HIGH mile 6.5L build thread...

[restoguy]

Thanks for the ideas WarWagon. I'm begining to think the iron might have been in the oil pan from the begining. The babbitt is probably new, though. The turbo is nice and tight, and spins freely. It might have been replaced. My 94 had 175K on it and the turbo was looser than this one. I didn't have an oil analsys done. Wish I had thought of that, it might have told the story. I pulled the oil cooler off completely, no cooler in the rad or anything. I drove it for several days (3-4) afterward and there were no problems. I never pulled it or drove it hard, just to town and back, 60-65mph. The last day I got out and let it idle while I checked something and when I got back in the oil pressure was almost 0. It might have been low for a few miles before that, but I keep a pretty close eye on it so it hadn't been that way long. When I gave it a little rpm the pressure came up some, but not enough. About 20lbs hot was all it would do. Other than the damage to the bearings, everthing else inside the engine was exactly as expected for a used motor. No piston scuffing, or evidence of it being hot, and nothing out of place. It may have something to do with the internal bypass. It may have a piece of that metal stuck in it. The machinist is going to check things out for me.

Turbonator, do you see problems with the cast rockers not oiling well and wearing stuff? I mean, in the engines you take them from. The article I read said that's common, so they switched to the stamped style for the engine they were building. Do you rebuild them or just put them on as-is? Were they only used on '82 engines? I'm looking for a set, but I'm not too hopeful. Any info you can give me would be helpful. Got any you want to sell?

 

[restoguy]

Here's a little update on the plan for this engine.
I'm going to reuse the stock parts. I figure I'd rather give this stuff another chance and save money for the day a P400 is cheap enough I can afford it.(or I win the lottery, which ever comes first!)
I want to put a gear drive in it, if I can find one.
I will try to source some cast rockers from a 6.2L, and I will put head and main studs in it. My machinist has used the inserts that Missy, and others, love so much so I asked him to put them in whether it's cracked or not.
I will probably make a couple tie bars for the bottom end, but they will not be of the 'bed frame' variety!
I'm on the fence about the compression. I've wanted a low compression engine for so long, and now people are saying that with the ATT it's not necessary. I was going use +.010 head gaskets to drop the compression to 19:1. I figured that was a good compromise. But if it needs bored, I thought I would get the pistons that have the pin moved up .010 and use a standard gasket. Maybe I should just go back stock...
A 4" exhaust, gauges, and Heath tune will be included for sure.
Eventually I'd like to get a fluidampr and an ATT. When ever funding allows. Until then I'll either run the GM8 or get a craigslist HX35.
I think I'll put a new IP on it, since it seems to still have the original, and a set of well matched hi-pop's.
I think it's only smart to put a new water pump on. Spending all this money anyway, why cut that corner!?
Am I missing anything? Anyone see room for improvement? I don't tow much(frequency or weight), but when I do it's mostly in Colorado. Having more power, I will probably find more reasons and heavier loads to tow with it as well!

There's one little suprise that I'm not telling until it's already done. I'll post pics....

 

[3500GMC]

IIRC Bill Heath actually bumped the compression UP on that half ton salt flat truck he built. IDI diesels are weird.

I'd recommend a Fluidampr to anybody that wants to prolong their cast cranks. With the shitty chinese oem type dampers out there, the Fluidampr will outlast 20 of them. Probably more.

 

[randomid25]

we use the cast rockers on all our motors, they run much quieter and IMO are more possitive than the stamped junk...

GM got rid of cast rockers because they would crack, and eventually, break in two. The stamped rockers are better IMHO. However, the plastic pins that hold them on the pivot shaft is pretty goofy

 

[restoguy]

Just a little update on the progress.
I talked to the owner of the machine shop today. The heads are cracked between the valves. He didn't say how many cylinders have cracks, but I understood it to be several....maybe 8! They weren't leaking and he's fixed this problem before, so I'm thinking I'll let him try to save them.

The block hasn't been mag'd yet so we don't know if it's cracked or not, but the shop owner said they investigated the oil pressure problem. He believes the oil became super heated from being forced through the 3/8" hole in the bypass. After enough miles it broke down and wouldn't hold good pressure any more.(didn't someone suggest this before?!!) He said they plasti-guaged some main bearings and they were at .0025! Not too dang bad for an engine with almost 300K on it! I'm interested to hear how much wear the cylinders have too.

Hopefully I can be going back together with this thing in a couple weeks. I'm needing that 8' box and 1 ton diesel towing power everyday, it seems. I hate borrowing a Ford or Dodge from the guy I work for! Plus I'm excited to see how this thing runs with goodies on it!

 

[turbonator]

Thanks for the ideas WarWagon. I'm begining to think the iron might have been in the oil pan from the begining. The babbitt is probably new, though. The turbo is nice and tight, and spins freely. It might have been replaced. My 94 had 175K on it and the turbo was looser than this one. I didn't have an oil analsys done. Wish I had thought of that, it might have told the story. I pulled the oil cooler off completely, no cooler in the rad or anything. I drove it for several days (3-4) afterward and there were no problems. I never pulled it or drove it hard, just to town and back, 60-65mph. The last day I got out and let it idle while I checked something and when I got back in the oil pressure was almost 0. It might have been low for a few miles before that, but I keep a pretty close eye on it so it hadn't been that way long. When I gave it a little rpm the pressure came up some, but not enough. About 20lbs hot was all it would do. Other than the damage to the bearings, everthing else inside the engine was exactly as expected for a used motor. No piston scuffing, or evidence of it being hot, and nothing out of place. It may have something to do with the internal bypass. It may have a piece of that metal stuck in it. The machinist is going to check things out for me.

Turbonator, do you see problems with the cast rockers not oiling well and wearing stuff? I mean, in the engines you take them from. The article I read said that's common, so they switched to the stamped style for the engine they were building. Do you rebuild them or just put them on as-is? Were they only used on '82 engines? I'm looking for a set, but I'm not too hopeful. Any info you can give me would be helpful. Got any you want to sell?

we dismantle everything and reassemble the rockers on the back side of the shafts which look brand-new.... in the "pugg" motor, jim re-surfaced the sections of the oil-pump and at idle it puts 28-30 psi oil pressure, also these rockers take out alot of the tinny rattle sound that the stamped ones make.....

 

[restoguy]

Here's a little update, for anyone who cares.
My machinist and I were unsuccessful finding a torque plate to bore the block and I changed my mind anyway. I'd hate to spend a bunch of money on this block just to have it split in two when I put a little squeeze on it. The ex-military Optimizer engines are, frankly, cheap for what you get and I'd feel better spending money on one of them. My old block checked out crack free so I'm gonna put rings and bearings in it and see what happens. The bores are worn a little at the top, but without actually measuruing I'd guess it to be .010 or less. If it'll go a few more miles I can put the money together for a military engine.(And maybe they'll start selling P400's by then!) And all the power goodies will transfer over to the new motor when I get there, and I really want my diesel back!

 

[restoguy]

Oops....I may, or may not, have bought a used ATT. OK, ok. I did! Pretty excited about it, too!

I know this thread has been dragging along and I apologize to anyone who is watching. I was planning to be done with this by the end of Janurary...I just don't know which year! It's getting closer, though. I'll have more pics and progress in the next few weeks.

 

[GM Guy]

keep it up! you need to go sailing in the CCLB land yacht someday!

 

[restoguy]

Thanks for the good word. I'll bring it up to Colby when I get it together and you can check it out first hand! (that way I don't have to brag on myself, you can do it for me!) jk!

 

[restoguy]

Here's another update.
My direction/ideas continue to change. I'm still doing a ring/bearing job on the old girl, but I'm keeping it pretty cheap. I found a couple interesting things when I went to work on the engine. I'll post some pics and you guys can tell me what you think.

First, here's what the cylinders looked like before honing. Still some crosshatch, but not quite all the way to the top

While honing I found 2 cylinders with some 'damage'. In the first there is a ring of dots around the cylinder. I noticed the same thing on one ring when I was cleaning pistons.

The other cylinder looks like it had water in it sometime. Maybe it was condensation that acumilated while the truck sat for months before I pulled the motor? I don't know, but I'm 100% sure it's never had work done to the engine.

 

[restoguy]

Two other oddities I found.
The first is the 'ring' around the cylinders. It looks like some erosion around the fire ring, but I don't know why. Anybody?

The other is this damage to a couple pistons. This one seems the worst, but there were3 or 4 like this. I don't remember seeing this before I sent stuff to the machine shop, but I didn't really look. At first I thought a piston got dropped, but when I found several that way, I began to question what happened.

 

[restoguy]

Another thing I've never noticed before. There was no timing cover gasket, just some form-in-place gasket material. This is the way GM built it. No question. Look at the machining marks in the sealant.

My gasket kit didn't come with this gasket either. I was sure I've used a gasket here on the other engines I did. Anyone have any thoughts?

 

[restoguy]

I promised a suprise. Here's a hint....

BTW, the guy at the truck shop that ordered it for me PROMISED it would make more power and not fail(cracked block, broken crank, etc.) if I used this paint! It had better for $20 a can! (P.S. Detroit recommends 1 can per cylinder for their engines. Ouch!)

 

[3500GMC]

I like the paint choice. :thumbsup:

The piston looks 'melty'...

The bores actually look pretty good considering. Looks like you've HONED your technique by looking at the new cross-hatch... pardon the pun.

Lack of gaskets on these is the norm. Black RTV is a good choice.

Keep the assembly clean and pay attention to the little things.. Looking good.

 

[turbonator]

GM got rid of cast rockers because they would crack, and eventually, break in two. The stamped rockers are better IMHO. However, the plastic pins that hold them on the pivot shaft is pretty goofy

its funny, all the cast rocker assemblies that we have sourced and used are in excelent condition other than the shafts are a little used..... and these come from motors with upwards of 200,000km....

 

[restoguy]

"Melty" is what I thought too. Not good, but I'm gonna run them again anyway. The saggy spot was at the bottom of the cylinder near the reccaro(sp?) bowl on each piston.

I'm skipping the black RTV....and using grey. Because it matches the blue paint better! Seriously!

I can't believe this truck shows 290K on the odometer and still has the original water pump. Proof a 6.5 can be just as good as anything else. Just too bad more of them weren't like this one...

 

[tanman_2006]

Gives me hope for when I tear into Ol' Blue! :hihi: :rolleyes5: I am sure your truck wa better cared for than my 94, sounds like you had alot of highway miles with nearly 300K in 10 years.

I haven't heard the truck run in 4 years, but when jumped it turns over and TRIES to puff smoke, needs its own set of fresh batts before she will fire and a tranny, tcase, and whole front axle assembly before she can roll.

 

[restoguy]

"Gives me hope for when I tear into Ol' Blue! :hihi: :rolleyes5: I am sure your truck wa better cared for than my 94, sounds like you had alot of highway miles with nearly 300K in 10 years."

Yeah, you may be pleasantly suprised by what you find inside! So get after it!

300K in 10yrs makes it sound better than it is! I bought the truck in '07 with 289K on the clock. And a carfax showed it sold in '03 with only 117K! Someone put over 48,000mi per year on it before I got it! It doesn't(and never did) have a hitch in the bed. I've considered that the cluster may have been swapped for a junkyard unit showing more miles than the truck had, but I think it's not likely becasue these trucks don't have too many cluster problems.

 

[tanman_2006]

My 94 has had a hay trailer loaded with ~30,000 behind it on a regular basis. I doubt it is in good shape still but if the truck will start and I can find axles for an SAS/dually conversion I will get the project rolling.

At the moment it is one truck at a time and I have my 2 dd trucks in serious need of help. Ol' Blue will have to wait until next winter unless a miracle happens and I can find a ford or dodge dually with drivers drop front axle.