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Author Topic:   need rpms
unlucky13
Member
posted June 02, 2003 07:06 PM
valve float?


racer17j
Member
posted June 02, 2003 09:36 PM
i'd check valve lash and and whats your tires roll out to be?


unlucky13
Member
posted June 02, 2003 10:21 PM
one more thing you might want to look into is tranny or rear end gear i had my tranny go bad on me would only turn 2500 on the track could turn as much as i wanted in the pits but once i put her in gear got to 2500 and nothing didn't miss or studder or anything just pulled like a big dog. another thing thats alot of timing back her down to like 34 and see what it does


STREET16
Member
posted June 02, 2003 11:01 PM
Ran into identical problem, put a different carb on it and it went away. took the carb apart and didn't find anything wrong. tempted to box it up and send it to kplugnut. see if you can borrow a carb from someone. if it were valve float, you would here it. also, if you used a timing chain with triple keyways, you may want to double check it.


unlucky13
Member
posted June 02, 2003 11:30 PM
sounds like you may have a distributor problem. maybe it's retarding the timing at high rpms. try a different distributor.


unlucky13
Member
posted June 03, 2003 09:33 AM
Some stock HEI modules have been known to retard 10-20 degrees.


gerald berry jr
Member
posted June 03, 2003 10:54 AM
weak valve springs


unlucky13
Member
posted June 03, 2003 03:14 PM
ac 45ts


ruggs66
Member
posted June 04, 2003 01:41 AM
what is a mwms #1 cam ?

any specs on that?



jay116
Member
posted June 04, 2003 09:53 AM
I think I found the specs http://www.parts123.com/PartFrame.asp?ZTM=cadefjgb&GHOME=www.midwestmotorsportsinc.com&TITLE=Midwest_Motorsport

Internal Duration @.050" 256
External Duration @.050" 264
Internal Lift 504
Exhaust Lift 504
Lobe Separator 105
Advance Internal Duration 287
Advance Exhaust Duration 295
Valve Lash .026-.026

Increased comp, advised, street stock with 2/barrell, 3/8-1/2 mile

------------------
Jason Boivin
http://www.rcracing-team.com


dirtbuster
Member
posted June 04, 2003 10:37 AM
personally i think your cam is to big and you may not have enough torque to pull more rpms. With your flat tops and 882 heads you prob are only around 8.7 maybe 9:1 compression. Not enough in my opinion to run a 256/264 cam. Try going to something in the 245 duration range.

Does your carb open completely when the pedal is on the floor?



unlucky13
Member
posted June 04, 2003 04:36 PM
Nope cams not to big ran the same one with 993 heads w/1.94 valves and it didn't peter out until around 6400 for us.


unlucky13
Member
posted June 09, 2003 10:58 AM
I agree with Dirtbuster on the cam being too big for your compression ratio.

& try something with 108-111 lobe separation.



rocket36
Member
posted June 11, 2003 12:28 AM
seems a little odd.
why not ring MWMS and ask them, if they recommended that cam and you told them that you were running 9:1 CR then there is a good chance it will be right.
CR shouldn't change the amount of RPM you can pull, it just won't have the get up and go that it should. remember most modern cars will be running around the same CR from the factory and rev up pretty good. also some racing divisions have a CR limit of 9:1 and still rev up to 7500rpm.
I think you need to check inside distributor and make sure it is still locked. we have had one where the advance plate has come loose and kept retarding the engine.
also double check cam timing (take off timing cover) and if possible degree cam to make sure that you have the cam timing right or it will be a real slug.


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