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Author Topic:   WONDERING HOW TO PULL VACUME
chapa73
Dirt Maniac

Total posts: 169
posted April 11, 2005 11:44 AM  
Okay,this is all kinda hypithitcal here.
The track I race at has a limited mod class,just like a 'A' mod,but with a vacume rule and take off tires.

My question is I run a 350,scat crank,5.7 rod,.275 dome piston,462 double hump,2.02 valves,Cam I think is a MWM #7,I think!

My question is,is it possibleto get 16" of vacume at 1200 RPM with just changing cam,I dunno what This motor will pull,I checked it last year,I used the big vacume port on the back of carb,and it had like 8-10",Im gonna figure the new motor will have alittle more compression,but same cam.

Im just wondering about it,thats all.

Thanks in advance!
Glen

iowatoolman
Dirt Freak

Total posts: 369
posted April 11, 2005 11:24 PM  
yes by changing the cam it is possible

i have to pull 15" @1000rpm

sorry no secrets to give out now

drive hard or drive home

rico 08
Dirt Forum Champ
Total posts: 1139
posted April 12, 2005 04:21 PM  
There are really no secrets to it,i have a hydraulic cam with rhoades lifters that pulls 16 inches that i'll sell for $75 with the lifters plus shipping.here's the specs:
234-244 dur at .050 .488-.509 lift 112 deg lc
3000-6500 rpm range

chapa73
Dirt Maniac

Total posts: 169
posted April 13, 2005 01:46 PM  
What are Rhoades lifters?

Thanks for the offer,Im not looking at the limited class right now,I hate to be limited to 1 track,Just keeping it as a possible option,Was wondering if it look all kinds of different stuff,Or basicly a cam/lifter change.

wrenchnerd
Dirt Roller

Total posts: 16
posted April 13, 2005 05:42 PM  
rhoades lifters don't fully pump up at low rpms, makes the valve train a little sloppy, i had no luck with them, ran them 2 weeks now they are sitting on the shelf, call what ever cam company you deal with and tell them your specs and they will get you the cam you need. cam and good ring seal are 2 biggest factor in vacuum.

rico 08
Dirt Forum Champ
Total posts: 1139
posted April 13, 2005 08:46 PM  
mine have 12 races on them...they are sweet
cam sounds totally stock

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