I am about to install my new cam, Summit 1103, into 327 sbc, stock block, double hump heads (unsure of head specs), 3 x 2 Rochester carbs, lakester headers, 350 auto, 3.5 nine inch 32 inch tyres. My question is should I install cam 4 degree's + 4 degree's - or at zero. My cam card does not recommend, but I think cam may be 4 degree advanced from new. I have a double row cloyes timing chain that allows + or - 4 degrees. I am after low end power and am leaning towards standard position - is advancing cam going to suit me better. I have a degree wheel and can dial in cam to what is better suited to my needs but have no experience with sbc cams. Glen
It says it wants the intake lobe center at 107°. Put it where they recommend, or as close as your timing set allows.
I have the same cam from Lunati.. I installed mine straight up, plenty of torque off idle and beyond.
The numbers look a lot like a popular hot rod cam from the 60's The ONLY way to find out how you and your engine will like the cam...is to instal it. As others have noted, I'd instal it straight up as the cam card says (107°), initially. THEN...after driving it a while, advance the cam 4° with your timing kit, and...drive it. See which way you like it best..! That's the ONLY way that you'll find out how you will like it. No one has a cam-crystal ball to magically predict things. Unless they have an engine built just...like yours and have the same...cam. One thing. While I doubt that you'll have a problem, be sure to check BEFORE you start the engine with the cam advanced, check the intake valve to piston clearance. Many ways of doing this. Consult the internet for the method that you'll be happiest with. One way to sort of, predicting the outcome... Take a dynamic (gauge) compression test both with the cam at the original location, then after you advance it. The higher compression numbers will normally indicate a better running engine at lower, mid rpm ranges. Just make sure that it isn't above about 200psi. That's too much for todays gas. Mike
advance or retarding the cam will mainly shift where the powers range kicks in. one way lowers the rpm range and the other way moves the rpm range higher. say around 500 rpm
The thing that strikes me about the cam specs is that it says its for engines from 262 to 400 cubic inches. A cam will have a different effect depending on the displacement of the chosen engine. Thats a pretty wide displacement range, so advancing or retarding the cam may be needed if your engine is near either end of that range. Most likely its optimized for 327/350 but works in other displacements. Like was mentioned before, you probably need to try it and see if straight up works well and then experiment if you want something more. You might try calling the tech line at Summit and ask them.
The thing I like to do on a street car is install the cam 2° advance to alow for chain stretch so it's close to strait up after it's run. Chain stretch happens fairly quickly depending upon how much valve springs you have.
whatever you decide on, set the cam up with degree wheel and dial indicator and see what the intake lobe center actually is...
Install it straight up . If you need more torque adjust fter break in . Dont forget to check piston to valve clearance when / if you adjust cam timing .
Also factor into your engine budget the cost of checking the advance curve of your distributor by a professional on a machine, whether using a used or a new distributor.
That's a pretty mild cam. That is about 10 degrees less intake duration than the old 327/350 hp cam, with same duration on exhaust as the 327/350 cam. It will have plenty of low end installed straight up. It will have just perceptible lope at idle. Sent from my SM-G950U using The H.A.M.B. mobile app
What size are your intake valves? -With 1.94 valves it gives you 21 CID/Inch of valve diameter and an optimal LCA of 108. -With 2.02 valves it gives you 20 CID/Inch of valve diameter and an optimal LCA of 109.5.
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