dave1123

The only thing eliminating pushrods does is reduce valvetrain weight. This has no bearing on power produced or fuel efficiency that I'm aware of. Overhead cams require complicated drive systems and are prone to timing irregularities, as in stretched chains or worn idlers. Short stroke engine do tend to keep cylinder temps higher for less unburnt fuel being wasted however, but they need to run at higher rpms to get the power output. Think about the internal stresses on a 2.0L V-12 F1 engine running at 12,000 rpm!

GreaseMonkey17

Callsign-Rio

So going along the lines of a new engine, what have you guys heard, if anything, of the ATK remans. from Quadratec? What are some companies well known for good quality engines?

CobraMarty

Junk Yard.

Friar Mountain XJ

This is where I purchased my replacement engine. Best warranty I could find and never needed to use it. I have over 130,000 miles on it so far.

S. Snake

Seems there is a huge debate here about junkyard engines and ATK remanufactured engines. Depending on what your budget and time looks like yeah you could go to the junkyard and grab an engine and hope for the best just like you can pull the engine you have and have it bored .30 or .40 over (if it hasn't been bored over the limits already) and spend all that time and energy and hope there aren't any issues and you reassembled everything correctly (some do, some don't) or you could save your chips and buy the remanufactured longblock with the warranty. Either way gets the car running again. Most people are satisfied with the remanufactured engines from companies like ATK, enough that they are still in business and build performance engines too.

dave1123

I'm toying with the idea of buying a rebuilt engine for my 2000 WJ so I've been looking at different options. I spoke in the phone with 2 different rebuilders asking them if a rebuilt 2000 4.0L still had the 0331 head on it. Both of them told me they would have whatever head was on the core when it came in, but would be fully inspected and reconditioned before it was sold. So, in other words, it could have. Not good enough for me since I already put a Clearwater head on mine. I'll be going with a short block and cleaning up my Clearwater head. I couldn't buy a later model engine to replace my 2000 because you have to give them your block number before you buy so that they know exactly what they'll be getting in return. Sucks!

I also don't understand why you would rebore a 4.0L .030 or .040 oversize if it will clean up at .010 over. You won't gain a whole lot by going that much oversize and you'd be reducing the longevity of the rebuild. Remember the oversized pistons still weigh the same as standard pistons so there's less metal in them, PLUS you'd be thinning the web between cylinders where the gaskets usually blow out. I'm trying to use logic here, but I know you guys don't care much for logic. LOL!

Callsign-Rio

I'm good with logical XD