Problems using non turbo 3.8 crankshaft?

[rb68rr]

What kind of problems would you run into using a crankshaft out of a non turbo 3.8 that has been turned .010 in an '87 GN? Would there be a balancing problem and possible vibration? Etc? Thanks, R.B.

 

[Nick Micale]

There is no balance or vibration problem with using a non-turbo crank. It is not as strong as a rolled fillet turbo crank, but some cars have had success running with them.

A recent thread on this subject can be found by using the search feature for LOTS more info!

 

[rb68rr]

The reason that I ask these questions is because a Buick dealership replaced the rod and main bearings in my car a year ago. They took out my crank and sent it to a machine shop to have it turned .010. This week the bearings went to hell in a hand basket and also ruined the crank! Now when my mechanic, not the Buick dealership, dropped the pan he found a non turbo crank instead of my original! Would that piss you off or what? R.B.

 

[rb68rr]

ttt

 

[wh1-Denver]

I would pay the dealership a visit with the original receipt of their repair, a note from your mechanic stating that the crank is not the original one, and if you can bring the crank with you to show them. I would talk to the service manager and demand that they replace the crank with a turbo one. If they don’t agree to I would talk to the general manager of the dealership. If he doesn't want to replace it then ask for the owner. Go all the way to the top and if they still don't, then I would threaten to sue them for all the cost associated to getting it back to a turbo crank and all the labor and parts that it took to do it. I would be pissing fire and I would not leave the dealership until they agreed to rectify their f-up.
If they try to say it is not their fault it’s the machine shops then you tell them that is their problem to deal with the machine shop they are the ones that hired them not you. You hired them to fix your car they hired the machine shop. So the responsibility lies on them first. They are responsible to repair you car with the correct parts.
This kind of $hit pisses me off. I am sure your bill was outragous being a dealer.

 

[rb68rr]

wh1-Denver, I agree with everything you say! Today they agreed that they owe me a crankshaft. However, who in their right mind would let this same dealership install it?? My "real" Buick mechanic has the right crank and he is installing it today. I really believe that the dealership should have to pay my mechanic the labor cost! I guess I'm going to end up with an extra crank. R.B.

 

[wh1-Denver]

You can sell it to me. Email me to work something out if you want.

 

[sixgun86gn]

By your sig and the times you have run I would not have worried.My motor has a non-turbo crank.

 

[broke1]

Banning runs one and his car has gone 10.90s and it has hyper pistons HTH

 

[rb68rr]

I guess it just the principle. They took out my original crank to have it turned and put back a non turbo crank in it's place. But you probably don't know the whole story. This was a year ago. Three weeks earlier they replaced my timing chain and cranked it up without priming the oil pump! That's when all this s#$t started! Now, one year later, the bearings go to hell and ruin the crank! This is when I found out they put in the non turbo crank. One year later! Just venting some anger. Sorry. R.B.

 

[sixgun86gn]

I understand completely.They probably just got a crank kit for exchange at a local machine shop and didn't realize the difference.That is the bad part about bringing your car to a non buick specific place.Though some of them have a bad rep too.The bearings were probably just cheap rebuilder specials.I got those with my NA crank from the machine shop,but I threw them away and put in King bearings.They are real good bearings and don't cost much either.

 

[Ormand]

The rolled fillets on the turbo crank do NOT make it stronger. But they will make it last longer. The purpose of the rolled fillets is to extend fatigue life, not to increase torque capacity. So you can run a non-turbo crank, it just won't last as long. If you tear down and inspect regularly, checking for cracks, you can forget about the turbo crank. Otherwise, it is good insurance.

 

[Taffy]

Originally posted by Ormand
The rolled fillets on the turbo crank do NOT make it stronger. But they will make it last longer. The purpose of the rolled fillets is to extend fatigue life, not to increase torque capacity. So you can run a non-turbo crank, it just won't last as long. If you tear down and inspect regularly, checking for cracks, you can forget about the turbo crank. Otherwise, it is good insurance.

Metallurgically, compression rolling the fillets indeed makes the crank stronger. The strength of a metal is it's ability to resist bending. The filets in the turbo cranks make it stronger than the N/A cranks.