To stroke or not to stroke??

[dieselenthusiast]

How do you know that the mopar stroker is actually quality? Do you know anyone that owns one? Do you even know what is inside it? Any one can put a warranty on an engine, it does not make it good quality.

The engine was heavily field tested in Moab, out on the highway, and in other areas of testing. The engine passed the same powertrain testing as all other Mopar remanufactured engines. They used the ATK remanufactured long block. Mopar used, “roller rockers to actuate upsized valves housed in new heads. Hypereutectic pistons, which contain a percentage of silicon to harden the aluminum and prevent scuffing, are supplied by Sealed Power. The new cylinder dimensions are 3.875 by 3.906 inches, because "4.7 is about the limit," Muldoon told us. "Beyond that, you're pushing it." The engine also contains a heavy-duty timing chain and a high-volume oil pump.”
I was giving the OP an alternative option that had not been mentioned yet. This is not a debate over which engine is better built. This is simply an option for those who may prefer to pay a little more for a factory like warranty.

 

[Talyn]

All that money and it doesn't even have forger pistons wow. Thats a deal. The roller rockers are an option btw. And most dealers here have a really good reputation too.

 

[Talyn]

My take on why it wouldn't idle well with 24# injectors is maybe at idle, so little fuel is required that the computer didn't have fine enough grained control of the injector pulse width to avoid running extremely rich. The slower the injectors pass fuel, the grainier your injector pulse control can be without losing precision on the amount of fuel you're actually injecting.

Other thoughts are that the PCM wasn't reset after the injector install, clogged injectors, maybe a weak fuel pump.

On the other hand if you end up running lean when you're really beating on it, you need faster flow injectors because the ECU can't make the injector pulse long enough to inject enough fuel.

As well as the fact that in WOT open loop the PCM is reading off the stock fuel map, which could run it very lean.

 

[xj bmx]

Id go with a pre built but motor but the extra money and the fact id have to save for so long and eating bringing lunch to work and not getting real food with no signs of something happening will drive me nuts and id have to spend it useless stuff. (A.D.H.D) So im going to buy parts each week so i can see it happening. That and im going to start looking for a 8.8 or D44/60 set hehe.

As for the fuel pump/injector deal and with a (wile im at it theory) im still on the stock 230Kmile pump, should i just up it with a beefy external pump?

 

[dieselenthusiast]

Id go with a pre built but motor but the extra money and the fact id have to save for so long and eating bringing lunch to work and not getting real food with no signs of something happening will drive me nuts and id have to spend it useless stuff. (A.D.H.D) So im going to buy parts each week so i can see it happening. That and im going to start looking for a 8.8 or D44/60 set hehe.

LOL, I'm a little ADHD myself, so I know what you mean.

 

[xj bmx]

Soo playing with the motor on the stand today and i can move the rods side to side on the crank, is this normal?

 

[Talyn]

That is normal, but only 0.010 to 0.019 in.

 

[xj bmx]

Today i decided to tear in to the engine so i can get it to the machienest (yess i kept it in order), i found some interesting things.

I think 2 of the Rod to crank (not shure of proper name) berings were to tight and got burnt up what causes this? Do they come in difrent thickneses? or did the get over torqued?

Also piston one looked to be taped in with a hammer, its not deep but will this be an issue if i re-use them?

And just some pictures for fun (makes the tread more interseting)

Before tear down.

Jeep Workbench.

 

[Talyn]

That piston looks like it made contact with a valve at one point. As for the bearing. Something is definitely wrong there. You shouldn't see copper on the bearing surface.

Do you have any other picture of the other bearings? Pictures of the piston skirts?

 

[xj bmx]

I dont think its the valve since its in random spots, i would think if it was a valve it would be in the same spot?

The bearings all look pretty good becides the one in the picture, another has a score down the center but no copper and nother with some copper showing on the side.

Ill get more pictures after work, anything else you would like to see?

 

[87manche]

those bearings are worn, make sure the machinist checks the corresponding rod/crank surface for damage. They do come in different thicknesses, you need to google "plastiguage" and learn how that works for checking bearing tolerances.

Top of the piston, looks like something was bouncing around in there. It make have had a plug broken off or sucked something through the intake at some point. It's probably not that big of a deal, you're not building a racing motor. I'd be more concerned with damage to the mating section of the head/valve seats/valve stems if there was something bouncing around in the chamber.

 

[xj bmx]

Hmm, I'm gonna ask the guy I got it from who the guy that built/owned it it was so I can ask about its history, like I said Im thinking it was a hammer that did that damage due to the consistent shape. But a foren object is a posibility.

As for the head/valves they are getting rebuilt also.

 

[87manche]

yeah, but I'd expect someone that's building an engine to know better than using a framing hammer to install pistons. :dunno:

I have seen similar damage from spark plugs that have come apart and dropped the electrode into the chamber.
Of course none of that may matter, depending on what the machinist tells you about the block you may end up with new pistons anyway.

 

[old_man]

If you are going to stroke the motor, you really have to bore the cylinders and get new pistons and rings. As a engine wears, the rings remove metal from the cylinder walls. When you stroke an engine, the piston ends up moving up and down in the cylinder more than a stock engine. The rings will not take well to running along on a worn section of the cylinder, then having to bump up and run on the non worn section. That is a recipe for busted rings and maximum mahem.

 

[xj bmx]

This is true tho as discussed above, the story is the motor only has 2k miles on the rebuild and most are saying if this is true all i should need is a cross hash and she will be ok, but thats all after the machinest looks at it. But it doesn't have any ridges from ware on wall soo.