this is a simple mechanical setup. the way i see it there is only 3 ways you can have slack.

the tensioner is faulty and not providing the proper tension

the tensioner may be fine but it works on
oil pressure and that may be your problem

the chain is stretched

the cam doesn't have bearings, it rides on the head and it is held down with caps. yes the surface can be worn but that would only make slop and excess play.

ask ted what he thinks and let us know.

 

A significantly decked block, decked head, streched timing chain, I dunno...

Hey - what about using an incorrect timing chain.. I suppose they are different between early and late blocks...

You might ask Ted - send him your photos. I don't think you're dragging his name through the mud either, but he'll probably have some ideas for you.

I'd check my oil pressure with a gauge at idle.. Absolutely no way you got that tension on there incorrectly?

 

I guess the head could have been shaved at some point. I am not the original owner. It must be the deck or head that has been changed to cause that kind of slack. It's wierd because it is tight when it is sitting there.

 

i still think its a tensioner problem. maybe not the tensioner itsself but the little oil pump bolt that it binds on. if not you may want to try a .020" thicker hg.

 

>>>*Been awhile since I wandered in here, sorry, I have been dealing with some property issues.

The load side (straight) of the chain will not reach the stock type bolts when all is normal, if that were the case the stock type guiderail sure wouldn't last very long and we see cases where even the nylon style guides run well over 200,000 miles.

In those cases the straight guide shows very little wear, since it does not even touch except perhaps briefly during startup, etc. Yet the inside of the stock type gaurd has that very same bolt in the very same place?.

The weak link, like always, is the tensioner and I concede I hate the design.

Dirt, debris, silicone, overtorque, wrong upper holddown bolt, a timing cover with a bolt boss inside brushing the pad, mildly misdrilled holddown bolt locations and we see returns of around 1% no matter what brand of tensioner we supply.

I did add a worksheet mentioning some possible errors, that reduced returns to about half of what they were before.

If the chain can rub against the bolts, then the tensioner is inoperative for some reason...This is something I am 100% sure of, I will hazard a guess we have around 6000 of them out there running that don't....*EB

 

I can push the tensioner in with a screwdriver and it pops back out all the way. I only get a noise at and around idle. I did not change my oil pump but I suspect that I might do this next. The guage never goes above half even when cold. It also has 370k km on it. I will try this next and see what happends. After that I guess the damn cover has to come off.

 

didi you clean out the oil pan? I can't remeber if you talked about that but is it possible that the oil sump is clogged?

 

no I have never had the pan right off. I can't see that being a problem though as it would take a lot of crap to plug up the screen on these engines. If changing the pump doesn't work and I pull the timing cover I will drop the pan and have a look.

 

i had a bearing spin due to an oil pickup screen being clogged up....

 

Did your old timing chain guide get chewed up? If so, I am guessing it is clogging up your sump. It seems to be a highly recommended by forum readers to clean out the oil pan when changing the timing chain.