Thanks for giving me the initiative I need! 
main bearing cap issues
main bearing cap issues I've got an 04 LS1/6 block that I bolted goodies on. The only thing I did to the lower end was add ARP 2000 rod bolts. Mains weren't touched. Block had ~27,000 mi on it and looked great. I ran it for about 1200 miles. When I tore it back down, one of the main bolts was resting on the windage tray 
So it backed itself completely out for some reason. My rod bolts were still on the money... torque wise. I was just going to torque that one bolt back down and rock on. I soon decided I better at least "check" the rest. So i bumped them and could tell they weren't near what they should be. So then I backed off everything (all 4 main bolts on all 5 caps) so I could start over. I forgot to back off the side bolts. I didn't remember them till the last. I went ahead and torqued them (they were a little loose as well) when I was all done. The pan is on and the motor has been sitting for a few weeks ready to go in the car. Now I'm getting a little nervous about the side bolts pulling some while the center bolts were loose. Now I understand the cap fits tightly in a recessed area as well as barely sliding in the block sides. Could a cap really have moved side-to-side on me? I need to know before I slide that thing back in. The "safe" answer is re-do it. The more logical answer is the book is having you torque the 4 main bolts first to pull the cap down because of the tight fit. Agree?
So it backed itself completely out for some reason. My rod bolts were still on the money... torque wise. I was just going to torque that one bolt back down and rock on. I soon decided I better at least "check" the rest. So i bumped them and could tell they weren't near what they should be. So then I backed off everything (all 4 main bolts on all 5 caps) so I could start over. I forgot to back off the side bolts. I didn't remember them till the last. I went ahead and torqued them (they were a little loose as well) when I was all done. The pan is on and the motor has been sitting for a few weeks ready to go in the car. Now I'm getting a little nervous about the side bolts pulling some while the center bolts were loose. Now I understand the cap fits tightly in a recessed area as well as barely sliding in the block sides. Could a cap really have moved side-to-side on me? I need to know before I slide that thing back in. The "safe" answer is re-do it. The more logical answer is the book is having you torque the 4 main bolts first to pull the cap down because of the tight fit. Agree? Last edited by frito1; Feb 4, 2009 at 10:38 PM.
If I remember correctly the side bolts are supposed to be replaced with new ones. The four inner main bolts can be reused, depending on who you talk to. If its out of the car I would support the General and spend the ten bucks or so it will cost to get the new side bolt and go through the whole torque sequence again, which calls for side bolts to be torqued last. I know I would sleep better once I know it was done correct. Some may say fire it up, but for peace of mind I would do it "by the book".
The side Bolts are Reuseable, BUT you have to add the red/orange silicone to make sure they don't leak. They only get 18 FTLB. of torque. It is recomended to replace them ONLY because of the sealer... If you get new ones they come with sealer already installed...
As far as redoing. Yes, I would loosen the side bolts and redo it to make sure the cap is properly tourqued in place. Remember you were already having problems with the bolt holding it tourque/stretch Value. Gm recomends the side bolts being tightened last for a reason. I dont want to get into the theroy behind all this. Basicaly you need to make sure the main bolts are not getting a False stretch value as a result of not lossening the side bolts. If the bolts dont see the proper amount of stretch, Once the engine starts Heat Cycling, they may come loose again Possibly causing catastrophic results...
I know it sucks but think about it like this. The peice of mind Vs. the cost of replacing and engine... Priceless...
P.S. My new engine is sitting for the same type of reason. I wont go any further till the new rod bolts arive. And Yes I am going to pull the rods back out to install the new rod bolts and make sure the big end is still on size. I dont have the money to spend on another short block so I want to make sure it is correct before I ruin something...
Good Luck!
I know it sucks but think about it like this. The peice of mind Vs. the cost of replacing and engine... Priceless...
P.S. My new engine is sitting for the same type of reason. I wont go any further till the new rod bolts arive. And Yes I am going to pull the rods back out to install the new rod bolts and make sure the big end is still on size. I dont have the money to spend on another short block so I want to make sure it is correct before I ruin something...
Good Luck!
As far as redoing. Yes, I would loosen the side bolts and redo it to make sure the cap is properly tourqued in place. Remember you were already having problems with the bolt holding it tourque/stretch Value. Gm recomends the side bolts being tightened last for a reason. I dont want to get into the theroy behind all this. Basicaly you need to make sure the main bolts are not getting a False stretch value as a result of not lossening the side bolts. If the bolts dont see the proper amount of stretch, Once the engine starts Heat Cycling, they may come loose again Possibly causing catastrophic results...
I know it sucks but think about it like this. The peice of mind Vs. the cost of replacing and engine... Priceless...
P.S. My new engine is sitting for the same type of reason. I wont go any further till the new rod bolts arive. And Yes I am going to pull the rods back out to install the new rod bolts and make sure the big end is still on size. I dont have the money to spend on another short block so I want to make sure it is correct before I ruin something...
Good Luck!
I know it sucks but think about it like this. The peice of mind Vs. the cost of replacing and engine... Priceless...
P.S. My new engine is sitting for the same type of reason. I wont go any further till the new rod bolts arive. And Yes I am going to pull the rods back out to install the new rod bolts and make sure the big end is still on size. I dont have the money to spend on another short block so I want to make sure it is correct before I ruin something...
Good Luck!
Dont worry, My stuff is sitting there too! I am always looking for an excuse not to get around to fixing it. Luckly this weekends excuse Is rain and I decided what the hell since I need to take the pistons and rods out I might as well buy upgraded rod bolts right....
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Cool. Always a good idea to put stronger rod bolts in! I'm not in a huge hurry as I'm still waiting on my tranny to get here 
So I'll flip it upside down and the main caps.
Actually I'm heading out your direction this week, Brick! Myself and some friends are heading out in my D-max tomorrow morning to hit up some Glamis sand! I like to play on my Honda 310R and another guy has a new LS2 powered long travel rail he is taking. Should be a good time.
So I'll flip it upside down and the main caps.Actually I'm heading out your direction this week, Brick! Myself and some friends are heading out in my D-max tomorrow morning to hit up some Glamis sand! I like to play on my Honda 310R and another guy has a new LS2 powered long travel rail he is taking. Should be a good time.
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Verdad Gallardo Cool. Always a good idea to put stronger rod bolts in! I'm not in a huge hurry as I'm still waiting on my tranny to get here So I'll flip it upside down and the main caps.
Actually I'm heading out your direction this week, Brick! Myself and some friends are heading out in my D-max tomorrow morning to hit up some Glamis sand! I like to play on my Honda 310R and another guy has a new LS2 powered long travel rail he is taking. Should be a good time.
So I'll flip it upside down and the main caps.Actually I'm heading out your direction this week, Brick! Myself and some friends are heading out in my D-max tomorrow morning to hit up some Glamis sand! I like to play on my Honda 310R and another guy has a new LS2 powered long travel rail he is taking. Should be a good time.
After taking everything loose and seeing how tight the tolerances are, I feel very confident that my work was all for nothing. There is no way those caps could have shifted side-to-side.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
After taking everything loose and seeing how tight the tolerances are, I feel very confident that my work was all for nothing. There is no way those caps could have shifted side-to-side.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
At least you caught it now.... We got Heavy rain today so I have to see what got wet....
The garage floodes when that happens so I have to make sure everything else is high enough in case the floods again.... 
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After taking everything loose and seeing how tight the tolerances are, I feel very confident that my work was all for nothing. There is no way those caps could have shifted side-to-side.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
I decided to pop a couple of caps off to look at the bearings. I'm not sure I liked the way the bearings looked. Kinda looks like some aluminum (#7 piston came apart) is embedded in the bearings and then the crank smoothed it over. Crank is like new but the bearings aren't anymore.
The motor has 28,000 miles on it. Yes, I ball honed and replaced the piston/rings in that one hole with OEM (same weight) because I didn't want to pull the crank to re-balance for new aftermarket pistons. I was going to leave good enough alone. I looked at the #7 rod bearing when I pulled that one piston. That rod bearing looked like new.... like a 28,000 mile motor should. So this main bearing took me by surprise.
Last edited by frito1; Feb 16, 2009 at 09:33 PM.
The GM manual has the side bolts being torqued after the 4 bigger ones are fully fastened. So I dont think it was such a bad idea that you redid it. The bolts have the sealant becuase these main caps are porous as all hell. Oil will actually bleed thru the cap and into the small tapped holes in the side.
The GM manual has the side bolts being torqued after the 4 bigger ones are fully fastened. So I dont think it was such a bad idea that you redid it. The bolts have the sealant becuase these main caps are porous as all hell. Oil will actually bleed thru the cap and into the small tapped holes in the side.
Last edited by frito1; Feb 16, 2009 at 10:09 PM.
I've got an 04 LS1/6 block that I bolted goodies on. The only thing I did to the lower end was add ARP 2000 rod bolts. Mains weren't touched. Block had ~27,000 mi on it and looked great. I ran it for about 1200 miles. When I tore it back down, one of the main bolts was resting on the windage tray So it backed itself completely out for some reason. My rod bolts were still on the money... torque wise. I was just going to torque that one bolt back down and rock on. I soon decided I better at least "check" the rest. So i bumped them and could tell they weren't near what they should be. So then I backed off everything (all 4 main bolts on all 5 caps) so I could start over. I forgot to back off the side bolts. I didn't remember them till the last. I went ahead and torqued them (they were a little loose as well) when I was all done. The pan is on and the motor has been sitting for a few weeks ready to go in the car. Now I'm getting a little nervous about the side bolts pulling some while the center bolts were loose. Now I understand the cap fits tightly in a recessed area as well as barely sliding in the block sides. Could a cap really have moved side-to-side on me? I need to know before I slide that thing back in. The "safe" answer is re-do it. The more logical answer is the book is having you torque the 4 main bolts first to pull the cap down because of the tight fit. Agree?
So it backed itself completely out for some reason. My rod bolts were still on the money... torque wise. I was just going to torque that one bolt back down and rock on. I soon decided I better at least "check" the rest. So i bumped them and could tell they weren't near what they should be. So then I backed off everything (all 4 main bolts on all 5 caps) so I could start over. I forgot to back off the side bolts. I didn't remember them till the last. I went ahead and torqued them (they were a little loose as well) when I was all done. The pan is on and the motor has been sitting for a few weeks ready to go in the car. Now I'm getting a little nervous about the side bolts pulling some while the center bolts were loose. Now I understand the cap fits tightly in a recessed area as well as barely sliding in the block sides. Could a cap really have moved side-to-side on me? I need to know before I slide that thing back in. The "safe" answer is re-do it. The more logical answer is the book is having you torque the 4 main bolts first to pull the cap down because of the tight fit. Agree? I rolled out 3 mains and 2 rod bearings. The rod bearings look like a 28,000 mile motor should. The mains look like I trashed a piston and the filter didn't catch it Needless to say, I got Clevite "P" series main and rod bearings ordered today.
Needless to say, I got Clevite "P" series main and rod bearings ordered today. 
got some sort of contamination in it. ive seen engines with worse bearings that had great oil pressure no knocks and ran just fine. You got really lucky catching it when you did though. I would put arp bolts or studs into it on the next go around. i would have the main caps checked for roundness and have them aligned checked for straightness. there is my .02