Too close to run??
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Im going to obsolutely lose my mind.
Today I decided to check ptv with the dial indicator and solid lifters in and torque the head down with a gasket and checking springs in. Intake I got like .035 intake, .070 exhaust before the valve stopped going down. Im going to stab myself in the eye with my dial indicator soon. I even pushed on the valve and rotated the engine a bit to make sure it was hitting the piston and it was the piston.
How is this possible?? Im so pissed right now, I dont know what to do anymore.
Today I decided to check ptv with the dial indicator and solid lifters in and torque the head down with a gasket and checking springs in. Intake I got like .035 intake, .070 exhaust before the valve stopped going down. Im going to stab myself in the eye with my dial indicator soon. I even pushed on the valve and rotated the engine a bit to make sure it was hitting the piston and it was the piston.
How is this possible?? Im so pissed right now, I dont know what to do anymore.
If you read the famous GM High Tech Performance LS3 Cam Comparison article, it states:
"We checked the biggest cam with the tightest LSA (that subsequently was not chosen for the test because of too much cam overlap) to verify piston to valve clearance. With a 232/246-duration, 0.614/0.619-inch lift on a 112 LSA, this cam still had 0.100-inch clearance on the intake valve and 0.120-inch on the exhaust valve. We generally like to see at least 0.080-0.100-inch clearance on the intake and 0.100-0.120-inch on the exhaust, depending on how brave you are and how confident you are the valvetrain is in control."
I know your pistons are dished in the center and these are flat, but the outer ring of the piston (it being flat) I assume should be similar in relation to the deck of the block.
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Im going to do the poor mans fly cut and get an intake and exhaust valve and mount some sand paper to them and sand them down. Seen that trick on here somewhere. The great guys at Scoggin Dickey are sending me some valves.
Brian, Ive never read that article but ya my cam is bigger then that one so, and the numbers are close, so that makes sense. The fly cutting will solve my problems.
Brian, Ive never read that article but ya my cam is bigger then that one so, and the numbers are close, so that makes sense. The fly cutting will solve my problems.
Are you sure the solid lifter was the same height as the installed and adjusted height of Comp 850 hydraulic lifter? Back in my Mustang days I would compress my lifter .060 and take all my clearance readings from that height. I installed the checking springs on #1 intake and exhaust with dial indicator vertical on the valve tip for checking. You can push each valve down by hand and take your readings. The two lifters must be at the correct adjusted height or you will get erroneous readings.
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Im going to obsolutely lose my mind.
Today I decided to check ptv with the dial indicator and solid lifters in and torque the head down with a gasket and checking springs in. Intake I got like .035 intake, .070 exhaust before the valve stopped going down. Im going to stab myself in the eye with my dial indicator soon. I even pushed on the valve and rotated the engine a bit to make sure it was hitting the piston and it was the piston.
How is this possible?? Im so pissed right now, I dont know what to do anymore.
Today I decided to check ptv with the dial indicator and solid lifters in and torque the head down with a gasket and checking springs in. Intake I got like .035 intake, .070 exhaust before the valve stopped going down. Im going to stab myself in the eye with my dial indicator soon. I even pushed on the valve and rotated the engine a bit to make sure it was hitting the piston and it was the piston.
How is this possible?? Im so pissed right now, I dont know what to do anymore.
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Are you sure the solid lifter was the same height as the installed and adjusted height of Comp 850 hydraulic lifter? Back in my Mustang days I would compress my lifter .060 and take all my clearance readings from that height. I installed the checking springs on #1 intake and exhaust with dial indicator vertical on the valve tip for checking. You can push each valve down by hand and take your readings. The two lifters must be at the correct adjusted height or you will get erroneous readings.
I set the lifters up to be as close to the retainer as possible, so they got almost no play in it at all, should I have set them up a little different simulated some preload?? Thats one thing Im not sure of, is with a normal hyd lifter in a running engine, where does the lifter run?? Like is it always at the preset preload that you setup during assembly while running??
Should I take my lifters apart and set the cup down a bit to represent my preload?? This still may not be enough to get me into the safe zone.
Hey, Mike. Frustrating is'nt it? Take a big deep breath and sit down and think. It's hard to believe there could be that much difference between the two methods, so obviously YOU are doing something in the process that is affecting the outcome. You said that you checked to make sure you were getting FULL lift at the VALVE when you turned the engine over with the playdo...right? If so, I would probably trust the playdo. That being said...I would want to know WHY you did'nt come up with a similar measurement doing it the other way. I know this sounds stupid and simple, but are you sure your reading the dial indicator right and that your not running out of travel with the way its set up? The lite checking springs will give a slightly less measure than checking it with the actual springs, because the heavy ones take up the slack,(maybe .010-.015) but it is hard to set up any leverage to do it that way. (I have). I would go back through it with the dial indicator set up on the retainer inline with valvestem, making sure it has enough travel for full valve drop and then check my numbers. It's easy to read .030 instead of .130. Don't give up! It's going to be something simple you missed. I'll bet on it. Ron
Im watching the two year old today, so I wont be able to get too much done, but Ill try.
Thanks for the help you guys.
Thats one thing Im not sure of, is with a normal hyd lifter in a running engine, where does the lifter run?? Like is it always at the preset preload that you setup during assembly while running??
Should I take my lifters apart and set the cup down a bit to represent my preload?? This still may not be enough to get me into the safe zone.
Should I take my lifters apart and set the cup down a bit to represent my preload?? This still may not be enough to get me into the safe zone.
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Thanks Larry, thats helpful. So just now Im out in the garage. Here's what Ive done.
I adjusted my lifters to be as close as I can to my calculated preload will be. They are both around .050.
Now Ive installed my head with checking springs with a gasket torqued down. My adjustable pushrod was set for a length of 7.35" and my lifters are 'preloaded". This has given me a bit of slack at the tip of the rocker. Intake ptv is .090, exhaust ptv is lots at .125.
When I adjust the pushrod to 7.400 ( the length of rod Im going to run and gives me the preload that Ive set my 'solid' lifters to) the clearance drops off, Intake is .018 and exhaust is .095".
The exhaust clearance is right near the end of the valve closing event as the piston is chasing the valve up.
The intake is shortly after the valve starts opening and the piston is right around TDC. With this cam the intake valve is opening a few degrees before the piston gets to TDC.
Looks to me I need to do about .085 flycutting to get me up to .100 on the intake and exhaust is marginal, I might just leave it.
I adjusted my lifters to be as close as I can to my calculated preload will be. They are both around .050.
Now Ive installed my head with checking springs with a gasket torqued down. My adjustable pushrod was set for a length of 7.35" and my lifters are 'preloaded". This has given me a bit of slack at the tip of the rocker. Intake ptv is .090, exhaust ptv is lots at .125.
When I adjust the pushrod to 7.400 ( the length of rod Im going to run and gives me the preload that Ive set my 'solid' lifters to) the clearance drops off, Intake is .018 and exhaust is .095".
The exhaust clearance is right near the end of the valve closing event as the piston is chasing the valve up.
The intake is shortly after the valve starts opening and the piston is right around TDC. With this cam the intake valve is opening a few degrees before the piston gets to TDC.
Looks to me I need to do about .085 flycutting to get me up to .100 on the intake and exhaust is marginal, I might just leave it.
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Brian, I think this has been covered pretty good in this post, the inventor of this method...
https://ls1tech.com/forums/generatio...ee-almost.html
Its where I got the idea from.
https://ls1tech.com/forums/generatio...ee-almost.html
Its where I got the idea from.
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Hey, Mike. I finally accessed your #2 page. Never did figure out why I could'nt do it earlier. Anyway, after reading yours and everyone elses posts, it looks like you have decided to flycut the intake. I would like to make a suggestion if I'm not too late. Call Dave at Lindy Tools and rent one of his tools. You'll be glad you did. He's a great guy and will set you up with the right size and they are simple to use and fast. I used one on my LS2 not long ago. I think it cost me $114.00 for the tool and UPS and when I sent it back he refunded I think $48.00? You can see the tool and find his phone # by going to the search box and typing in flycutting tools or I can dig up his # and PM it to you. Good luck on whatever way you decide. I went back and found his # in case you or someone else wanted it. Ron
www.lindytools.com 1-800-823-2887
www.lindytools.com 1-800-823-2887
Last edited by rojs234; Jun 25, 2011 at 01:56 PM.
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Thanks Ron, Ive already done the poor mans flycutting. It worked ok. The hardest part is making sure you go down a consistent amount into each piston. I sent you a PM too.
Ill look into lindy tools tho. I called Isky Cams last week or the week before and they 'rent' the tools too, but they didnt have any till like the middle of July he said.
Ill post some pics later of what my pistons look like now. I took a good bit out for the intake and just a little bit for the exhaust.
Ill look into lindy tools tho. I called Isky Cams last week or the week before and they 'rent' the tools too, but they didnt have any till like the middle of July he said.
Ill post some pics later of what my pistons look like now. I took a good bit out for the intake and just a little bit for the exhaust.
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Everything went pretty good with the garage fly cutting. The biggest problem I had was getting consistancy from cylinder to cylinder. I just got the car running for the first time last week and I've been on vacation with the family since. It ran barely but seemed like a healthy camshaft. Gotta tune it now.
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Everything went pretty good with the garage fly cutting. The biggest problem I had was getting consistancy from cylinder to cylinder. I just got the car running for the first time last week and I've been on vacation with the family since. It ran barely but seemed like a healthy camshaft. Gotta tune it now.
I probably missed it in one of your posts, but.... out of curiosity....is this going to be a carbureted engine or EFI? Anyway, just wanted to say good job and good luck. Ron 