Questions about performance on an OHV 4.0L engine.

[Marx4.0]

Hi to all out here. I'm a new member here so you'll have to pardon my ignorance. First off, I'm actually not a Ranger or Explorer owner. I am, however an owner of a 4.0 OHV. We have just gotten this engine built and installed in a 1995 Aerostar AWD. That's ok, you can laugh now.
Seriously can someone tell me what the best MAF, TB and injector combo would be on an engine like this? The guy who built this motor told me we should leave it at 19lb inj. and keep the stock intake and MAF till we see how it performs. He also mentioned that I would likely want to get it tuned. I'm am NOT a mechanic and have since found that "tuning" this engine is not all that easy! It's an EEC.
Now I wanted to make sure we have the best all around build possible and then continue to pursue the tuning option. Right now the engine runs but is a pig on the road. Lots of hesitation and jerking/sputtering.
Help me out here, could this just be my throttle body or injectors or MAF? I would glady get all three as long as I knew this was going to help and as long as I knew what kind of specs I should look for. It's not that I don't want to spend the money to do it right.
The guy who installed the motor has gotten a unit called the TwEECer which is supposed to be able to make the EEC motor run on OBDII(??) but he is having difficulty as no one seems to be able to guide him through all this. Said I'd see if there was other things we should look at changing up in the mean time, ie intake, injectors, etc.
Can anyone help??
The ENGINE build:
1995 4.0 OHV bored 0.39" over, 10.6:1 compression, KB 3156HC Hyperteuctic Pistons, Ported 98T Heads & Intake, Comp 422 cam, Comp 988 valve springs, 19lb injectors, NGK5-1 plugs, true dual 2.5" exhaust with x pipe and turbo style Cherry Bombs

 

[jd4242]

For starters how did you get 10.6:1 compression?? Also did you use longer pushrods with the 422 cam?did you have the heads machined to fit the 988 springs?

 

[jd4242]

Also a 95 with the 5r trans i thought was OBD II.and if you are really at 10.6:1 i hope your running 93+ octane,it wont run on anything less

 

[Marx4.0]

For starters how did you get 10.6:1 compression?? Also did you use longer pushrods with the 422 cam?did you have the heads machined to fit the 988 springs?

As I said I'm new to posting stuff and I'm just the sorry owner getting everything custom done. I have the sheet which the engine builder gave me it says:
-Head small chamber opened up
-Bowls and short side radius and port matching
-Grind # FV6 270HR-12
-gross valve lift.500"

 

[jd4242]

As I said I'm new to posting stuff and I'm just the sorry owner getting everything custom done. I have the sheet which the engine builder gave me it says:
-Head small chamber opened up
-Bowls and short side radius and port matching
-Grind # FV6 270HR-12
-gross valve lift.500"

That just says where he ported the heads and the cam specs.i would call whoever built it and ask if the milled the guides and seats to fit the 988 dual springs and what size pushrods they used.stock CAN NOT BE USED! also with your setup you will be at 10:1 not 10.6:1 you still need to run atleast 90+ gas

 

[Marx4.0]

For starters how did you get 10.6:1 compression?? Also did you use longer pushrods with the 422 cam?did you have the heads machined to fit the 988 springs?

As I said I'm new to posting stuff and I'm just the sorry owner getting everything custom done. I have the sheet which the engine builder gave me it says:
-Head small chamber opened up
-Bowls and short side radius and port matching
-Grind # FV6 270HR-12
-gross valve lift .500"int..500"exh
-Duration @.050" 215int 224exh
-Lobe separation 112 degrees
-Adjustable rocker arms taken from a 2.9 V6
-Valve springs 117lbs seat pressure, 230lbs open pressure @1. 6"
As far as the fuel goes: have been running 91 plus 6point octane boost.
We are running an after market controller for that 5r55. That part seems to be working ok.
Does this tell you anything? Definitely ask me what you need and I'll try to get you as much info as I can.
Sorry for the double post

 

[jd4242]

As I said I'm new to posting stuff and I'm just the sorry owner getting everything custom done. I have the sheet which the engine builder gave me it says:
-Head small chamber opened up
-Bowls and short side radius and port matching
-Grind # FV6 270HR-12
-gross valve lift .500"int..500"exh
-Duration @.050" 215int 224exh
-Lobe separation 112 degrees
-Adjustable rocker arms taken from a 2.9 V6
-Valve springs 117lbs seat pressure, 230lbs open pressure @1. 6"
As far as the fuel goes: have been running 91 plus 6point octane boost.
We are running an after market controller for that 5r55. That part seems to be working ok.
Does this tell you anything? Definitely ask me what you need and I'll try to get you as much info as I can.
Sorry for the double post

Yea tells me a little.who is building this motor? The 2.9 have different offsets and ratios and those springs sound like beehav springs.you cant run any of that.you have to use stock rockers and compcams 988 springs with the stem and seats milled.then you need longer pushrods because the 422&410 cams base circle is .050 smaller to be able to get that .500 lift and fit in the cam journals

 

[Marx4.0]

Yea tells me a little.who is building this motor? The 2.9 have different offsets and ratios and those springs sound like beehav springs.you cant run any of that.you have to use stock rockers and compcams 988 springs with the stem and seats milled.then you need longer pushrods because the 422&410 cams base circle is .050 smaller to be able to get that .500 lift and fit in the cam journals

He says they're stock push rods -for the 2.9-. Stems where not milled, just cleaned up, yes, heads where machined to fit 988 springs.

 

[Marx4.0]

He says they're stock push rods -for the 2.9-. Stems where not milled, just cleaned up, yes, heads where machined to fit 988 springs.

Also he says the guides where trimmed.

 

[jd4242]

why would he use the rockers from a 2.9?they seem like they would fit but havent heard back from anyone that has tried them.the 2.9 and 4.0 pushrod seems to be the same length. being that the 2.9 are adjustable you may be ok but can they adjust up to .050 without messing them up.i still dont understand why he would use those?the adjustable ones where for non hydro lifters..why not use 4.0 rockers and the right pushrods?

 

[Marx4.0]

I believe he was having a terrible time finding push rods. I'll ask him. Get back to you on this. Thanks for your interest in this project. I thought we where getting close to the end of this escapade but... more $$ I guess.

 

[jd4242]

Well if he did his math and measurements right then he may be good.just let him know that that cam uses .050 longer pushrods when set up in a 4.0 with 4.0 rockers. Most people go with 5.550 pushrods from smithbrothers push rods.to me he has his valvetrain geometry off or a vac leak

 

[Marx4.0]

Thanks for the help. I'll bring it to the builder n see what he can find. My installer and I where under the impression that we just needed a tune. Now I realize there's quite a few guys that have never tuned and are running pretty good. Hopefully we can find the issue. Wow do I hope that motor doesn't have to come out again! She's built in there pretty far

 

[jd4242]

I run about the same setup except i have SI stainless steel port flow valves and im really at 10.6:1 compression. Ive run that for awile untuned and have had no problems.i also run sealed power 4.0 rockers with smithbrothers pushrods 5.535 rods,my heads have been shaved .030 to get me to 10.6:1

 

[BrooklynBay]

Welcome to this forum! I've moved your thread into the Aerostar section.