Jeep Strokers

Hey Ya'll.

I thought I'd go ahead and outline my engine build now that it's coming together. It's going in a 3500 lb XJ. Deavers front and rear, 12" travel front/rear. 33" Toyo MT's and 5.13 gears. 9" rear, HP 44 front. Detroit locker rear/true trac front.

So far I have the bottom end assembled.

I'm using a Russ Pottenger kit stuffed into a 1999 Cherokee block I was able to find locally for free as my "core".

-Ported Edelbrock head with larger valves. Flow #'s here - https://docs.google.com/spreadsheets/d/ ... F_ung/edit
-LS valves 1.97/1.55
-valve springs - comp cam 26125 installed height of 1.610 using +.050 locks from PAC racing springs
-10.8:1 Compression ratio (17 cc dish piston .010" above deck, 55CC chamber, .043" gasket)
-Custom Lunati Solid flat tappet - 233/241 @ .050 and lift coming in at .530 int/.554 exh (114 LSA) Nitrided
-adjustable roller rocker arms
-Forged pistons, badass SCAT rods (from Russ), SCAT crank
-Doug thorley header "ported" by me to better match up to the exhaust ports, open 3" outlet (about 12" of 3" pipe extending off of it). I wrapped it to keep some heat out of the intake manifold
-Newer model intake manifold also ported by Russ
-F&B 70MM throttle body
-Firepower ignition kit, NGK V-power spark plugs a step colder
-26 lb injectors
-RPM range 2000-6000
-Might use these guys to change the stall of my converter - http://www.importperformancetrans.com/c ... -5432.html
-I will first see if the stock converter will work with the 5.13/33" combo and the aggressive camshaft
-My AW4 has a transgo shift kit installed

My goal this whole time has been 350 HP. I was striving for a 10:1 power to weight ratio. Should have a brilliant TQ curve.

You guys think the intake manifold and a 70MM throttle body can support 350 HP?

350hp n/a? I think that will be real tough to reach. I'm watching this thread and hoping I'm wrong though!

SkylinesSuck wrote:350hp n/a? I think that will be real tough to reach. I'm watching this thread and hoping I'm wrong though!

I feel the same way. I looked at blowers and hair dryers but didn't want to spend the money or deal with the tuning. Also this plan is the lightest and I am bending over backwards to keep weight down. Including replacing the lead battery with 3 motorcycle lithium batteries with a combined weight of 9 lbs!

Forgot to add some other measures for less parasitic loss in my first post.

-Hesco HV water pump - this was really just for the obvious advantages, but they also advertise an "unexpected" 2% dyno gain or something due to the more efficient impeller
-No A/C
-Taurus electric cooling fan

My engine should weigh about 40 lbs less than the original 4.0L. Between battery, engine and A/C that might be as much as 90 lbs taken off the front end.

You will certainly still need tuning to get anywhere close to 300hp let alone 350, n/a or not. What year XJ is this? Engine management is why I ask.

It's a '97 XJ.

I'll use an adjustable MAP to get me running. Then I'll go through http://www.frptuning.com/ (flying Ryan) for more tuning

What about running a megasquirt style stand alone system? Would this make it easier to make more power?? Or should I be able to get where I need to be with Flyin' Ryan?

I don't think Megasquirt or any other ECU is going to get you any more power than a tuned factory PCM is going to get you, especially considering Ryan's experience. An N/A stroker just isn't going to make that kind of power, period. Low 300's maybe. A bit more with something radical revving higher maybe. If you need that much, it's either going to be forced induction or a different motor I think.

Please try to prove me wrong though. Seriously, I hope you can.

Okay so what is it you think limits the HP potential? RPM? Or the amount of airflow the intake manifold and TB can provide at that RPM?

These guys at Newcomer racing seem to be making serious power. Plenty of videos of their builds. http://www.newcomerracing.com/jeep-products.html

https://www.youtube.com/watch?v=jhQYB623Bto&t=30s

https://www.youtube.com/watch?v=UCb_PD8pVJA

I emailed them asking how they spin their engines to 6500 RPM and his response was very simple. "Good valve train, pushrods and springs"

I was looking for an upgraded harmonic balancer, but it appears in their videos they use a stock HB.

Just looked closer, this must be the intake manifold they're using in that video. http://www.shop.cliffordperformance.net ... 4520WH.htm

Did you build that engine?
Do you have a dyno result?

No it's in progress. Hoping to finish it this month. Cam just arrived yesterday. Getting some more parts needed to make the swap from hydraulic to solid from Russ. Those are arriving tomorrow.

I got a little crazy and cut my "newer" style intake manifold apart, ported and knife edged (rounded, not actually knife edged) runners. It's being welded back together tonight. Got the TB opening hogged out to 70MM.

Anyone think it would be that crazy to run a carb instead of FI. I'm somewhat remote in Kodiak, AK and I just think tuning would go a littler easier with carb. I have to rely on one of two companies to help me tune it remotely. But I have 2 friends with plenty of experience with high performance carb engines.

If you were going to go that route I would do a self tuning bolt of EFI throttle body like Fitech, Sniper, etc. I think your best option is to have Ryan tune the factory ECU though.

My best result is 232 HP at rear wheel.
2006 Tj Rubicon
33" tires
E-Locker
4" Lift
Nsg370

If some one have dyno result, please upload and share...

jpg

That's probably approaching 300 HP to the crank right?

What are your engine specs?