2V maxidyne, issue pulling heads off

[Lmackattack]

2 minutes ago, mechohaulic said:

pulling both as one unit  -no problem . except when only lifting device is two hands and strong back.  the reassembly done MANY times as one unit works. prefer reassembly as two separate  units myself. 

No way I could pull this assembly up by hand !!!

I had a service crane with 4 chains to keep it level. 

[mechohaulic]

1 minute ago, Lmackattack said:

Hope not. Liners were very smooth so she probably needs new rings and a cross hatch. At that point might as well inframe it. I'm not sure if it's ever been rebuilt.

Pistons looked very clean for it's age. No carbon build up on them or heads.

What is the 542c stamp on the piston telling us.?

 

 

 

is that not a crack in liner ??? 542c  ??

[Lmackattack]

3 minutes ago, fjh said:

Trent you sure that’s not a 315?

Yes sir. ITS A 283HP ENDT676

[Lmackattack]

Just now, mechohaulic said:

is that not a crack in liner ??? 542c  ??

No clue. I could not feel it with my fingernail.  I'll get a better Pic of it. 

[mechohaulic]

enlarged to max ;that's not a crack . 

[Lmackattack]

1 minute ago, mechohaulic said:

enlarged to max ;that's not a crack . 

I'll get a better picture of it tomorrow. I got done with work around 4. And spent the next hour, pulling the heads off before i had to head home. I didn't feel anything but I also don't have a lot of experience with engine internals. 

[mechohaulic]

3 minutes ago, Lmackattack said:

Yes sir. ITS A 283HP ENDT676

memory is correct the 675 becomes a 676 with the tip turbine. I  do recall a 300 /315 version talked of way back then when they were NEW products. wasn't a lot of rebuilding then being new  and the  slogan "built like a Mack truck meant something.

[Lmackattack]

4 minutes ago, mechohaulic said:

memory is correct the 675 becomes a 676 with the tip turbine. I  do recall a 300 /315 version talked of way back then when they were NEW products. wasn't a lot of rebuilding then being new  and the  slogan "built like a Mack truck meant something.

I think that is correct. What's odd is the 285 tipturbine is a maxidyne where the 315(300+) was still considered a thermodyne. These 2 valves were pretty bullet proof and easy to work on 

 

[mechohaulic]

thing about the "early mechanic days" ,  if you had half an interest in your job, you learned and studied. like high school what you put in is what you got out. thing is not much attention was paid to minor items as a thermo or maxi dyne. if it was gold it was a maxi  anything else was a mack. to see the start of the computer age in trucks wasn't easy to accept. how could an engine 250 hp become a 300hp with this little box plugged it. not a wrench involved. also 300 plus rings a bell.

[Lmackattack]

1 minute ago, mechohaulic said:

thing about the "early mechanic days" ,  if you had half an interest in your job, you learned and studied. like high school what you put in is what you got out. thing is not much attention was paid to minor items as a thermo or maxi dyne. if it was gold it was a maxi  anything else was a mack. to see the start of the computer age in trucks wasn't easy to accept. how could an engine 250 hp become a 300hp with this little box plugged it. not a wrench involved. also 300 plus rings a bell.

I think the concept of the 315 (300+) was a great option for those who did not like the maxidyne with only 5 speeds.

I the maxidyne made slightly more overall torque than the 315 but the 315s had more hp and their max torque more in the mid rpm range. The few 315s I drove seamed to pull better in the hills. 

 

And yes I was always surprised when a new diesel just needed a little reprogram to get +50hp.

It goes against everything we learned on mechanicals.

[Lmackattack]

300+ made 1050ftlbs where the endt676 maxidyne makes 1080ftlbs.

 

Both are tipturbine engines 

[JoeH]

Sounds awful trying to pull both heads together.  Glad you have the service crane for it though.

[JoeH]

Pistons are usually done in balanced sets.  The C probably dictates what weight tolerance range the pistons are in.  

[Lmackattack]

9 minutes ago, JoeH said:

Pistons are usually done in balanced sets.  The C probably dictates what weight tolerance range the pistons are in.  

Thank you. That's what I figured. My book made no mention of that they were all stamped the same

[fjh]

NOT SURE BUT  that does looked cracked my hopes are dashed! Liners come in standard 2 thou over 10 thou over ect!  on second glance with the pic blown up its a trickle of something!😅

[Lmackattack]

I didn't get a chance to get pics today. But the heas gaskets with fire rings are on the way. Hope to button it up over the weekend.

[Lmackattack]

Weather finally let up from the heat wave we have been dealing with. 67 degrees all morning so I jumped on getting the heads back on. Barely broke a sweat working outside until 2pm.

You can see the carbon build up on the 2 studs that was not allowing the heads to come off. I spend 2 hrs removing the stuck nuts from about 30 studs then wire brushed all the studs and threaded holes. Ran a tap thru them to clean them out and was able to put the studs in with just my fingers.

Scrubbed all the old gasket material off the mating surfaces, Pressure washed the heads  put New head gaskets on with new fire rings. 

Was able to set both heads on as an assembly just how i had removed them with absolutely no trouble.

 

One thing I noticed with this job is when I had removed the head studs/nuts all but a few came out with just a hand held 1' long 1/2" ratchet. They took no where near the effort of 175ft lbs to remove them.  Today I used a 3' long torque wrench and it was pretty obvious the old gaskets were not held down as tightly.

 

I suspect the old gasket was just soft with age or someone did not torque them properly. My book says to check them again after 1 hour of under load time. 

[fjh]

Yup I would retorq  for sure after some decent work time!

[Lmackattack]

https://youtu.be/ZXFH3xLgHtM?si=ZVOMdnOkcFqnAi1L

[Joey Mack]

I know that has to be a great feeling.. 

[Lmackattack]

26 minutes ago, Joey Mack said:

I know that has to be a great feeling.. 

I was nervous, I'm not going to lie!

 

Hopefully button it up after a valve adjustment and new valve cover gaskets

[Joey Mack]

I totaly understand....  I still worry when I crank one of my re-builds...  

[Lmackattack]

Can someone confirm if I adjusted the valves right. I think I may have miss understood the process. And I have never done a valve adjustment before.

 

I rotated the engine till the pointer was on the TDC mark of the damper with #1 on the compression stroke.

I adjusted cylinders#1 And #6 at the same time.

Then rotated normal engine rotation direction 120* to the next tic mark on the damper labeled cyl 5-2 and adjusted them both

Then rotated another 120* to adjust cyl 3-4 and adjusted them both.

 

I rotated  the engine 3 or 4 full rotations by hand to make sure no valve interference then started the truck and it runs fine but definitely seams to have more rocker ticking noise.

 

Where did I go wrong🙃

[Joey Mack]

roll it back to 1&6... dont go passed it..  then look at #2 exh. rocker arm... if it is rocked, valve open, then you are up on #1..  if not,,, you are up on #6..  if so,, go around one more time to 1&6.  then run the valves...  

[Geoff Weeks]

Just to add a bit of clarity, it take  TWO revolutions of the crank to adjust all the valves, when it point to 1-6 that means you adjust EITHER 1 or 6 not both (depending on which is on TDC compression) then you go to the next mark in line do the same there, when you come back to 1-6 you adjust the cylinder that was TDC exhaust the first time around, and continue on until all have been adjusted. 

 Unless it is different then I remember.