I've been a ford guy since I was a wee one LOL. I've been reading about aftermaket heads for the 4.0 ohv. I believe I have a cracked head on a 94 Ranger.(the oil looks like chocolate milk and it looks like burnt coffee in the water) I just got this truck in a trade for doing a clutch install into a 7.3 psd. It looks like the PO before didn't take very good care of it plus he told me that it got really hot once. My question is what is the best head to put on this truck? I'm leaning towards a 95tm head to get a higher compression ratio. I see a lot of heads 95/98tm with the smaller ex. ports. I'm planning on bumping the power up just a bit on it. Or should I just stay with the stock lower compression heads?

Thanks, Brent...

 

The stock compression ratio was 9.0:1, as long as you stay below 9.3:1 you should be OK for Regular gas, if you have an EGR system then a little higher might be OK.

My '94 4.0l also got a cracked head, but yours would have to be a head gasket since coolant got into the oil, but the cracked head may have started the overheating that caused the head gasket failure, so "chicken and egg"
The casting was weak between the valve seats that's where they cracked, this was corrected on later model years.

I replace both heads, not sure of the casting numbers, but I want to say 95tm.

 

Yeah if your looking for power i hear Tom Morana racing does some pretty crazy things with the 4.0s I'm looking at his roller rockers for my 3.0 may take a look at his page might find something that catches your eye.

 

Well I'm not 100% sure there's water in the oil. I just did an oil change and I figured I'd see what it look likes in a week or two. But I'm planning on the worse. Like I said the guy I got it from was hard on it. The T-stat is stuck in the open position so the engine doesn't get up to operating temperature at an idle after 30 minutes of running its barley at 120 degrees. I've been to Tom's web page and hes got some nice toys in there! Might be more than I can afford. I don't know how my pocket book would like it she tends to get upset and I don't like sleeping on the couch. LOL besides I'm just wanting to bump it up a little.

 

Yeah the "pocket book" killer of all dreams lol. But id go for the newer ones like the other poster said boltons are definitely cheaper and net you a few ponies I'm happy with my bolt ons so far but I'm sure the 4.0 can do more with them haha

 

Bolt on's or 5.0 you choose lol

 

I'm not a huge fan of the 5.0. I've had a couple 5.0's and felt like it was wanting someone to get out and push. LOL my 67 bronco had a built 302 and the Windsor that was almost stock felt like it had more umph imho...

 

So you don't have a cracked head?

After 30 minutes of driving with a cracked head or head gasket issue you would be blowing coolant out the overflow tank and your temp gauge would be in the HOT range.

So switch to electric cooling fan, that frees up a few HP.
Set of headers for low-end power and your set.

Stock Air intake is better than any bolt on.

 

It's pushing coolant out the overflow you can see air bubbles coming out of the radiator and there was an brown oily scum in the top of both radiator/overflow tank. As for running hot is not. It might be because it in the 30's here. I'm pretty sure it has a cracked head tho.

 

Stick to OEM Heads unless you are thinking high HP.

Just to back track a little… a 5.0 that feels like it need a push is not running correctly, maybe the computer went into limp mode and you didn’t reset it.

My 5.0L Ranger, auto, 3.73, 4x, ran like a raped ape, the exhaust sound was so good I would run it higher in rpms just to listen while cruising.
The 5.0L was made for the Ranger, auto or standard, and will produce more HP than you will ever need, with all of the aftermarket bolt-on power equipment.
some Mustangs run in the 8’s with 5.0L, so I think yours needed some help.
Also, the 5.0L Ford is a Windsor unless you are talking the newer Coyote 5.0L.

 

It was my sister's 95 explorer 5.0 w/auto trans. plus every 302/5.0 I've had in the past total of 4. I just wasn't happy with them. Take my 67 bronco it has had both a 302 and 351w (non computer engines btw) the 351 got better mpg and much more power, both motors were built with a RV cam and 10:1 compression ratio, and a 303 three speed. I'm not planning or street racing or anything like that just using it as a DD and pulling a small trailer from time to time plus my kids are 14 and 15 1/2. It being a manual I want them to learn how to drive it before using the lazy mans auto LOL. Heck maybe its all in my head about 302/5.0's LOL. I have driven a 2013 Mustang with the new 5.0 and yes that one does move!!!

 

Well two things that are opposites are MPG and Horse Power
Many have tried and many have died, lol.
I mean turning off cylinders while driving????? really

They are making engines more efficient now, so you can get better MPG while leaving HP alone, computer controlled EFI really helped that.
And manufacturers also have the EPA to deal with, which can be an HP killer as well.

Gas prices being what they are manufacturers will tune 95% of all models for best MPG and lowest emission, not best HP.
So a 302 that seems under powered is setup that way, or as said, is not running within parameters.
There are models targeted at drivers that want HP, the MPG is secondary to those buyers.

Now there is "no replacement for displacement", lol, so between a 302 and 351 the 351 would be the one, but..........a well tuned 302 will deliver good HP and reasonable MPG, I would never mention MPG in a positive manner with a 351