Swapped Cams...now power problems

[Gregolas]

Literally swapped out my stock cams for some mild regrinds I picked up...took it out for a drive and am having severe problems making any power to move the car. Checked timing at least 12 times as the exhaust cam slipped on me when I was reinstalling the sprockets. Timing on cam sprockets is neutral...15 rivets from point to point...TDC on crank was measured at cylinder (and on pulley) as I have an M20 lite fly so I cant lock it...Could I be off 6 degrees? Car runs and drives, but is so laggy and makes almost no power. I am at a loss right now as I am thinking the crank sprocket might have slipped a tooth but it seems like that may not be possible given the guide at the bottom...

Need help guys, I am at a loss and am not trying to swap a tooth and have valves meet pistons. Car idles fine and no hiccups there.

[roguetoaster]

Are these Delta regrinds or what? I am sure you have checked this, but are the indents on the came squares up at TDC? As for locking with the flywheel just try a socket, breaker bar and length of pipe (maybe tied/taped in place to hold slack) on the crank bolt wedged up against the chassis. Hopefully you are just off slightly because you cannot lock the FW.

[bmwman91]

Did you accompany this change with a custom chip tuned for these cams? If not, there's your problem. Years ago I tried messing with the cam positioning by advancing the intake...ran like shit because the fuel and ignition tables were mapped for stock timing. You need a tune to go with the cams; just popping them in will do nothing but bad things for performance.

[Gregolas]

They are delta regrinds... and no custom chip for the cams (I have the Dinan chip in it). Gonna swap the stock cams back in and hopefully that will fix the problem.

Thanks for the answers guys, I appreciate the responses!

[jlevie]

I would suspect suspect an error in cam timing. And you can check that without tearing anything apart by measuring valve opening at TDC on the exhaust stroke. I don't have the ideal numbers for an M42 engine, but a good approximation would likely be both valves open the same amount. You should be able to obtain the ideal numbers from the folks that ground the cams.