Fuel System redone

[Paveltolz]

Any idea whether the heads were GM, GEP or some knockoff?

In review I note that I missed your question on the heads, apologies.
The heads are GM OEM units. And Yes, the main issue appears to be the valves and springs. My theory is that one’s 635 (Ted) purchased for the build, like the Clevite main bearings, apparently were not used and failed. I’ve got my suspicions on the builders motives but…karma got him after his dad passed away and depression reared and took him and Diesel Depot down. So many others screwed over can attest.
“Life, Be In It”

 

[Big T]

In review I note that I missed your question on the heads, apologies.
The heads are GM OEM units. And Yes, the main issue appears to be the valves and springs. My theory is that one’s 635 (Ted) purchased for the build, like the Clevite main bearings, apparently were not used and failed. I’ve got my suspicions on the builders motives but…karma got him after his dad passed away and depression reared and took him and Diesel Depot down. So many others screwed over can attest.
“Life, Be In It”

I just hope this time around you get a normal 6.5 that lives to a healthy age, replete with all the customary issues.

 

[Paveltolz]

I just hope this time around you get a normal 6.5 that lives to a healthy age, replete with all the customary issues.

You and me both.

Small update as I learn and comprehend more.
The old valves’ manufacturer is still an unknown.
Springs were OEM but didn’t hold correct tension given the valves collapsing making the valves stems essentially longer so things got looser up top. “Rattly old diesel” comes to mind. A trained ear would recognize the difference between normal and “running stupid” though and I don’t have those ears.
Hence, the new Springs, retainers, etc.

Still a mystery is why the pistons ordered by Diesel Depot (original builder) weren’t the correct height in that they did’t/don’t protrude from the block 010” as is “normal”. When I bought the new pistons in 2012/13, I went with those specs. Built a lower compression motor without realizing it.


I’m going to (probably incorrectly) guess this was another reason why the heads were machined as much as they were which turned out to be .030”. Get the correct valve protrusions and get back to a more correct compression ratio.
What’s next…
Pre Cups themselves will not have their faces cut down, rather, their sockets in the heads will be recut with special tooling (on order) so they’ll sit correctly.

I'm extremely blessed to know people who have the knowledge, expertise and tools to do all this cause I’d have scrapped the truck after discovering the cam key wasn’t the issue (back on page 5).

 

[DieselAmateur]

Glad you've got forward motion on the project and will hopefully have a good running engine for years to come

With the heads being machined down like that, are the valves machined down on the flat face to match, or are the seating surfaces recessed accordingly?

Also not sure if you've seen it on a few other threads here but Chris @Twisted Steel Performance developed some stiffer valve springs with beefier pushrods to match. Not sure what your plans/ power goals are for the engine, but given the valvetrain issues figured you may want to know of possible upgrades out there

 

[Paveltolz]

For those interested, here’s a copy of the 2008 Article by Diesel Depot and 635's original build. I reproduced it so the file size would upload here.

 

[Paveltolz]

Glad you've got forward motion on the project and will hopefully have a good running engine for years to come

With the heads being machined down like that, are the valves machined down on the flat face to match, or are the seating surfaces recessed accordingly?

Also not sure if you've seen it on a few other threads here but Chris @Twisted Steel Performance developed some stiffer valve springs with beefier pushrods to match. Not sure what your plans/ power goals are for the engine, but given the valvetrain issues figured you may want to know of possible upgrades out there

Thank you for the ideas and suggestions.
For what I'm trying to do, power wise, now with the motor is just make it happy so the replacement springs are fine. Sorry Chris, maybe next time?
Valve clearances and such along with the piston height were all taken into account before the machining of the heads started. Valves have been profiled and, once the heads are done with the pre-cup holes recut to correct depth, will be test fit again just to be certain the 'negative protrusion' is what it should be.

 

[Paveltolz]

While waiting for Mother Nature & Holiday Crush to give UPS/FEDEX a break so the tool to cut pre-cup holes back to correct depth, the main caps were removed to inspect the bearings. “Something” has been moving through the oil with and while the bearings were OK, there was some signs of wear and on them that a <20K motor shouldn’t have. Crank surfaces were unmarried. So, the oil pump and pickup screen was inspected and a new set of Clevite bearings were installed. Bottom should be buttoned back up shortly. Once tooling arrives the process to finish the heads and get them reassembled and installed can begin. Might take another roadtrip up there to be around for the rebirth.

 

[EWC]

Don't know why someone would be cutting into the head , especially in that area . Why can't you take some meat off the cups with a surface grinder ?

 

[Big T]

While waiting for Mother Nature & Holiday Crush to give UPS/FEDEX a break so the tool to cut pre-cup holes back to correct depth, the main caps were removed to inspect the bearings. “Something” has been moving through the oil with and while the bearings were OK, there was some signs of wear and on them that a <20K motor shouldn’t have. Crank surfaces were unmarried. So, the oil pump and pickup screen was inspected and a new set of Clevite bearings were installed. Bottom should be buttoned back up shortly. Once tooling arrives the process to finish the heads and get them reassembled and installed can begin. Might take another roadtrip up there to be around for the rebirth.

Are Clevite bearings Amish made?

 

[Paveltolz]

Don't know why someone would be cutting into the head , especially in that area . Why can't you take some meat off the cups with a surface grinder ?

Other than attaining uniformity on all the pre-cups? My other thoughts are that it will preserve the cup's engineered outlet shape. Diamond/Square, T and one or two other types each have different outlet shapes. Removing to much from them and you'd probably start changing fuel distribution patterns. But, what do I know?

 

[EWC]

Don't take any off the face . I'm talking about the smaller diameter that goes into the head first . I wouldn't touch the face .

 

[Will L.]

There is also the lip on the face.
Gm specified cutting the head not the pre-combustion chamber. You cut the deep part and the lip area of the head.

You can cut the face of the precup, it will work. But the precup is inconel which is wicked hard. So doing it eats tooling quick. Yes cutting the face ever so slightly will alter the port- but so slightly I wouldn’t worry about it.

The big mistake some shops make is trying to resurface the head with the cup in place. It wrears their tooling bad and the precup is too low then.

 

[dieselolds]

There is also the lip on the face.
Gm specified cutting the head not the pre-combustion chamber. You cut the deep part and the lip area of the head.

You can cut the face of the precup, it will work. But the precup is inconel which is wicked hard. So doing it eats tooling quick. Yes cutting the face ever so slightly will alter the port- but so slightly I wouldn’t worry about it.

The big mistake some shops make is trying to resurface the head with the cup in place. It wrears their tooling bad and the precup is too low

I had 1978 5.7 diesel heads rebuilt by a shop an hour away from me back in 2007 and when I got them back they looked good and after I torqued them down using arp head bolts and ran the engine,it had a tissing noise like a loose spark plug that was expelling compression past the threads.It was only on the driver side bank so I took the head back off and examined it and one precup had sunk slightly downward past the surface of the head.

I sent the head back to them and they claimed nothing was wrong with it and they remachined the surface again leaving the precups pretty thin.It was nothing but pure bad workmanship on the part of the machine shop.It was pretty shotty service on the way the work was performed.

I since take my work to another shop which has a better reputation.I’m having a 1981 5.7 diesel rebuilt now.The heads,block and crank are at that shop now to get gone through.After that I’ll bring the connecting rods to them to get bushings and arp rod bolts installed.

 

[Paveltolz]

Block repainted satin black. 6.2 oil pan reinstalled. Turns out the black one I sent up was for a 6.5 block. Oops.
Still waiting on delivery of the machining tool to cut pre up chambers back to correct depths. Probably in a UPS/FedEx trailer stuck in a snow bank on I-94 in Minnesota.

 

[EWC]

When you get that tool , could you post some pictures and info on it ?

 

[Paveltolz]

Here’s a picture of the tool getting created that will be used for correcting the pre cup ridge depth. The main chamber tool is still getting fabbed. Since the New Jersey company originally tasked with providing the tooling has utterly failed us, Mike Eaton of Jessco racing is coming through for us again (he suggested and provided the Fly Cutter used to resurface the heads. Thing looks like it belongs on the wheels of a war chariot. Mike designs and builds tools so he can machine his motorcycle race motors to include the block and everything inside. Come see them at the Salt Flats. They usually set up near where Chris and Vesco Racing (Turbonator II [503mph]) does

.


.

 

[Paveltolz]

Tooling arrived and initial cuts on the pre cup insets are partially done. As it turns out the Pre Cups are getting replaced. I suspect another short cut by the original builder that assembled this thing for Ted. Once we get those, then final cuts on the heads will get done…when the machinist returns from a trip to AZ to thaw out. The trick was sourcing them, new and OEM. It isn’t like GM has a bunch of these still laying around. Turned out a friend of his at AMG came through so those are on the way. Unfortunately, they ain’t cheap.
Ted tried to talk me out of this in 2013. Proof again, ‘life is tough. But, its tougher if you’re stupid.’

 

[Will L.]

There are vendors that sell the AM General parts if you don’t want to do the direct order thing- it is a pain.

Care to share current pricing on factory GEP precups?
Guessing they are the square stamp ones? Thats what was available when I bought my set a couple years ago and had cut out to diamond specs.

Did he just take the heads off or has he opened the oil pan? Just wondering how the studs are doing and if y’all know the torque they were done to when built for Jody. There has been several of the early main studded engines fail now- (why I went through that clamp force testing thing). And on that - because I am good at spending other people’s money- while it is out is a prime time to add TSP girdle if you want to help that bottom-end.

 

[Paveltolz]

There are vendors that sell the AM General parts if you don’t want to do the direct order thing- it is a pain.

Care to share current pricing on factory GEP precups?
Guessing they are the square stamp ones? Thats what was available when I bought my set a couple years ago and had cut out to diamond specs.

Did he just take the heads off or has he opened the oil pan? Just wondering how the studs are doing and if y’all know the torque they were done to when built for Jody. There has been several of the early main studded engines fail now- (why I went through that clamp force testing thing). And on that - because I am good at spending other people’s money- while it is out is a prime time to add TSP girdle if you want to help that bottom-end.

Last check GEP was $6-800 for Pre Cups but, that was years ago. Not sure what kind of price we'll see but, it won't be that high, They are 'in the mail' though. I'll get a picture when they arrive I'm sure.
Oil pan came off, bottom end inspected, oil pump gone through, mains came off for inspection and bearings were replaced as a precautionary. Not sure about the torque values. Pan is back on so, too late really for the TSP girdle. My high RPM, put it on the flats druthers are gone. Just a weekend errand running / lumber getter, salt flats camping and support ops truck now.

 

[Will L.]

On the main studs- if you would please ask and share. I think gathering more information from people and how long the engine lasts will be really helpful for people in the future. The things that everyone knows now is only because people learned and shared before.