• Welcome to The Truck Stop! We see you haven't REGISTERED yet.

    Your truck knowledge is missing!
    • Registration is FREE , all we need is your birthday and email. (We don't share ANY data with ANYONE)
    • We have tons of knowledge here for your diesel truck!
    • Post your own topics and reply to existing threads to help others out!
    • NO ADS! The site is fully functional and ad free!
    CLICK HERE TO REGISTER!

    Problems registering? Click here to contact us!

    Already registered, but need a PASSWORD RESET? CLICK HERE TO RESET YOUR PASSWORD!

ARGGGG, more 6.5 blues

dually man

dually man

New Member
Messages
108
Reaction score
0
Location
Sandpoint, Idaho
OK, getting pissed off now. I just found that my 599 1993 6.5 NA out of a van with 52,000 miles that ran awsome has a cracked main web on one of the main bosses, it goes from the outer hole with the smaller bolt towards the cylinder wall, looks like an inch or so. Then I pulled down my other spare 599 block from a hummer 1999 model with oil squerters and 90,000 miles has major cracking on ALL the main webs, all four heads were cracked between the cylinders, and 15 pre cups are cracked to the firerings. Looks like I have paid 1000 dollars for 100 dollars of scrap metal. Is there anything I can do to save the 1993 block with the single crack? just about ready to blow 600 dollars on a cummins to gm bellhousing adaptor and solve my blues:mad2:
 
HAAAA, all I want for christmas is a non cracked 6.5 block, IS THAT TOO MUCH TO ASK?????? I looked at 3 more used 6.5 blocks today, well guess what THEY ARE CRACKED WTF??? now here is one for you, my origional 6.2 with a turbo killed the pistons by cracking and meltdown, I ran this thing hard, like 17 pounds of boost for a minute or so, after teardown there was no cracks in the block or heads, sold that block to a guy and he had it magnufluxed, no cracks found....The 6.2 I just put in my blazer, I pulled the mains off to inspect, no cracks, and for the record I have NEVER seen a cracked 6.2 block, and I have seen and ran many of these old 6.2 engines, even rebuilt a few for buddies. The 6.5 is supposed to be better ehh??
 
Cracks in the main webs in the old GM 6.x castings are a common fault. The local efforts here don't even sell them as used take outs anymore. They just yank 'em and toss 'em on the scrap pile. Too many comebacks, too many refunds.

However, Your 599 block may be salvageable if it's just cracked in one outer bolt hole. Stitch-lock inserts are what they are called IIRC. Missy goodwench does some. The insert is supposed to pull the crack shut and make it stronger than original. Usually installed by a machine shop.

Do a search and check it out.

I would highly advise sending the block out for a thorogh magnetic particle inspection (magnaflux) before sinking any repair/machining work into it...
 
So, I contacted 7 local machinist today withen 200 miles of me and all of them have done "lock and stiitch", but none would attempt it on a 6.2 or 6.5 block, as soon as I told them it was a 6.5 they were like NOPE absolutily NOT, even for any amount of money!!!!!!!!!!!WTF is wrong with people?
 
dually man said:
So, I contacted 7 local machinist today withen 200 miles of me and all of them have done "lock and stiitch", but none would attempt it on a 6.2 or 6.5 block, as soon as I told them it was a 6.5 they were like NOPE absolutily NOT, even for any amount of money!!!!!!!!!!!WTF is wrong with people?
Click to expand...

Nothing wrong with them, it's the bad rep the GM 6.5 carries with it.

They probably don't want to do the lock and stitch and have you come back saying they messed it up if it fails.

Probably "polishing a turd" in their opinion and guaranteed come back when it fails.

Come backs are avoided like the plague in the automotive industry. On top of costing money up front for the extra repair, it ruins a shop's reputation when word gets around by the layman, which costs them even more money in the long run.

They probably would just prefer to avoid the whole issue. Honestly, I can't say I blame them.

If anyone knows that a design is prone to failure, it's rebuilders. They have to sift through a lot of cores to find a good one if the design is faulty from the get go.

Probably much the same reason most wreckers around here just yank the GM 6.x engines and chuck 'em on the scrap pile. Not worth the "come back" headaches...
 
Ok then off with their heads and to the scrap yard they go, not gonna buy anymore used 6.5 diesels, matter a fact, I wont toutch anything other than an optimizer now, anything else is a waist of my valiuable time in this short life I have....
 
Not blaming anyone but myself but on the internet forums and in my home town, I was advised to look for 599 casting 6.5 blocks and it will be a good builder, WRONG... like I said before the 6.2's I have scrapped and rebuilt never had bottom end cracks, but they always had bad pistons and stuff like that. I am a firm believer of a 6.2 with 6.5 turbo upgrades and using the lower compression ratio of the 6.5 turbo engine. That combo with ceramic coated 6.2 pistons otta work well. My new name for 6.5's: crackers....
 
I just hope and prey that my wifes truck with the 6.5 and 160,000 miles holdes up, it runs great for now, atleast she dont tow with it. If that engine goes I would prolly build 6.5 with a 6.2 bottom end for it. The amount of time it would take to save for an optimizer block would be astronomical.
 
Well, you were and you weren't given good advice on forums.

Of the gm cast blocks (turbo), the 599 is the most likely not to have cracks.

That doesn't mean it won't, it's just your best chance.

I have no doubt there's 506 gm castings running around out there "crack free". The problem is you might have to strip 10 blocks before you fine a good one.

I've seen bottom end cracks in other designs, just not to the extent and frequency that the gm 6.x design has.

An alternate source of better castings are the military surplus optimizers. If you can find a GEP casting, it should be a runner or at least a good core.

You just have to remember that even though you may get a GEP block, it's a used military take out. It may have had a short service life due to the repower program, or it may have been beat to within an inch of it's life. Buyer beware.

A new optimizer will run you 6,000-7,000. A military take out can run from hundreds at auctions to a couple thou from a reseller.

Good luck.
 
I take that back, the 1999 6.5 I had was a 506 casting, with the oiler holes in the lifter galley for the center mount turbo. Anyways if I was to get another 6.5 it would have to be a NEW optimizer nothing used, Im not risking that again.
 
LIVE AND LEARN........when I bought these two engines I assumed the were crack free, I guess this is a hard lesson learnt, I was too lazy at the time to check the mains ARGGGGGGG
 
My 599 block i bought off craigslist had no cracking whatsoever on the block itself. Only on the heads. Im sure i got lucky.
 
You must log in or register to reply here.
Back
Top