Help! valve train damage!
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
Bret
Thanks bud!
I been around the block a few times but,,,,,,theres ALWAYS something that needs learning! As much info as I provide people,,,, there are things that I lack. I will admit that I am NOT savy with tuning!
and ,,, LS engines are always a learning curve.
The tuning guys have my greatest respect!
Thanks for the complements!
Bill Curlee
Thanks bud!
I been around the block a few times but,,,,,,theres ALWAYS something that needs learning! As much info as I provide people,,,, there are things that I lack. I will admit that I am NOT savy with tuning!
and ,,, LS engines are always a learning curve. The tuning guys have my greatest respect! Thanks for the complements!
Bill Curlee
Tech Contributor
Joined: Dec 1999
Posts: 32,910
Likes: 2,402
From: Anthony TX
CI 6,7,8,9,11 Vet
St. Jude Donor '08
ISeeRed
Ahhhhhhhhhhhhhhh! I have a saving grace! My new caddy racings lifters are BRAND NEW! So,,,,they were never pubped up.
Note to self: self,,,,,,,,,,,,,,,,,,,DO NOT DO THAT AGAIN!! BAD SELF!
BC
Racer
Joined: Sep 2006
Posts: 260
Likes: 1
From: Chesterfield MI
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
The only other thing I can think of that could cause this, other than the other theories suggested, was the heads could have been over CNC'd and the one that failed had the bosses fail from fatigue. i.e. the floor of the rocker compartment became too thin from excessive machining of the ports. I've seen pictures of this on other boards, but it usually only happened on one cylinder, not all. It's rare to hear of the rocker bosses failing, but it does happen occaisionlly.
Former Vendor
Joined: Apr 2007
Posts: 1,331
Likes: 4
From: Jacksonville Florida
I have seen something like this happen before, and the culprit was the porter took to much meat out of the intake ports, which caused the structural integrity of the rocker boss's to fail.
Thread Starter
Advanced
Joined: Apr 2007
Posts: 60
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From: Brookings SD
The rockers cleared the heads so that shoudlnt be a issue. I wouldnt say that the porting was to thin because it had about the same lift cam in it that I took out and put in and im sure they broke because of the severe interference with the valves and pistons. Im taking the heads off today and have another set of better one to put on. All I can think of is set the lifters by the book and roll it over by hand to make sure there is no interference. If you guys have more suggestions Im deffinatly still open. Thanks for all the help and concern, you guys are great!
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
The rockers cleared the heads so that shoudlnt be a issue. I wouldnt say that the porting was to thin because it had about the same lift cam in it that I took out and put in and im sure they broke because of the severe interference with the valves and pistons. Im taking the heads off today and have another set of better one to put on. All I can think of is set the lifters by the book and roll it over by hand to make sure there is no interference. If you guys have more suggestions Im deffinatly still open. Thanks for all the help and concern, you guys are great!
I'm still not sure of how the car was set up before your most recent mods, and how it is now. Without a specific setup and change history we can only guess what happened. However, it still would be a crapshoot until you get in there and see what happened in actuality. Good luck, and please post up what you find.
Last edited by ArKay99; May 3, 2008 at 12:56 PM.
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Le Mans Master
Joined: Dec 2003
Posts: 5,561
Likes: 447
From: Atlanta metro Ga.
It would be unlikely but as intimated in an earlier post, is it possible the lifters were pumped up at the time you spun the motor over? I can't see how they wouldn’t have bled down from the time you installed to buttoning everything up, but...
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
The rockers cleared the heads so that shoudlnt be a issue. I wouldnt say that the porting was to thin because it had about the same lift cam in it that I took out and put in and im sure they broke because of the severe interference with the valves and pistons. Im taking the heads off today and have another set of better one to put on. All I can think of is set the lifters by the book and roll it over by hand to make sure there is no interference. If you guys have more suggestions Im definitely still open. Thanks for all the help and concern, you guys are great!
Please make sure you have the proper clearance!
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
You can also use modeling clay on top of the piston, torque the head down, rotate the engine, cross section the clay and use a dial caliper to measure it's thickness. Get with a machinist or tuner that you trust to discuss the thickness that you measure versus what it should be.
Safety Car
Joined: Sep 2003
Posts: 3,558
Likes: 2
From: Cape Coral FL
The way to check piston to valve clearance isn't to turn the motor over by hand to see if it stops. You should put low tension springs in place of the standard valve springs in one cylinder to hold the valves up and turn the motor by hand and then put a dial indicator across the retainer. When you get into a close interference position, push on the spring and you need at least .030" clearance at an absolute minimum ( if I remember the distance correctly) to run the motor. You can't simply make sure that it doesn't hit while turning it over by hand. Lifters pump up, metals swell and change clearances etc. at .030", those numbers will change at 6800rpm on a hot engine!!
Please make sure you have the proper clearance!
Please make sure you have the proper clearance!
Thread Starter
Advanced
Joined: Apr 2007
Posts: 60
Likes: 0
From: Brookings SD
Ok fellas, I got the heads off and all the valves were bent on the drivers side as well. The cam is .575in and .589ex w/1.7 rocker 226/232 @.050 115+2 Im am positive the cam is lined up right because I never removed the crank gear so it was just line up the dots. The only thing I can come up with now is that the lifters did not bleed down maybe. I removed 2 of them and they are hard as a rock, I tryed to compress the plungers with no luck. But if that was the case why did just the intakes bend and not the exhaust? Or maybe the cam is wrong which I find hard to believe cause I bought it off of a fellow forum member. I do have access to a piston to valve clearance tool with the little spring and such which im deffinatly checking this time. Oh I was gonna ask are those MLS head gaskets reusable, thanks
Team Owner
Joined: Mar 1999
Posts: 22,025
Likes: 192
From: At the beach in little Rhody
That cam shouldn't result in this problem. Either cam is not ground correctly or timing is FUBAR.
I wouldn't start buying new parts until you figure out why this happened.
Can you photograph the timing sprockets/chain?
I wouldn't start buying new parts until you figure out why this happened.
Can you photograph the timing sprockets/chain?
Tech Contributor
Joined: Apr 2007
Posts: 10,924
Likes: 77
From: Forney Texas
Ok fellas, I got the heads off and all the valves were bent on the drivers side as well. The cam is .575in and .589ex w/1.7 rocker 226/232 @.050 115+2 Im am positive the cam is lined up right because I never removed the crank gear so it was just line up the dots. The only thing I can come up with now is that the lifters did not bleed down maybe. I removed 2 of them and they are hard as a rock, I tryed to compress the plungers with no luck. But if that was the case why did just the intakes bend and not the exhaust? Or maybe the cam is wrong which I find hard to believe cause I bought it off of a fellow forum member. I do have access to a piston to valve clearance tool with the little spring and such which im deffinatly checking this time. Oh I was gonna ask are those MLS head gaskets reusable, thanks
If you don't figure out what happened, you put yourself at risk of it happening again.
If your gaskets are in good shape, some may say that they are reusable, but they're too cheap not to replace in my opinion. If you do reuse them, just clean them well.
Do let us all know when you check your PTV what you end up with.
Thread Starter
Advanced
Joined: Apr 2007
Posts: 60
Likes: 0
From: Brookings SD
Well I guess I just as well bite it and tear it down to the cam again and see what is going on. That has to be what it is. I must have missed something or goofed which I guess can happen to the best of us. Thanks a million fellas and I will keep you posted
Race Director
Joined: May 2005
Posts: 15,960
Likes: 21
From: West Norriton PA
St. Jude Donor '08
I'll be doing a cam / heads job along with several items in the next month or so. I'll be watching to hear what the problem was so that I don't end up doing it too.