Broken timing belt

[Cocacolakidd]

Well that did it - at 35k miles on a timing belt it let loose and tore up the head, valves in number two and three. Spun rod and main bearings - all in all alot of damage. I have the crankshaft in the shop to have it cleaned up, but they are telling me that it will clean up at .010 under for the mains, and .020 under for the rod journals. Good guys down there and have done allot of work for me, so they say they will do the crank for me for $100.00, and ballence it for another $50.00 - I think that this is cheep enough (Sort of like a favor). My question is will the crank shaft be any good for racing at .010 under mains, and .020 under for rod journals? Also can one find the proper bearings for this undersize crankshaft?

Any help appreciated,

Ed (AKA: Cocacolakidd)

[2Tight]

Originally Posted by Cocacolakidd

Well that did it - at 35k miles on a timing belt it let loose and tore up the head, valves in number two and three. Spun rod and main bearings - all in all alot of damage. I have the crankshaft in the shop to have it cleaned up, but they are telling me that it will clean up at .010 under for the mains, and .020 under for the rod journals. Good guys down there and have done allot of work for me, so they say they will do the crank for me for $100.00, and ballence it for another $50.00 - I think that this is cheep enough (Sort of like a favor). My question is will the crank shaft be any good for racing at .010 under mains, and .020 under for rod journals? Also can one find the proper bearings for this undersize crankshaft?

Any help appreciated,

Ed (AKA: Cocacolakidd)

Never heard of spinning all the bearing from a T-belt failure, I bet it was the other way around with the bearings failing first. For $100 you can get a good used crank. You still have all that head work to do plus pretty much a full rebuild. After spinning that many bearings I would scrap the block as you will have to completely disassemble it to get all the bearing material out. Personally I would start over with a good motor from a wrecked car with a known service history. I've sold 2 NA motors (83 and 87) in very good shape for less than $500 each.

[callmethewander]

Yeah, i think that mght be the way to go also, unless you were gonna work the engine

[Cocacolakidd]

The motor will be completely rebuilt with many mods. While they are cleaning up the crank they want to fly cut it, cross drill it, and also micro balance it - all this for $150.00. I am just not sure if the crank will hold up under 15# to 18# boost at 6.8K to 7K RPM's. I have done many favors for them there and they are returning the favor - If the crank will hold up under power I think I will do it. Then again I have not tried to find the bearings that will fit it yet. If those bearings are prohibitive in cost then I have lost the advantage of almost free machine work.

Thanks for the replies,

Ed.

[nynor]

if you are worried about it, get the used crank and have them do the machine work on that. better yet, spend some money and get the three liter crank and build a stroker!

[Cocacolakidd]

Hello all,

Wow that's a great idea. If I get a good used 3ltr. Crank and have it machined will it fit my M44/02 block, and forged turbo rods (accuired for this rebuild)? Also will the 3ltr. crankshaft add any to the compression ratio? I'm trying to keep the CR at or below 8:1

Great suggestion, and thanks.

Ed.

[nynor]

i think it will just fit your block. i've read that some of the material will have to be machined from the block skirt in order for the rods to clear. if its all apart, this is probably not a big deal. not sure about the compression ratio.

a guy at the local shop builds these engines, 2.7L strokers, and claims to have built one with around 500HP at the wheels. he may even be able to get you the crank and some pointers. salt lake motorsports, 801 487 6733, talk to Garrity.

[Cocacolakidd]

Hello,

Thanks allot for the info. I will call and speak with garrity about a 3ltr. crankshaft.

I appreciate all of the feedback here - absolutely a great site for the MARK.

I also checked out the .010 under bearings here and they are an extra $220.00 above Std., and close to the same for the Rod Bearings. Probably save the cost of a 3ltr. Crank by using std. bearings on all.

Ed. (AKA: Cocacolakidd)

[944 Ecology]

Originally Posted by Cocacolakidd

I also checked out the .010 under bearings here and they are an extra $220.00 above Std., and close to the same for the Rod Bearings. Probably save the cost of a 3ltr. Crank by using std. bearings on all.

Ed. (AKA: Cocacolakidd)

Dream on. The cost of a 3 liter crank is around $1600, if you can find one...

[nynor]

what is an extra $1100 when you are redoing the entire engine? and you are looking to boost it at 18PSI, plus....

[944 Ecology]

Originally Posted by nynor

what is an extra $1100 when you are redoing the entire engine? and you are looking to boost it at 18PSI, plus....

Yeah, don't forget the custom pistons and custom rods... The $1600 is just the tip of the iceberg...

I thought that the idea was to get this done cheap, although the cheap thing would have been to replace the timing belt at 30K miles for $50.

[nynor]

well, he is talking racing, mods, and higher boost, so i assumed (yeah, that) he was spending some money. plus a complete teardown with new bearings, seals, gaskets, etc., is not going to be exactly cheap. plus, he can part out the stuff he isn't going to use, like the pistons, rods, etc.

[Cocacolakidd]

Sorry guys I just thought I would ask if this crank was useable any more. If not I will just chuck it.

Many thanks for all of the replys,

Ed.