4.0 and 3.0 OHV

[C.Fuller305]

I have a 4.0 ohv motor that has bad heads and I can not afford to replace them. However I have rebuilt 3.0 ohv heads will they interchange so that I can get my motor back or is there modification required? also if it is possible will I have to change anything to adapt to the 3.0 heads?

 

[Josh B]

I think they are different engines. If you can, try coming up with a parts truck, if you can do that on the cheap, and manage a space to park it, you will have all kinds of spares, but realize they could be bad also

Or you might possibly find a swap for the 3.0 for some 4.0 heads

 

[rusty ol ranger]

No.

3.0 heads will not go on a 4.0

 

[snoranger]

Not even close to working.

 

[19Walt93]

The 3.0 was designed for the 86 Taurus and built in Lima Ohio, the 4.0 is based on the 2.6, 2.8, and 2.9 Cologne engines from Germany. I think the only thing they share is oil capacity. I second the motion about swapping the 3.0 for some heads or maybe a complete 4.0, unless you're up for a major engine swap project.
If your heads are cracked and leaking coolant into the oil- like I've seen many times- you could try some Bars Leaks or a similar product as a temporary fix. You'll just have to flush the crap out of your radiator and heater core once the engine is finally fixed.

 

[rusty ol ranger]

I dont know what your budget is but where have you been shopping for heads?

 

[rhekman]

As rusty stated, budget and where you're looking for heads will make a difference.

I just looked up my receipt from March 2021, and I snagged a complete head from AlliedMotorParts for $269.14 with tax, shipping and $50 core charge. Checking there and eBay motors it seems 4.0 OHV heads are north of $300 a piece now. (Thanks Joe.)

If you're rubbing pennies together for warmth, and you're just looking to get something that runs, I think the absolute cheapest you could go would be --
1. Borrow a compression tester from the local parts store and figure out if only one head is bad.
2. Strip the head(s) off and check for damaged valves, springs, rockers, etc.
3. Buy a bare head (eBay $120) and swap over your good parts.
4. Lap in the valves with valve compound.
5. "Plane" the deck with a straight edge and sandpaper.
6. Buy just the gaskets you need - head, intake, valve stem probably required, valve cover if you trashed the old one on removal.
7. Reuse your old head bolts (they're technically one time use, but if you're not racing, you can gently put them back in service.)

Please note - no one would ever recommend the above as a the right proper and correct way to fix a motor with a bad head. But if you only have say $300 to spend it technically could be done.

 

[bobbywalter]

generally....300 buys a good running engine

 

[rusty ol ranger]

Id say go to the boneyard find a OHV 4.0, yank the head, spend 50 bucks getting it decked and roll with it. Probably less then 200 total. 4.0s still seem pretty common in junkyards.

try www.car-part.com

 

[C.Fuller305]

Thank you all for the input however my motor is already torn apart. One head is cracked and the other has major wear on the valve seats causing issues, also my block needs to be bored 30 over. I am now looking for a good motor to replace it and my local junkyard wants 600 just for the block and heads then another appx 75 for warranty and then tax. I have been on selling sites looking for a parts truck but cant find one of that year. I have seen 89-92 rangers with the 4.0 ohv and I am now wondering if that block and head will work with my truck any additional advice is greatly appreciated.

 

[alwaysFlOoReD]

The transmission bolt pattern is different between the 2 motors. You need to swap the trans as well.

 

[C.Fuller305]

So basically I have to find a 93 or 94 ford ranger 4.0 or I am looking at changing transmission or wiring harness?

 

[rusty ol ranger]

So basically I have to find a 93 or 94 ford ranger 4.0 or I am looking at changing transmission or wiring harness?

Any OHV 4.0 will bolt in.

If you go 95+ youll have to switch it over to run on EEC IV instead of OBD II

Shoot for a 90-94 4.0 OHV.

I think @alwaysFlOoReD thought you wanted to swap in a 3.0

 

[bobbywalter]

Stock number. B22139

$400

MP&H Auto Parts Inc USA-NC(Hoffman) Request_Quote 910-281-3151

 

[C.Fuller305]

Any OHV 4.0 will bolt in.

If you go 95+ youll have to switch it over to run on EEC IV instead of OBD II

Shoot for a 90-94 4.0 OHV.

I think @alwaysFlOoReD thought you wanted to swap in a 3.0

I did at first but i would have to change to an automatic transmission when my truck is set up for a manual and 4wd the 3.0 came out of a 2wd so im trying to find another motor that is the same but another person said that the pre 93 4.0 is a different bolt pattern for the transmission so that means i would need the transmission too. When preferably i would like just another 4.0 that will work for my truck because I have already bought entire engine gasket set, water pump, brand new ac system (yes every component), New rings, cam and crank bearings. so i would like to be able to use the 700 dollars plus in parts i have.