6.2 Block for 6.5 rebuild?

[afgunn]

I am wanting to rebuild my 6.5 (in sig below) in about 2 to 3 years according to the TurboDiesel Project truck engine build. And I want to start looking for a block now. From what I have read here and by following the Project truck, it would seem that it would be best to get a 6.2L block and have it bored to 6.5L IIRC, like Jim did for the Project truck. This would allow for cylinder cleanup and alignment without oversizing and avoid the weaken block from the oil passages. I also want to avoid the expense of "splayed caps" and the girdle, as in the Project truck. My truck is not and will not be used for towing so, I should not have the associated heat and stress problems as those who do tow. My main interest is in a solid, dependable light duty diesel daily driver pickup truck!

Ft Bragg is here in Fayetteville so, getting a block from a HMMWV or CUCV might be a little easier than other places.

Questions:
1) Would a 6.2 block be best? If, yes then which one(s)?
2) Would a 6.5L block be a good second best? If yes, then which one(s)?
3) Will I have any problems with bolting my 6.5 accessories, heads, intake/exhaust manifolds, etc. onto a 6.2 block?

[john8662]

Only late '92/'93 6.2 blocks ending in '599 for the cast can be bored out to 6.5L specs, they're somewhat rarer, If I found one of those, I'd run it as a 6.2 still.

As far as a 6.5L block. Any good crack-free '599, '141, or '929 cast block would be suitable. Other than that a good AMG block is the only way to go.

You wouldn't have any trouble bolting your accessories to a 6.2L block, with the exception of the oil cooling lines. The 6.2 and earlier 6.5 oil lines were 3/8", the later '506 block (which your '98 has) will be equipped with 5/8"

You can adapt and overcome though...

This is considerin you're using the late 6.2. Early 6.2 blocks can't be bored out safely to accept 6.5 pistons, and they don't have an oil provision on the front of the block to feed oil to the turbo, you can tap elsewhere though.

I wouldn't even consider building one of these engines without at least a girdle in it. They're NOT that expensive.

Splaying... Well.. It's a pain to get done, who knows how good it will be down the road in the long run... But, none-the-less, I had one done a while back..

[Robyn]

Both my 94 Burbs have 599 blocks.
In the recent rebuild I did on one Burb 247K miles the cylinders were sweet.
I just honed lightly and stuck in a fresh set of rings and a new set of bearings, heads and sundry other small items.
If these engines have been cared for at all the cylinders can go a looooooooooooong way.
I would not hesitate at all to drop a fresh set of pistons in a used bore as long as it was within reason. (No more than .002" taper and .002" out of round. Hone lightly with a bottle brush glaze remover and use a set of those total seal rings.
Select fit items are common in these engines so measure everything. bearings, pistons, crank journals ect
Check your bottom end for fit and if all is well install new soft plugs and a set of bearings and a new rear main.
The cam will run long too. If the lobes are not scored or worn a set of lifters is all you need.
New timing chain and gears (sprockets)
Of course gaskets and such.
I would deck the thing .010" and use the thicker gasket.
This is pretty much where mine went and it runs sweet. Oil pressure at 50 down the road and all is wonderful.
Not full race but this little beast will run a long time for not all that much $$$$$.
Heads are a must, I used a set of Clear water units and a new set of squirts and glow sticks.
Hope this helps
Robyn

[afgunn]

Ok. Thanks guys for your info. And yes it is very helpful! And quite likely will save me $$$hundreds!

Seems like it would be easier and better to find one of these '599, '141 or '929 6.5 blocks. Bit of a dummy here, I assume the numbers are the last 3 of the block numbers? And, where do I find these block numbers? My current block may be good and a good one to build. I don't know because I have not checked it yet. Want to have some options in case mine is not a good block number to rebuild or it has cracks. Plus it would save some down time to be able to have all the block work done before pulling my current engine. And yes, I probably should seriously consider the girdle if I am not going to use the splayed main caps - it would just bolt on and give that extra measure of insurance.

It might be easier for me to find a good used AMG block here in Fayetteville but, I have read that you can only get a new AMG block by getting one of their short or long block assemblies.

Anyone know which AMG blocks are good and which ones to avoid - years or numbers?

On a 6.5 block, should I avoid the ones that have the oil passages for spraying the pistions?

I do not know how well the engine has been taken care of, it had 170K when I got it. I do know that it has been used for towing some time back. Someone had put in a "fifth wheel" in the middle of the bed and the hitch has definitely been used. I seem to hear a light knock when the engine is warmed up but it may be regular diesel noise - I am not experienced enough with diesels to know. I will have to get someone with more experience to checK that - someone I know and trust that is. I have a neighbor that is a diesel mechanic, thankfully.

[afgunn]

I understand the '599 block is stronger because it does not have the oil passages for the piston spraying. Why are the '141 and '929 blocks stronger/better?

[john8662]

I understand the '599 block is stronger because it does not have the oil passages for the piston spraying. Why are the '141 and '929 blocks stronger/better?

They also don't have provisions for the piston oil spray cooling.

The '599 and '929 block are identical, the 141 is identical on the bottom end but has casting up top like a '506 block, basically for rear mounted turbo setup, if drilled out etc. Otherwise, it's a good candidate for building, cause it ain't got no sprayers takin' meat out of the block!

J

[afgunn]

Great! Got it! Thanks a million! You guys at this site have the best info without all the BS!