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Piston to valve clearance help

Old May 16, 2022 | 01:16 PM
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Default Piston to valve clearance help

So getting my L33 together. Block is stock, I had the 799 heads shaved .020 and I'm going to run a .045 cometic head gasket. Running a BTR "truck norris" cam which is 212/22X, .552/.552, 107 LSA. planning on checking pTv clearances but first I have to make some solid lifters. In the mean time, is it necessary to check for how much I took off? It's a manual so that's why I'm concerned.

Also for push rod length, I do have the tool which I will be checking but just wanted some input on whether I would need shorter/longer ones. This is my first time messing with an engine in this way. Thanks.
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Old May 16, 2022 | 01:32 PM
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Originally Posted by 1970hemicuda
So getting my L33 together. Block is stock, I had the 799 heads shaved .020 and I'm going to run a .045 cometic head gasket. Running a BTR "truck norris" cam which is 212/22X, .552/.552, 107 LSA. planning on checking pTv clearances but first I have to make some solid lifters. In the mean time, is it necessary to check for how much I took off? It's a manual so that's why I'm concerned.

Also for push rod length, I do have the tool which I will be checking but just wanted some input on whether I would need shorter/longer ones. This is my first time messing with an engine in this way. Thanks.
Your ptv clearance should be fine with that cam, but it's always best to check.

You may need shorter pushrods. What lifters are you planning to use?
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Old May 16, 2022 | 01:35 PM
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Couple great threads on this subject from the past few weeks, make sure you check them out too.

https://ls1tech.com/forums/generatio...s6-04-z06.html

https://ls1tech.com/forums/generatio...g-opinion.html
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Old May 16, 2022 | 01:53 PM
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Originally Posted by SCJW
Your ptv clearance should be fine with that cam, but it's always best to check.

You may need shorter pushrods. What lifters are you planning to use?
Lifters are morel 7717s
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Old May 16, 2022 | 06:33 PM
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So I did the clay today. I used an old lifter with the internals swapped to make it solid. I used my factory push rods which I think are too long. After spinning the motor over and getting the clay I saw it had completely punched threw the clay. No good.

While tightening the rockers on I did notice that even on the base circle of the cam the rocker pushed the valve down slightly while tightening, so I think my whole test was off. It was about to rain and since I had everything together at thay point I just spun it over. Can I use a push rod checker tool as the pushrod?
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Old May 16, 2022 | 06:56 PM
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Originally Posted by 1970hemicuda
So I did the clay today. I used an old lifter with the internals swapped to make it solid. I used my factory push rods which I think are too long. After spinning the motor over and getting the clay I saw it had completely punched threw the clay. No good.

While tightening the rockers on I did notice that even on the base circle of the cam the rocker pushed the valve down slightly while tightening, so I think my whole test was off. It was about to rain and since I had everything together at thay point I just spun it over. Can I use a push rod checker tool as the pushrod?
I would not do that if I were you.
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Old May 16, 2022 | 06:59 PM
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You made solid lifters from stockers but running Morel lifters? Is the lifters you're going to be using in the engine now with the head torqued down on the head gaskets?
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Old May 16, 2022 | 07:56 PM
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Originally Posted by 01CamaroSSTx
I would not do that if I were you.
Yeah I saw that it was strongly advised not too after some research

Originally Posted by 01CamaroSSTx
You made solid lifters from stockers but running Morel lifters? Is the lifters you're going to be using in the engine now with the head torqued down on the head gaskets?
Heads are still off the engine. I just put it all together and hand tightened a couple head bolts for the test. And yeah I took my old stock ones and made them into solids so I can accurately measure it. Final assembly will be with the brand new morels.
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Old May 16, 2022 | 08:00 PM
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You made solid lifters. And used a stock PR for the clay test.
That doesn’t work.

What you need to do is set your checking PR to 0 lash. Put light weight springs on one cylinder. Then do the clay test.

You will need to use the Morels when you measure for correct pushrod length.
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Old May 17, 2022 | 06:54 AM
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I don't have any checking springs handy and none local to me. I found a thread where the guy used a factory push rod but only tightened the rocker bolt down to 0 lash. Not the 22lb tight. Would that work at all?
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Old May 17, 2022 | 07:34 AM
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Originally Posted by 1970hemicuda
I don't have any checking springs handy and none local to me. I found a thread where the guy used a factory push rod but only tightened the rocker bolt down to 0 lash. Not the 22lb tight. Would that work at all?
Instead of leaving the rockers loose, maybe shim the stands up with washers to make up for the pushrod length.
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Old May 17, 2022 | 12:12 PM
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I prefer to use a dial indicator, a PR length checking tool with homemade solid lifters and light weight springs to measure P-V. Also important to have a degree wheel installed to watch the valve events.
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Old May 17, 2022 | 05:54 PM
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Clayed the engine twice today. Solid rollers, rockers at 0 lash. I got .13 in for the intake valve and .08 for the exhaust twice. Timing is dead on and 0 lash is set with rollers on base circle. I know the exhaust is too close but I don't really get how much closer it is than the intake. I had the heads shaved .020 and Im using a brand new .045 cometic. Thought I would be alright. Thinking of running standard gm gaskets to safe it? Don't really want to fly cut.
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Old May 17, 2022 | 07:55 PM
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Originally Posted by 1970hemicuda
Clayed the engine twice today. Solid rollers, rockers at 0 lash. I got .13 in for the intake valve and .08 for the exhaust twice. Timing is dead on and 0 lash is set with rollers on base circle. I know the exhaust is too close but I don't really get how much closer it is than the intake. I had the heads shaved .020 and Im using a brand new .045 cometic. Thought I would be alright. Thinking of running standard gm gaskets to safe it? Don't really want to fly cut.
You will be fine with .080.
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Old May 17, 2022 | 08:17 PM
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And I'd want at the very least .100
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Old May 17, 2022 | 08:20 PM
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I had .157 P-V on the exhaust without a head gasket on my LS370 which has 12cc domes, a 238/246 .633SL camshaft and 823 cylinder heads which I could have milled .030 but didn't.
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Old May 17, 2022 | 08:59 PM
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I ordered some stock gaskets. Ill clay it again with those and see where I am at. I definitely lean more cautious and would rather be safer than make a 1/4 more compression.
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