Newbies poorest man's stroker

[Russ Pottenger]

Talk to [email protected] about having your OBD II ECU remapped.

I work with Chris on my customers projects and also recommend him.
When he gets busy he may be a little slow getting back to you, but is a great guy to work with.

[TJW319]

Are all stock 4.0 rocker arms the same? Both Fitment and lift?

[Cheromaniac]

Are all stock 4.0 rocker arms the same? Both Fitment and lift?

Yes.

[TJW319]

Does the quench have an effect on spark plug selection?
I.E.: a tighter quench use a colder plug?

[TJW319]

Bump ...---...

[Russ Pottenger]

You're not going to change the heat range of a spark plug based off of quench.

[TJW319]

Dose it seem likely that I could run a set up like this on pump gas (92 octane)
SCR 10.03:1
DCR 8.17:1
DCR @ alt 7.93:1
Quench of .043

[TJW319]

Well I think I have the " recipe " finished and looking for your input.
I'll be building a short rod stroker
The heart and soul will be the 1978 12 weight 258 crank
1978 258 rods
1992 4.0 block.060 over decked with a -.008 deck height
1992 4.0 head surfaced with a light porting and a polished 62cc combustion chamber
677ap Pistons with a 20cc dish
Victor Reinz MLS head gasket
MC-809 cam
Comp cam timing chain advanced 4deg
Stock 4.0 rockers
2002 4.0 intake
Ford blue top 24# injectors
60mm T/B all the way through
Chris tuned ECU
Chinese eBay header
2-1/2" exhaust with FM and cat delete

I've probably forgot something but that's basically it.
I'd like to thank everyone for their input, if I didn't take your advice it was probably because I couldn't afford it right know.
Extra special thanks to Russ, you are The man and your knowledge is amazing and very much appreciated!!!
I've had a great time learning and trying to figure out how to put this all together. I'm a couple weeks away from getting everything back from the machinist so I can start assembly.
If anyone has input on my build I'd love to hear it!!

[jsawduste]

Not sure you want to advance the cam 4 degrees. Curious why you would want to do that.

60mm TB ? Do you mean a 62/62mm ?

[TJW319]

I think the mc809 has 2deg built in and I was thinking that adding 4 more to lower the torque range would be a good thing as in my normal DDing I'm rarely over 3500 and off-road we do a lot of mountain trails and are commonly idling at 750 in low range, so I was looking to get more torque at the bottom. And yes I meant 60mm the stock necks down to 58 I believe so open it to the same size all the way through but without changing the butterfly. Please correct me if you don't agree

[TJW319]

I should also mention that I'm running an AX15 with NP231 and 3:73's turning 35's. I had planned on a gear change but it's working pretty darn good with a 190000 4.0 pushing it so the stroker with some added low end grunt should keep me smiling.
Oh and if someone with a desktop dyno wanted to plug this in that would be very cool!

[jsawduste]

Hi TJ,
you make some compelling comments which are influenced with the altitude (Mountain Trails comment and DCR corrected to alt.) that has to be factored in.

The MC809 is a very mild cam. Even milder then some OEM applications. While I understand your desire for low end I have to wonder if that might be undercammed even installed straight up (-2). Add the 4 degrees (net +2) and the cam effect is even more pronounced. It`s an interesting balance as you add cam duration the DCR (generally) goes down. Which is the bigger evil correcting for altitude.

It would be nice to have someone else at altitude to comment on the cam selection. Personally I think a little more cam is in order.

I am aware of the taper in the stock TB but again considering your altitude I have to wonder if a 63 might be a better choice. There are several places that offer modified OEM that I or I am sure Russ can help you with if you decide to go to 63.

Gearing, that`s an interesting subject. Along with Russ I am an advocate of deep gearing. 5.38`s on 37`s and Russ is even deeper.

Perhaps this link might give you some insight and consideration.
http://www.grimmjeeper.com/gears.html

[Cheromaniac]

I think the mc809 has 2deg built in and I was thinking that adding 4 more to lower the torque range would be a good thing as in my normal DDing I'm rarely over 3500 and off-road we do a lot of mountain trails and are commonly idling at 750 in low range, so I was looking to get more torque at the bottom. And yes I meant 60mm the stock necks down to 58 I believe so open it to the same size all the way through but without changing the butterfly. Please correct me if you don't agree

The specs are identical to the '87-'95 OEM cam so it's better installed straight up.
A 62mm TB is the minimum size I'd install on a mild stroker. You could even go slightly bigger.

[TJW319]

Jsawdust,
I tried the link you included but it didn't work for me.
My DDing is spent at 1300-1500 ASL and trails 2000-6000.
What cam would you all suggestion I run? I'll look for a tb that's 63+. It seams like I read somewhere that there is a 65mm TB that came on mid 90's mustangs that works on the 4.0

[jsawduste]

Hmm, Google jeep gear ratio calculator and the "grim jeeper" site should come up. It's well worth your time to see what gear ratios and tire sizes do to your speed/RPM/feet per minute crawl ratio etc.

Cam wise id talk to Russ. He has some custom ground sticks that I'd bet would work very well for your altitude. Something short on duration with a decent lift and a wider LSA work work well in the thin air of elevation. Not to much duration so your not losing a bunch of DCR but with enough lift to fill the cylinder.

Jensen can change the MAP tables and the fuel trims plus add a bit of spark lead to help with the altitude.

Really think you could see some big gains with the TB. Russ or myself can hook you up Dustin and have a stock TB bored or you can go to the BBK.

Your going to be happy with your engine. Properly setup they run PDG.

Am curious why you went with the short rods though.

Plus I owe you an apology calling you TJ (buddy of mine) instead of TW.