Over Tightening Main-Bearing Bolts

[yoyo13131]

1992 Eclipse 2.0 non turbo 6 bolt

If I over tightened all my main bearing cap bolts because the manual was wrong, should I replace them?
Would it have stretched out the bolts??
(manual told me to do 18 pounds with an additional 90 degree turn.... it's suppose to be 49 ft lbs only)

Asking because Mitsubishi doesn't have anymore main bolts and APR bolts are to expensive and are unnecessary for my non turbo build.

help?

 

[hondaslayer1]

you should replace the bearings.might be able to reuse the bolts but not a good idea.

 

[yoyo13131]

you should replace the bearings.might be able to reuse the bolts but not a good idea.

The main bearings are brand new, I'm definitely not replacing them, there fine. The main bolts are the thing I'm worried about.

Does anyone happen to know the correct length for the 10 main bearing bolts? So I can measure mine to see if they stretched at all?

 

[hondaslayer1]

have a used set out of my old block pm me if u want them.they are 2g turbo bolts.if u over tighten the bolts it will stretch the bearings open and could pinch the crankshaft and score it all up. not worth the risk if u ask me.

 

[needsy]

Check with the vendors. For example, ExtremePSI claims to have OEM bolts.

EXTREME PSI : Your #1 Source for In Stock Performance Parts - OEM Main Bolts : Mitsubishi Eclipse (6 Bolt)

 

[hondaslayer1]

did not see the 6 bolt part sorry.

 

[BogusSVO]

set your torque wrench to 18 do 1 man cap... then re set the torque wrench to 49 ft/lb and see how many degrees it took you to get there... I would GUESS about 60* or so..

most bolts you can over toque by 10% (except TTY bolts) and be just fine.

since your a Non Turbo... your bearings will be just fine...

also check the bolts just above the threads and see if they have streched, they will be a tad thinner in this area if you truly streched and junked the bolts....

 

[yoyo13131]

set your torque wrench to 18 do 1 man cap... then re set the torque wrench to 49 ft/lb and see how many degrees it took you to get there... I would GUESS about 60* or so..

most bolts you can over toque by 10% (except TTY bolts) and be just fine.

since your a Non Turbo... your bearings will be just fine...

also check the bolts just above the threads and see if they have streched, they will be a tad thinner in this area if you truly streched and junked the bolts....

Here are some pictures, are they suppose to be fatter right at the head of the bolt?

<img src="http://i85.photobucket.com/albums/k64/yoyo13131_88/DSCF1115.jpg?t=1270162641" width="600" height="800"></a>
<img src="http://i85.photobucket.com/albums/k64/yoyo13131_88/DSCF1116.jpg?t=1270162716" width="600" height="450"></a>

 

[hondaslayer1]

they kinda look stretched but cant see all that good.

 

[BogusSVO]

yes they are supposed to have that just under the head of the bolt.

did you check them like I told you too?

 

[2slow4now]

The contact patch on the head looks scored up. Did you install them with any lube or dry? +1 bogus He knows what he's talking about The threads should be the same diameter all the way down. If you have a thinner spot they have been stretched.

 

[yoyo13131]

yes they are supposed to have that just under the head of the bolt.

did you check them like I told you too?

Yes I did check them, torqued them all in proper sequence to 18 pounds with my snap-on torque wrench, then torqued only one to 49 pounds....

around 43-45 degrees to exactly 49 pounds. Sooo... looking back on this I waaaay over torqued these little suckers... way beyond a 10% over torque. The bolts look perfectly fine though besides the bottom heads being a little chewed up.

yes I used a little lubricate (light amount of 10-40W clean engine oil) since they were going in real hard at first because my block was magnafluxed cleaned.

I guess I'll just buy that set of bolts off of Extreme PSI to be safe... not worth risking all the work I've done to have it all blow up for a pair of $35 bolts...

 

[burnerdaddy]

how can u see a streched bolt. They have to be measured with a caliper. I ran into this problem with a subaru motor. Some places will say a certain ft/lb and some will be torque to yeild (degrees) subaru told me to do it by degrees and not listen to anything i see. Id lube them bolts and put in back in. Its not a race motor getting trashed on all day. But thats working at a dealership will do to your thinking. If it was mine buy the new bolts.