4.7 stroker and engine life

My engine has 135,000miles. There hasnt been any major problems, but I'm not getting the performance I used to. HOw would a 4.7l stroker kit affect the engine life?

Your engine should still have a lot of mileage left in it. With a little TLC, the 4.0 will go well past 200k miles. Your combustion chambers and valves might be gummed up with carbon deposits causing a slight loss of performance. Get a can of Mopar Combustion Chamber Cleaner, spray some of it via each plug hole into the cylinders, and leave for about an hour. Spray the rest down the TB with the engine idling. Once finished, rev the engine up and watch the clouds of gray smoke come billowing from the exhaust.
Also change the plugs, plug wires, cap, rotor, air filter, and fuel filter if they haven't been done recently. Your cat could be plugged up so you could try gutting it.
Finally, a stroker engine should last as long as a 4.0 as long as it's built to the same tolerances and treated with the same respect.

alos along with Dynos ideas some good oil and a can of "restore" amd get the big V8 can of it ehrn you put your new oil in. I've use tthat stuff on a lot of didfrennt cars and it has worked great. I knoe some here would love to flame me for that but go ahead. Also a good fuel treatment to clean out you injectors might help.

I agree that you should have a lot of miles left. My '88 XJ is at 239,000 miles and going strong. I know of others that have gone over 300k.

But to answer your question -- there is no reason a "stroker" should be any less reliable than a stock engine. In essence, it IS a stock engine -- sort of. It's a stock 4.2L crankshaft in a stock 4.0L block. The 4.2L engine has been around since the early 70s -- there must be millions of them on the roads, and they are just as reliable as the 4.0L. I see no reason using the crank from one in the block from the other should result in any less reliability, unless you go to way high compression and a wild cam in search of maximum horsepower.

All other things considered such as proper maint and using high quality oil and air filters the longer stroke motor is technically going to wear the pistons and cylinders slightly faster due to increased piston side thrust and increased piston speed. valvetrain components will last just as long as a 4.0 engine.

This is theoretical...improved materials and manufacturing methods for the pistons and rings could offset this additional wear as compared to older OEM parts.

Injected motors virtually eliminate cold start washout, one major cause of piston/cylinder wear...

Most of the engines I have torn down for examination because of appearant piston/cylinder issues were found to have suffered from poor maint..

REDXJ4FUN said:

alos along with Dynos ideas some good oil and a can of "restore" amd get the big V8 can of it ehrn you put your new oil in. I've use tthat stuff on a lot of didfrennt cars and it has worked great. I knoe some here would love to flame me for that but go ahead. Also a good fuel treatment to clean out you injectors might help.

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I've used "RESTORE" and you can feel the difference! Also, some dealers charge and arm and a leg for a fuel injector cleaning, but a reliable mechanic told me that the $3 fuel injector cleaner works just as good! I've used it and you can also feel the difference. You can buy both for under $10, you may want to try it before doing something more expensive!