Ahh good point... Forgot about that. Great idea on the crank rotation. Ill have to give that a try tomorrow as I can't keep driving the truck as I am only getting roughly 200 miles to a tank.

 

How many gallon tank?

 

It is a 16gal tank.

 

one would expect a new chain would rotate the rotor almost instantly, and any real rotation is due to chain stretch? What are the measurements of rotation that would indicate a chain stretch beyond a good performance spec?
ive never learned much on non-efi engines, and a lot of auto carburetor tech has been forgotten. If spark is controlled by crank sensors and fuel via Cam position a chain stretch would essentially delay fuel injection timing no?
ive been trying to understand how performance is effected by chain stretch, as with a efi based engine, the ECU would compensate for chain stretch if I'm assuming right? Effectively making timing chain replacement a mere preventative maintenance issue.
I was talking with a long time mechanic buddy who scoffed at the notion of timing chain seriously effecting performance as I was skeptical myself. Yet he told me to check the timing, which would suggest he's not that familiar with these engines or it's been quite awhile for him.
Now learning the mechanism for spark and fuel timing I can understand how performance could seriously be effected by chain stretch. I guess I'm gonna get to know this Dodge even more in the near future. lol

 

Its the same effect you get on a carbed motor. Retarding the cam will move the power band up the RPM range. (costing you low end power, which is what you really want in a truck.) And since the intake isn't really designed for high rpm operation..... retarding the cam (via chain stretch) cost you power across the board. (by effectively lowering dynamic compression ratio.)

There is also the additional factor of injector timing. The PCM uses the cam sensor to determine when, and which, injector to fire. Given that the injector events are still synced with valve events, I can't really say just how much of an issue that really is.

The PCM can't compensate for chain stretch, as it has no way of measuring it.

Also consider, most of the 'adjustable' timing gears give you plus or minus 4 degrees. Starting going beyond that, and any benefits you get from whichever direction you go, start falling off, rapidly. (although, I don't consider moving the power band UP, on a truck motor, a 'benefit'......)

On my 96, I ended up doing my timing chain and gears, as the ONLY change to my motor, due to a timing cover coolant leak. I figured while I am in there, might just as well change it out, on my 170K+ motor...... I was absolutely amazed at the difference in how the engine ran before/after. It was THE single best improvement I made to the truck.

Every manufacturer has their own spec for chain stretch. On the dodges though, fuel sync (relationship between cam, and crank sensor signals) is plus or minus 7 degrees. Go to far on either side of "0", and things start acting odd. So, I would 'suppose' that if you are getting more than about 10 degrees of slop in the chain, it is going to start effecting performance.

 

Ya I realized the flaw in my thinking was the vavles. So the effect is as basic as the crank and cam being out sync and the timing off. Yet with no way to adjust the timing. Yet even if you could retard the spark, your still out of sync with the crank and pistons.
I read somewhere dodge used nylon gears and a single roller chain on gen 2 318's. Not sure if that's true, but could explain a lot.
When I read that your chain and gear job made the biggest difference I was pretty intrigued. I strongly suspect the same would be true with the ram I just got. It feels like the truck's been castrated, mainly when it's pulling a trailer. Lower RPMs especially. That and it sucks the gas towing.
Part of the problem for this truck is gears, yet it's got a power issue I'm almost positive. Ideally a 3/4 ton or another truck with lower gears would be the way to go. But I might just slap a chain and gears on it just for educational purposes. lol
thanks Hey you.

 

My 3/4 ton with 3.55 gears, and 265's wasn't real happy about hauling my dump trailer either. Of course, at that point, it was over 200K miles, and I think the engine was just tired. It ran good, and drove fine when unloaded, but, just didn't have the getupandgo I thought that it should. So, I replaced it with a two year newer truck, with about half the miles, and an 8 liter V-10.... WOW. THAT was a big difference in power. Granted, you take a hit on gas mileage..... but, given my driving duties, it really doesn't matter all that much for me. Not like I commute 30 miles one way to work every day. Even when I DO work, it's less than 8 miles in.

So far as I know, the stock chain/gears are all metal. (mine were) It's a morse style chain though, no rollers at all, and they were notoriously prone to stretching.

 

A 3/4 ton with a 3.55 rear? Sheesh. My 1999 3/4 Chevy with a 6.0 and 3.72 rear pulls like a dream with 180k miles. Sorry for the Chev love, lol. I love passing newer 1/2 tons pulling trailers up big mountian hills. Yet they pass me while I'm getting another $100 in gas, lol.

 

LOL.

Yep. Familiar with that.