Stroker list

onetallmj

NAXJA Forum User
OK, my old 4.0L is going down hill fast, everything I have tried to " cure " my blowby has failed so my stroker project is getting moved up.

I plan to use this engine for 70% - 80% street( top cruise speed of 70mph) and the rest rockcrawling/offroad.

I have 33" tires and 4.88 gears and plan on going to 35" tires eventuallly, with a stock AW-4 tranny.

this is what I have so far:
258 , bearings, connecting rods, 24# injectors, and new timing chain.
I also have a boneyard 4.0L with everything on it except the starter.

#1 question - I would like to reuse as much as I can from the boneyard engine with the exception of a new camshaft - How can I tell if the valves, springs and lifters can be reused?, Same for the oil pump? I never heard the engine run so....?
I plant on stripping it down and taking to the machine shop soon, maybe they can give me a good idea on whats reusable?
#2 question: the boneyard engine has a clutch on it, do I need to use my flywheel(auto) instead of the manual one? or is there no difference in flywheels from auto and manual?

Any recomendations on camshafts?

thanks for the long post

Wade
 
Here's a start - I'll have to review my cam notes before I can say anything on that...

NEVER NEVER NEVER install used lifters on a new camshaft! Over time, the lifter feet wear in to match the wear of a cam lobe. Install them on another camshaft, and you mjust made a scrap iron stick (it's only a matter of time...) In fact, if you pull the lifters to put on a new cam, they have to go back in the same order. I've had to throw away sets of perfectly good lifters because someone mixed them up when I wasn't looking. Call it "cheap insurance."

Ditto the oil pump - you don't know what shape it's in, and you've got the engine torn to bits anyhow. Replace it - a new oil pump now is cheaper than a replacement for it and whatever gets taken out later...

A flywheel is used to provide intertial mass for a manual transmission, the automatic uses the fluid-filled torque converter. You'll need your flexplate (the AT version) which should switch right over. Suggest you use new bolts - ARP has a kit for Pontiac which will work (I don't recall the P/N, but it's a kit of six threaded 1/2-20.x.500")

Since you don't know the running history of the engine, you will want to have the rods Magnafluxed (or at least dye-checked) for cracks before you install the pistons to them. That's the problem with junkyard kits...

Valves should be checked for straightness, springs checked for proper tension. I can look up those values, I'll have them for you to-morrow (I'm getting ready to go out for my wife's company Christmas knees-up...) If you're careful, the springs can be checked reasonably well on a bathroom scale. Pushrods should also be checked for straightness - I roll them gently on a flat piece of glass and look for any oddity. A known flat metal plate will also work, but glass has always been more reliable to me.

Given your intended use and your tyres and axles, you'll want a cam with a low "native" rpm range - Crane 750501 likes 1600-2200 cruise, with 1000-4000 torque band, and Isky 1331-M seems to live around 1000-3800 fairly well just looking at Cam Cards. If you're not in a hurry, I can go thru my cam notes that I've got mfor my book and give you more ideas (I've got 67 listed...)

I'll be happy to help you more when I have some more time (like to-morrow - I'm "designated drinker" to-night, and I do my job well...)

Still have that M35, or did you manage to unload it? I sent you a PM, but you never got back to me and I'd like to make sure. I'm still interested, if we can come to an arrangement.

Oh - I'll also have a first edition of my Jeep I6 Performance book out soon (self-printed and published) - I'm polishing and finishing chapters right now...

5-90
 
Thanks for the info.

My rods are new so they should be good.
I cruise now at about 2900-3000 rpm down the highway, I would like to get a cam that has some power in that band and a little after it( up to 4,000rpm) but good torque down low for crawling.

Ok so new lifters and oil pump, and check the valves and springs.

what about pistons? I would like to run 87 octane - so a low CR is nice.

the M35 is gone, sorry, sold it about 2 months ago to a farmer down here.

Wade
 
Lots of people on here have done strokers and there is a lot of tech on the site. A search on strokers should yield you a ton. Yahoo has a stroker list as well.
 
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