Resolved Timing belt stripped questions

[ReliantK]

Friend has a 1990 Mitsubishi Eclipse GSX, the car died and we checked the timing belt and found it was shredded with only like 1/4" width of the belt holding the cam gears still timed correctly together, but the timing belt was all stripped where it goes on the crankshaft pulley. So the crank was spinning and the cam gears not moving. We bought a new belt and are attempting to put it back together to see if the valves are bent.

My first question is: Because the cam gears are still aligned, does that mean the valves won't be bent?

Second question is: We put the new belt on but didn't replace the tensioner yet, we aligned everything up the way it should be, cams, crank, oil pump, etc and turned the motor over a few times with a wrench on the crank and everything stays aligned, everything rotates like normal and we could hear the motor had compression when turning it but when it gets to a certain point the belt becomes loose on top of the cam gears in between them then tightens back up, I'm assuming the car needs a new timing belt tensioner?

Third question: If any of the valves were bent, would the cam gears still turn? I would think the cams would lock up but wasn't sure. Any tell-tale signs to look for while we still have it all apart? Thanks ahead of time!

 

[Turbo Talon DL]

:thumbdown

Friend has a 1990 Mitsubishi Eclipse GSX, the car died and we checked the timing belt and found it was shredded with only like 1/4" width of the belt holding the cam gears still timed correctly together, but the timing belt was all stripped where it goes on the crankshaft pulley. So the crank was spinning and the cam gears not moving. We bought a new belt and are attempting to put it back together to see if the valves are bent.

My first question is: Because the cam gears are still aligned, does that mean the valves won't be bent?

Second question is: We put the new belt on but didn't replace the tensioner yet, we aligned everything up the way it should be, cams, crank, oil pump, etc and turned the motor over a few times with a wrench on the crank and everything stays aligned, everything rotates like normal and we could hear the motor had compression when turning it but when it gets to a certain point the belt becomes loose on top of the cam gears in between them then tightens back up, I'm assuming the car needs a new timing belt tensioner?

Third question: If any of the valves were bent, would the cam gears still turn? I would think the cams would lock up but wasn't sure. Any tell-tale signs to look for while we still have it all apart? Thanks ahead of time!

Your engine is Plain and simple. If you said the crank turned with out the synchronous drive belt (timing belt) then yeah, you have some pretty unhappy valves and a very very upset wallet! Take off the head and inspect.

 

[ReliantK]

so there's no way the valves aren't all bent? even if the cams were still lined up at the time the belt was stripped at the crank? even if the cams still turn fine?

 

[halligoo]

so there's no way the valves aren't all bent? even if the cams were still lined up at the time the belt was stripped at the crank? even if the cams still turn fine?

Pistons and Valves share the same space. Crank moves pistons. Cams don't turn = valves not moving out of the way. Ouch!!

Bigger problem: If belt isn't broken, you have some serious issues that would have to occur strip it as you describe. Any of the pulleys/tensioners could have seized up which caused all of this mess to start with.

I am so sorry. I just went thru this. It is too cold for this kind of trouble.

 

[Defiant]

so there's no way the valves aren't all bent?

Only if they have mastered intermolecular migration to the extent the pistons and valves can occupy the same space at the same time.

even if the cams were still lined up at the time the belt was stripped at the crank?

When the belt strips, the cams stop. The pistons don't. Smack-o.

even if the cams still turn fine?

Even if. You're screwed.

 

[ReliantK]

What are the differences between the turbo and non turbo 1g heads? Is it just the cams? We plan on using a non turbo head and swapping over his cams, is this all that's needed? Thanks

 

[kicker91laser]

I have been told by road race engineering that the only difference is the cams, and by using a non-turbo head, you will have a head that has not been abused with the heat from a turbo, yet.

 

[Skunked tsi]

I have been told by road race engineering that the only difference is the cams, and by using a non-turbo head, you will have a head that has not been abused with the heat from a turbo, yet.

I have heard the same thing aswell.
Tyler

 

[Turbo Talon DL]

Dont forget about the oil feed for the turbo!!

 

[BluemeanieTSi]

Dont forget about the oil feed for the turbo!!

only the bolt differs...one has a plug the other a banjo bolt

 

[kicker91laser]

Dont forget about the oil feed for the turbo!!

Just block it and feed it of of the filter housing, unless your turbo doesn't like clean, high pressure oil.

 

[nickrule99]

Just block it and feed it of of the filter housing, unless your turbo doesn't like clean, high pressure oil.

Like most BB turbos?

 

[Tallen]

Yup it is just cams that are the major difference. Actually the N/T cams are probably just fine to run in a turbo car, in fact I believe the intake cam on a N/T is better than an A/T Turbo.

 

[Stapl3]

Cams.
Exhaust valves.

Source: NABR