Valve to piston clearance
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Valve to piston clearance
I am currently in the process of rebuilding my 305, I am running some new flat top pistons and a Comp Cams Extreme energy hydraulic roller cam. The cam has .498 intake lift and .502 exhaust lift with 270 degrees of duration.
I am told that there should be an ID plate of the front passanger side of the block and if its absent that means the block may have been decked. No such ID tag was present on my block.
The method everyone has told me to check Piston to valve clearance with is to clay the pistons, except I would like to use 1.6 ratio rocker arms instead of 1.5, so I am wondering is there anyway to check this clearance without having rocker arms? I would hate to buy a set of 1.6 and then have them not work.
I am told that there should be an ID plate of the front passanger side of the block and if its absent that means the block may have been decked. No such ID tag was present on my block.
The method everyone has told me to check Piston to valve clearance with is to clay the pistons, except I would like to use 1.6 ratio rocker arms instead of 1.5, so I am wondering is there anyway to check this clearance without having rocker arms? I would hate to buy a set of 1.6 and then have them not work.
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Joined: Aug 1999
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From: Jackson County
i prefer using an indicator and soft springs any more, but have done a couple with play dough. check it with 1.5s and then do the math and you can estimate the clearance with 1.6s. be better to wait till you had the 1.6 rockers, but i bet you find you have .15 or more clearance without a gasket.
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Well the problem is, I have no rocker arms and I am trying to decide which ones to get. I would prefer 1.6s but I am not sure how to got about checking.
Can I get away with buying 2 1.6 rockers and testing one of the pistons?
Can I get away with buying 2 1.6 rockers and testing one of the pistons?
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Joined: Jul 1999
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From: Loveland, OH, US
Car: 4
Engine: 6
Transmission: 5
I'd agree with what ede says, except that I'd be willing to bet yu'd have even more clearance than he suggests.
Yes, you could get 2 rockers and measure it one cyl at a time, if you're really worried about it.
SBCs almost never have valve-to-piston clearance problems with any combos you can run on the street. Don't worry about that, worry more about getting the right valve springs, which will need to be 1.45", which will require machine work. Go ahead and get the 1.6 rockers, if that's what you want, you won't have a clearance problem. Depending on what heads you have, you may need to lengthen the push rod slots. All of that pretty much needs to be done before the heads are installed, and won't bother anything if you decide to use the 1.5 ratio rockers instead.
You're not looking for a "tag" as such, but rather some numbers stamped in the deck surface right in front of the pass side head.
Yes, you could get 2 rockers and measure it one cyl at a time, if you're really worried about it.
SBCs almost never have valve-to-piston clearance problems with any combos you can run on the street. Don't worry about that, worry more about getting the right valve springs, which will need to be 1.45", which will require machine work. Go ahead and get the 1.6 rockers, if that's what you want, you won't have a clearance problem. Depending on what heads you have, you may need to lengthen the push rod slots. All of that pretty much needs to be done before the heads are installed, and won't bother anything if you decide to use the 1.5 ratio rockers instead.
You're not looking for a "tag" as such, but rather some numbers stamped in the deck surface right in front of the pass side head.
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