dirt track racer 81

iTrader: (45)

ok i get my circle track motor back this week and get it put in the car and i strap it on the dyno tonight and does a whopping 234 hp..should be around 380-410, this cam should pull all the way to 7200 and it drops off at 6000..the compression ratio of this motor is roughly 12.7-13.0:1, using a compression tester it was 126 lbs of compression..should be 200-208 thats what ive had before with new motors with these heads..the guy said the cam card to have 4 degrees advance in it..would this have anything to do with the low compression?? A/F was in the 12's and the timing was set at 36 degrees..

DOES ANY ONE HAVE ANY CLUE WHAT'S WRONG HERE??

kbracing96

iTrader: (26)

New motor? sounds like the rings aren't seated yet. 4* cam advance should be fine, just gives you a little lower power curve. What class/ type of motor is this?

dirt track racer 81

iTrader: (45)

6 inch rod , flat top forged pistons, top proline 50cc heads, comp 4/7 swap cam, 290/300 advertised duration, .558/.549 lift 106 lsa.. high rise single plane intake, 800 cfm c&s areosol billet holley double pumper, (www.candsspecialties.com), msd 6al box.

kbracing96

iTrader: (26)

Gas or alky? Was the jetting right? did they dyno/ breakin the new motor?

PS, the link doesn't work

dirt track racer 81

iTrader: (45)

gas, i let the motor run for 30 mins at 2000 rpm like i have all of my motors and changed the oil in them, yes the jetting was right, same jets i had in the pretty much the same motor i had in last time, http://www.candsspecialties.com/ those carburetors are expensive..very snappy throttle response..

kbracing96

iTrader: (26)

Ya, those carbs are some nice pieces. I don't think the cam is the problem. I think it just need some more run time and some load put on it to get the rings to seat. Do you know what kind of rings they used? Some of them take some time to start sealing. How many dyno pulls did you make? That combo should make some good power. What kind car, Late model, Mod?

dirt track racer 81

iTrader: (45)

i think pro seal or power pro or somethin like that i dont remember..but if the rings werent seated in it would have some blow by to it wouldnt it?? i ran it at 4000for a while then ran it up and down to 6000 10 times then let it idle for 10 more minutes..its called a street stock here..its a stock 74 chevelle frame shortend to 108 wheelbase..3100 lbs..stock lower trailer arms. with a j-bar and with a pull bar..i run a 600 gear in it

kbracing96

iTrader: (26)

Did you run the car this weekend? How did it run? You dirt guy get to run some damn nice motor in your "street stocks" But, as with all dirt racing, get the power to the ground it most of the battle . You probably have to run a really crappy tire .

Oh and as far as blow by, the oil ring could very well be sealing and the compression rings hadn't sealed to well yet. Let me know how it turned out.

CamKing

Check to make sure the cam is degree'd in correctly.
If the engine builder just put a +4 botton in and put it in, it may be way off.
The pins are not always in the correct location on a cast iron cam.