Crank hard to turn

[TRBOLeSABRE]

I am just getting finished freshening up a 79 turbo block. New gaskets, rings and bearings. I have the mains and rods torqued to specs and the crank wont turn by hand and it needs about 140ft.lb on the torque wrench to spin. The block has 45k on it. I decided to do the freshen up because there was a carb problem and it fouledn up the engine pretty bad. Any help? what did i do wrong?

 

[usetaboost]

HOLY SH!T

It takes 140ft lbs to TURN IT?

Dude, better take that thing apart and see what you damaged by turning it. It shouldn't have needed any of that stuff at 45k unless it lived on the racetrack. I had waay more miles on my turbo 79 motor and barely developed a lower rattle that was barely heard at certain rpms and that was after driving 20 miles on a bad head gasket. Kill me now guys, but I wasn't gonna leave the car sitting, especially with billet specialties wheels on it.

If you don't know what you are doing find someone to help. FYI, All the caps need to go back the same way and in the same location. Rods almost always need to be resized. Tear it down see what's messed up or have someone look at it for you and walk you through it so you don't make the mistake again. If you want some bigger 2 dot rods I got some from the n/a block that is in my car. I would sell to you, they have pistons attatched. Also have a driver's manifold from those era carbed turbo cars.

 

[TRBOLeSABRE]

I had the bottom end apart and the bearings are fine. I read in a thread that you have to seat the crank with a dead blow on the front and flywheel? Ill give this a try... the engine was running and everything was put back in the same order; the mains are marked with arrows and numbers so they dont get mixed up

 

[usetaboost]

First of all, you need to tear it back down and start over. If you've already done that this is what you need to do. If you are reusing your pistons you need to make sure they go in the same way they came out along with the same bore. Caps, everything need to be put back the same. I would definitely take the rods down to a machine shop and have them checked for resizing. Cheap insurance. I'd take the block down there too and have it checked out. Just as well have it boiled and magnafluxed while its all apart. Have the check the crank, mains, rods, anything that is round and spins to make sure its within spec. Shouldn't cost more than 50-60 for block and if the shop is not a rip off they will only charge a few bucks for the rest. At least have the crank polished. If you don't want to do this don't have to, just what I would do. TO each his own. BUT, you definitely need to get some plastiguage for checking ALL the bearing clearances. It's time consuming but well worth the assurance that you will have a lasting short block. And get you some assembly lube or at least some 30W oil. If you have any questions on how to do things by all means ask before you do! It's more embarrasing wasting your time and money on a gernade than it is to ask questions, learn what you need to do, and build a lasting engine

 

[BlackBandit]

It's more embarrasing wasting your time and money on a gernade than it is to ask questions, learn what you need to do, and build a lasting engine

That's the truth. What size bearings did you put in it. It needs to come apart and that's one of the first things I would check. You should be able to spin that thing by hand. Good luck. james

 

[Nasty Wendy]

Double check that all the rod caps went back on the rods they came off of. Hopefully you marked them. Make sure that none of them are on backwards. Yes I have screwed that up before.:redface:

 

[usetaboost]

tear it down and let us know

 

[turbo nasty]

Fo sho somtin aint rite

What was your plastigage readings?

 

[gossamer]

Did it spin fairly easy when you just had the crank in it or did it get tight when you put the pistons in it? If it was free with just the crank installed, then the main caps are probably installed correct. If it's tight after the rods/pistons are put in, check the orientation of the pistons and the rod caps. Take it apart and measure everything! Take note of when the crank starts to spin freely and that will be a good indictor of where the problem lyes. Good luck and report back

 

[TRBOLeSABRE]

I will take everything apart once more and measure everything and post my clearances. I will indeed take it to a machine shop within the next couple of days. post later tonight

 

[TRBOLeSABRE]

I got the crank to turn now. I had some uneven wear on 2 of the main bearings. i took a dead blow and gave the crank a whack at the front and the end. then i had to tap the main caps a little bit to get them to torque evenly. It takes only 30ftlb now to to turn, thats quite a difference.

 

[mikestertwo]

I got the crank to turn now. I had some uneven wear on 2 of the main bearings. i took a dead blow and gave the crank a whack at the front and the end. then i had to tap the main caps a little bit to get them to torque evenly. It takes only 30ftlb now to to turn, thats quite a difference.

If it takes 30ftlbs to turn the crank without the rods on it that's still too tight.

 

[usetaboost]

YUP! Crank should spin freely

 

[Chuck Leeper]

You don't

I got the crank to turn now. I had some uneven wear on 2 of the main bearings. i took a dead blow and gave the crank a whack at the front and the end. then i had to tap the main caps a little bit to get them to torque evenly. It takes only 30ftlb now to to turn, thats quite a difference.

set the thrust w/ just a "whack on the crank"..
You don't "whack the caps" to get them to torque evenly...
Maybe back to auto shop 101, or find someone to help, that knows WTF is going on??

 

[Nasty Wendy]

set the thrust w/ just a "whack on the crank"..
You don't "whack the caps" to get them to torque evenly...
Maybe back to auto shop 101, or find someone to help, that knows WTF is going on??

He didn't WHACK it. He adjusted it......with a 2lb deadblow hammer.

 

[TRBOLeSABRE]

Ok whack, not quite, i suppose that sounded kinda backyard mechanic. I did tap the caps to get them to seat right and get accurate torque readings. Mains are at .002 all the way down and rods are at .0015 all the way down. it takes 12ftlb to spin with the rods connected. Its tough to do it by hand, but i can turn it. Im still learning the little quirks with this block.

 

[BlackBandit]

IMO you should never have to touch the caps with a hammer. Also, assuming you used assembly lube the crank should spin like it's riding on air without the rods attached.

 

[usetaboost]

Yup

 

[TRBOLeSABRE]

my cranks turns effortlessly.A little elbow grease thats all. I talked in detail to the man i bought this car from and he said he had the main caps off the bottom end for a day while he was working on the bottom end. I hope my troubles were from the fact that the block may have warped a bit from having the caps hinkingoff so long. Not that block warpage is a good thing, but good that i got on it after a short time and hopefully was able to correct what minute shifts did occur with some taps on the caps. So let me know what you think.. Am i overthinking? Do i really have a problem? because i have good measurements...

 

[chasmat2316]

something ain't right!

Sounds like you should find someone to help you with your project who know's what they are doing & double check everything! Everyone has problems from time to time- don't feel bad, just check everything & ask for help when needed!