my block is currently at RnR getting assembled (2.3 stroker). im using a 2.4 crank from a used galant motor which didnt seem (to me at least) to have any damage. I was called a few days ago that the crank needed to be machined .010 over and that now i need bearings to match. i've searced high and low and cant seem to find any...i was hoping to use acl race bearings but at this point i guess i'll use what i can. apparently RnR is having a hard time finding them too.

does anybody know where i can find these? im curious to know if i even order the .010 over bearings if maybe the specs might not match the clearance what would happen then...i was also under the impression machining a crank was no no?

 

Clevite makes over sized 4G63 bearings, I'm sure many others do as well.

 

got any links?

 

Mitsubishi historically did not list oversize bearings for the 4g63T motor, because the cranks are nitrided from the factory, and grinding them causes the hardened layer to be thinner or completely removed. However, there were other Mitsubishi motors with the same size crank journals for which bearings were offered by Mitsubishi in sizes to fit crankshafts that had been ground undersized. For example, Mitsubishi trucks using 2.4 cranks in a non-turbo application, or non-turbo 2.4 cars may have factory undersize bearings available.

You might check with http://www.jnztuning.com/ at (215) 997-6850 (Eastern Time) and ask them if they have a bearing solution for an undersized crankshaft identified for your particular application. These guys were formerly the Mitsubishi parts managers at Concelli Mitsubishi, and have served the DSM community with factory OEM parts for different applications for many years. Hope this helps.

 

Another point you might consider is that the cost of another set of bearings and the machine work will be at least half the cost of a new crank. Maybe you should get another crank and avoid the potential pitfalls mentioned by COvr4

 

Dont forget guys....he is using a 4G64 crank.....as far as oversizing the bearings and realiability is concerned. I wouldnt worry to much...it is pretty common for the V8 guys to do it. Call another shop. Ask their opinions. Alot of times the big names might have a spare used crank laying around they might be willing to sell you as well.

 

There are a number of identified problems with using the 2.4 non-turbo crank. In the 6 and 7 bolt versions used in DSMs, there have been a number of reports of metal failure at the #4 crank journal in high HP stroker uses, even with uncut standard bearing size factory cranks. Others, that were machined, may have failed due to grinding/polishing the cranks undersize, or to the fact that the machine shop used a unsatisfactory radius on the journal when grinding it, but the reports of #4 journal failure are common enough that it sticks out. BTW, the crank used in the 7 bolt DSM versions is the same crank that the Evo owners would be looking for.

The 2.4 crank has basic physical characteristics that are different than the 2.0 (including the fact that it is not nitrided and the harmonics of the longer throw), and the 2.4 was never designed by the factory for stroker turbo applications in our cars. I'd strongly suggest that if you are going to spend the substantial cost of a stroker anyway, you use the best part you can find (at reasonable cost), which is the factory crank, uncut and unground. If it can't be used with just a micropolish (and not a grind), find another one. Used 2.4 cranks are not expensive, comparatively speaking. You can find them for $300 or less. If you'd rather have a brand new one, they cost $600 or so. New Eagle stroker cranks are $700. Subtract your machine costs and the cost of non-factory bearings, and it's not much extra for peace of mind.

Remember, if your used and ground crank fails, the stroker builder will not usually warranty it at his cost. That's your problem, and it usually takes many of your other expensive parts with it, not to mention the time and cost of removal and reinstallation...

 

what sucks is that i already had the standard size bearings. the crank already's been turned...

i just found a crank locally for 200 used. they said its in excellent condition but is there anything to look for that will let me know if its good or not?

 

Man I love EVOm ... very informative people here!

 

go here & scroll down to the bottom

http://www.store.partsdinosaur.com/page18.html

i wouldnt worry about having the crank turned down, as long as the people who are doing the work, know what they're doing. Make sure it has been check for straightness & have the undercuts & oil holes polished.

The eagle crank route sounds like a good option, buty not everyone has that extra cash when they're taking on a build like yours. Especially since your paying someone else to do the work.

Good luck

 

You can buy new bearings for alot less than $200. Autozone can get the Clevites.

 

If your going to get a new crank you can get a new OE one from Mitsu for about $550. Thats what I did when I built my stroker.