my first corvette, my first "build" thread
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
Likes: 418
C5 of Year Finalist (performance mods) 2019
The youtube video feom Scruff’s Garage shows how to make a solid lifter and how to measure for zero lash woth your tool on base circle. Then based on what the lifter manufactures recommendations for preload you add that length to the checker length and get your pushrod length if I remember correctly
If you pull the push rods from those same lifters and toss 7.350 push rods in. You can tighten the rocker arm to zero lash and then place your hand on the valve spring and feel the rocker compress the spring.
The lifters are acting like solid lifters. If you put a push tod in and push down you get zero rebound. Usually you'll feel a bit of "squish" i get none of that. Its almost like the push rods are too big for the lifter (diameter wise)
I am absolutely making sure the pushrod is seated in the lifter during installation too.
at this point pulling a head just makes sense. I dont know if the piston in these lifters is stuck or what. But clearly something isn't right. Cam looks fine and even if I wiped a lobe it still wouldn't explain what's going on. And this is happening on both sides. On all cylinders.
Ya so... i followed scruff garage's instructions for pushrod length not realizing that part 1 he shows how to lock out the lifter haha. That will get corrected here shortly.
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
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C5 of Year Finalist (performance mods) 2019
Pulled the heads and the lifters. one lifter is pretty messed up. it actually cracked on top by opposite the link bar.. almost all are siezed. it looks like the lifter that's the most messed up locked piston extended. because there's the SLIGHTEST mark on that piston from the exhaust valve. just enough i can catch my fingernail in. Cam looks fine and it made good oil pressure still. so hopefully the lifters took the damage and nothing else did.
so i ordered a new valve just for peace of mind. And my new lifters come in today. I'll start over and measure pushrod length CORRECTLY this time haha. But it was a bummer that i killed a very nice set of lifters...
But this is how we learn sometimes haha. Valve should be here tomorrow. So hopefully i have this up and running by the weekend.
Also, i hate the GM engineer that designed the alternator/power steering bracket lol.
so i ordered a new valve just for peace of mind. And my new lifters come in today. I'll start over and measure pushrod length CORRECTLY this time haha. But it was a bummer that i killed a very nice set of lifters...
But this is how we learn sometimes haha. Valve should be here tomorrow. So hopefully i have this up and running by the weekend.
Also, i hate the GM engineer that designed the alternator/power steering bracket lol.
Last edited by 2k2wranglerx; May 19, 2020 at 09:52 AM.
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
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C5 of Year Finalist (performance mods) 2019
Ok, so the new ls7 lifters have been soaking in oil since yesterday. the new valve will be here today. I'm going to put the new valve in, lock out 2 lifters, and remeasure for the pushrod length.
Also, these morel lifters will clearly never go back into a motor so i started pulling some apart to try and see what is going on. And what i'm finding is almost all are locked OUT. so it's not like the pushrod slammed the piston down and they stuck. More like they're all stuck extended... I'm starting to think they came DOA from sitting. My buddy that ran them kept them in a bag with oil in it (not submerged or anything just with oil in the bag) but i'm starting to suspect that they were locked out when i got them... I can't really come up with any other conclusions. I can't imagine a pushrod being too long would have locked the lifters extended...
Anyway, here's what i'm talking about.
Also, these morel lifters will clearly never go back into a motor so i started pulling some apart to try and see what is going on. And what i'm finding is almost all are locked OUT. so it's not like the pushrod slammed the piston down and they stuck. More like they're all stuck extended... I'm starting to think they came DOA from sitting. My buddy that ran them kept them in a bag with oil in it (not submerged or anything just with oil in the bag) but i'm starting to suspect that they were locked out when i got them... I can't really come up with any other conclusions. I can't imagine a pushrod being too long would have locked the lifters extended...
Anyway, here's what i'm talking about.
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
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C5 of Year Finalist (performance mods) 2019
and that valve had the broken lifter... I have no idea man. going to check PTV when i do the pushrod length check too. pretty crazy. I double checked that my rockers are stock and they appear to be. hopefully going back to the ls7 lifter solves some problems.
Drifting
Joined: Apr 2019
Posts: 1,562
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From: Morristown, TN
Eh its just crazy. Looking online it is made out to be pretty straight forward for most of this work but even when I did mine it didnt go right thus why I had a shop assembled my engine the second time around.
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No Hostility Be Happy
Joined: Aug 2018
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From: South Hill Wa
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
2k has your block ever been decked and have your heads ever been milled? Most LS builds don't stray too far away from 7.40s with a lot of cam swapped cars sticking to 7.40.
Thread Starter
Drifting
Joined: Feb 2018
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C5 of Year Finalist (performance mods) 2019
The heads are off a CTSV and the previous owner said they have never been decked. But that's unknown too because he hasn't had that car since new either.
No i was crazy careful about that. that was my biggest fear. firing it up with a messed up O ring and having no oil pressure haha. It makes like 40 at idle and 60 running at speed.
Last edited by 2k2wranglerx; May 20, 2020 at 10:35 AM.
No Hostility Be Happy
Joined: Aug 2018
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From: South Hill Wa
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
Yup. and I should clarify I was speaking on behalf of GM based lifters. I have no experience with those fancy boutique lifter brands.
Thread Starter
Drifting
Joined: Feb 2018
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C5 of Year Finalist (performance mods) 2019
What i'm thinking is going on is the lifters were all locked OUT the entire time. So they were acting like solid lifters. So when i added the lash with the shorter pushrods the valves were no longer hanging open.
No Hostility Be Happy
Joined: Aug 2018
Posts: 10,095
Likes: 7,405
From: South Hill Wa
2022 C5 of the Year Finalist - Modified
2021 C5 of the Year Finalist - Modified
LS7 lifters recommended .080 to .090"
I am probably closer to .065 so I just left it. It's proven to work just fine for me.
I am probably closer to .065 so I just left it. It's proven to work just fine for me.
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
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C5 of Year Finalist (performance mods) 2019
Melting Slicks
Joined: Nov 2016
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From: East Metro (Twin Cities) Minnesota
St. Jude Donor '21
Awesome to hear, hoping your first real test drive after the tune goes well! If you would not mind reporting back with an an after action list of things "you wish you had known" prior to the cam swap that would be very valuable to the forum.
Continued good luck!
Toys.
Continued good luck!
Toys.
Thread Starter
Drifting
Joined: Feb 2018
Posts: 1,403
Likes: 418
C5 of Year Finalist (performance mods) 2019
Awesome to hear, hoping your first real test drive after the tune goes well! If you would not mind reporting back with an an after action list of things "you wish you had known" prior to the cam swap that would be very valuable to the forum.
Continued good luck!
Toys.
Continued good luck!
Toys.
I went and washed it real quick too because it was filthy.
