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4.6 stroker in a Full Size Jeep

Posted: December 3rd, 2011, 7:45 am
by Zorm
Ok, starting this build, was thinking about upping to a V-8 because I have a 83 cherokee (last of the big ones) Have the 258 engine in her and picked up a 91 4.0. I have the 4.0 head on the 258 along with the HEI dizzy and the 2100 2 bbl carb.

Was going to put FI on the modified 258, then thought about the stroker. I have asked a few questions with a few threads but now, well, yesterday, I took both engines apart. What I want/need is a stroker that can run on either the regular pump gas, not really the top octane. This cherokee will be a weekend / some trail driver.

So I will be taking the 4.0 head and block to the shop for a tree angle valve job and cleaning. Also the block needs to be cleaned up(water areas) the cylinders look real good so I really don't know if I should get the block bored.

My thought is, 4.0, 258 crank, not sure if I want to use the 258 rods or the 4.0 rods. Really don't plan on boring the block unless I need to so maybe new stock size pistons (need to find some that aren't priced through the roof ) I did see a post someplace about a stock 96 cam is better than a stock 91-94 cam? so maybe a 96 cam. Also looking at getting the gasket set with the .47 head gasket, saw that in a post someplace also. In the end I will be putting a 2000 intake with the bored out throttle body. and mating this all this up to my T176, unless I can find another newer tranny cheep.

thoughts welcome

Re: taking the plunge, poor man's?

Posted: December 3rd, 2011, 10:14 am
by Cheromaniac
You already have most of the parts you need to build a modified "poor man's" stroker:

4.6L modified "poor man's" stroker

Jeep 4.2L 3.895" stroke crank
Jeep 4.2L 6.125" rods
Keith Black IC944 +0.020" bore pistons
9.25:1 CR
Stock 4.0 camshaft
Ported HO 1.91"/1.50" cylinder head
Mopar/Victor 0.043" head gasket
0.070" quench height
Ford 24lb/hr injectors with stock 39psi FPR for '87-'95 engines

I advise you to bore out your '91 block but just the minimum required to make the cylinders round and true. You could either use your 4.0 rods with a Keith Black IC944 piston/ring set (modified poor man's) or use your 4.2 rods with cheaper 677P pistons (traditional poor man's). You could also reuse your '91 camshaft to save on cost. The only other parts you'll need to complete the rebuild are new main/rod/cam bearings, oil pump, timing set, lifters, upper/lower gasket sets, and 24lb injectors.

Re: taking the plunge, poor man's?

Posted: December 3rd, 2011, 11:28 am
by MoFo
Will this thing run on 87 octane pump gas at sea level, with the 9.25:1 SCR, Stock 4.0 camshaft and 0.070" quench height?

Re: taking the plunge, poor man's?

Posted: December 3rd, 2011, 12:58 pm
by Zorm
thanks Cheromaniac, I will more then likly go the non Keith Black pistions, those are like $4350.00 for the set, not really looking to spend that much. I agree with MoFo, I am at sea level. This Jeep may go on trips at high elevations but nothing like the Rockies. Will that combo ping?

Re: taking the plunge, poor man's?

Posted: December 3rd, 2011, 3:50 pm
by SilverXJ
Zorm wrote:thanks Cheromaniac, I will more then likly go the non Keith Black pistions, those are like $4350.00 for the set,
I hope you have and extra 0 on there.

Re: taking the plunge, poor man's?

Posted: December 3rd, 2011, 6:51 pm
by Zorm
umm yea, too many 0's

Re: taking the plunge, poor man's?

Posted: December 4th, 2011, 2:18 am
by Cheromaniac
Zorm wrote:thanks Cheromaniac, I will more then likly go the non Keith Black pistions, those are like $4350.00 for the set, not really looking to spend that much. I agree with MoFo, I am at sea level. This Jeep may go on trips at high elevations but nothing like the Rockies. Will that combo ping?
Summit Racing have the IC944 pistons for $416 per set of six and the Z677P pistons for $198. Unfortunately they only have the stock bore versions of the 677P (and 677CP) pistons in stock.

http://www.summitracing.com/search/?keyword=ic944&dds=1
http://www.summitracing.com/parts/SLP-677P/

My "poor man's" combo will run on 87 octane without pinging as long as it's less than 90*F outside and it's only under light load. Otherwise I run it on midgrade fuel (91 octane over here) and it's fine even when it's 120*F outside.

Re: taking the plunge, poor man's?

Posted: December 13th, 2011, 7:07 pm
by Zorm
OK with my choice of the poor man's, would a stock cam or for that matter, a valve train from a 2001 4.0 pep it up or hinder the engine?

another question, what carb is anyone running with their stroker and how did you mount it?

Re: taking the plunge, poor man's?

Posted: December 14th, 2011, 8:00 am
by Cheromaniac
Since you're using a '91 block, you can use a stock '91-'98 cam. A stock cam from '99+ won't bolt into the block.

Re: taking the plunge, poor man's?

Posted: January 1st, 2012, 7:08 am
by Zorm
Ok, got the Sep rod bolts, cam bearings, and freeze plug kit from Summit last week. Should be taking the crank out of the 258 today. Maybe send everything to the machine shop this week. Need to swap the jeep over to hydroboost before the new engine goes in

Re: taking the plunge, poor man's?

Posted: January 11th, 2012, 8:44 am
by Zorm
OK, everything is ready to take to the machine shop. Found out I have the 707 casting 4.2 piston rods and the 544 cast 4.0 piston rods, both I have read are stong, still plan o using the 4.2 piston rods. What about the push rods or will that matter? both 4.0 and 4.2 look the same.

Plan on reusing the 4.0 lifters since I did not see any real wear on them, how should I clean them. I saw my father one time take the hydro lifters for a ford 360 engine, put them in a can of oil and compress them a few times to fill them, is that a good idea to do again?

for my injectors, is there something better than or newer then the ford #24 injectors? just a thought.

Re: taking the plunge, poor man's?

Posted: January 11th, 2012, 8:50 am
by Cheromaniac
Zorm wrote:OK, everything is ready to take to the machine shop. Found out I have the 707 casting 4.2 piston rods and the 544 cast 4.0 piston rods, both I have read are stong, still plan o using the 4.2 piston rods. What about the push rods or will that matter? both 4.0 and 4.2 look the same.

Use the 4.0 pushrods.

Plan on reusing the 4.0 lifters since I did not see any real wear on them

Not a good idea unless you place them in the same lifter bores that they came from AND if you're reusing the old cam. Otherwise get new lifters.

for my injectors, is there something better than or newer then the ford #24 injectors?

Those injectors are probably the best choice if you're using OBD 1 engine management.
:mrgreen:

Re: taking the plunge, poor man's?

Posted: January 11th, 2012, 9:25 am
by Retlaw01XJ
Zorm wrote: Plan on reusing the 4.0 lifters since I did not see any real wear on them, how should I clean them.
Right, make sure they go back on the same lobe.
To clean them, take the clip out and disassemble. Clean with solvent, and lightly oil for reassembly. No need to fill them or pump them up with oil, that will happen when engine starts up.

Re: taking the plunge, poor man's?

Posted: January 11th, 2012, 9:54 am
by Muad'Dib
Why not just replace them for cheap insurance? You can put new lifters on a used cam.. as long as you do a normal cam break in.

Re: taking the plunge, poor man's?

Posted: January 11th, 2012, 4:48 pm
by SilverXJ
Its not worth it to try to reuse the lifters. If high mileage you may have wear and not even see it. The foot of the lifter is convex. Put the lifter on a straight edge and look for light at sides of the lifter or at the center. If you see light at the center, or none throw the lifters away. If light is at the sides there is still some life in them.

However, you should a) never use old lifters on a new or different used cam, b) never mix up the bores up where the lifters cam from, c) never use them in a different engine block. Basically to reuse them: same block, same cam, same spot.