Brown Truck Under the Knife Project - Engine

[towcat]

tear into it.
an intake gasket is not the end of the world if you have to change it again.
head gaskets are a fair amount more work........

 

[icanfixall]

Ok.... I understand the motor ran fine... Then the pushrod bent... But the bigger question is why. Try to use a straight edge across the tops of the valves. That will tell you what the heights are and if the offending valve is not closed against the seat. You will have an eyebrow imprint on the piston from the valve head.... How big and how deep is yet to be known. Have this shop guy measure the head thickness with you watching. It should be from 4.795 to 4.805 measured from the top of the valve cover rail to the bottom of the head... Don't tell them what it should be. Exhaust valves are sunk in the heads 0.051 to 0.063 deep. Intake is 0.042 to 0.054. Precups can be + or -2 1/2 thousands either above or below the head... The head flatness can be as much as 0.003 in 6 inches or 0.006 overall.

 

[towcat]

Ok.... I understand the motor ran fine... Then the pushrod bent... But the bigger question is why. Try to use a straight edge across the tops of the valves. That will tell you what the heights are and if the offending valve is not closed against the seat. You will have an eyebrow imprint on the piston from the valve head.... How big and how deep is yet to be known. Have this shop guy measure the head thickness with you watching. It should be from 4.795 to 4.805 measured from the top of the valve cover rail to the bottom of the head... Don't tell them what it should be. Exhaust valves are sunk in the heads 0.051 to 0.063 deep. Intake is 0.042 to 0.054. Precups can be + or -2 1/2 thousands either above or below the head... The head flatness can be as much as 0.003 in 6 inches or 0.006 overall.

you'd swear this guy is spec'ing a rocket motor.....
seriously speaking, if I still had an engine machine shop, I'd have his working for me.

 

[6 Nebraska IDIs]

Yea Gary's a bit **** isnt he? lol
I don't even know if this machinist looks into it that closely. But maybe he did and thats part of what he was complaining about.

 

[f-two-fiddy]

Yeah but I'd rather have someone like Gary touching My parts.

I got My last VP gasket off'n ebay for $44

 

[6 Nebraska IDIs]

Yea I hear ya. I wish he would have been my machinist. Then I wouldn't have had any doubts about them in the first place. My IH dealer and my dads work just raved about the guy I had machine my heads. As much he complained about them when I picked them up you'd think he had never touched a diesel head before.

 

[Agnem]

This motor was running fine, but then obviously something got hung up. This is my big argument about not running a motor hard when it's first put together. My ears are only so good to be able to hear a noise, and then when you do it's time to shut it down. There was indeed a audible warning just before this thing went bang.

 

[david85]

Not sure what defines running ******* a break in, but I did the standard proceedure with mine.

Let it warm up on the shop floor to make sure everything was in order.
Drive it out to an open stretch of road very gently.
Then began the high throttle acceleration/release runs gradually increasing the power and RPM with each run. Did that a couple of times for the initial break in, then changed the oil and drove it however I want ever since. For a while after break in, I would cycle between 3rd and overdrive while cruising just to keep the RPMs fluctuating a little.

I used a set of new/rebuilt heads off the shelf that were shaved on the deck and had the valve stems trimmed a little to match. I measured 5 thou was taken off the deck and 10 thou off the valve stems. However, I also had the pistons shaved so that made the possibility of valve to piston collision very low. One of the pistons had a valve imprint on it when I tore the engine down.

My understanding is you HAVE to run it hard during a break in to make the rings seat and prevent glazing up the fresh bores. However, I did my best to keep EGTs below 650. Thats the idea behind accelerating then letting off. The hard accel puts load on the rings, but the decel allows you to control the EGTs. Steep hills were avoided.

 

[camo85]

oops

 

[6 Nebraska IDIs]

I've listened to a video I have of the engine when I first started it and I really can't hear anything abnormal for a diesel. Diesels rattle so much anyway it's very difficult to pick out a noise until it become obvious. By that time something has already happened.

 

[icanfixall]

Rob..... I'll have Travis "touch your parts".... Thats not what I do..... I do thank you guys for your words of support. I'm really not much different from any of you, I just try to go the extra mile. When something fails, I like to do an RCA (root cause analysis), then try to rebuild the broken or failed part so it won't happen again. Then I freely share my fixes here. It really bothers me when someone breaks their rig becase they didn't know. Those buffoons up in Canada trying to kill an id by driving it thru the water and without coolant really bothers. It's like holding someone under water til they inhale water and then pulling them up to let them feel what its like to survive. Then there's the YouTube idiots running the cash for clunkers till they stop running. It really bothers me.

 

[6 Nebraska IDIs]

I've been calling around to a couple different reputable diesel shops in Omaha today trying to get an idea of some reputable machine shops up that way and I got two, but neither of them will touch the head now that the other guy has and taken 9 thou off of it. They especially wouldn't mess with it if it did turn out to be something at fault to the other machinist. They both said they don't like turning away business but in my case they could feel better sleeping at night knowing they didn't have to deal with my problem. So now I'm really #@cked.

 

[Pearl_Diesel]

Tear that old mechanic a new one, and have him pay for replacement heads

 

[f-two-fiddy]

Well, IF the heads were milled to much, and the valve stems weren't. You'd prolly have had contact the first time You ran the RPM's up.

Gotta do an autopsy, there's no other way of knowing what the problem was/is.

 

[6 Nebraska IDIs]

Yea I know the head will need pulled to know for sure. I guess I'll probably be pulling it since I have basically everything I need to seal it back up. The real problem now is that I'm not sure I can get another machine shop to do the head for me now that the other guy has worked on them. My dad had good experience with CarQuest in town that has a machine shop, they did the new head for my grandpas truck 15+ years ago. Maybe I'll take the head into them and not mention anything about the other guy working on it. If they come back to me and say the head's milled down too far, the valves aren't cut right or sunk into the head properly or anything like that then I guess I can go after the other machinist to make it right.