Cam change a flop!

Bob T · Dec 27, 2003

Please don't be so quick to take that cam out. You may not be able to run pump gas even after you go through the tuning steps but after all the effort of swapping cams at least give the cam a chance. I would start by putting in at least a mix of race gas and pump gas to eliminate too low octane from the equation as you experiment with ignition timing and carb tuning. As already mentioned, if the engine is pinging or if you have to pull the timing back a lot to keep it from pinging, you probably aren't seeing any where near what that cam is capable of doing. Then after you have the ignition and carb sorted out start lowering the octane more and more to see how close to pump gas you can run.

Big James 4XL · Dec 27, 2003

Sorry Bob, but the switch is on, I have coolant draining from the radiator as I type!

ezstriper · Dec 27, 2003

IT'S VERY POSSIBLE THAT ADVANCING THE CAM CAUSED SOME OF YOUR PROBLEMS ALSO, COULD HAVE RAISED YOUR STATIC COMP. RATIO. YOU CAN CHECK THIS OUT BY RUNNING A COMPRESSION CHECK ON A COUPLE OF CYL'S, CHANGING THE CAM DEGREE AND RUNNING IT AGAIN, IF YOU LOOSE SOME SHOULD HELP YOUR PROBLEM
ROB...

phel69 · Dec 27, 2003

I think that mr 4 speed might be on to it. You seem to always have had a detonation issue with that engine from reading your previous posts. I run 10.3:1 comp and open chamber heads which are SUPPOSEDLY more detonation prone and my engine never shows a hint of detonation. I think you have a timing issue.

427L88 · Dec 27, 2003

James, sorry to hear. Your experience goes against every other experience I've had/heard about a switch to solids. Speaking of hearing, are you sure its not the valves you're hearing?But 10.5:1 is tricky with these small cams, and with iron, well, too much.

My old Crane cam , which is set on a 114 lsa ( intake closes at 80-82 ) would have been fine, or the 272/282 on a 112-114 LSA.

No matter, its a done deal, hope it goes well. Getting good at cam swaps yet, are ya!?

baddbob71 · Dec 27, 2003

If you are swapping the cam, do a compression test first to see what that cam is producing compressionwise. Then if you install your old cam straight up you can check the compression again and let us know what the difference was. I think the solid cam was a good decision but tuning would be required.

Cam change a flop!

Bob T

Big James 4XL

ezstriper

phel69

427L88

baddbob71

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