599 blocks

[625fireman]

While putting new head gaskets in I looked and found out that I have a 599 block. Is there anything special I should know about them??? Weakness, strengths.....etc

 

[DieselSlug]

I think i was told they are one of the "more" sought after blocks. My new engine is a 599 block...

 

[THEFERMANATOR]

599's are said to be the better 6.5 blocks for non squirters, and the 04+ 506 AMG blocks are the best overall from what I have read. The early 599's were also found in some 6.2's as GM used the same blocks and just bored them out furthur. Some have said they have bored 599 6.2's out to stock 6.5's with good results.

 

[Missy Good Wench]

The 599 casting is a late 6.2 early 6.5 block. It was used for the real late 6.2's 90-91 and later. Has the one piece rear main seal just like all the rest of the 6.5's..

The 599 has the large outer main bolts on the center mains (97 and later blocks used a 10mm washer headed bolt on the 6 center bolts to try and reduce the cracks.

These blocks will see center main web cracks just like all of the 6.2 engines of days gone by.

They dont generally have issues with cyinder wall cracks like the later squirt blocks (97 506's)

Overall a 599 that is in good shape is definately a keeper.

The 929 casting is also a good one to use.

Stay totally away from the early 506 squirt blocks. These have a 12mm outer main bolts and the large oil squirt holes in the main saddles.

These early squirt blocks are notorious for cracking through the main saddles and into the lower cylinder walls.

Even worse was the later (98-99) 506's as these late blocks had a nasty habit of cracking the number 8 cylinder wall at the top rear.

599's are about as good a chunk of iron as you can hope for unless you step up to the new AMG/GEP Blocks.

Now if you find the small cracks that are common in the center outer mains this is not a terrible thing.

These cracks ccan be repaired nicely with the Lock and stitch full torque inserts.

The issue is simple, as long as the cracks dont go below the bottom of the bolt hole (preferably not below mid level of the hole or less) your good to go with the inserts.

I recommend doing all six center outer holes even if they are not cracked.

Its not If they will crack, Its when will they !!


The other issue is deck errosion around the number 1 and 2 cylinders where the fire ring contacts the deck.

Coolant lays against the block in the passage in the gasket and the stainless ring of the gasket and the Iron block makes it a great spot for electrolysis to set up.
The gasket etches into the deck of the block and will eventually fail.

You can deck the Block .010" and use the Felpro .010" thicker gasket.

Now this said, ALWAYS check the piston to deck measurement.
With the piston at TDC it should be flush with the deck.

Do this on both sides before tearing the engine completely down.
These blocks are getting old now and its easy to end up with a block that some shop has decked one side and not the other at some point earlier in the engine life.

You can get a special custom gasket thats made to order from Cometic but they are spendy.

The Block that I used on DaHooooley wound up getting decked and I did not find out that it had been decked before on one side until after I started putting it back together.

Was a real PITA to deal with. Ended up having to buy a .070" thick gasket for the one side and used the .010" thicker gasket (.055" thick) on the other (Felpro)



Check any blocks before spending a buttload on machine work.

Easy to do.
Drop a set of mains in the front and rear saddles (used are fine) and a piston and rod (Less rings) in the cylinders and check the deck to piston measurements.

The factory spec will place the piston flush with the deck. Some may be a couple thou below deck to a couple thou out of the hole.

Any major amount to piston protrusion means that the thing has had the deck/decks cut.

Hope info helps things out.

MGW

 

[HighSierra86]

Thanks for the above info missy.........but i do have one more question, what about the older 6.2 blocks?? ive got a line on one with 20K original miles but i think it is an earlier style. Ill have to find out the casting number

Is there anything to watch out for if i am going to add a turbo? or am I better off with a 6.5 block?

 

[packratt]

That's what my new motor is based on. Have early 6.2 block with 2 piece rear main seal. Rebuilt 6.5 heads and remainder parts off my old motor.

You will need the oil pan that goes with the 2 piece seal blocks (different than the one piece 6.2 and 6.5)

Turbo oil supply is T'd in back at the OPS port.

 

[chevyCowboy]

i found a guy that is selling a 6.2 motor out of an 84 that he put in the truck in 96 said it was a create motor would this be a desirable block he is checking on the casting numbers