i have a 383 stroker 10 to 1 compression double hump heads, headers, the whole works....what do you guys set your timming at?...

 

30-32* total would be a good starting point on pump gas.

 

hows that cam working for ya....i have a .480,.480 cam on 1.5 roller rockers, should i go with a more aggressive cam?

 

It works like a champ, 504/538 N/A the engine dyno. It's not what your looking for though, there are too many differences in our engines. I've got aluminum heads which flow in the 290 range and still make good torque with a cam that big. With just a touch over 10.1 compression the valve timing events still give me a 9.28 Dynamic compression ratio. I have to pull 4* timing and run a 160* thermostat for everyday driving on pump gas compared to the race gas configuration I tried on the dyno. Peak torque is also at 4500 rpm. Have I scared you away yet? Good , I hope so.

With that head your going to need something with a split pattern to help things out. I would look for something in the 220-230 range with under 500 lift for your application. Make sure you stick to one of the street performance lines so you don't get into trouble with the DCR. If I had to recomend one cam it would be the Comp XE268H grind number 12-242-2. This thing belongs in the generic camshaft hall of fame.

Hope this helps
James

 

There are a lot of factors that can decide how much timing a motor likes. I know the combustion chamber design can play a big factor. That fact that you have an older style combustion chamber usually means your motor will like more timing than an LT1 or vortec style combustion chamber. If you are not detonating, I would go with 36-38* total timing on pump gas.

I know my vortec headed setup loved 36* of total timing, 34* and it lost 2 tenths and 2 mph, 38* and it lost 2 tenths and 2 mph. I had been running my car for a few months running consistant 12.6's at 108 mph with 34* total timing, I remember I was shocked when I advanced the timing to 36* and went 12.4's at 110 mph- easiest horsepower I ever made .

 

I agree 100% But with detonation always a possibilty I think its paramount to work your way up and not down with regards to ignition timing. There are just too many variables out there to mess things up. I don't know what all is included in the "works" but I know from experience that a cast piston is not very forgiving We don't know about the spark plug heat range or plug gap either, nor is their any mention of the quench distance. Also a stock balancer must be set with a dialback light and I don't trust one any farther than I can throw it. 38 can quickly turn into 40-41 and one batch of bad gas could ruin a new motor. Lets not even talk about vaccum advance.

End of Rant

start small and after your engine is broke in listen and check your plugs to watch for detonation and you can probally realize some power gains with additional timing, just don't get too carried away with it.

James

 

advanced timming right?

 

yes

 

I run 34 degrees in mine.