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HP500 Piston to valve clearance

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Old 01-18-2005, 07:16 PM
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Default HP500 Piston to valve clearance

Does anyone know if a crane "651" cam will work in an otherwise stock HP500 and have enough piston to valve clearance? Stock heads and stock JE pistons...I plan to measure anyway, but curious from anyone with experience on this set-up. Thanks.
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Old 01-18-2005, 07:40 PM
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Default Re: HP500 Piston to valve clearance

That cam has .034 more intake lift and .020 more exhaust. I would think that it is a big cam for a stock compression low displacement engine. I was going to use that cam on a 9:1 Whippled 540 with dry tail pipes. I am sure the experts will chime in.
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Old 01-19-2005, 06:07 AM
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Default Re: HP500 Piston to valve clearance

Too big. Unless you plan to spin the engine over 6000 rpm. Use the 741 instead. It will clear the pistons however.
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Old 01-19-2005, 07:25 AM
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Default Re: HP500 Piston to valve clearance

It will be blown and turn 6000+, thanks for the info partiyacht.
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Old 01-19-2005, 09:23 AM
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Default Re: HP500 Piston to valve clearance

Want to buy a pair of 651's? I think I still have a set of the correct length pushrods for GM heads also. Only about 40 hrs.
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Old 01-19-2005, 10:34 AM
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Default Re: HP500 Piston to valve clearance

The 651 is not a blower cam. Blowers do not like lead. Cam is way to big for blown 502 even at a max of 6000 rpm.

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Old 01-19-2005, 11:01 AM
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Default Re: HP500 Piston to valve clearance

Crane has it in their blower cam section. It would not be my choice either. I should say "had", on their old web site.

Last edited by PatriYacht; 01-19-2005 at 11:07 AM.
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Old 01-19-2005, 11:22 AM
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Default Re: HP500 Piston to valve clearance

Parti,
In the 15 years I have been messing with camshafts and lobe designs for engine combinations I have NEVER had a shaft ground with advance to go into a blower enigne. It makes no sense to open a valve early when you have something that is going to stuff air and fuel into the chamber.

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Old 01-19-2005, 11:54 AM
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Default Re: HP500 Piston to valve clearance

Thanks for the info cstraub.
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Old 01-19-2005, 11:59 AM
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Default Re: HP500 Piston to valve clearance

Chris;

What cam would you use, hydralic roller? Stock 500HP except for 8-71's and (2) 825 blower carbs.

I gotta tell you though, I know several people who run that cam on blown 502's with great success, not only on the dyno but in their boats.
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