will this setup work?

[GoMopar440]

Not really. This is a relatively small website, but it's pretty focused on what we talk about here. The good part of that is that topics get a lot of knowledgable advice. The bad is that the sometimes questions get answered slower than you would like. The pros (the "been there done that" guys) do have lives of their own to live. Just hang in there and be patient, they will get around to answering.

FWIW: I wouldn't call my self a pro yet since I'm still just collecting parts at this point, but from what I can see, yes, that sounds like a good start.

[Cheromaniac]

ok ok I think I got it now.

4.0 push AND connect rods (oreillys)
4.2 crank (on hand)
kb944 pistons .030 over
http://www.summitracing.com/parts/UEM-IC944-030/

and molly rings.
http://www.ebay.com/itm/ws/eBayISAPI.dl ... 0846167064

Instead of getting the pistons and rings separately, you can get them as a kit:

http://www.summitracing.com/parts/UEM-IC944KTM-030/

As someone suggested earlier, try to get as many parts as possible from the same vendor to minimize handling charges and shipping costs.

[Muad'Dib]

mine is a 90 renix, therefore i need an intank FPR $150

Are you saying that you think you need a FPR that goes into the fuel tank? If so this is not accurate. The FPR on 87-90 (RENIX) and 91-96( or 99?) is on the fuel rail which sits on top of the Intake Manifold.

[GoMopar440]

I know on my 97 XJ the FPR is on the pump pickup assembly in the tank. Not sure about the other years...

Just checked Hesco's website and found three types of FPRs
87-90 http://www.hesco.us/shop.asp?action=det ... 021&catId=
91-95 http://www.hesco.us/shop.asp?action=det ... 022&catId=
96+up http://www.hesco.us/shop.asp?action=det ... 029&catId=

The first two for Renix and OBD I types are adjustable, the last one for 96+ OBD II, appears to be a factory type replacement.

[ftpiercecracker1]

mine is a 90 renix, therefore i need an intank FPR $150

Are you saying that you think you need a FPR that goes into the fuel tank? If so this is not accurate. The FPR on 87-90 (RENIX) and 91-96( or 99?) is on the fuel rail which sits on top of the Intake Manifold.

http://www.strokedjeep.com/regulator.html
This is the website where i read about the in-tank FPR. Believe me I hope hes is wrong and you are right. the last thing i want to do is to have to drop the fuel tank.

[ftpiercecracker1]

Also, here is a cam i was recommended based on my current setup.
Comp Cams
High Energy™, 260H
Great for Towing, 4WD & Off-Road, Smooth Idle
68-201-4

[GoMopar440]

That website says the same as Hesco's. 87-90 (Renix) and 91-95 (OBD I). I didn't see where they mentioned anything about in tank FPRs though.

The link is not working for me in the above post, but it looks like you're referring to the Comp Cams #68-201-4 right?
I'll let the others that know more about the aftermarket cams cover that one. I'm thinking of just sticking with a new Melling OEM replacement (96-99) in my build.

[ftpiercecracker1]

That website says the same as Hesco's. 87-90 (Renix) and 91-95 (OBD I). I didn't see where they mentioned anything about in tank FPRs though.

"We '91-'95 and Renix guys have a nice advantage over the later model Jeeps, the fuel pressure regulator is mounted up front on the fuel rail instead of in the tank."

Taken straight from the page the link takes you to.

[GoMopar440]

"We '91-'95 and Renix guys have a nice advantage over the later model Jeeps, the fuel pressure regulator is mounted up front on the fuel rail instead of in the tank."

Taken straight from the page the link takes you to.

The "later model Jeeps" comment in the quote above is referring to the 96+ ones that have the FPR in the tank.That website dosen't offer anything for the 96+ so that's what I was referring to.

Your Jeep is a 90, but are you using the original fuel system, computer and wiring?

[ftpiercecracker1]

Oh, I see. . . once again I am a moron. I confused later with earlier.
You may now kick me in the a**

and yes to the original setup.

[ftpiercecracker1]

Alright, i've been doing some more reading and even though i have the better 707 cast 4.2 rods, i read on Dino's stroker pg that it would be better to go with the 4.0 rods? Would someone please explain to me why that would be, i thought the point of a stroker was to make the stroke length longer? it says right on his pg that the 4.2 rods are .25 shorter than the 4.0. soo what gives? does it really make that big of a diference?

thanks for all the help.

[GoMopar440]

The 4.2 crank stroke is longer than the 4.0 crank stroke. That's where you get the "Stroker" part from.

The benefit of the 4.0 rods is the longer rods are supposed to be more efficent than the 4.2 rods. It has something to do with the longer 4.0 rods having better angles as the whole rotating assembly spins. The FAQ has a pretty decent write up on it and can explain it way better than I can. That said, there doesn't appear to be enough of a difference to say the 4.2 rods are a bad choice.

Essentially it boils down to the piston pin height requirements of the different rods. The 4.2 rods can get away with using either stock 4.0 or relatively cheap aftermarket cast pistons. To use the 4.0 rods you have to get either KB Icon pistons or some other custom forged pistons with a higher wrist pin hole in the piston to keep them from sticking out above the top of the block deck. There are lots of factors that dictate which rods and pistons are best for your build like what do you want to use it for, will it ever see boost or NOS, how quiet you want the engine to be, etc. However, it seems like a lot of the time the biggest deciding factor of which rods most people use with their builds is usually the cost of the pistons.

[ftpiercecracker1]

Well sh*t on a stick then. when i was doing the tear down of my 4.0 i scraped my rods, thinking i was going to use the 4.2. I plan to get the KB pistons so where can i find the 4.0 rods, again. Scrap yard?

"will it ever see boost or NOS, how quiet you want the engine to be"

I would love to put a turbo on it or nitrous for that matter, but i highly doubt it will happen in the near future. And as for the engine sound, i dont really care how loud it is, so long as it does not effect the engines performace or longevity.

[GoMopar440]

"How Loud" is in reference to the piston slap you would hear when the engine is cold if using a forged piston. The forged pistons heat up and expand and the noise usually goes away. Cast pistons expand less than forged so they are generally quieter.

To put it into perspective, (don't quote me on this because I'm trying to go off memory here) the cast pistons require about .002-.0025 clearance, forged pistons may take about .003-.004 clearance. This varies by each piston type so just follow the manufacturers specs for the piston you'll be using and you'll be fine.

Now how much clearance did your bores have again? Yea, looks like new pistons either way you go.

Have you asked the machine shop if they have any 4.0 rods? They can usually get parts like that pretty reasonably. Why not just run your 4.2 rods with a set of nice new coated skirt cast pistons ($150/set) and do the stroker since you'll have to replace the pistons anyway?

The down side is the bores will probably need machined out to fit, but it looks like that's going to be the case even if you want to keep it a stock 4.0 so...

EDIT: I Googled a few engine machine shops and it looks like boring averages about $20-30 per hole, so maybe figure $120-$180 for boring/honing to fit the new pistons. If you go with the 4.2 rods and cast pistons you would come out way cheaper than buying more 4.0 rods, forged pistons and then still having to get the cylinders machined as well.

[ftpiercecracker1]

i've always said great minds think, here is what i figure.

Since i've thrown away my 4.0 rods and have the stronger 707 4.2 rods, I will just go with the cheaper cast pistons (http://www.summitracing.com/parts/SLP-677CP30/), use the 4.2 rods and save my self the 500 dollars.

(sigh) and I was so looking forward to taking a mortage out on my house(sarcastic)

so basically exactly what you just said.