Checking Connecting rods??

[ranger250x]

So i finally got around to tearing down my motor. the connecting rod bearings are scored, spun and/or smashed to ****. it appears as though the crank has walked causing the con. rod bearing failure, but there is NO damage to the mains. If possible i would like to re-use the con. rods. What do I need to check on the con. rods?

engine is a 1.8 out of a 1999.

[RotorNutFD3S]

How did your thrust bearings look?

In any case, if the rod bearings are shot and the mains are not, I'd be hesitant to use those rods again simply because it's probably now missing material on the bearing surface, and who knows what caused the problem at this point. However, if you insist, a good machine shop will be able to get everything back into shape and make sure the rods are still straight, and then measure the clearance between the rod bearing surface and crank and then get you going in the right direction for new bearings. You'll have to use a custom sized set.

Depending on your goals (IDK if you're just rebuilding the engine so it runs or heading for boost), a simple WTB ad on MiataTurbo could get you some forged H-beams for about $300-350. Much stronger than stock and you're eliminating a regular failure point in our engines.

[metalman]

I have a set of stock 99 rods I'd sell cheap. Also have low mile block & crank.
Will let the whole thing go elcheapo.

[Doppelgänger]

Sounds like the ever-so-popular thurst bearing issue....

[ranger250x]

thanks for the suggestions. the motor has to stay stock. since i already have a new motor this one will become a Spec Miata motor

Metalman i might take you up on the the rods and crank. I will let you know before Monday.

[ranger250x]

Well i dont think i will be able to buy anything for the motor rebuild at all. Had a massive coolant leak on PIB and had to tow the car to the shop I work out of. Not a reliable Miata at all.

[simontibbett]

Bad Miata BAD.