Brown Truck Under the Knife Project - Engine

[icanfixall]

Yes... A lifter could fasil but this needs to be found out if in fact its happened. These are roller lifters with a needle bearing in the roller. I have a set of lifters that are bushing bearings... I have no idea when they were ever installed in this motors... Maybe in the early 6.9... It may just be a very good idea to change all the lifters but... These are not really a wear item like main and rod bearings.... Just more what ifs on the table... I think its time Sean gets a measurement of how much may have been milled off the head....

 

[6 Nebraska IDIs]

Yea, the lifters were used lifters but I cleaned them up and flushed them out very well. I don't really expect there to be any problems with the lifters. It looks fine as it is right now. What I'm guessing and hoping happened is the valve got stuck up in the guide for some reason the lifter returned letting the push rod come out of alignment and then when the piston smacked the valve it bent the pushrod because it was not seated correctly.

 

[6 Nebraska IDIs]

Talked to the machinist who did the work tonight and he said he wants to see it but doesn't see any possible way it could be related to anything he did (I didn't even imply it had anything to do with his work, he said that on his own). He said he wants to see it right away and take a look at it. He himself mentioned that it sounded like the valve was starved for oil and seized up in the valve guide. So then I mentioned that, "yea I brought down the valve cap style seals that are supposed to be used on those exhaust valves but you installed all the positive seals on all of the valves." He responded with the same thing he said when I picked them up and questioned him about the positive seals being on all of the valves, "The exhaust is the side that gets them anyway so that shouldn't have anything to do with it. I'm betting your pushrod wasn't flowing oil or something. Exhaust valves just don't fail like that."

So now what do I do? Actually take this head back to this guy and let him make it right? Money is still tight so $80 saved in fixing that valve with this guy on his dime rather than me take it somewhere else is a major bonus right now. I just dont know if I can trust him.

On another note, if it does look like the valves are gauled then is it feasible for me to just pop off the positive seals on the other head with it on the motor and go from there? I have the tool for removing the valve springs on the motor, even have a conversion pipe to plug into the GP hole and compress the cylinders so that the valves dont fall.

 

[RacingSTude]

Uhhhh...you know some of that does not apply here. They are rollers in these, so there is no convex/concave surface. I understand where you are going though.

SWS

Shows ya how much I know about the insides... You're right, no crown on the lifters. However, I'm still of the opinion that the lifter pumped up for some reason and I would still recommend a new set, cheap insurance...

 

[65sixbanger]

I would suspect a lifter if the motor had a few hundred miles and nothing major was changed.. kinda like the head. According to his sig, they had only 84,000 miles....

 

[icanfixall]

Sean... You do not want the positive seal on the exhaust. The red positive seals go on the intake. They have the spring around them and work fine... We have plenty of oil going into our intakes from the CRD.. The exhaust needs the white seals snapped into the retainers up under the top of the spring. Not down on the guide or head in our place... We don't have replaceable valve guides.. Just cast iron but.. These heads can be machined out and many differant types of guide material installed. Yes... You should remove the passenger side positive seals on the exhaust and do it correctly. Make sure this ****** didn't knurl the guides... Thats really crappy type work I don't care what others say about it. I even had a shop once knurl an exhaust valve in my big block 454... Boy was I angry when I found that mess..... That shop went out of business before I could take them for a walk in the desert...... If you know where I'm going....

 

[sle2115]

I'm not a big fan of knurled guides either, but when I worked in the machine shop, I learned there are at least two ways of doing it, one is MUCH better than the other, and the tooling to do the better way is very expensive...of course, they had the tooling to do the better way (actually had the other method too) but I still like new guides, just my preference.

 

[6 Nebraska IDIs]

So, the guides aren't replaceable? What did he do to my heads then? lol God I hope he didnt knurl them. I'm really hoping the other valves dont look gauled too badly. If they don't I'm going to pull those exhaust springs on the passenger head and put the other seals in them, cross my fingers and hope they give me a nice long life.

 

[sle2115]

So, the guides aren't replaceable? What did he do to my heads then? lol God I hope he didnt knurl them. I'm really hoping the other valves dont look gauled too badly. If they don't I'm going to pull those exhaust springs on the passenger head and put the other seals in them, cross my fingers and hope they give me a nice long life.

If you got the tools to do them, ANY I ever found were replaceable!

 

[typ4]

The valve hole is bored into toe head casting, the SOP of replacement is to bore the hole and install a replacement guide, most use cast iron. I like a particular brand of bronze. I bet the guide was too tight these valves grow a lot in dia and all it would take is a couple tenths and it will stick. Not likely a lifter unless you have 100 psi oil pressure. The piston will be fine, the top ring is a ways down. Also unless he took tons off the head it wont come close to the valve. I have not read the whole thread, cant sit that long. sorry for any duplicate info.

 

[icanfixall]

Russ.. You pretty much hit the high spots about this issue. Cast iron guides can be installed just like any other material guide. I will try the PEP type bronzanium guide material next set of heads. As I recall thats what you are running now. Just looking at the reads on this post and the answers its gotten to be such an interest for most... And it keeps going....

 

[sle2115]

Russ.. You pretty much hit the high spots about this issue. Cast iron guides can be installed just like any other material guide. I will try the PEP type bronzanium guide material next set of heads. As I recall thats what you are running now. Just looking at the reads on this post and the answers its gotten to be such an interest for most... And it keeps going....

My favorite were a bronze lined guide. They had a very slight groove spiraling down them, to help them provide good lubricant. I'm guessing it was maybe .003 or so and maybe made two complete revolutions in a 3 inch guide (not a knurl, just an oil groove).

 

[6 Nebraska IDIs]

Well I finished finals today and finally got a chance to run the head back to the machinist. He popped the valve out and first thing he said was "wow, I'm sorry I've never seen one do that before." The valve had galled to the point that it took 5 smacks from a hammer to get it out. I told him that everyone here was telling me that if it was a galled valve the valve had been starved for oil because of the seals. He showed me his book and it sure did say that the exhaust was supposed to get the positive seals and the intake got the valve cap seals. So his book is written backwards. We looked at all the rest of the valves in the head and they all looked fine, even had quite a bit of oil on them. So at that point we started to check the guides, the rest of the valves didn't feel bad but the galled valve felt pretty tight in the guide. So we came to the conclusion the valve failed because of the combination of an abnormally tight guide as well as the positive seal that had been installed. He said he'd buy me a new valve and a new guide, install the valve cap seals on the exhaust valves and clean everything up for me by Monday. I can't wait to have my truck back.

 

[6 Nebraska IDIs]

The guides are not knurled either, I looked at them they are smooth standard guides.

 

[sle2115]

What about the other head? Head gasket? Etc.?