Well it almost cost me an engine , Close call...

[Phoenix]

This weekend I finally got my SHO out after cutting the rear springs a bit , finished the exhaust (ditched the fart cans) , re-do all the brake hard lines and replaced a leaking fuel tank.

After 5 miles , it started knocking on top of the front valve cover , I stopped in an empty parking lot , opened the hood and I saw the front cam sprocket bolts were all loose (through the timing cover window I had made) and were holding by a couple threads....

WTF I did those with the impact gun .... but wait , I painted these.... They had loosened with the paint behind the bolts with the vibration (solid mounts).

So my wife convinced me to call a tow truck before the sprocket fails and destroys the valves and pistons (40+ cams) , I was ****** but it was the right decision. I was really afraid I had already damaged something with that knocking...

Fast foward today , I removed all the paint re-tight everything with lock-tite and started it , THANK GOD no more knocking. Phew.

 

[St Louis SHO]

Dont feel bad, I did the same thing on my white 95 after the 3.2 swap

 

[yamahaSHO]

You tightened the cam sprockets with an impact gun???

 

[Phoenix]

Yes , its a super cheap ass impact gun - dont get me wrong I didnt hold it like it was a wheel nut. Plus I re-checked with a ratchet.

 

[SHO_DOODmorrris]

still... an impact gun? comone guys how hard is it to use a tq wrench

 

[38SHO]

I take it you've never been to a mechanic shop and seen people take off crank pulleys and cam sprockets before......

most professional mechanics laugh at torque wrenches.......

theres only two things I've ever torqued on my car

rod bearing caps
and valve cover bolts(more so just to have an even pressure applied and seal better)

 

[yamahaSHO]

I take it you've never been to a mechanic shop and seen people take off crank pulleys and cam sprockets before......

most professional mechanics laugh at torque wrenches.......

They're only professional in the fact they get paid... not skill.

rod bearing caps
and valve cover bolts(more so just to have an even pressure applied and seal better)

That's funny to see because the bolt has a collar (a stopping point where it cannot clamp any more). As long as they're tight and not stripped, it will ALWAYS have even pressure applied. That is a bolt where a torque wrench is NOT needed if you're any good with mechanics.

 

[Phoenix]

I take it you've never been to a mechanic shop and seen people take off crank pulleys and cam sprockets before......

most professional mechanics laugh at torque wrenches.......

theres only two things I've ever torqued on my car

rod bearing caps
and valve cover bolts(more so just to have an even pressure applied and seal better)

Bingo , for me its the intake bolts and rod/main caps.

The question is not what I used to tork it , the thing is that the paint loosened up behind the bolt and it did what it did.

Im not talking about a stripped bolt here.

Dont be such pansies guys. Geesh.

 

[SASHO91]

There are certain parts that require the use of a tq wrench... Cam sprockets? no thanks, tight is tight in that department.

My foreman would throw all of my tq. wrenches, ft. lb wrenches in the garbage if I used it on something silly like cam sprockets.

Not to mention most high grade impact guns have a varible tq setting. My 1/2'' IR has 4 settings and they are DAMN close! (checked with a tq. wrench).

I used my little 3/8'' butterfly impact to put my sprockets on. And that was back in Dec. IIRC.

 

[93rev2sev]

most professional mechanics laugh at torque wrenches.......

I don't think I'd go THAT far. But I agree, the torque wrench CAN be overused.

I can't beleive you used an impact on cam sprocket bolts, though. Aren't those like m8x1.25...

 

[yamahaSHO]

The question is not what I used to tork it

You said you ran it in with an impact. If you didn't run it in all the way, then there was no relevence in this post.

WTF I did those with the impact gun

Paint loosened up? With proper torque that paint shouldn't have an effect. Most piant would stick and take a set. If the paint were rolling off when you tightened it, it could effect torque reading...

I'm going to guess it was improperly torqued.

 

[38SHO]

They're only professional in the fact they get paid... not skill.

That's funny to see because the bolt has a collar (a stopping point where it cannot clamp any more). As long as they're tight and not stripped, it will ALWAYS have even pressure applied. That is a bolt where a torque wrench is NOT needed if you're any good with mechanics.

well if you don't have one down all the way it wouldn't seal right now would it? or if you crank on it too hard you might strip it...... thats why I put the torque wrench to it, to keep me from going too much on it

these are some of the smallest fasteners on our engine and I really don't want it to leak after I put it together..... this is why this is one of the bolts I torque..........

more importantly, the amount of torque a bolt can take is really about what material the bolt goes into, because its not the bolt that usually messes up.. its the threads of the head..... so when i think torque wrench and trying to do it right, I think aluminum heads... small bolt.... then I think how much of a pain it is to fix it once its stripped.... yeah I don't want to spend all day putting helicoils in my heads.... I'll take the torque wrench

I guess I'm just a horrible mechanic cause I put a torque wrench on a valve cover bolt on my own car...... let me go end myself because the almighty doesn't approve!

:woo-hoo:


seriously, talking about irrelevant posts, all of yours are on this thread

 

[yamahaSHO]

There are certain parts that require the use of a tq wrench... Cam sprockets? no thanks, tight is tight in that department.

My foreman would throw all of my tq. wrenches, ft. lb wrenches in the garbage if I used it on something silly like cam sprockets.

I know someone who didn't properly torque their cam sprockets and had a bolt break. It resulted in two melted and one cracked piston.

 

[yamahaSHO]

well if you don't have one down all the way it wouldn't seal right now would it? or if you crank on it too hard you might strip it...... thats why I put the torque wrench to it, to keep me from going too much on it

Like I said, if you're any good at what you're doing, you can't mistake the stopping point. Most of the people that I've seen strip this boltson this forum were using a torque wrench.

these are some of the smallest fasteners on our engine and I really don't want it to leak after I put it together..... this is why this is one of the bolts I torque..........

I guess I'm just a horrible mechanic cause I put a torque wrench on a valve cover bolt on my own car...... let me go end myself!

:woo-hoo:

Feel free to torque them, but I hope you're not doing it with a torque wrench that reads up to 150 ft-lbs. I run them down until they stop, then turne just a smidge more and they're done.

 

[Pro*banshee]

Do the +40 cams turn the engine interference? I could swear they didn't...

 

[93rev2sev]

I thought +20s did in an MTX.

 

[SuperchargedSHOguy]

Unless I remember incorrectly the stage 1 and +20s are not interference. Stage 2 and +40s make it interference.

 

[SHO_DOODmorrris]

depends on the pistons i thinbk. if you go forged i belive the valve reliefs are deeper.

 

[yamahaSHO]

That depends on what forged piston you get. Not all are created equal. But yes, with the Wiseco's I bought, I could run Stage II's and still not be an interference motor.

 

[ManySHOs]

+20's are interference. I proved it when I did the timing belt install a few weeks ago and rotated the pistons into a few valves.

I rarely use an impact to torque anything down unless it's a long bolt. I like to ensure that the bolt or nut is properly threaded - there's no feel with an impact and it's too easy to cross thread something or deform the fastener if it's small enough. Once I have most fasteners threaded part way, it's usually only a few more turns with the ratchet I was already using. Using an impact gun on cam sprocket bolts seems excessive.

Ian