My 2.9 top end fix

[Vanner1993]

I had serious running issues with the truck, finally got down to having to pull the heads. As I pulled the rocker arm rail off the driver side head, the #6 intake spring fell off. I found 1 of the retainers, hopefully the other is in the pan. After I pulled the heads, passenger seems ok but driver side had a bent valve. I figured ok, I will throw another valve in, pulled it out and there is 3 cracks around the valve area. So I will most likely get a head out of the junkers tomorrow and I will try to get an 88 and newer one if I can. Is the piston ok with that mark from the valve? Here's the pictures.

 

[Big Jim M]

I would pull that piston to the top and take a sharp knife or sandpaper and get any sharp edges off of the bruises. Then I'd go ahead and keep that piston in place.
The reason for taking the sharp edges off is they concentrate heat and MIGHT cause predetination in the future..
So in short that piston looks Ok to me. I have reused much worse looking pistons.
Big JIm

 

[ranger]

i would get an 89 or newer 2.9 head that's when they had the thicker heads.

 

[Vanner1993]

I am gonna get a set of newer heads from the wreckers tomorrow.

 

[Vanner1993]

I got the heads, they were in an 89 ranger. The engine was complete and it was in a wreck. Funny thing is I remembered the truck when it was on the road. Took about 2.5 hours and good thing the exhaust was cut so I removed the manifolds when they were out off the truck. 5 out of 12 bolts broke, but they are removable. There is a big difference in thickness from the older heads too.

 

[rusty70f100]

I'd still have them checked at a machine shop. I know someone with an '89 Ranger that the heads cracked. I don't think they improved them enough.

When the heads on my B2 ever crack, and they will eventually, I'll get new castings. I don't trust the factory heads.

 

[Big Jim M]

Nope!

I'd still have them checked at a machine shop. I know someone with an '89 Ranger that the heads cracked. I don't think they improved them enough.

When the heads on my B2 ever crack, and they will eventually, I'll get new castings. I don't trust the factory heads.

Rusty if you keep the mixture correct and the coolant FULL they won't crack in their lifetime.
Heads are made to last, and they do. It takes a really high temperture to crack our heads. That cannot ever happen as long as the coolant is full and the mixture is correct..

Big JIm

 

[rusty70f100]

I call BS. This guy is so careful with his trucks, that there's no possible way it overheated. He even said that it never overheated.

It's a design flaw that they never fixed correctly. After a certain number of thermal cycles they crack. The 4.0L would crack heads too. I know, it happened to me.

 

[jhammel85]

Yep, it's a proven problem with 86-87 heads. Some are OK with tons and tons of miles and some crack pretty much randomly..There's plenty of members here who will back that up.

 

[Psychopete]

It's a design flaw that they never fixed correctly.

It would seem so - most common cylinders to crack are #1 and #6.

 

[Vanner1993]

Haha, mine was #6 but it was my own stupidity. Where is the common area to crack? Where mine did?

 

[rusty70f100]

Was it right by the valve guide, on top, by where the spring sets? Between the valves?

 

[Vanner1993]

It was underneath the head, at the end of the guide. I also cleaned my heads and painted them today. How hard is it to install valve stem seals?

 

[Big Jim M]

As easy as buttoning your shirt!
Big JIm

 

[Vanner1993]

I ordered the gaskets today, I will have them tomorrow. Since the 86 valve covers won't work with the 89 heads I ran to the junkyard for the valve covers I left there. Cleaned the inch of sludge off of them, they were rust free haha, and sanded and painted them to match the heads. Valve stem seals I will do friday.