I need some help, guys...

For the past five months I have been trying to turn a 90 vette into a much nicer, more powerful 90 vette. 383, Superram, new everything. some progress has been made...

Ive never done auto mechanics before i did this. I was SUPPOSED to have help from an experienced friend, but he got a new girlfriend, new job, yadda yadda yadda. He bailed on me...*SS hole.

I've got a timing chain that won't let the engine turn smoothly when installed. It gets hung up at a certain point. I know THAT just won't work. The rotating assembly is just fine until I put the chain on, and then as i rotate it around, it hangs up. The gear is not rubbing anywhere. So like now what????!!!????? I guess i got to take the crank gear off and start over. WTF fun that will be....

Every $*$&$^ bolt on this car is virtually stripped or frozen. I got brake lines that i cant get off, tranny cooler lines i can't get off to drop my new radiator in. Now the half axle u-joint strap bolts (at the differentail end) are frozen/half stripped and I just know I'm up crap's creek without a paddle.

I halfway feel like taking this pile of expensive new parts and BS rusted bolts and hauling it over to a GM Certified mechanic and getting reamed just to get this nightmare over!

SIGNED


Frustrated, at wits end, and broke.


OK NOW I FEEL BETTER.

Thanks for reading my rant. I wouldn't have gotten anywhere without the help from people on this forum. But ive got a long row to hoe, and the weather is nice, and im dying to get on the road and this car is about to get the best of me.

 

When you build a stroker sometimes you have to get a small base circle cam. I sounds like the rods are hitting the cam when you rotate the crank and cam at the same time.

 

Is the cam gear hitting the bolts on the retaining plate? Crank gear pressed on all the way?

 

You are right...its supposed to be a small base circle cam. I do know that a regular timing gear wouldnt work, i had to buy one with a smaller pattern of bolts to fit it. But I wonder???? if that is the problem, that is good to know.

 

No, i checked on that. From TDC, with the points lined up, the top gear makes a complete revolution and more without any problem, so i think if the (Cloyes double roller) gear was hitting the bolts it would show up. this problem occurs the second time around, just past TDC.

I believe the nose gear is on all the way. I put it on the right way, and got it down to an eigth or 16th inch, and then all the way down so i saw no gap.

 

Look very closely. Sometimes the cam gear will rub on the upper middle oil galley boss. Also with a stroker, the rods can hit the block, cam, oil pan baffle, oil pan etc. I even had to profile the m55 oil pump on the last one I put together. Some grinding to allow for clearance between the crank counterweights and block.

 

It could be my provider didnt get this right. . . as i mentioned in previous post, i know that the cam required a smaller diamter bolt patterned timing chain.

How can one tell if he has a small base circle cam?


This is Comp Cam
Chevy 262-400 Xtreme Energy Computer Controlled XR276HR Cam

 

If the cam is making 2 full turns before it binds, it is the rotating assembly binding somewhere. First stroker motor I built came apart 8 times before I got everything resolved. Now that I have done a few, once and done.

 

THe engine does not have a problem without the cam shaft gear on...
It rotates smooth as silk...i did take the oil pan off to check if that might be it, but, no. One CF member suppested the grind on the boss, i dont recall who, but i ground it today, and it made no difference. The company that built the stroker checked it for clearance too, and assembled it/tested it for oil pan/baffle, pump compatibility.

Im thinking its the cam, not being correct. great, i can handle that.

 

Pete, why would the rotating ***. do just fine, on its own, but when the cam attached to it, it would hang up like that? Let's say it was the cam. not being small base circle. would any part of the rotating assembly touch it at any point? I think once i noticed that rotation caused the cam to bump once (when the chain was off). i dont have any lifters or push rods in...

 

If memory serves, the rod bolts on 1,2 5,6 come the closest to the cam. Stock rods need to be chamfered a bit to work with a stock base circle cam. Rods hitting the cam makes senses it happens with the chain on but spins free with the chain off. If this is the case, swapping the cam for the smaller base circle is a valid option. Be aware though, smaller base cam will require custom length pushrods. Option 2 is to disassemble after finding which rod or rods hit. You can chamfer the rod bolts and hope for the best. However rebalancing the crank after grinding the rods is the "correct" way to do it.

 

If they didn't have the chain attached, they couldn't rightfully claim there were no clearance issues. The cam could not be in proper position to the crank as they turn the motor over. If the crank turns over almost twice, i bet its the bottom end hitting a lobe somewhere (rod bolt, possibly). The cam rotates at half the speed of the crank, giving you the two crank turns to hit your "stop".

 

thanks fellows!

Yes, im sure that this is the problem. I will look into this tomorrow. I appreciate the help.