has set the initial timing at 12 degrees w/vacuum advance disconnected. We didn't change the springs that came from the factory so this puts the total timing at 32 degrees.

From everything I've read the total timing should be at 36-38 degrees and I believe if this were the case it would help my cooling issue.

The 396 does have a Comp Cams cam, roller rockers, bored 30 over (as far as we know) so the 32 degrees total just doesn't seem right. Timing is definitely something I need to learn more about but until I do I'm hoping you all can help. If you need any add'l info just let me know. Any help will be appreciated.

 

[rocks66ss]

Well it seem's to me if you're at 12, and have 32 total now and you want 38, set it at 18. Take your timing light and bump it in 2 degree increments and see if it runs better.



Rocky

 

[vegasjones]

Sorry, I should've made my question a bit clearer. I'm not sure if I necessarily want to be at 38, but everything I've researched says I should be around 36-38 total so 32 seems too low to me. So ultimately, what should my total timing be at approximately?

 

[Raymond]

Each engine is a little different. Agree with rocks66ss. Just try bumping it in small increments until it pings and back it off some.

 

[Highway Star]

These guys are right. Give it some more initial timing. Have you stabbed in the new distributor yet?

 

[SWHEATON]

So I've been trying to tackle a lack of cooling issue with the 396 I just out in my 65. After a lot of trial and error I believe it's coming down to timing. Today I bought a new distributor, an MSD Pro Billet with vacuum advance.

Here's my dilemma. A good friend of mine, who I really do trust and is a good mechanic, has set the initial timing at 12 degrees w/vacuum advance disconnected. We didn't change the springs that came from the factory so this puts the total timing at 32 degrees.

From everything I've read the total timing should be at 36-38 degrees and I believe if this were the case it would help my cooling issue.

The 396 does have a Comp Cams cam, roller rockers, bored 30 over (as far as we know) so the 32 degrees total just doesn't seem right. Timing is definitely something I need to learn more about but until I do I'm hoping you all can help. If you need any add'l info just let me know. Any help will be appreciated.

===============

Your 10% correct 7&on target thinking your motor setup & cam could use more timing bieng currently at only 12/32.

I find many aftermarket perf cams in general run well in old school street perf sbc/bbc motors at approx 18 deg base and 36-38 total all in by 2600-2800rpm max.

So your going to be just fine trying 18/38 deg timing curve with your 396 & comp cams perf cam combo. (use 93 oct fuel)

So at this time your motors running approx 6 deg retarded for base & total timing which is significant and retarded timing (Esp base) can increase engine/exhaust temps a bit.

Adv the base timing to at least 18 deg making total go to 38 and see how motor respnds to it,use 93 octane fuel with that timing setup.

Also, setup/limit vac adv for 10-12 deg max hooked to full int vac for approx 50 deg timing when at low load cruise.

If vac adv gives over 12 deg install a crane cams vac adv limiter plate to limit the vac adv,its avail from summit.

If motor detonates with this timing setup usuing 93 oct fuel either back off timing in 2deg steps untill ping stops loosing power and making motor feel mushier or keep all the timing to retian full power/perf and get some real lead 130 booster from Bills corvettes .

Mix it to increase pump fuel from a non leaded 93 octane to leaded 97-98 octane which should be enough octane to stop the ping/detonation at that point.

Also,the additional timing at idle from vac adv with perf cam can help it run a few deg cooler esp when at idle in traffic but it wont normal reduce engine a lot if you motors running maybe 20-30 deg too hot on a hot day.

But when engine temps are too hot by 20-30 deg i usually find thats issues with people running aftermarket elec cooling fans on an old school car/chevelle with thicker rad core where the elec fans are not able to handle cooling duty which is a more common issue then you would think. (180 deg + - few deg in head temp is the sweet spot for best perf with an old school street perf sbc/bbc motor)

Scott

 

[overdriv]

The springs that come on the MSD dist provide a very slow advance curve. To slow for most applications I think. You may want to experiment with the springs a bit to find what works best for your combo.