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Author Topic:   ENGINE RULE
PURESTOCK 46
Dirt Roller

Total posts: 12
posted March 02, 2002 11:39 PM
THE RULES AT MY TRACK FOR THE PURESTOCK CLASS ARE AS FOLLOWS
ENGINES: Engine and body must be of same manufacture such as Ford to Ford, GM to GM, etc. Stock production cast iron engine and heads only. Tie down chains acceptable. No setbacks allowed. No factory performance heads such as Chevrolet small block angle plug heads, bowtie, Ford SVO, etc. allowed. No racing engines or parts, super chargers, turbo chargers, nitrous oxide, alcohol, nitro, etc. No Fuel injection or computers allowed. Engine must be naturally aspirated. Stock mechanical fuel pump only and must be block mounted and in stock location. No roller cams, roller rockers or roller tip rockers. Rockers must be stamped steel only. No stud girdles allowed. Engine must be able to idle at eight hundred (800) RPM with a minimum of fifteen (15) inches of vacuum measured by the track vacuum gage and equipment at time of inspection. No more than one hundred eighty (180) pounds of compression allowed at time of inspection with track gage. No solid left cams allowed. Camshaft for GM and Chrysler can be no more than .260 lift on intake lobe and no more than .390 lift at the valve. Camshaft for Ford can be no more than .260 lift on intake lobe and no more than .418 lift at the valve. No dome pistons allowed. No porting, polishing or pocket porting. No deburring of any kind on heads or manifolds. No big blocks allowed. No factory high-performance engines allowed. No mini starters allowed. AMENDMENT 12/19/01 SUBJECT PISTONS: Flat Top Pistons with a minimum of two (2) valve reliefs will be allowed in engines with the exception of the 400 cui small block Chevrolet. 400s must use dish pistons.
I WAS JUST WANDERING WHAT WOULD BE THE BEST ENGINE TO BUILD HERE. IS THERE ANYWAY AROUND THE CAM RULE.

THANKS FOR THE HELP

[This message has been edited by PURESTOCK 46 (edited March 02, 2002).]

racer17j
Dirt Forum Champ
Total posts: 1565
posted March 03, 2002 12:46 AM UIN: 54865418
get a 350 with 882 heads and a set of flat top pistons should be all right as for the cam i have no idea i thought our cam rule ***** but yours takes the cake man

Slam_Shifter
Dirt Full Roller

Total posts: 53
posted March 09, 2002 01:04 AM
Depending on how they tech the cam rule . you may be able to get around the cam rule to a point with 1.6 ratio rockers. they make a 1.6 ratio stamped rocker availible through summit racing and they are affordible and stock appearing.The 1.6 rockers will give you more lift than the same cam with stock 1.5 rockers. Plus i don't remember it saying anything about rocker arm ratio in the rules and if i am thinking correctly those were a stock part on a few production chevies. Others here may know more about that. It shouldn't hurt your vacuum much either.

Flatlander
Dirt Freak

Total posts: 310
posted March 09, 2002 10:25 AM
if you use the 1.6 rockers you will probably need to use a longer pushrod also and be sure that you have clearance so you will have no bind anywhere in your valvetrain

racer17j
Dirt Forum Champ
Total posts: 1565
posted March 09, 2002 10:43 AM UIN: 54865418
flat i run 1.6 with stock pushrods as long as you have not done alot of head and block work and run the stamped steel long slots like slam mentioned you shouldn't need to change to much but i'm not a engine guys so i could be wrong all i know is it works for me with stock ones

Flatlander
Dirt Freak

Total posts: 310
posted March 09, 2002 11:59 AM
Yeah I just learn from what I do just try to mention anything that may cause a problem I'm probably overcautious in a lot of cases

nate 11
Dirt Full Roller

Total posts: 52
posted March 11, 2002 05:39 PM
I read an ad in circle track about a cam that comp cam makes. They call it a launch cam. It's supposed to get around the lift rule, but will meet the vacuum rule. Contact comp cams.

Gene
Dirt Freak

Total posts: 230
posted March 11, 2002 06:50 PM
I'd go and get me a Studebaker to run there, account the spec guy cant shoot anything down and they run real good too.

uforacing51
Dirt Freak

Total posts: 349
posted March 15, 2002 01:20 PM
Be careful with the cam and the vacume rule, I just spent 2 months trying to figure out why my daughters street car (79 Monte) wouldn't pull more than 14 lbs of vac. I still haven't got it figured out. I made her park the car for now and she is waiting for me. the cam and vac rule could end up being frustrating for you. (the car just loads up and fouls the plugs.)

neverenoughbrew
Dirt Forum Racer

Total posts: 82
posted March 17, 2002 06:42 PM
quote:
Originally posted by uforacing51:
Be careful with the cam and the vacume rule, I just spent 2 months trying to figure out why my daughters street car (79 Monte) wouldn't pull more than 14 lbs of vac. I still haven't got it figured out. I made her park the car for now and she is waiting for me. the cam and vac rule could end up being frustrating for you. (the car just loads up and fouls the plugs.)

Sounds like a bad canister purge valve on your daughters car. When they go bad, they suck vaccum to the carb bowl vent (which the vacumm line is as big as the PCV valve hose)and ***** large amounts of gas straight out of the bowl.


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