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Author Topic:   down on RPM'S
doghouse racing4
posted August 24, 2004 07:33 PM
I run a IMCA mod and run alcohol. I ran a junk roller motor last year, 355 with 13-1 pistons...dart heads and turned 7200 rpm's. This year I am running a 383 solid cam with all top of the line parts in it, same carb and gear etc. This year I have been running 6500 rpm's which I thought was low at the same tracks as last year. I changed plugs and re-timed, now I am running 6200. What is the problem? I was running 32* timing and I checked it and it is at 30*. If my timing is not enough total advance, would this cause the rpm problem? I checked the lash and it is all ok. The engine runs good and I would have never known lower rpm's if it weren't for the tach.

posted August 25, 2004 04:12 AM
are you just as fast as last year?
Maybe the tach is the problem.

Jason Boivin

posted August 25, 2004 06:49 AM
Earlier in the season we couldn't build any rpm and the motor felt like it was down on power a little. Turned out a piece inside the distributor was broken.

Have you ever had the two engines dyno'd to see what the difference is. Different cams, different heads?

300 rpm worth of difference can be caused by changing track conditions.

Perhaps a gear change is in store?

posted September 06, 2004 09:59 AM
I know some one that just had a big bore short stroke motor built with good heads and new dist. He is having the same problem. It will not go over 6000 rpms and says it wont get out of its own way. Not sure what the cam is and all that stuff but could find out. Any ideas would be great. Hes pretty bummed out about the hole deal and id like to help.

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