TIMING OF SMALL BLOCK CHEV.

[noluck]

if it is a sock engine with a stock distributor then set at stock spec's

 

[Wireman]

The distributor is not stock I recently purchased.
They did not have electronic dist.in the 80's

 

[Old Fisher]

Base timing is just that,it's a starting point total advance is most important.
My dist.will put out a total of 24 degrees of total advance.
I know need to figure out how far do I push it
I don't have a race engine with fancy heads and pistons or high compression
It's stock 1980 260 HP 4 barrel chev based engine with electronic ignition.

It's difficult to give you an exact number for total timing. It depends on your engine configuration, usage, fuel, etc. Most small block Chevys will be happy at 34-38 total mechanical advance. In some applications you can go higher, in some you may need to stay a bit lower. The manufacturer has said 8 degrees BTDC because that's a conservative number. If your distributor has 24 degrees in it, you will end up with 32 which is a conservative (safe) value for running regular pump gas. You can likely go higher but remember that more timing does not always equate to more performance. Each engine has its own favorite timing range. I would suggest starting at 34 total and possibly inching your way up slowly while checking for detonation and reading the spark plugs after a hard run. If you don't want to bother with that, just run 32-34 and you should be ok. If you go higher, keep checking engine performance - if you are gaining performance while avoiding detonation, you can keep advancing (cautiously) but when you get to the point where it no longer gains power after advancing the distributor you should go back 2 degrees and lock it down. You want to find the point where the engine is "happy" - it makes good power under load and it is still starting and idling nicely.
Remember that, unlike a car, the engine in a boat is under constant high load and so you want to be careful about putting too much timing in it. A car on the highway is under almost no load so it's engine can withstand more timing and that's where vacuum advance comes into play.

 

[jim morrow]

when my old 165 hp Mercruiser distrib was worn out, I found a guy in south Delta who would send them out to get a new bushing pressed in. He was an MSD igntion retailer. He had previously worked with timing Funny cars at Mission raceway. He lives down on 25th avenue. He told me to use the initial advance of 14 degrees. Told me that unleaded takes longer to burn. The guys at the machine shop can tell you your head will last about 1000 hours. Then you need to rebuild them.
Are there some different distribs you can buy that have different advance curves?
Is the distrib that you have recommended for this engine?
I got a new distrib for a regular car, removed the vacuum advance, plugged that hole, and used it with just the mechanical advance. I was tired of spending money on rebuilt distribs, so far from my house at that time.
Hope that there is some part or way to tighten timing chain over the years to keep the timing as good as possible.
You may need to see some racers with dynamometers, or hang out in the pits at Mission dragstrip.

 

[Old Fisher]

Wireman beware. Tuning high compression race car engines designed to run on high octane fuels is VERY different than tuning a stock constant load marine engine!

 

[Wireman]

I am going to run 32 degrees of total timing,take the boat out for a hard run and check spark plugs