How to tell what series of heads from vin number?

[Knome]

Sorry that this is my first post here but i really really need this answered as i haven't been able to get my 1994 explorer 4.0 V6 OHV working without finding the right heads at a junk yard.

My situation is this. The vehicle has two blown heads and i need to get new ones. The issue is that it seems like ford made different heads throughout the production cycle for that model of explorer. Is there any way to tell what series of heads the vehicle has without tearing the entire thing apart to get at the number stamped on the head? Like some number in the vin number or something?

The number on the heads currently on my car starts with ty94 but from what i can gather i need ty93 heads. Is this true? Will any one work that has the same motor or is one better than the other? Or am i completely off base and all the heads were the same? (it may very well be a possibility).

 

[dansnyder22]

as long as the donor vehicle is a 93-94 your in the clear you could even use 91-92 heads too. a popular power adder is to put 1995 OHV heads on it and it bumps the compression up to 10:1 I would do that because its a simple bolt on that you already have to do all the work for

 

[Maniak]

90tm are on the 91 & 92 X..
93tm are on the 93 and 94 X..

Same heads... different casting..

Also, when we were looking for heads we tried the yards first.. of the 3 sets we grabbed, all 6 heads were cracked.

Not worth going to the yard...

~Mark

 

[rayford2]

as long as the donor vehicle is a 93-94 your in the clear you could even use 91-92 heads too. a popular power adder is to put 1995 OHV heads on it and it bumps the compression up to 10:1 I would do that because its a simple bolt on that you already have to do all the work for

10:1 compression heads require PREMIUM gasoline..OK if you can afford it.

 

[YBCold]

outstanding. i wish u had posted earlier so i wouldnt have had to figure this out on my own.

 

[SysIntegr8tor]

will the heads from a 4.0 mustang bolt to a 97 4.0 explorer?

 

[Maniak]

The 4.0 from the mustang (I'm assuming you mean an s197 model) is a sohc. As to whether or not the heads fit, I don't know.. I haven't seen any good info on the newer/late model heads yet...

~Mark

 

[SysIntegr8tor]

What are the possible consequences from re using the head bolts We are "supposed" to replace? If I did the heads last year and didn't replace them, should I take it more seriously the second time around? How ""stretched can they get and still function correctly?

 

[jhclance]

reused even once they are verry likely to break or at least stretch to the point that you blow a gasket reusing them a second time is just absurd and asking to ruin an engine. Which may very well be what has caused you to have to replace them now

 

[SysIntegr8tor]

I agree that the head bolts may very well be the reason I am doing it over.
What irks me is that the sources from which I got the install instructions (3 different - purportedly professional - sources) did not mention torqueing to "yield", only listed the foot pounds of torque.
Are there any other applications of "torqueing to yield"?
I feel like such an amateur. Wait a minute...I AM an amateur! LOL

 

[Maniak]

I've heard of a few people re-using them once without issue. I never heard anyone trying to reuse them twice though..

I did get one set that I didn't like. I put them in and while doing the torque sequence one just didn't feel right. It was turning way too easy during the final torque. I replaced that bolt with a different new one (I was lucky and was able to get a single new one).

Its only been 33k miles or so since the motor was rebuilt (I was rebuilding the motor that time since it had lots of miles).

~Mark

 

[SysIntegr8tor]

I had that same experience with one of the bolts and being a half-wit. I simply forged ahead. Now I have to do it over. I bet when I get it apart, it is that bolt that is closest to the breach. Hope the head isn't warped or cracked.
I think I remember putting a dob of loctite in the torx head to mark it for later as I wanted to retoque it or at least stare at it with animosity and malevolence. The mechanic I asked about it didn't mention torque to yield either. Are you the only guys with a clue out there??

 

[Maniak]

Until I worked on the X, I never heard of it either.. and many "old school" guys haven't either..

Aparently, TTY is more common on newer vehicles..

My chiltons and haynes both mentioned it.. I never actually look at my FSM to see if it said it but the instructions with the bolts did.

~Mark

 

[SysIntegr8tor]

Ah, there you go. If I had had the sense (and the resources) to get the head bolts I would have done it up properly.
So TTY, your post which describes a head bolt which actually stretched too easily or continued to turn easily past the spec point - I can't recall, I think it was like 125 ft lbs...When I was torqueing them, as I reached spec, I went back over the bolts a number of times too be sure I had them correct. (When you refer to "final torque" I assume thins is what you are describing)
That resulted in most of the bolts initially sticking at the 125 setting, and then when I went back to them again they would move a little further before the wrench would click out. I would guess that most of them got approx 80 degrees or so by that process before they actually stuck on 125 without moving anymore. So. Is TTY 80 degrees past that FINAl torque?
I'm embarrassed. I need to do better homework before getting out the wrenches. I'm asking questions that wouldn't need to be asked had I done better research.

 

[Maniak]

You almost have it..

When torquing(sp?) the intake/heads, the 2nd to last set of torquing on the heads is to about 60 ft lbs. The last set is then 80-85 degrees more. Your done at that point with the head bolts.

~Mark

 

[SysIntegr8tor]

torquing [sic] from the Latin word torquēre (to twist)
My sister asked her husband (a right side engine wrench on a Nitro pro dragster) what it meant. He said: " Well, honey.""You know how when I get up in the morning with a "Pisson" and when I bend it down to hit the bucket my feet fly out from under me?" "Well, that's torque!"

 

[kifferarri]

torque to yeild is the point at which the bolt begins to strech, reusing a tty bolt will not give you the proper torque (because the bolt has already begun to strech)... plain and simple: do not reuse bolts according to the book... doesnt mean it hasnt been done tho... in a bind, sometimes its ok, but i dont think i would reuse a second time. tty has been around for a long long time. main bolts and head bolts (and some lower intake bolts) are the main users (almost always for main and head bolts/studs). anything that has a torque spec, then a number of degrees to turn after, is a torque to yeild.

 

[SysIntegr8tor]

Yeah, Just one more example of someone who's not a mechanic per se, thinking they have got what it takes and flubbing the result. The transmission threads are rife with cases where the problems are either caused by or exacerbated by inept attempts at repair. All the more reason why ExplorerForum becomes such a valuable resource. Heck! I wouldn't know how dumb I was without having come here to learn and to understand the damage I have caused myself! I can see that if I was more able, that I would reap huge benefits from the resources and opportunities which present in such a forum. Bless you all

 

[jd4242]

ford loves tty bolts!!but not all head bolts are true "stretch" bolts and if you ask them and they just say you should always use new ones then they are prob not "stretch" bolts.the way you can tell a true "stretch" bolts is if it has thread more the 50% of the length of the bolt.now with that said i have reused bolts before but never if the motor has been over heated or if the motor has been turbo or on gas.also the piston rod bolts on these motors are tty but not the crank caps or the long lower intake bolts,witch are not threaded all the way up.also dont forget the heads and the lower intake need to be torqued in a sequence so the lower intake gasket will seal right.