First time engine build and stoaked!

[crusher242]

Any particular reason. I'm sure there have been failures of the single type where a double roller would have been better, but is it actually justifible?

[SilverXJ]

There have been failures of the single roller type on strokers. That alone should be enough reason not to go with one. Other than that doubles are stronger, less prone to stretch, etc. Also, the doubles are usually made with a better chain. I don't know if the single ones are even rollers.

[604rail_king]

i just came across stoker thread (here or naxja?) where a single roller was used and stripped many of the teeth off in a short time. must be all the tq! that was enough evidence for me to go with a double roller in my up coming build

[crusher242]

Looks like I'm going double when the time comes.

[IH 392]

My dad blew three of the single row chains in his race engines, he went back to the link type, those do ok, he's to cheap to run a double row chain.

[crusher242]

Well, I bought a ol' early 4.0 H.O. motor. Actually traded some parts for it. So I began playing with the stroker calculator. Let me know what you think.

94' Block and head
Port and polish
4.2 crank and rods (yj flavor)
2229c at .030 over dished to 30cc
0.043 mopar/vitor gasket
stock deck height (if possible)
62 mm TB
99 Intake

I'm looking at 3 differnt cams.
Late 90's stock 253/114/4
Comp 68-231-4
Comp 68-115-4

Compression is going to be around 8.56. Am I too low? Any opinions.

[crusher242]

Anyone? Kinda curious if this is exceptable.

[SilverXJ]

Looks good. What is your SCR and DCR? Also, your quench may be a tad high.

[titan]

94' Block and head
Port and polish
4.2 crank and rods (yj flavor)
2229c at .030 over dished to 30cc
0.043 mopar/vitor gasket
stock deck height (if possible)
62 mm TB
99 Intake
I'm looking at 3 differnt cams.
Late 90's stock 253/114/4
Comp 68-231-4
Comp 68-115-4

Why a late 90s stock cam? Personally it's one of the ones I'm looking at since I want to keep things mild, but if you've got a car to drive why not get something bigger to suck more fuel down and get more power? Check out how the 68-232-4 compares to the stock 99 cam http://www.jpmagazine.com/techarticles/ ... to_16.html. It added 12hp/18lb-ft! Why leave that power on the table? I don't think you want the 115 either, it'll probably push peak power down from the stock cam to give you more torque down really low. It looks like of your choices the 231 is best for you, provided it gives you the right Dynamic Compression Ratio (the only compression ratio that matters).

It looks like you got the (almost meaningless) Static Compression Ratio of 8.56 from http://www.jeepstrokers.com/calculator/ ? I don't directly trust that calculator. It has details like the Piston Ring Height, but not Piston Compression Height and it doesn't factor in rod length into the SCR!

Depending on if you build an engine with 4.2 (5.875") or 4.0 (6.123") rods the piston will sit an extra 0.248" higher in the cylinder at TDC! That is going to have a HUGE effect on the static compression ratio. Imagine a theoretical combustion chamber being perfectly piston shaped so the piston could completely fill it. If the 4.2 rods left you with 0.25" height for the combustion chamber and you switched to the longer 4.0 rods you'd have just 0.002" left! That's going from 15.58:1 to 1947.5:1 SCR!!

[crusher242]

Here's what I'm looking at:

Stock cam: 8.56 SCR 7.11 DCR 0.0645 quench through out.
231 cam: 8.56 7.51
115 cam: 8.56 7.81

I'm leaning toward a stock cam as I've been reading about Comp cams having some sort of issue in combination with the cam bearings. Don't know If I'm being parinoid again.

I'm also a bit confused on injectore sizes. I know I'm gonna need 24 lb injectors. Dino's site mentions that I need accel, not the Ford injectors. After checking Ebay, those injectors get kinda pricey for being used, but the Ford injectors are dirt cheap. On top of that, I live near a u pull it and I can get those ford injectors for next to nothing. Will I be ok with the ford injectors, or am I asking for trouble?

[Retlaw01XJ]

Check out how the 68-232-4 compares to the stock 99 cam http://www.jpmagazine.com/techarticles/ ... to_16.html. It added 12hp/18lb-ft!

It looks like you got the (almost meaningless) Static Compression Ratio of 8.56 from http://www.jeepstrokers.com/calculator/ ? I don't directly trust that calculator. It has details like the Piston Ring Height, but not Piston Compression Height and it doesn't factor in rod length into the SCR!

1) The jp magazine test used an 1989 cam, which is much different than the later '96-up cam. I bet the later cam would outperform the '89 cam due to the closer lobe centers and earlier closing intake....which should boost low-end power.
Don't get me wrong, I like performance cams, but by the time you buy the correct springs and retainers, you're looking at almost a $500 investment!
Was there ever a published test of the early vs late cam?

2) The calculator uses 'deck clearance' instead of rod length and piston compression height. Deck clearance spec is the one that counts.... but you'll have to do a trial assembly to see what it really is.

[crusher242]

Anyone have any idea's for the injectors? I'm not finding the info that I need. I heard about useing 5.9l injectors. Will that work with a late 98' (actual production year, not model year) TJ setup?

[Missourian]

You might check here.

[crusher242]

Thanks for the link Missourian. But it reads like VCR instructions. I see from what info I gathered that I have a 49psi system and I will be requireing a touch over 24lbhr injectors. I'm still not sure what I'm looking at. The way I look at it (which is probably completely backwards) I could still run ford 24 lb injectors or any other injectors because my fuel system produces more psi and therefore the injectors would be at their own maximum potential.

[crusher242]

Well, I think I found a few sources for injectors from guys on here who were working on 97' and newer wranglers. So thanks to all of you TJ guys on here. Here's a good general question. If I deck my block, I'm going to need new push rods right? I've been playing with the calculator and my quench height keeps coming up around .065 or so without decking it. I'd like to get it down a bit, so it loooks like it'll need to get decked.