Questions about 4.0L OHV headgasket replacement and engine rebuilding.

[Maxsaaty]

Hey ya’ll,
I’m new here and I just bought a 1993 Ranger with a 4.0 OHV for cheap but it needs a headgasket. The story goes that the previous owner had a bad thermostat and overheated the motor causing it to “blow a headgasket.” From my research on these things, it is very likely to need a new head too. My plan is to replace everything from the piston rings up. I might replace the pistons too but the truck only has 61k miles so I’m going to see how they look first.
What I’m wondering is:

Can I remove the pistons by leaving the motor in and dropping the oil pan then pushing the pistons out through the top.

Has anyone heard of 12degrees north? They have a set of roller rockers with ratios from 1:5:1 to 1:8:1. The set comes with push rods, rollers, and rocker mounting bars. The set is pretty pricy sitting at a price of $1300 so I wanted to know if this may be worth it. If it is worth it would a ratio of 1:6:1 be good to get a bit more lift?

Does anyone know a place where I can get some good valves? I saw the manleyperformance ones listed in the “how to build ford v6” article but wanted to know if there’s any alternatives.

Is the Comp Cams 49-410-8 worth it? If so do I need longer rods? I saw there was a little debate here about if you should do longer rods or not.

Is there anything I should know before I tear this thing apart.

Thank you,
Max

 

[rumblecloud]

Welcome To TRS.

On my 94 4.0, you can't drop the oil pan without lifting the engine. Something about the crossmember getting in the way. Not sure if it's the same deal for 93. Others will be along shortly to offer more input.

Sounds like a big project, but with a low mileage Ranger it would be worth it. Good Luck.

 

[Shran]

1993 has a 5 digit odometer. It resets every 99,999.9 miles. Are you SURE it's never rolled over? Maybe it's really got 361k on it and it's just worn out at this point?

Is there any coolant mixed with the oil? That is really hard on everything inside the engine. If it was run quite a bit with it full of milkshake oil, I'd suggest tearing it down and inspecting everything.

 

[Maxsaaty]

Welcome To TRS.

On my 94 4.0, you can't drop the oil pan without lifting the engine. Something about the crossmember getting in the way. Not sure if it's the same deal for 93. Others will be along shortly to offer more input.

Sounds like a big project, but with a low mileage Ranger it would be worth it. Good Luck.

Ah I see that’s very helpful to know. Hopefully mine is different, I haven’t really looked yet.

 

[Maxsaaty]

1993 has a 5 digit odometer. It resets every 99,999.9 miles. Are you SURE it's never rolled over? Maybe it's really got 361k on it and it's just worn out at this point?

Is there any coolant mixed with the oil? That is really hard on everything inside the engine. If it was run quite a bit with it full of milkshake oil, I'd suggest tearing it down and inspecting everything.

As far as the title says and the carfax says it hasn’t ever been to 60k before. From what the person I bought it from told me the truck sat under a shipping port for most of its life.
Yes, the coolant is definitely nice and mixed. The person told me they parked it immediately after they knew it blew but who knows how much driving it had before. I’ll definitely give it a good inspection before replacing anything.

 

[Shran]

Might be a good time to just tear it down and inspect everything. If it was yours all along and you knew how long it had been run with milkshake oil, you could make a different judgement call there.

I don't trust Carfax or vehicle titles one bit for what it's worth. In South Dakota nothing over 10 years old gets the mileage logged on the title and Carfax probably receives 0.001% of what actually happens. My F250, for example, the odometer reads something like 135k right now. The dealer I bought it from said they messed with it and it actually had over 200k on it. The old title said 170k I believe... my title just says "Exempt" because it's over 10 years old. It's hard to guess with '94 and up, almost impossible to know for sure on anything before that and people lie.

Anyway I bought a '94 last year that I am sure had only 63k on it when I bought it, just judging from its overall condition and I had pretty much the same problem you have now except someone tried putting new heads on it. It had a ton of blowby and I think the rings were either stuck or totally wiped out. I ended up just replacing it with another engine and will tear down the original one sometime but I am expecting to find that it needs bearings and who knows what else.

 

[Maxsaaty]

Might be a good time to just tear it down and inspect everything. If it was yours all along and you knew how long it had been run with milkshake oil, you could make a different judgement call there.

I don't trust Carfax or vehicle titles one bit for what it's worth. In South Dakota nothing over 10 years old gets the mileage logged on the title and Carfax probably receives 0.001% of what actually happens. My F250, for example, the odometer reads something like 135k right now. The dealer I bought it from said they messed with it and it actually had over 200k on it. The old title said 170k I believe... my title just says "Exempt" because it's over 10 years old. It's hard to guess with '94 and up, almost impossible to know for sure on anything before that and people lie.

Anyway I bought a '94 last year that I am sure had only 63k on it when I bought it, just judging from its overall condition and I had pretty much the same problem you have now except someone tried putting new heads on it. It had a ton of blowby and I think the rings were either stuck or totally wiped out. I ended up just replacing it with another engine and will tear down the original one sometime but I am expecting to find that it needs bearings and who knows what else.

That is good to know for the future. Thank you. This thing probably has 161k max because the condition is also very good. The interior looks amazing and the wear on the steering wheel and pedals is very limited.
I’m curious what you’ll find on that first engine of yours. If the heads are nice you might get lucky and be able to save them for another project, depending on how much beating they got. From my time at Volvo I learned to save every good part off an old engine just to have as a free backup.

 

[SenorNoob]

I wouldn't trust them either. This is from an AutoCheck after I bought my truck:

I'm not gonna say it was wrong at that time but it's definitely fishy. You'd get the same result if you ran it today, but I know for sure the odometer has tripped 2 times since I've had it.

 

[lil_Blue_Ford]

Yeah, CarFax isn’t worth the paper it’s written on half the time. I’ve seen a number of “clean, one owner” CarFax reports on cars that have been totaled and have “frame” damage. If there’s enough records you can piece together the likely mileage but otherwise, with the 5 digit odometers there’s usually no way to be certain unless you owned it from before it rolled over or knew and trusted the person who did. I love seeing all these 30+ year old trucks that people are claiming low mileage on anymore… @snoranger has a good story on that…

I’d just pull the motor and put it on a stand to work on it, way easier than trying to do it in the vehicle and really not super hard to pull motors on these trucks. My Choptop I once pulled a motor, did head gaskets and stuff on another motor and dropped it in the truck in about 4-5 hours. I don’t even have a garage. Usually, unless parts are needed, it’s an easy weekend job to do a motor.

 

[Shran]

I know my '86 F150 has 106k actual miles on it because my grandpa bought it new and gave it to me in excellent condition with 55k on it. The rest of the miles were all me. It's impossible to verify 5 digit odometers without some provenance that proves the actual reading. I took it to Quick Lube for an oil change about 15 years ago and they logged it as 202k... I guess it probably looks like that now but I know the truth.

That is good to know for the future. Thank you. This thing probably has 161k max because the condition is also very good. The interior looks amazing and the wear on the steering wheel and pedals is very limited.
I’m curious what you’ll find on that first engine of yours. If the heads are nice you might get lucky and be able to save them for another project, depending on how much beating they got. From my time at Volvo I learned to save every good part off an old engine just to have as a free backup.

I have worked on a couple Volvos and my take on them was they'd be better driven off a cliff than attempting to fix them!

 

[Maxsaaty]

Yeah, CarFax isn’t worth the paper it’s written on half the time. I’ve seen a number of “clean, one owner” CarFax reports on cars that have been totaled and have “frame” damage. If there’s enough records you can piece together the likely mileage but otherwise, with the 5 digit odometers there’s usually no way to be certain unless you owned it from before it rolled over or knew and trusted the person who did. I love seeing all these 30+ year old trucks that people are claiming low mileage on anymore… @snoranger has a good story on that…

I’d just pull the motor and put it on a stand to work on it, way easier than trying to do it in the vehicle and really not super hard to pull motors on these trucks. My Choptop I once pulled a motor, did head gaskets and stuff on another motor and dropped it in the truck in about 4-5 hours. I don’t even have a garage. Usually, unless parts are needed, it’s an easy weekend job to do a motor.

When you pulled yours did you bring the trans out with it? I don’t have much experience with pulling motors from the top unfortunately. Every engine I’ve ever replaced I’ve dropped out the bottom and most of the motors I’ve rebuilt were inside the car.

 

[Shran]

It is possible to pull the engine & trans together but in my mind that is a LOT of extra work. I would much rather just pull the engine. Getting it wiggled up and past the AC lines without disconnecting them is the hardest part. Removing the hood will be a necessity.

 

[Maxsaaty]

It is possible to pull the engine & trans together but in my mind that is a LOT of extra work. I would much rather just pull the engine. Getting it wiggled up and past the AC lines without disconnecting them is the hardest part. Removing the hood will be a necessity.

The ac compressor on mine is shot so I’ll probably just take the lines off. For the trans I’m assuming once I get the motor off of it, I need to have some sort of support to hold it right?

 

[Shran]

The ac compressor on mine is shot so I’ll probably just take the lines off. For the trans I’m assuming once I get the motor off of it, I need to have some sort of support to hold it right?

Nope. Transmission crossmember and the radius arm crossmember will hold it just fine. You will probably need to put a jack under it when you reinstall the engine just to line everything up perfectly though.

 

[Maxsaaty]

Nope. Transmission crossmember and the radius arm crossmember will hold it just fine. You will probably need to put a jack under it when you reinstall the engine just to line everything up perfectly though.

Oh ok sweet. This doesn’t sound all that bad then. I appreciate the help and I’ll probably put an update in this form once I get it torn apart.