I talked to Jason at MTI last Feb. and he told me the same thing that he said in the mag..................

 

Sorry to admit, I locked my bottom 1 month after installing heads/cam. But, if you remember Madwolf's thread "Dirtiest LT1 ever

http://web.camaross.com/forums/showt...t=dirtiest+LT1

That was my original engine. Bought that car for $3500 running a year ago with nice cowled hood. I think it was time for the engine to go, but probably head and cam install helped the block to die.

 

WOW. Poor LT1... When I pulled my Intake for the cam swap the lifter valley was like new with 110K on the clock. I was really impressed to see it looking so good. I didnt have any gum anywhere.
Im not really worried about spinning a bearing with just a cam swap though either. I really think if you change the heads and the cam and rev the motor high on a over 50% of the time you are gonna spin one on a high mileage motor. I seen it happen to a friend of mine that put a older BB 396 in his Monte and he change the heads and cam without looking into the bottom end. He spun a bearing two months later at the track.
I know of a racer that worked as a Gm Tech and he told me when I was installing my cam not to go big unless I was gonna rebuild on a high mileage LT1 because of this issue of bearings because he said the #2 downfall besides the opti on the LT1 is the oil pump and he had seen a few motors go at the track because of the stock oil pumps on high mileage Lt1s. They had heads and cam done. The cammed only cars lasted and he didnt see any of those take a dump. Thats why I only did cam til rebuild time.

But I look at this way also you know a rebuild is gonna have to be done one day and you will already have heads and the cam you want. I say to all with heads and cam just keep

 

Are you being serious or sarcastic? Does it surprise you that a motor went at 117K? Why would you relate it to a head/cam swap done 23,000 miles earlier???

Rich Krause

 

I don't see any reason why if you used OEM head bolts and torqued them in perfect sequence and evenly that you could not avoid spinning bearings. After all, the factory has to install the heads. True, this is done with machines I am sure, but heads are not the same as a torque plate. If you went to the same torque specs as the factory and in the right sequence why couldn't you distort the block almost exactly like it was from the factory. In other words save yourself from a line bore/hone.

 

I think it's bull****. I did heads/cam at about 125k miles. I upped the rev limiter 400 rpm, and now with 133.5k miles I'm still ok. Granted I take very good care of my car, and and religous with the maintenance, but if you do major work like that you should be.

Isn't MTI behind this way of thinking? I think they are just trying to make an extra profit on heads/cam work.

 

It is pure claptrap. MTI wants to sell engine packages, not install camshafts. Installing a cam in an LT1 car is pretty much the same amount of work as installing an engine, why not sell the extra parts?

 

why is the block now useless. just because of the bearing failure?

 

I know this is a simple question for you experienced guys , what is a symptom of a spun bearing ??? I hear it all the time but dont really understand it. It kills the engine right ??? Big time mechanical failure ???

 

Im just exaggerating a little. Its just locked solid now. Block is probably salvageble, don't know yet.

Rich - Im not blamming the Head change, I just know ive changed heads on many other cars before without incident for 50k + miles.. this just seemed rather sudden to me, maybe intirely coicendence.