New shortblock clunks when rotated...
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I need a gauge for that
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From: Huntsville, AL
New shortblock clunks when rotated... I just got my shortblock back from LME with basically a complete rebuild and new pistons, everything looks good but when I turn the crank by hand and at one particular part of rotation it feels like its contacting something and will make a loud clunk if I rotate the crank quickly to that spot. It feels smooth throughout the remaining rotation. I thought it may have been piston to valve clearance even though I checked that so I pulled the rockers off and it still does the same thing. I can rotate it completely around past the part where it clunks but I am hesitant to install the engine with this going on. I couldnt see any obvious contact points when looking at the bottom end, and its the weekend so I havent called Brian about it. The only thing I can think of is number 8 piston wasnt installed in the right spot to clear the reluctor wheel, but that seems awfully sloppy of a shop with the reputation of LME. I have the engine fully assembled now, but I am about to pull the pan and windage tray off to see if I can see anything.
I would like to install it tomorrow, but want to figure this out first. Any suggestions are welcome.
I would like to install it tomorrow, but want to figure this out first. Any suggestions are welcome.
Thread Starter
I need a gauge for that
iTrader: (37)
Joined: Jan 2006
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From: Huntsville, AL
Yes, K1 stroker crank. I put the pan on, and did the rest of the longblock assembly. I have it sitting on my stand right now, with the pan and tray off, and it still does it. Happens just ATDC on cylinder number 1. Although it sounds much quieter now with the pan off, its still noticeable and I can feel it in the wrench while turning the crank by hand.
And I checked the reluctor and its not contacting anything that I can see.
And I checked the reluctor and its not contacting anything that I can see.
Thread Starter
I need a gauge for that
iTrader: (37)
Joined: Jan 2006
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From: Huntsville, AL
Im pretty sure its coming from the front end of the block...anyone heard of an oil pump making a noise at any certain point? Ive run this block before with different pistons, but same crank and rods, and dont remember having this issue, ie, the block should already be clearenced. It doesnt happen at BDC of any of the pistons either.
The faster I turn the crank through that point the louder the sound is...
The faster I turn the crank through that point the louder the sound is...
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Start pulling it apart until you find it, no way in hell would i start it until you know. Prolly something in the rod moving or wrist pin. Look to see if the rod shifts to the side as it clunks.
Last edited by O2Form; Dec 18, 2010 at 09:45 PM.
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I need a gauge for that
iTrader: (37)
Joined: Jan 2006
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From: Huntsville, AL
Joined: Nov 2001
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From: Texas and Qatar
Look closely at the lowest camshaft retainer plate bolt. That particular bolt passes through the block into the crankshaft webbing area. If the wrong bolt is used it will have interference problems. I would actually look there first, especially if you have or reused the 10mm hex headed style bolts (the newer torx style bolts do not interfere and are easier to keep in the right location). 
Also if you have a chain damper block that is located between the two timing gears, make sure those bolts are not too long as well.
Also if you have a chain damper block that is located between the two timing gears, make sure those bolts are not too long as well.
Thread Starter
I need a gauge for that
iTrader: (37)
Joined: Jan 2006
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From: Huntsville, AL
I have the ARP camshaft retainer bolts, but I will check nonetheless. I think you may have nailed it with the dampener bolts. I had LME tap the block for it and they included on the bolts for it as well; I didnt have it on my last build. Do you know how long those bolts are suppose to be? I will have to wait for morning to get a pulley puller to get the front cover off 
By the way, I have your book on how to build and modify LS engines and thoroughly enjoy it and find it very useful. Its an excellent book and I learned a lot from it.
By the way, I have your book on how to build and modify LS engines and thoroughly enjoy it and find it very useful. Its an excellent book and I learned a lot from it.
Joined: Nov 2001
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From: Texas and Qatar
Well if it is the ARP bolts I don't think that could be the issue then, they are obviously the correct length. I see a lot of people re-use the GM cam bolts in place of the GM cam retainer bolts, and that will not work on that lower bolt location.
From the oil pan area looking upwards you -might- be able to see the interference. Had one just last week do that (LS7 damper on LSX block doesn't work BTW...) The bolt length depends on the type of damper, I can measure the two styles I have by Monday. (LS2 and LS7)
Glad you enjoy the book and thanks for the feedback!
From the oil pan area looking upwards you -might- be able to see the interference. Had one just last week do that (LS7 damper on LSX block doesn't work BTW...) The bolt length depends on the type of damper, I can measure the two styles I have by Monday. (LS2 and LS7)
Glad you enjoy the book and thanks for the feedback!
Thread Starter
I need a gauge for that
iTrader: (37)
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From: Huntsville, AL
I actually had a small mix up with those bolts during assembly because they are very similar except for the length so I am going to double check that tomorrow as well. I believe I have the ls2 dampener but perhaps you could confirm from this picture
If it Is the dampener bolts, could I use washers space them?
If it Is the dampener bolts, could I use washers space them?
Nice looking setup for sure. Thread Starter
I need a gauge for that
iTrader: (37)
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From: Huntsville, AL
Yep, you were right Joesph. Apparently I didnt get the cam bolts and retaining bolts sorted correctly because the bottom retainer bolt was actually one of the cam bolts and was hitting the counterweight on the crank. I corrected that and now everything turns smoothly. Just to reiterate, my issues were not the fault of LME, but my own mistake during assembly.
And the dampener bolts are 38mm...
Thanks for the help guys, Im hoping to have this engine in today.
And the dampener bolts are 38mm...
Thanks for the help guys, Im hoping to have this engine in today.
Joined: Nov 2001
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From: Texas and Qatar
Glad to hear you found the problem!
The damper bolt profile in the picture look like the same ones I use, I believe the correct bolts come with the damper as well.
Sounds like the truck will be fun. Turbo trucks always are a great time.
The damper bolt profile in the picture look like the same ones I use, I believe the correct bolts come with the damper as well.
Sounds like the truck will be fun. Turbo trucks always are a great time.
Thread Starter
I need a gauge for that
iTrader: (37)
Joined: Jan 2006
Posts: 10,921
Likes: 3
From: Huntsville, AL
I am very happy I decided to find the source of the problem and fixing it instead of just throwing the engine in and trying to find it later. I removed my old engine and have this one sitting in the frame, but ran out of daylight before I could fully reinstall it. I should have it running by early afternoon tomorrow though.
My goals are for 800rwhp with 35" tires, 80e, and 14b axle. Should be a very fun indeed.
My goals are for 800rwhp with 35" tires, 80e, and 14b axle. Should be a very fun indeed.
