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Major engine rebuild taking place

A

arveetek

1/2 ton status
Joined
Mar 1, 2002
Posts
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Location
Granby, MIssouri, USA
Hey all!

Sorry I haven't been around for a while. I let my membership lapse and was debating whether to renew it or not...but I decided to come back! :D

I pulled my engine out this weekend to do a little "maintenance." I had a collapsed lifter that was ticking, and I wanted to install the DSG timing gears, stud girdle kit, and replace the worn out motor mounts. I decided it would be easier to do the work with the engine out. However, after pulling the engine apart, I realized it was time for a major rebuild.

My cylinders are worn and tapered, and the pistons are sloppy. So, I'm going to have the block bored, decked, and squared, and then I'm going to install custom fit low-compression ceramic-coated pistons. The Diesel Depot is supplying me with the 20:1 pistons at a great price.

I have two crack-free blocks, and I'm trying to decide which to use for my build-up. I think I'm going to ditch the one I've been using and use my spare block, because the starter ear on that one hasn't been broken off. My current block was welded and repaired, but the starter has always made a terrible grinding noise. Maybe now I can fix that.

So, when I'm all done, I'll have done the following: low-comp ceramic-coated pistons, new rings, bored block, new lifters, new bearings, stud girdle kit, new headgaskets, DSG dual-idler gear drive, new water pump, new oil pump, and I'm also going to install Energy Suspension motor mount inserts in the truck. I have all the parts here now, except for the pistons. I'll have to get the block bored and decked so I can get the correct pistons to fit.

I can't wait to get it back together! I hate having my Chevy down!

Casey
 
Casey,

Glad to see you decided to stay. It is interesting to hear about the stuff you do with these engines. How much do you estimate the rebuild will cost you?

Mark
 
Why the lower compression pistons if the engine is NA?
 
Looks like I'll have around $1300 invested with all the parts and machine work, unless I think of something more! I'm toying with the idea of a high flow Peninsular water pump and dual T-stat....but maybe I should draw the line somewhere.

At least I've been buying a lot of the parts over the past few months, so the cost has been spread out considerably.

My engine is not n/a. I'm running a turbo at about 14 psi max right now.

Casey
 
Ah, ok, I missed that part, 20:1 sounds good, I think with 18:1 you might see starting problems, let us know how it turns out!
 
Welcome back Casey! I was wondering where you went...

Keep us posted!

Rene
 
I got my block completely torn down and ready to take to the machine shop tomorrow. I decided to use my current block for a couple of reasons. First, it's an actual '82 block, with a date stamped on the rear deck of March of 81. It was also originally painted red. The other block had a date of September of 82. It was also originally painted black. That means it's actually an '83 block. Even though both blocks are crack free, I know that my current block has been run hard for 9 years and is still crack free. I don't know about the other one. It may not hold up as well, it's hard to say.

I also noticed on the '83 block that it had a flat spot cast into the block right above the passenger side water pump hole. On that flat spot it says "GM 6.2L." My '82 block doesn't have that flat area. This also lends to the idea that the '82 blocks are different.

The only reason I was thinking of swapping was the starter issues, but I've lived with that for 9 years, so I guess I can deal with it.

The more I research into it, it looks like the '82 red blocks are about the strongest GM made, and almost always end up being crack free.

Casey
 
A bit of a hijack Casey, but have you read or heard much about the AMG blocks?

I wonder if that might be a cost effective route to take to ensuring you have a strong crack free block that will stay that way?

No idea how much one of those blocks run though...

Rene
 
Yes, the newest blocks being produced by AM General are supposed to be improved and the best out there. However, you can't purchase just a bare block. Another DP member just went through this search after his 6.5L blew. He discovered that the only way to get a new block, like David said, was to purchase a complete longblock. I think you may be able to get a shortblock as well, but either way it is mighty expensive.

As of the info I have right now, the most desirable blocks are the '82 red models, and the 92-93 599 blocks. However, I do know of cracked 599 blocks, so nothing is for sure.

Casey
 
I talked to the shop yesterday and found out they had to bore it .030" over to get the cylinders cleaned up. They also decked it, and are ready to install the cam bearings. Should have it ready to pick up on Monday.

Now I have to decide whether to have the rotating assembly balanced. It will cost $150, and they'll balance the crank, rods, flexplate, etc. I'm rapidly running out of funds on a project I didn't actually intend to do. Whaddya think? Is balancing worth the money?

Casey
 
arveetek said:
I talked to the shop yesterday and found out they had to bore it .030" over to get the cylinders cleaned up. They also decked it, and are ready to install the cam bearings. Should have it ready to pick up on Monday.

Now I have to decide whether to have the rotating assembly balanced. It will cost $150, and they'll balance the crank, rods, flexplate, etc. I'm rapidly running out of funds on a project I didn't actually intend to do. Whaddya think? Is balancing worth the money?

Casey
Click to expand...

If you think balancing it will take someof the vibes out to help the dampner live longer then yes, if not then I think it's not worth it, you will not be screaming this engine at 8000 RPM's will you?
:D
 
imiceman44 said:
If you think balancing it will take someof the vibes out to help the dampner live longer then yes, if not then I think it's not worth it, you will not be screaming this engine at 8000 RPM's will you?
:D
Click to expand...

I'm not planning on turning it that fast!

That's kind of what I'm thinking....this engine has run for at least 23 years and who knows how many hundreds of thousands of miles, and it hasn't cracked the block or snapped the crank, or anything else like that. Even the machine shop said I wouldn't be able to tell any difference myself, but that the engine would know. While I agree that it would be a good thing to do, I've got to start restraining the spending somewhere!

Casey
 
I ordered my pistons this morning. The Diesel Depot said they'll offset the wrist pin location by .010" to compensate for having the block decked, and then they'll shave another .010" off the top of the piston to lower the compression, and then they'll ceramic-coat 'em to top it all off. They had to order the .030" over pistons, but should have them by Wednesday, and then hopefully have them ready to ship by the end of the week.

Compression ratio should be somewhere between 19.75:1 to 20:1.

Casey
 
Ha! I wish I'd known you were going to do all that! I just went through the same process. I had low compression in two cylinders and my fuel pump was on its way out. When I pulled the engine apart I found two cracked pistons, worn out valve guides and a cracked block, and the beginning of a crack in one of the heads. Well, I found a good block with no cracks for $190, but having all the work done (boring, honing, grinding, fixing the heads) ended up costing me a ton! When it was all said and done, I think I've got nearly $2500 into it. Let's see, uh Heads: plained, new valve seats, seals, guides, and springs. Block: bored to 040" over, honed, plained. Rebuilt fuel injection pump, ground and polished crankshaft, new 21.3:1 pistions, new rings, new wrist pins, new bearings (main, cam, and connecting rod bearings), new gaskets through and through, new vaccuum pump. Original or unreplaced parts include water pump, oil pump, followers and lifters (I have roller followers and they are perfect), camshaft, and uh, that's about it. I feel your pain, originally I thought this was going to cost me around $500 or so, maybe $750 including the injection pump rebuild. Oh well, what can you do! :grin:
 
Yeah, the money can start to fly when you start building one of these diesels.

How long did it take for you to get the engine back together and running, once you found a good block?

I wasn't going to do anything with my heads since it was running just fine, but I took one of the valves out, and it was sloppy in the guide, so it looks like I'll be dropping them off at the machine shop soon!

So far I've got at least $1400 spent. I'm not planning on touching the injection pump or injectors at this time. That can be done later if needed. I'm not sure how much the head rebuilds are going to cost me yet.

However, it looks like I may have an old cargo trailer sold for $900, so I may have some extra money to play with so I can get this done right the first time! I've been trying to sell that trailer for quite a while, but nobody was willing to pay me what I thought it was worth, so I decided to just keep it. Yesterday, a couple stopped by and wondered if it was still for sale. They're supposed to be by next week with the money. We'll see. If so, I'm definitely going to have the rotating assembly balanced.

Casey
 
I think that all the work I had done on the heads was nearly $700. That included: Valve springs, guides, guide seals, seats, surface grinding, cleaning and fixing one crack that was just starting to form. Labor only. The big expense was fixing that crack. Though, I would still count on spending $400 to $450 for the guides and surface grinding. It costs like half as much for gasser heads! Go figure! Once you get all the parts together, I would give yourself 2 days to get the engine together, back in the truck, primed, filled with oil and coolant, and ready to fire. It really helps to have an engine stand during the reassembly. I'm assuming you have one, but if you don't, it's well worth the $60 or whatever at your local parts store.
 
$700 for head work? Holy Cow!:blush: That seems outlandishly high to me! You can by new/rebuilt 6.5L turbo heads for that much.

How much did they charge you for the block work? I just got the block back from the shop this weekend, and for boring the block .030 over, resurfacing (decking), cleaning, inspection, and installing new cam bearings, they only charged me $355. That's parts and labor. I can't imagine rebuilding the heads costing twice as much as the block work.

Casey
 
Yeah, it kinda put a dent in my wallet! It was so expensive because they had to fix a crack. That included all the new parts for the valve stuff.
 
fbronson said:
Yeah, it kinda put a dent in my wallet! It was so expensive because they had to fix a crack. That included all the new parts for the valve stuff.
Click to expand...

Yeah some of these shops will screw you knowing you have better options liek getting a new part cheaper.
I was asking about turning a crank and they quoted me $350, that was before I knew that those cranks are not supposed to be turned since the surface is nitrided and I don't believe these guys were going to do that.
 
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