Solid Roller Valve Lash
Thread Starter
Pro
Joined: Nov 2008
Posts: 680
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From: Denham Springs LA
Solid Roller Valve Lash
I have a Reeds solid roller cam in 468 BBC. I had the engine rebuilt a few months ago. At that time I didn't have cam specs. Engine builder set valve last at 0.016". Just found cam specs on Internet and it says to set valve lash at 0.026". That sounds really large. Engine runs fine at 0.016".
Trying do decide if I should adjust them to 0.026", or leave at 0.016", or somewhere in between.
One advantage would be increased vacuum. At idle it only has 5.5"Hg.
Valve train is pretty quiet (as expected with tight gap).
What do you think?
Thanks
Roger
Trying do decide if I should adjust them to 0.026", or leave at 0.016", or somewhere in between.
One advantage would be increased vacuum. At idle it only has 5.5"Hg.
Valve train is pretty quiet (as expected with tight gap).
What do you think?
Thanks
Roger
Race Director
Joined: Dec 1999
Posts: 11,096
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From: Sierra Foothills CA
I wouldn't change anything until you either locate the actual cam card or talk to him and/or the cam company to make sure you have the right info. Websites can list bad info sometimes.
Thread Starter
Pro
Joined: Nov 2008
Posts: 680
Likes: 5
From: Denham Springs LA
Les,
Reeds cam is no longer in business. I found an old catalog on the Internet.
The guy I bought the engine from doesn't have any info on the cam (imagine that).
I do have a number for a guy that used to work for Reeds cam, specing cams. I will give him a call.
Thanks
Roger
Reeds cam is no longer in business. I found an old catalog on the Internet.
The guy I bought the engine from doesn't have any info on the cam (imagine that).
I do have a number for a guy that used to work for Reeds cam, specing cams. I will give him a call.
Thanks
Roger
Le Mans Master
Joined: Dec 2003
Posts: 5,727
Likes: 38
From: Fremont CA
Reed cams have needn't gone long enough that there is no way that that cam runs a 0.016" valve lash, I would at least bump it up to 0.022"int/0.024"ehx clearance
So called "tight lash" cams have only been around 25 years, I hope the roller lifters are top quality. You should check out the Chevelle tech forum for a good data base of big block owners who run solid rollers.
So called "tight lash" cams have only been around 25 years, I hope the roller lifters are top quality. You should check out the Chevelle tech forum for a good data base of big block owners who run solid rollers.
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From: Corsicana, Tx
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You won't hurt anything running .016" or even tighter. But as you mentioned..vacuum can get better as you loosen them. Often the clearance ramps are pretty long and there isn't much difference in sound at .022" or so..but most likely a little louder.
Remember..cold lash with aluminum heads is set about .005-.06" tighter than hot lash..which is what all cam card say.
JIM
Remember..cold lash with aluminum heads is set about .005-.06" tighter than hot lash..which is what all cam card say.
JIM
Thread Starter
Pro
Joined: Nov 2008
Posts: 680
Likes: 5
From: Denham Springs LA
Jim,
Glad to hear 0.016"isn't a problem.
I'm hoping to increase vacuum and maybe even low end power a little by increasing valve lash.
I have 990 steel heads. Maybe will move up to aluminum in a year or two.
Thanks,
Roger
Glad to hear 0.016"isn't a problem.
I'm hoping to increase vacuum and maybe even low end power a little by increasing valve lash.
I have 990 steel heads. Maybe will move up to aluminum in a year or two.
Thanks,
Roger
Team Owner
Joined: Oct 2004
Posts: 81,241
Likes: 3,063
From: altered state
St. Jude Donor '05
Youll pick up some low end torque with more lash
Reed is still around and grinds tons of cams
Mine is spec'd for .028 hot
.020 cold is the tightest Id go.(ran best I think at .022 cold) leaves hot about 25, 26 which is just about right if that helps. If you do go real "tight" let it really warm up good before you start revving/driving it. If the cam was designed for a fair amount of lash it surely wont hurt anything. Besides who doesnt love the sound
Reed is still around and grinds tons of cams
Mine is spec'd for .028 hot
.020 cold is the tightest Id go.(ran best I think at .022 cold) leaves hot about 25, 26 which is just about right if that helps. If you do go real "tight" let it really warm up good before you start revving/driving it. If the cam was designed for a fair amount of lash it surely wont hurt anything. Besides who doesnt love the sound
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Melting Slicks
Joined: Oct 2008
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From: Regina Sk Canada
My 468 had a cam motion soild roller. Springs were 1.625 and came with the AFR heads. I ran Isky red zone lifters, and ran .025 lash int and exh. cam was .692/.684 with .262/.272 @.050. motor made 708 hp ran to 7400 rpm.
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From: Sierra Foothills CA
It looks like Solid LT1 nailed it! Way to go Eric.
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Les