6.5 Block and Head Questions

[ak diesel driver]

Its in the valley under the IP

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[DieselCash]

Here is a picture I could find.

 

[THEFERMANATOR]

It has the international diamond near where it says "506".

There is a post on here someplace with the picture of it.

Not all INTERNATIONAL castings had the diamonds. They poured them for about 6 months I believe before they added the diamonds to the molds(they used up the last of GM's molds with there updated metal for the castings). Also GM did a revised casting starting in 99 that had quite a few improvements. I don't think any made it into trucks, but vans got them as they were cast for the military for HUMVEES. you also need to check the date code and see if it was cast in 2000 or not.

 

[Chevypoor]

I was worried when I bought the truck that the block was a 506. I was thinking based on mileage that the original motor was rebuilt between 98-01. I was glad to discover it was a rebuilt stock block. While I prefer the 95 model anyway I tend to shy away from 96-98 trucks as a rule because of the blocks, ie the early oil squirters. Aren't all the oil squirters 506s? I realize all 6.5 blocks can crack my understanding is those are the most likely to crack.

 

[fentontruckdiesel]

That Makes Sense. I Have Yet To See A Diamond Block In A Truck. 506 I Ha E Run Into ARe A Ticking Time Bomb Unless Have A Ton Of Miles.

 

[THEFERMANATOR]

I was worried when I bought the truck that the block was a 506. I was thinking based on mileage that the original motor was rebuilt between 98-01. I was glad to discover it was a rebuilt stock block. While I prefer the 95 model anyway I tend to shy away from 96-98 trucks as a rule because of the blocks, ie the early oil squirters. Aren't all the oil squirters 506s? I realize all 6.5 blocks can crack my understanding is those are the most likely to crack.

All oil squirter blocks are 506's, but not all 506's have oil squirters. And the 506 blocks didn't start until about the 3rd month of 97 production as early 97's had 141 blocks.

 

[WarWagon]

With that amount of rust on the valve train I suggest you have coolant in the oil. Head gasket, cracked head, or crack in the block. I would check all the bearings and get different heads for sure. The pushrods, lifters, and rockers are done. Last rusty engine I looked at sat 6 months after mixing the coolant into the oil. I suspect your engine is not worth rebuilding. I imagine a valve could stick due to rust.



The crack was easy to see. It was still running on 7 of 8.

 

[Chevypoor]

WarWagon said:
With that amount of rust on the valve train I suggest you have coolant in the oil. Head gasket, cracked head, or crack in the block. I would check all the bearings and get different heads for sure. The pushrods, lifters, and rockers are done. Last rusty engine I looked at sat 6 months after mixing the coolant into the oil. I suspect your engine is not worth rebuilding. I imagine a valve could stick due to rust

Never thought of coolant in the oil. I have been wondering about all that rust. Surprisingly it has cleaned up well. Check out the Gallopin Gerdy thread in the projects section. The rust never made it to the lifters or the links. The bottom 1/2 - 1" of the pushrods were virtually rust free. The oil from the pan, filter, and cooler looked normal with no traces of coolant visible. The timing chain was clean but the injector gears were rusty. All the cylinders looked good as did the heads when I tore them down and inspected evrything. Hard to tell about the head gaskets as she had been sitting. She turned over real easy without any sticking. No rust on the block behind the timing chain and everything looked good as far as I could see into the oil pan with the front cover off. I will keep you guys posted as I am probably only a week or two away from firing the ol girl up.

 

[Chevypoor]

BTW forgot to mention that is one impressive hole in that cylinder wall!