Engine problem has been diagnosed

[Yukon Jack]

My engine with a fresh cam, lifters, springs and rocker arms bent a pushrod and broke numerous teflon valve seals. Got the passenger side head off last night and just got back from a machine shop with good news and information on what happened.

To start off, I was told the valve springs needed to be shimmed up as presently they were at about 70 lbs when closed and the cam specs required 90 lbs. The machinist said he would actually like to see a little higher than 90 lbs.

The whole problem surrounds the teflon valve seals. When the problem occurred a number of board members pointed their fingers at them and they were 100% correct. I reviewed alot of information when buying all the components and I sure thought I read that those valve seals could be used without machining but I was obviously wrong on that I now learn.

When the spring compressed the valve seal was not seated properly resulting in contact strong enough to bend 1 pushrod and destroy numerous valve seals.

While the heads are off the machinist will do a valve job even though he said they were not too bad - the heads are off so now is the time to do that and start fresh.

He will also machine the studs to accept the proper valve seals and then he will have the heads prepped for reinstall with new guideplates that I have that will be used in connection with 3/8" pushrods.

The total price for the head work will be in the neighborhood of $240 which sounds awfully fair to me.

Now I have to figure out how in the world I can put the heads back on without messing up the new head gaskets. It was a bear getting the head lifted off and I don't know how I will set the heads back on the installed engine without screwing up the head gaskets. Maybe I can install some all-thread rods to use as guides so the heads drop down cleanly.

Then I need to figure out how I am going to get the torque wrench on a couple bolts at the back of the heads. Clearance is minimal and as it is now a torque wrench will not get back there. Probably gonna have to lift the cab up one side at a time to gain enough clearance - oh the joy

Definitely a relief to know what caused the problem and that it's not going to be too expensive to fix. The extra time that will be involved sucks but oh well, what else do I have to do in the late evenings

As a side note he said I should stay with the peanut port heads as I am after low end torque with this very heavy truck (about 6,000 lbs) - really didn't want to finance different heads so that is good.

[Bram]

That's good news! I'm glad it wasn't anything major.

[vtblazer]

Thanks for letting us know, I was curious.

Did you do a hydro clutch conversion on that truck?

[Yukon Jack]

Yep, for the short period that the truck drove, the hydraulic clutch seemed to work really well.

[barn9]

Well Mark, if it were me, I would probably say it was worth the price just to put my mind at ease, lol. And now you know everything is right, so that has to be a relief. Good luck with the heads on that tall devil man, I know that must not be any fun. You have my number if you need anything.

[70 shorty]

I agree, $240 sounds like no biggie, so I'm glad to hear that the damage also seems to be pretty minimal.

[Palf70Step]

Glad to hear the news Yukon.
I think the thread guide rods would be great idea. I can't imagine doing any type of lifting in your skyscraper truck's engine comprtment .

Good luck with the reassembly.

[Yukon Jack]

Thanks guys. I will have to see how far I can lift the heads - may not be able to use the all-thread for guides if I can't get the heads high enough to slip on them.

Who's idea was it to through a big block in this truck anyway!

[Yukon Jack]

How dare I make a post without pics - here is what happens to your nice valve seals when you don't have the required machine work done