Hopping up a low mileage ohv.

[Mackhedq]

Not sure the directions I want to go with my low mileage 94 4.0 ohv. Don't say v8 swap nows not the time for me. First idea is

95mt heads
66mm bbk throttle
422 comp cam
Headers

94 motor + 95mt head would put me around 10.25:1. So thinner head gasket for 10.5:1 compression.

2nd idea

Rebuild heads
M90
Injectors
422 cam
Headers

Use the stock low compression to my favorite
And run 5psi.

Fabrication is no issue for me but tuning ob1 isn't the best I've heard. This was a good running motor when pulled out of a winter beater. Rust killed the frame at 74k. It will get pulled down to a short block so I can inspect the pistons and crank bearings.

 

[Roert42]

Might be a good candidate for a stand alone ecu.

 

[superj]

super chargers are cool with stand alone

 

[Blmpkn]

Is the vehicle the motors going in already owned and juiced up for OHV stuff? Or does the rest of the vehicle need built for duty?

Personally, I'd get the wagon squared away with the horse you have now before hitching a stronger one to it.

 

[gaz]

@Mackhedq ,

If your heads are serviceable, you can use 00+ Ford SOHC 4.0l flat top Pistons to raise the compression ratio a full point. You can mill your 94 spec. OHV heads 0.030" for an additional point of compression.

Instead of that cookie cutter cam, have a custom reground made, just for your engine; it will work better and cost less. Also, the stock throttle body can be bored to 64mm for quite a bit less $ than buying a BBK 66mm.

The non adjustable valve train is your next hurdle, several solutions are available.

With higher compression, I don't recommend forced induction but with a well adjusted valve train, custom cam, flat tops, milled heads, headers and a 64mm T/B, the 2 things left to consider are the ignition/coil packs and a proper flow bench port polished heads to intakes:
• MSD DiS4
• Davis Unified Ignition (DUI) 45v coil pack

 

[Blmpkn]

Ooooh wait....


Overhead valve.

Not off highway vehicle.


Nevermind me lol.

 

[RonD]

4.0l OHV used MAF system 1990-2000 so anything short of turbo or super charging upgrades will be taken care of by the computer, OBD1 or 2
Its adaptable to air flow changes, the point of switching from MAP to MAF system

Use new O2 sensors to get the best results, these are the ONLY sensor that wear out and have a time limit, 100k miles or 12 years and they are done

87octane loses its appeal around 9.4:1 compression ratio, so you will need to run higher octane compatible with the CR you end up with

The 4.0l SOHC ran 9.7:1 CR and could run 87octane because Ford added a knock sensor, but loss of power when using 87octane
Not sure it would be worthwhile adapting 4.0l SOHC PCM to the 4.0l OHV just so you could run 87octane

 

[Mackhedq]

@Mackhedq ,

If your heads are serviceable, you can use 00+ Ford SOHC 4.0l flat top Pistons to raise the compression ratio a full point. You can mill your 94 spec. OHV heads 0.030" for an additional point of compression.

Instead of that cookie cutter cam, have a custom reground made, just for your engine; it will work better and cost less. Also, the stock throttle body can be bored to 64mm for quite a bit less $ than buying a BBK 66mm.

The non adjustable valve train is your next hurdle, several solutions are available.

With higher compression, I don't recommend forced induction but with a well adjusted valve train, custom cam, flat tops, milled heads, headers and a 64mm T/B, the 2 things left to consider are the ignition/coil packs and a proper flow bench port polished heads to intakes:
• MSD DiS4
• Davis Unified Ignition (DUI) 45v coil pack

Plan for the 95-97 heads is to use them since they have the smaller combustion chambers. Looking to do this relatively cheap and all myself so rings and rod bearing is all I want to do on the bottom end. Heads definitely will get port matched to the intake and exhaust. Good to know about the throttle body I'll have to call in some favors... I'll have to do more research with the cam and see if it's worthwhile getting it reground. Forgot to mention I'll get valve springs too.

4.0l OHV used MAF system 1990-2000 so anything short of turbo or super charging upgrades will be taken care of by the computer, OBD1 or 2
Its adaptable to air flow changes, the point of switching from MAP to MAF system

Use new O2 sensors to get the best results, these are the ONLY sensor that wear out and have a time limit, 100k miles or 12 years and they are done

87octane loses its appeal around 9.4:1 compression ratio, so you will need to run higher octane compatible with the CR you end up with

The 4.0l SOHC ran 9.7:1 CR and could run 87octane because Ford added a knock sensor, but loss of power when using 87octane
Not sure it would be worthwhile adapting 4.0l SOHC PCM to the 4.0l OHV just so you could run 87octane

The motor definitely will get new sensors and supporting parts just to be safe. I don't mind buying high octane gas because this truck gets driven once a week now.

 

[gaz]

@Mackhedq ,

• Oregon Camshaft Grinders of Vancouver Wa. will grind make you a custom grind for $200, including shipping both directions.
• Mr David Endrigo of Poulsbo Wa. will bore your stock throttle body to 64mm and make a new correct size throttle plate for right around $200 (contact info available upon request).

I mentioned the SOHC flat tops because new pistons/rings are $135 vs the cost of heads; though if you are set on the fast burn heads and will be porting, the 98 spec. (same chamber as the 95+ heads) head is a better value due to the exhaust ports size/shape.

 

[Mackhedq]

Well got the motor up on the stand and torn down. So far so good. Man things I've noticed is man roadsalt is hard on iron. Had to weld a nut on some of the head studs. The exhaust ports are so rusty it's not worth reusing these heads. Cylinder#1 has some very light marking. Can barely feel it when dragging a nail across it.

I'm going to ball home it out if the crank looks good. Cylinders 2-5 look great though, still have cross hatching and everything.

Might go out of Moab in July. If this isn't done then I think I'll have someone trailer my bike instead and I'll ride that.

 

[Eddo Rogue]

@Mackhedq ,

• Oregon Camshaft Grinders of Vancouver Wa. will grind make you a custom grind for $200, including shipping both directions.
• Mr David Endrigo of Poulsbo Wa. will bore your stock throttle body to 64mm and make a new correct size throttle plate for right around $200 (contact info available upon request).

I mentioned the SOHC flat tops because new pistons/rings are $135 vs the cost of heads; though if you are set on the fast burn heads and will be porting, the 98 spec. (same chamber as the 95+ heads) head is a better value due to the exhaust ports size/shape.

Please fwd/pm me the contact info of these guys?

 

[gaz]

Please fwd/pm me the contact info of these guys?

Contacts sent

 

[Mackhedq]

Update for anyone. Torn it down to a bare block. It's getting sent to a local shop to get honed to what they see fit and new cam bearings fitted. Going to rebuild it completely fresh so it lasts another 200k miles like my trucks OG motor.

Plan is now 95tm heads and new stock pistons for 10.5:1. The 422 cam and all new stock sensors, fuel injectors, etc. The shop is about a month out so next update when it comes back!

 

[Mackhedq]

More photos. Everything checking out as normal. Probably could have run this bottom end but I'm leaving nothing to chance

 

[Mackhedq]

Well unfortunately the cam and valve springs are infinitely backordered... Ended up cancelling the order. Picked up a Lq9 and picking up a 6L80 next week. Planning on a np205 too.