comp cam ?

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comp cam ?

Postby rascal on Sun Jan 26, 2014 9:11 pm

hows any ran a comp thumper cam it seems like wen its idleing it loses vacum to the carb
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Re: comp cam ?

Postby durty on Sun Jan 26, 2014 11:18 pm

the thumper cams usually have quite a bit of duration, hence they wont build very much vacuum, may be able to put a vacuum canister on it and it should help with the low vacuum at idle
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Re: comp cam ?

Postby Siebert_Performance on Thu Mar 06, 2014 10:18 am

A vacuum canister is a good idea, also what is your base timing set at? If timing is low, advancing it will help.
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Re: comp cam ?

Postby amcamx on Fri Mar 07, 2014 6:04 am

I put a 350 horse cam in a 350 with 8.5 comp, and it would not idle at all. That cam is stock for a 327 or 350, and has .450 lift and about 268 duration. But it is for 11-1 comp, and would not run below 1,800 rpm.
I put in Rhodes lifters, and then the Vacuum went up to 20 in drive, at idle. Instant throttle response.
14.6 sec and pulled the wheels? That is low end torque.
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Re: comp cam ?

Postby zziggy on Fri Mar 07, 2014 12:52 pm

Thumpers are for cruising the Sonic. They're a cam that is supposed to SOUND wicked even though it's not/

The Thumper series is a poor choice for a real performance application. A real performance cam and the shortblock and heads to support it are your best choice.
A Mild HYD roller may not rumble a lot but it can make you plenty of power with complimentary engine parts..
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Re: comp cam ?

Postby rascal on Sat Mar 08, 2014 12:29 am

the vacum can fixed it
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