My ongoing engine rebuild nightmare
#1
Team Owner
Thread Starter
My ongoing engine rebuild nightmare
Quick recap. Wrong heads and lifters, broken pushrod, engine runs like crap, etc.
https://www.corvetteforum.com/forums...n-pushrod.html
Still waiting for the heads so I thought I will just make sure it's really a Lunati cam which is what I paid for. Well, it's a Lunati Voodoo but not the one I specified. This cam is one step up in duration from what it was supposed to be so maybe there was part of the problem. However, the big thing is they didn't install a button so the cam was probably walking back and forth in the engine. Take a look at the inside of the timing cover.
How long before something self destructed? I am so damn disgusted and disappointed, even more so now.
I haven't talked to the shop yet, I'm trying to decide just what I want them to do. He assured me he would make it right but at this point I'm not convinced he even can.
Good grief.
https://www.corvetteforum.com/forums...n-pushrod.html
Still waiting for the heads so I thought I will just make sure it's really a Lunati cam which is what I paid for. Well, it's a Lunati Voodoo but not the one I specified. This cam is one step up in duration from what it was supposed to be so maybe there was part of the problem. However, the big thing is they didn't install a button so the cam was probably walking back and forth in the engine. Take a look at the inside of the timing cover.
How long before something self destructed? I am so damn disgusted and disappointed, even more so now.
I haven't talked to the shop yet, I'm trying to decide just what I want them to do. He assured me he would make it right but at this point I'm not convinced he even can.
Good grief.
#2
Team Owner
I quit installing roller cam button timing covers and instead went to highest quality double roller timing sets. The chains are so strong that they are hard to install but the cam doesn't walk back and forth
In your case probably a non roller cam contact with the front cover is caused by the position of the bottom crank sprocket. You need to tap it back towards the block
Flat lifters ride on an angle which pushes the cam back into the block
In your case probably a non roller cam contact with the front cover is caused by the position of the bottom crank sprocket. You need to tap it back towards the block
Flat lifters ride on an angle which pushes the cam back into the block
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ratflinger (06-18-2020)
#3
Race Director
and when the cam walks forwards lobes lift the next lifter forward.
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HeadsU.P. (06-18-2020)
#5
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St. Jude Donor '05
Whats your builders stance on all this sounds like you got a royal mess on your hands
#6
When your shop gets the new heads hopefully they will pull them apart and check them over. Maybe make sure the correct push rod length is installed this time, with correct rockers and a cam button for that roller. I would also have them check the cam carefully. I see engines like this come into the shop and I just shake my head. I say this all the time, there is a big difference between a parts installer and an engine builder.
#7
Team Owner
Thread Starter
This is the timing chain that was installed.
I don't see a name anywhere and the work order does not specify either. Hosed on this, too?
Google says it's a Melling. Corvette Central sells them for $24. Answered my own question about getting hosed.
I don't see a name anywhere and the work order does not specify either. Hosed on this, too?
Google says it's a Melling. Corvette Central sells them for $24. Answered my own question about getting hosed.
#8
Race Director
that IS a double roller chain and gear(s).
#9
Melting Slicks
#10
If I was in your shoes, I would run away screaming like a girl.
I am very lucky to have Joe Jill at Superior Automotive 5 minutes from here.
I am very lucky to have Joe Jill at Superior Automotive 5 minutes from here.
#11
Team Owner
Thread Starter
#13
Le Mans Master
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I would rather have a cam bolt locking plate ($5) to insure nothing comes loose.
On the timing cover, have someone tack a piece of sheet metal on the inside for a new cam button to ride against.
On the timing cover, have someone tack a piece of sheet metal on the inside for a new cam button to ride against.
Last edited by HeadsU.P.; 06-18-2020 at 06:20 PM.
#15
"He will be long dead before this wears out."
#16
Le Mans Master
Pretty sure the cam walking issue is related to that roller timing chain. I agree 100% with gkull and have personal experience as well: There is no way a roller cam can walk forward in a SBC C3 with stout quality durable double roller timing chain...no chance....The chain is too tight and too strong.
I went through the hocus pocus about the roller cam, cam button, and cam walking hysteria back in 2014 during my rebuild of the 355 L-82 with a howards roller cam. After extensive personal reading on the subject, advice from knowledgeable car gurus who have actually used retro rollers in a SBC for a C3, and personal advice from my expert builder who did the short block build for me on the 355 L-82, i surmised the following which has been validated 6 years later with a perfectly operating L-82 355 roller cammed motor:
1. The GM OEM timing Chain cover will supposedly flex with a roller cam and cam button behind it pushing on the cover. Not in a SBC C3 where the cover sits directly against the back of the water pump which further reinforces the all ready heavy gauge metal cover....chance of flexing? None
2. The roller cam requires a cam button to prevent the cam from walking forward.....Nope...See my opening comment. A quality double roller timing chain will NOT flex, stretch or bend, allowing the cam to walk forward.
3. Using a cam button, which I did use for insurance, requires trial and error to get the clearance correct? Nope. Just slightly dimple the timing chain cover for a nylon cam button to fit snuggly and done.
4. Measuring the pushrods for proper fit also was completely overly complicated by many, and it too, is a clear procedure, and easy.
All told much of the roller cam install is very overblown and is moderately easy.....
I went through the hocus pocus about the roller cam, cam button, and cam walking hysteria back in 2014 during my rebuild of the 355 L-82 with a howards roller cam. After extensive personal reading on the subject, advice from knowledgeable car gurus who have actually used retro rollers in a SBC for a C3, and personal advice from my expert builder who did the short block build for me on the 355 L-82, i surmised the following which has been validated 6 years later with a perfectly operating L-82 355 roller cammed motor:
1. The GM OEM timing Chain cover will supposedly flex with a roller cam and cam button behind it pushing on the cover. Not in a SBC C3 where the cover sits directly against the back of the water pump which further reinforces the all ready heavy gauge metal cover....chance of flexing? None
2. The roller cam requires a cam button to prevent the cam from walking forward.....Nope...See my opening comment. A quality double roller timing chain will NOT flex, stretch or bend, allowing the cam to walk forward.
3. Using a cam button, which I did use for insurance, requires trial and error to get the clearance correct? Nope. Just slightly dimple the timing chain cover for a nylon cam button to fit snuggly and done.
4. Measuring the pushrods for proper fit also was completely overly complicated by many, and it too, is a clear procedure, and easy.
All told much of the roller cam install is very overblown and is moderately easy.....
Last edited by jb78L-82; 06-19-2020 at 07:15 AM.
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Haggisbash (06-19-2020)
#17
Dementer sole survivor
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2020 C3 of the Year Finalist - Modified
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I just installed my first roller cam this winter, measured and ordered the correct button, held in place with the chain/ cam lock plate......runs awesome! It’s so easy a caveman can do it!
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jb78L-82 (06-19-2020)
#18
Team Owner
I still say that all he needs to do is tap the lower sprocket back towards the block. That would give some clearance behind the upper cam gear. Both of my present motors have the Torrington bearing behind the cam gears to protect the blocks.
Someone years ago did the post about drilling the block with a tiny drill bit to actually be squirting oil on the chain from the cam valley area. I've never done it.
Someone years ago did the post about drilling the block with a tiny drill bit to actually be squirting oil on the chain from the cam valley area. I've never done it.
#19
#20
Melting Slicks
I still say that all he needs to do is tap the lower sprocket back towards the block. That would give some clearance behind the upper cam gear. Both of my present motors have the Torrington bearing behind the cam gears to protect the blocks.
Someone years ago did the post about drilling the block with a tiny drill bit to actually be squirting oil on the chain from the cam valley area. I've never done it.
Someone years ago did the post about drilling the block with a tiny drill bit to actually be squirting oil on the chain from the cam valley area. I've never done it.
-The drill bit for the oiling mod is just so insanely small I had to wrap it in a bit of duct tape to get the drill to even grab it; it was some kinda miracle that the drill bit didn't break. I did it to a press-in plug, I have NO IDEA how you'd successfully drill a hole that small into the thick screw in plugs...
Adam
Last edited by NewbVetteGuy; 06-19-2020 at 06:28 PM.