Like the title says... I just got this new timing chain set: https://sandiegoengineparts.com/prod...ets-08-9036t-9
and find that it is tight.. as in almost ZERO slack. If I press hard enough on either side of the chain, it will move... But it is taught like a guitar string. I can post a video if you guys would like to see it. USUALLY when I put new chains on I'm complaining about how much slack a brand new chain has... This time.... It has gone the other way. When I opened the box the instructions inside say that this chain is for a SBC as in OLD SCHOOL Chevy.. It's common I know on China parts to find the wrong instructions in the box though... This part was ordered through my machine shop. I never saw it until they handed it to me.. Being that this is an aluminum block engine, and there is a possibility that the chain could be stretched even tighter if the motor expands with heat... I'm nervous. Should I return/exchange it and hope that the next one has a little slack in it, or do you think this one will loosen up a bit after a little mileage? Again, I can make a video if anyone would like to view it.

 

Being that you were able to get the cam gear bolted to the camshaft tells me that it wasn't too tight. I'll think you'll be just fine.

 

Run it, I going to order one or three also.

 

It only needs enough slack to account for thermal expansion of the block, and no more.

 

G, and that is my point.. If it has almost ZERO slack right now..... how much is enough slack to aim for to account for thermal expansion? Ima run it as is. I've never heard of an engine failure due to "too tight a timing chain" so let's hope I'm not the first. The motor spins over just fine, and the chain has the same tension in all crank/cam positions. I was turning the engine over 1/4 turn at a time through 2 full revolutions checking that there were no loose spots (meaning the sprocket(s) centerline was off)... It's the same tension all the way around. It's gonna eat... Just let this stand as the record if it chews up the front cam bearing... we will know why.

 

That chain will stretch in the first few minutes of run-time. Only the Iwis and Avon chains are pre-stretched as far as I’m aware. We set up belt drives with a pretty tight belt and never saw cam bearing issues, on the non-roller cam bearing builds, so either way you should be ok here.

 

Right, of course. I was speaking in the general sense and was not considering the initial break-in.

 

^^^ This ^^^

It'll relax itself soon enough, you're good to go.

 

So, here are the pics... The chain dampener is a GM piece that I got from Summit racing-I think Chevelle70 recommended it. It bolted right on as he said it would. Look how TIGHT that chain is! If I press hard enough on either side of the chain I can make the chain contact the dampener.. But, without any pressure on the chain-it's tight enough that it does not touch either side of the dampener. I thought this was a China made part-but all over it "Made In the USA"... Wow... Not a bad price for a thrust roller bearing, 9 key way adjustable, TIGHT chain... Thanks to those who gave me advise on this subject. I appreciate it.

 

My cloyes timing chain is that taught on the dampener. It is fine. Just run it.

 

Alright, since nobody said it, and I've been patiently waiting.....Many things in life are better when they're on the tight side!!!

 

Sounds like you got lucky; I've replace my share of LS timing chains (mostly trucks), and almost without exception they had more slack in them than I'd like to see.
I've talked with other guys about this, and they've said the same thing.
For the record, I've always used Cloyes or Melling chains.

As far as the contact on the dampener goes, let me tell you something that will blow your freakin' mind: overhead cam engines run their chains against the plastic guides ALL THE TIME.

Just run it.

 

Just a quick update-I installed the motor last week and it fired on the first attempt. ZERO issues so far except on the first fire up I had not tuned it yet and it was popping codes for cylinder deactivation solenoid issues. Tuned those DTC's out and I have been driving it since then. Truck runs okay, but will need more tuning... After the first 200 miles it popped a code for P0420-cat effic. low bank 1. I cleared it and it has not come back.... yet..... I'm fairly confident that Bank 1 cat converter is probably toast as the old motor was burning a LOT of oil.. To the point the drivers side exhaust manifold was as slick as the Exxon Valdez inside. I ordered a Magnaflow Cat converter anticipating having to replace drivers side.. but code has not come back since I cleared it that one time. I'll keep driving it until the code sets again before I cut out the old one, and weld in the new one.

Oil pressure. I did end up re-using the original AFM/DOD pump, and even shimmed it like .080"... On a cold start it will jump to just under the MAX mark on the gauge... after hot, at idle sitting at a red light it's between the 1/4 and 1/2 way mark.. As soon as you accelerate it jumps to over the 1/2 way mark and just stays there as long as you are on the gas. I have not romped on it as I have not tuned for the BTR cam yet-and it still has very old gas in it. I've just been babying it around using 1/4 throttle max trying to see if it will set any engine codes, and giving it a few hundred miles of "shake down" before I do anything else. I'm trying to burn out all the gas in the tank and fill with new BEFORE any tuning as the truck sat for 8 months will a full tank... now that full tank is just OLD gas and I'm not gonna try and tune with it in there... so just puttering around until I've burned at least 2 full tanks of fresh gas.

Timing chain is apparently not an issue as the motor fires up instantly, is not currently setting any codes, and runs just like it should so far-even on old gas. That's the update! Thanks to those of you who posted to push me in the right direction.