4.6 4.7 stroker build too many options?

[97stroker]

. Hello to all.
I have been reading on here for about 3 weeks now as I have not had time to start working on this project. Wife has me remodeling the bathroom from the floor to the ceiling. So I have been taking some notes and trying to figure out how far I want to go with this motor. 4.6 or 4.7? This jeep is not my daily driver but I do want to only build this once and have a good reliable motor that will run dam good on the street and at the dunes.

I’m starting to get parts for my jeep stroker motor. What I have to start with is

current 1997 tj 2 1/2" lift 32" mud kings 4.0 good running engine with about 140,000 on the ticker. 3 speed automatic. With a stock motor.

Now I also have a 1997 4.0 long block setting in the garage that is stock with about 150,000 miles on it the last owner pulled it because of the high miles. Free to me. I also have a 1998 long block setting on the floor that makes a little noise when running. That is what I was told, never heard it run but I do believe the guy just is not that confident in himself. Free to me as well. Now I also just bought a 1999 long block with intake and throttle body for $75. This motor was ran out of oil but still the crank will spin. And last I have a 4.2 crank with a set of 4.2 rods (stock my need machining).

What I am looking at doing is using the 98 block with the 4.2 crank and the 99 intake manifold, having the throttle body punched out to 62 or 63 mills. I will be buying a set of 25# injectors not for sure what brand yet. As for the rods should I go with the 4.0 rods with KB pistons or use the 4.2 with new pistons? I am wanting to bore the block out .030 and deck the block to zero and use a .043 Head gasket. As for the head not for sure what one to use (witch one would be best?) I will be doing a 3 angle valve job on it and I will be trying to do my Owen port and polish job. I would like to use the stock rockers and springs along with a crane 68-232-4 As iam not wanting to rev it to the moon. I will also be getting a mopar double roller timing set.

So I guess my biggest Question is what rods would you use 4.0 or 4.2 and with what pistons?
Thanks

[doc65]

I have one short rod & one long rod stroker, the differences in how they run is very minor & can be completely attributed to the cam in each which is a whole different discussion than the rod length. For me it would came down to numbers, when I was looking for the crank for the second stroker I found it in the form of a complete short block with a crank in it that was polishable to within allowable tolerance for std bearings, that came with the short rods, $100 total. Now I had both a good set of short & long(from the donor block/engine) the machine work & bolts cost the same short or long, so that left the difference as cost of the pistons. I started shopping pistons, and found that to get where I wanted to be, (9.4ish SCR 8ish DCR, 040-050 quench) I was going to have to deck the block and have the piston dish opened up eitherway, so again $'s was a wash, but the 677 pistons I bought were $159ish shipped and the 944's(for the long rod version) would have run about $460 shipped. SO for ME that made the short rod version about $300 less than the same long rod other than the forged vs cash piston discussion and I'm fine with the cast, actually like that they are quieter initially.

[97stroker]

ok so I am thinking I would like to go with the 4.0 rods. Now I am not agaist the higher cost of KB pistons but I would like to spend less money on the pistons and more on the block. Do you feel that any other brand piston would be ok? Yes I will have the pistons dished out for valve clearance. On a different note I have read many good and bad stores about the HV oil pumps what are your thoughts.
Thanks again chad

[BDD]

I built a long rod 944 combo because my original 4.0 had cast pistons,and busted 4 out of 6.this took my daily driver out of service for two months.I realize ther're millions of cast pistons used every day,I've built a lot of motors with them.I just figure the $400 extra is well worth 100,000 miles of piece of mind,knowing i shouldn't bust a piston.I think the old school design of the motor is noisy anyways,and dont think my forged pistons make much more noise then cast,as long as your clearences are correct.

[doc65]

Once warmed up my long rod stroker is still louder than my short rod stroker with cast pistons but not unacceptibly much louder, the clearance is dead center in the middle of what Venolia said it should be, but at this point I can't remember what it was. I do think that if you don't let a motor with forged pistons warm up before working it you will add to the wear on the piston & rings due to piston rock and the top & bottom of the ring will wear more on the thrust side contributing to loss of compression. This can all be alleviated with proper warm up, but try telling that to my 18 year old daughter... As to cast vs forged longevity, the ZJ that got the long rod stroker was because the stock 4.0 had what sounded like a rod knock, but when I tore the engine down I found a broken skirt(cast piston). I was not able to determine why it broke the skirt as I bought it that way(I was told that it was just after an oil change, and I did find the oil to be significantly high, like 2 quarts), BUT it also had 192k on the stock engine. I don't see a broken piston at almost 200k as an indictment of cast pistons, my stock 4.0 in the 98 XJ is at about 190K as well, my last XJ(a 97) was still running strong at 267k when I sold it.

So for me, if I already have a set of short rods I'll go with the cast pistons, if I had to buy the short rods I'd probably go long rod with KB944's have the dished area dropped another .022" that should make the dish 24cc(.022 & 24cc are the safe limit according to KB support) I think that would get to within about $150 of the same.

As to other vendors for pistons there are several , it just that if you look around you can usually find the KB944's in stock on the shelf somewhere, and most of the other options are an order them & wait.

[doc65]

Oh, and I don't think that you are going to beat the KB944 on price by much if at all thru any other brand

[97stroker]

Yes I just dropped of the block (4.0 1997), head(0630) Crank (1990 4.2 , 4 counter weight that had the serpintine belt) rods are from the 97 block 4.0
They will be boring the block out to .030 I also told them to do a 5 angle valve job but first they are going to remove the valves so I can do a little porting to it. I will be buying the pistons this week once we are for sure that I can go .030 over bore. I will be buying kb944 pistons (forged) unless someone tells me that they are not wearth the money. As I was talking to the michince shop im not for sure if I should have them mock up the pistons and rods to find the deck to piston height or just have them cut it done .020 to .024 And at that point i belive i should have them dish the pistons out ( .022 or there abouts) And as for the head I will have them mill it if it needs it. Now for the cam I think I would really like to go one size bigger than stock (lets say) as I still plain on driving it on the roads and use it at the sliver lake sand dunes not a daily driver but i do drive it alot on the weekends. I will be in the need for some bigger injectors if anybody has a set they want to sell. And oh yes i will be sending out the throttle body to someone? to make it a 62mm and iam working on cleaning up the 1999 intake.
Oh and yes I will have them blance the rods and pistons together Is it wearth it ?
Man i am getting exsitted about this build.

Any comments are welcome.

[Cheromaniac]

Looks like this recipe is closest to what you're looking for:

4.6L low-buck stroker
Jeep 4.2L 3.895" stroke crank
Jeep 4.0L 6.125" rods
Keith Black IC944-030 pistons
9.6:1 CR
CompCams #68-231-4 206/214 degree camshaft
Ported HO 1.91"/1.50" cylinder head
Mill block deck 0.020"
Mopar/Victor 0.043" head gasket
0.050" quench height
Ford 24lb/hr injectors with stock 49psi FPR for '96 and later engines
264hp @ 4900rpm, 324lbft @ 3500rpm

[97stroker]

What do you think about trying to get the 9.6:1 CR down to closer around 8.9:1
I dont mind putting in midgrade fuel but i do want to stay away from the premium fuel if I can
thanks

[Cheromaniac]

That recipe should be able to run on midgrade fuel as it is. You could lower the CR a bit more by polishing the combustion chambers.

[97stroker]

I just got off the phone with summit racing and they are showing a 68-232-4 cam for the 4.0 97 block with fuel injection. But i was told that the 68-23-4 cam is really the one i should go with. Now i dont want a high rev cam as i will be driving it on the street and dunes. It will not see high revs over 4500 except once and a blue moon. I have heard the stock cam may also be the way to go also? What do you guys thank.

Also should i spend the extra $100 on a doulble roller timming chain set or go with just the standard double timming set (non roller)?

Thanks alot as i just have to many options!!

[SilverXJ]

68-232-4 and 68-231-4 will both work fine with the Jeep fuel injection. The 231 will give you a bit more top end torque. Its just a blanket statement because Comp can't do their home work.

Get the double roller. I've seen single rollers fail with better than stock valve trains.

[Cheromaniac]

I have heard the stock cam may also be the way to go also?

Only if you want to keep the cost down by reusing the stock valve springs as well. That said, reusing the stock cam with the rest of the stock valvetrain might also eliminate any worries about future aftermarket cam/lifter failure.

[97stroker]

Thanks guys I will be making my order today.. I will be going with the 68-231-4cam And I will be getting the double roller timming set.

[Cheromaniac]

I will be going with the 68-231-4cam.

Good choice. Make sure you get the Mopar Performance 5249464 valve springs with matching retainers and locks to go with it.