Need Help With LS Rebuild
01-14-2017, 12:30 PM
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Need Help With LS Rebuild 2006 LQ4 6.0
L92 Heads
LSx 454 Camshaft (Part # 19166972)
Lunati Valve springs, stock rockers, stock pushrods.
Edlebrock carburetor single plain intake
Holley 850
MSD ignition controller box
Long tube headers
Hello LS1 Tech,
My name is Chase, I am 20 years old and active duty military. I am in desperate need of some help/advice/recommendation on my LS rebuild (specs above). I am in way too far over my head with this project. This is the first LS I have built and also the first engine in general I have built, and it has been a learning experience to say the least.
About 4 months ago, I bought a 72 C10 with a modified LQ4, carbureted LS engine off craigslist. The motor was running and I drove the truck around the block for about 10 minutes. It was open headers, so it was too loud to hear if it had any problems. The plan was to take the motor and trans out and put it into my 68 C10 (its a nicer truck). The next day I pulled them both out. I was predicting it would take about a month, but after problems and problems, it kept getting delayed. I took the intake, valve covers, valley tray, and oil pan off and cleaned everything as best as possible, and painted the block. I found a little bit of metal shavings at the bottom of the oil pan, but I thought it was okay. A good friend of mine recommended I take one of the caps off a rod and check the bearings since I had the pan, pickup, and windage tray off. I chose not too (stupid), because I didn't want to mess anything up. I also rebuilt the carb with the same friend. It is a Holley 850cfm double pumper. A few weeks later, after putting the thing back together, I installed it in my 68, and hooked everything up. I tried to fire it up (still open headers) and it did run, but it could not idle. My first thought was that my friend and I did something wrong when we put the carb back together, and it just couldn't idle. It was basically holding at no less than 3000 rpm dead cold. I heard a lot of what I thought was possible valve train ticking or piston slap, and after about 100 seconds of total run time, there was a big BOOM. I tossed my hand in the air and pulled the engine back out, and back onto my engine stand. After taking off the pan, I found a big mess. I will attach pictures.
At first I thought that maybe there wasn't oil pressure and it caused a rod to spin, but after discussing with that same friend (his name is Dan), we determined that it was due to the bearings being bad in general. The guy I bought the truck from said he ran it hard at the Pismo sand dunes, and we think that sand made its way into the crankcase and smoked the bearings causing the rod to spin and then shatter.
I am currently in the process of rebuilding it. I had the block hot tanked at the machine shop and had the guy put in new cam bearings, and I bought a used crank and had it polished. I got two new refurbished rods online. Also, I got a rebuild kit off of eBay (all the parts look pretty good), and started re-building this thing a few days ago. I have been basically following a rebuild book for these things which has gone very smoothly until last night. The short block was completely assembled with no problems to the specifications in reference to the rebuild book. After putting on the heads and gaskets and torquing them down, I went to install the rocker arms and that's were I have hit my problem. After I put the intake and exhaust on for piston 1, the crank essentially stops turning and I believe I have a piston to valve clearance issue. I forced to to turn (stupid) which did eventually spin but I think I put an indent on my new piston.
This is where I need your help. What do I do to fix this? I really don't feel like throwing the rest of the thing together and risk having to pull it out and rebuilding it again. Smaller pushrods? Different rocker arms? Do you think I put on the timing chain wrong? Or is that cam just too dam big for this motor? I am open to any suggestions, and feel free to tell it to me straight. Like I said, this is a learning experience and I am happy to make any corrections needed. Thank you all very much, and have a nice day.
L92 Heads
LSx 454 Camshaft (Part # 19166972)
Lunati Valve springs, stock rockers, stock pushrods.
Edlebrock carburetor single plain intake
Holley 850
MSD ignition controller box
Long tube headers
Hello LS1 Tech,
My name is Chase, I am 20 years old and active duty military. I am in desperate need of some help/advice/recommendation on my LS rebuild (specs above). I am in way too far over my head with this project. This is the first LS I have built and also the first engine in general I have built, and it has been a learning experience to say the least.
About 4 months ago, I bought a 72 C10 with a modified LQ4, carbureted LS engine off craigslist. The motor was running and I drove the truck around the block for about 10 minutes. It was open headers, so it was too loud to hear if it had any problems. The plan was to take the motor and trans out and put it into my 68 C10 (its a nicer truck). The next day I pulled them both out. I was predicting it would take about a month, but after problems and problems, it kept getting delayed. I took the intake, valve covers, valley tray, and oil pan off and cleaned everything as best as possible, and painted the block. I found a little bit of metal shavings at the bottom of the oil pan, but I thought it was okay. A good friend of mine recommended I take one of the caps off a rod and check the bearings since I had the pan, pickup, and windage tray off. I chose not too (stupid), because I didn't want to mess anything up. I also rebuilt the carb with the same friend. It is a Holley 850cfm double pumper. A few weeks later, after putting the thing back together, I installed it in my 68, and hooked everything up. I tried to fire it up (still open headers) and it did run, but it could not idle. My first thought was that my friend and I did something wrong when we put the carb back together, and it just couldn't idle. It was basically holding at no less than 3000 rpm dead cold. I heard a lot of what I thought was possible valve train ticking or piston slap, and after about 100 seconds of total run time, there was a big BOOM. I tossed my hand in the air and pulled the engine back out, and back onto my engine stand. After taking off the pan, I found a big mess. I will attach pictures.
At first I thought that maybe there wasn't oil pressure and it caused a rod to spin, but after discussing with that same friend (his name is Dan), we determined that it was due to the bearings being bad in general. The guy I bought the truck from said he ran it hard at the Pismo sand dunes, and we think that sand made its way into the crankcase and smoked the bearings causing the rod to spin and then shatter.
I am currently in the process of rebuilding it. I had the block hot tanked at the machine shop and had the guy put in new cam bearings, and I bought a used crank and had it polished. I got two new refurbished rods online. Also, I got a rebuild kit off of eBay (all the parts look pretty good), and started re-building this thing a few days ago. I have been basically following a rebuild book for these things which has gone very smoothly until last night. The short block was completely assembled with no problems to the specifications in reference to the rebuild book. After putting on the heads and gaskets and torquing them down, I went to install the rocker arms and that's were I have hit my problem. After I put the intake and exhaust on for piston 1, the crank essentially stops turning and I believe I have a piston to valve clearance issue. I forced to to turn (stupid) which did eventually spin but I think I put an indent on my new piston.
This is where I need your help. What do I do to fix this? I really don't feel like throwing the rest of the thing together and risk having to pull it out and rebuilding it again. Smaller pushrods? Different rocker arms? Do you think I put on the timing chain wrong? Or is that cam just too dam big for this motor? I am open to any suggestions, and feel free to tell it to me straight. Like I said, this is a learning experience and I am happy to make any corrections needed. Thank you all very much, and have a nice day.
01-14-2017, 06:05 PM
#2
Where are you stationed?
You might have put the timing chain on wrong. If I remember correctly, that cam isn't really that big. You shouldn't have PTV issues, especially when there isn't any oil pressure in the lifters. Verify that the dot on the big gear is at 6 o'clock when the dot on the little gear is at 12 o'clock.
You might have put the timing chain on wrong. If I remember correctly, that cam isn't really that big. You shouldn't have PTV issues, especially when there isn't any oil pressure in the lifters. Verify that the dot on the big gear is at 6 o'clock when the dot on the little gear is at 12 o'clock.
01-15-2017, 07:55 PM
#4
These guys probably have your issue pointed out but most of the time it's cheaper to throw in the towel and find a good reasonable machine shop, especially for assembly. On thing goes wr ong and you spent twice as much as paying a professional. That's my .02 and have built a few motors.
01-15-2017, 11:17 PM
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Thank you guys so much for the replies, I believe you are both correct on the timing chain. I am on duty until wednesday and I will pop to timing cover back off and verify as soon as I can.
KCS, I am at US Coast Guard Station Morro Bay, California
KCS, I am at US Coast Guard Station Morro Bay, California
01-22-2017, 11:39 PM
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Sorry for the late reply, I did end up pulling the timing cover off and discovered that you were both right! When I was reading the rebuild book it said line up the dot on the timing gear with the dot on the crank gear. I thought it meant the dot that sets the gear on the cam and couldn't see the actual dot because it was covered by the chain (if that makes since). Thank you both so much for the help. I finished building the thing, and I just got my Holley Sniper EFI in the mail, and it is ready to be dropped back in!