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Author Topic:   HELP WITH CUSTOM CAM!
stockcar5
Member
posted March 24, 2004 11:17 AM
ok, a friend of mine bought a new crane cam from ebay for like 30$. it is a flat tappet with the welded inserts to prevent wear. it looks like an old nextel cup regrind? anyway the cam journal surfaces are set up for larger roller cam bearings and this is gonna go in a stock 400 block...so i think i am gonna have my cam grinder cut the journals to size for him. but on the crane cam card that came with it it says to use .875 tappets...stock is .841 i believe? can we run the stock size tappets and if not...why? what is the reasoning for larger tappets?

thanks!

luke

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www.geocities.com/dirtstockcar5


sdhnc29
Member
posted March 24, 2004 01:46 PM
I would not bother with this cam Luke. For a few reasons actually. The main reason will be that the lobes on the cam will not fit into the cam tunnel after your grind the journals down ( the cam is built on a larger diameter core). The cam tunnel would need to be bored, and 50mm roller cam bearings used.Another reason is that this cam will not work with the stock diameter lifters, trying this with stock diameter lifters will tear the lobes off of the cam. Lifter bore sleeves would need to be installed in the block to allow for the correct lifter to be used. These cams are also only good for a 500 mile race. It should also be taken into account that this type of cam, if it's a Cup cam, will be way to aggressive and the duration will be too long. These cams will use spring pressures similar to mild solid roller cams.Also if it a cam for a SB2.2 engine, it will not work with a 23 or 18 degree engine.

All in all, he will be better off buying the correct cam for his application.

Steve

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Hendren Racing Engines
Rutherfordton , NC
(828)286-0780
Check out my other business at www.solemnvow.com A special thanks to jammin for the awesome job he has done for me on this site!!


stockcar5
Member
posted March 24, 2004 04:29 PM
thanks steve...i tried to tell him that but he's kindof an impulse buyer. i found it it takes ford lifters (.875) and im guessing that you need a larger lifter because the lift and ramp rates on this cam are so high that the edges of a smaller lifter will hit the cam lobes?

also it is for a standard chevy..not sb2 and the specs on it are 308, 300 duration 106 lobe center and .640, .647 lift with 1.6 rockers! probably a little much for a mud truck..lol

thanks again

luke

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www.geocities.com/dirtstockcar5

[This message has been edited by stockcar5 (edited March 24, 2004).]

sdhnc29
Member
posted March 24, 2004 10:26 PM
"im guessing that you need a larger lifter because the lift and ramp rates on this cam are so high that the edges of a smaller lifter will hit the cam lobes?"

You got it!!

Steve

------------------
Hendren Racing Engines
Rutherfordton , NC
(828)286-0780
Check out my other business at www.solemnvow.com A special thanks to jammin for the awesome job he has done for me on this site!!


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