looking for engine guru advice on a 283 sbc

Hello there i just got a rebuilt 283 .60 from an uncle. He installed the pistons and crank but when he was torqueing down the caps ended up over tightening them due to a broken torque wrench. He tried to rotate and couldnt. So my question is what do i do now? is it as simple as loosening and retorque or do i need to pull the caps and check all the bearings? Thanks

 

same thing happened on my 327. I loosened and retorqued with no problem, 5 years running so far.

 

As long as nothing was "forced" to spin it then starting over should be a viable alternative. Take the caps off and look for any distress, also take a look at the main and rod bolts looking for thread distress. If no one tried to turn it with a 10 foot bar on the crank trying to turn it I don't see a problem

 

I would try to re-torque to the proper torque and see if the crank turns freely....it seems like you may have other issues. If it does remove the crank, inspect the bearings and if they look good use them.

 

Kinda doubt you could lock it up by just over torquing the bolts. Might want to pull all the rod caps and check for nicks from the rod bolts during assembly and plastiguage the rods and mains as well. If everything was overdone by quite a bit, the bolts may be stretched and weakened, especially those little 11/32" rod bolts.

 

No one in favor of replacing the bolts? We've got no idea how much of a gorilla this uncle was before he got a clue something wasn't clicking. SBC bolts are so common and so cheap, I'd go for another set just because.

jack vines

 

i agree with over- torquing may not be your only issue

i'd take it apart and mike everything...you may have the wrong bearings

 

thanks for the advice guys,

 

Or you could have one of the caps on backwards. CHECK EVERYTHING!

.bjb

 

Loosen and re-torque.... Try to rotate...

 

I would check all bearings and crank surfaces and replace the rod bolts. I also think that just over tightening would not do this so keep your eyes open for something else, also with a good torque wrench you should turn it with plugs out at 35lb-ft. JW

 

I'm leaning towards something other than overtorque being the problem. If bearing clearances were OK, I really think bolts would break before the metal mating surfaces of rods and/or mains would collapse enough to sieze onto the crank. You likely have wrong sized bearings, or a cap on backwards. Take them off one at a time, and try to rotate after each one is taken off. Are there any numbers stamped on the side of the rod caps?

 

just got the engine out of the back of the truck and on the engine stand, i plan on picking up a torque wrench and checking all this afternoon, thanks again for all of the suggestions, i appreciate it
My uncle build the engine a couple years back and had it in dry storage as he went with a crate 350, so i havent done anything yet. all i have is what he told me he did from back then, so it is probually best to check everything and start from scratch.

 

As the very minimum on the rod bolts...remove caps and spin the nuts all the way down the threads with your fingers. If there is resistance, the things have been stretched and should be replaced without question.
I also am very suspicious about overtorquing locking the thing up. HOW??

 

X2 probably something else.

 

X100 or whatever we are up to.
Not possible for an over torque alone to lock it up.
There'd definitely be another issue, finding it is the key.
At this point I'd tear it all down and start over.

 

This has nothing to do with it being a 283. If some gorilla armed individual has over torqued the mains or rod bolts enough that the engine will not turn over you have some serious issues to deal with; stretched rod bolts, stretched main bolts, rod and main caps out of round. Start over, new bolts and a line bore and resize of rods to start with I have worked on engines for a long time and I have NEVER seen an over torque make an engine not turn! The bolts that are being tightened are outside of the bearing surface, to tighten that much somethings have had to change shape. I think you have other issues going on here because a simple over torque should not cause your issues.

 

No way it locked up due to over-torquing. First thing I would be looking for would be a reversed rod or main cap. Then go from there. The "broken torque wrench" story sounds like just that, a story. I would be going through this thing with a fine tooth comb if it were going in my car, especially considering he decided to buy a crate motor instead. call me suspicious, but to me, that sounds a lot like code for "I f*cked up this 283 short block, but I'm not sure how".
When you are assembling a bottom end, rotate it and FEEL after you install every rod/piston assembly, and an issue like this will be readily apparent. I usually use an inch/pound torque wrench on the crank snout as I do this, and if the torque increase isn't linear, its time to stop, and figure out why. Pinched oil ring rail, bearing not seated right, ect, will be readily apparent.

 

If it's got a rope rear main seal that wasn't installed correctly, it could put everything in a bind.

 

^^Really good point Heathen.

 

On a very early attempt at assembling a 289 Ford years ago I installed a rod backwards and it had the same effect....There was not enough chamfer machined into the side that was SUPPOSED to be facing the other rod on the journal,but was now tightened down on the fillet radius of the crank.It locked it up solid.Easy mistake to make for a first timer,but was my face ever red when the mistake was pointed out to me....lol!


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While you are at it pick up some plasti-gauge and check your clearances. It might have the wrong bearings in it.

 

But you'd think that after the rear cap was torqued that would pop up makeing rotations and installing the pistons extremely difficult.

I always spin the crank before and after the mains are torqued, doesn't everybody.

There was a thread awhile back where a guy was building up a short block (ford i think) and it would roll over just fine after torqed. A Few hours later it wouldn't budge. Forget what the culprit was but he did figure out what was causing it.

 

If the crank journals were egged shaped due to improper or no machining and new or oversize bearings installed, could that lock it up?

 

I'm also of the opinion that overtorqueing wouldn't cause a lockup. The bolts will break before they could compress the rod or main caps. I had a clicker torque wrench fail and broke a rod bolt so all of the rod bolts were replaced. I don't like re-using rod bolts because they get torqued so many times, although the quality of new bolts might be suspect these days.

I've always turned the crankshaft over after torquing the mains and also after each rod is torqued. I squirt oil in the crankshaft holes and the cylinder bores to keep everything well lubed. I want to know which piston/rod causes it to turn harder or lock up. I dunk the piston heads in oil before installing to make certain the ring lands are full of oil.

 

I have to believe a cap is on backward or some are in the wrong place. The wrong bearings are the next possibility. Over torquing them wont lock it up. JC

 

^^ I agree. Well put Ebbs

 

283 doesn't (or shouldn't)have a rope rear seal, and I don't care how much you torque it you won't lock it before pulling threads or snapping a bolt.I am guessing caps on backwards,or mixed up, rods in backwards, there is a chamfer for the radius in the crank,or wrong size bearings.

 

reach out to GlassThamesDoug. He is an engineer at Cat and a builder of high performance 283 engines. He is very knowledgeable and willing to help

 

The '57-58 283"s definitely had rope rear main seals. The '59-up had neoprene.

jack vines