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Rebuilding A 6.5 Diesel First Time Need Help

DZZ71

DZZ71

"Living The 6.5 Dream"
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Alberta,Canada
Hello everyone im new to the site and im overwhelmed with all the info on the 6.5s here. I have been a dieselplace member sine last year and never knew of this site until i got a truck and was told about it form the owner. Now i got a 1995 chev 6.5 and the engine is gone in it. I just got a newer block today with a reground crank shaft, new pistons,used camshaft,harmonic balancer and the old pistions and conecting rods. Apon inspection at home a found a few cracks on this 599 block and im not sure if i should do my build off it. I did do some research about the LOCK AND STITCH fix but i need some second opinions. All of these parts have been sitting in a garage for 2 years until i bought them today. Also the block has been machined out 30 tho over. I will be using the heads from the old engine asuming they are still good.
 

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DZZ71 said:
Think there is enough there to hold the starter?
Click to expand...

If its fixable/weldable it would have the best shot being out of the truck, that's for sure. Does the bolt hole go all the way through? If not, couldn't you drill it through, tap the entire length, and use a longer starter bolt?
 
Hey DZZ71!

Glad to see you found this site....FWIW guys - this is the hotrod that he is putting back together...treat him well...
 
The heads in the hotrod are good....you may want to swap out the precups for larger ones if power is what you are after...
 
I hate to say it but that starter hole is kinda scary to me.. A lot of torque needs to be absorbed there and on the side of the block. Maybe you can fix it, maybe not. I like to sleep warm and fuzzy at night, knowing there is a patch job on an important part of the engine is scary..... If it was just the cracks and not the broken starter hole i would say good to go, but man that starter hole sucks....:confused: I dont think there is enough there to hold a starter. I would frain from using that block, Do you have the broken off piece?
 
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I do not think those other small cracks are an issue, certainly worse still in service with no problems.

could you weld a stud in the start bolt hole? Would it go on that way? I never took mine off before.
 
Hi there.

That starter bolt hole being broken out like that is a dead Knell to that block.

The 6.5 needs two good starter bolts that have good solid threaded holes.

I would not even start building on a block with that chunk missing.
Stripped holes however are easily repaired with a Heli coil

Small cracks in the main web outer bolt holes are easily fixed with a Lock and Stitch insert.

The 6.5 block is not a good candidate for welding either.

Find another block that is sound to build your diesel monster with.


MGW
 
The guy had over $800 worth of work done to the block from what he said. I do not have the piece that broke off. What if i drilled it right out and re threaded it? The guy that sold it to me also mentioned there is a bracket you can put on starter to take the torque off that hole? What do you guys think? I could try and weld it as long as no other cracks will start. How much is a new block? I just hope i dident waste $900 yesterday.......
 
I think you got took on that block. Cranks are not grindable on these engines[surface hardened].
 
The stress in that area is severe. The broken bolt is still visible in the pix.
The first 1/4 inch approx of the hole has no threads and the Knurled portion of the bolt goes in there.

This setup gives the bolt a very tight fit and assures the best alignment and minimal starter movement.

This sort of break is caused by leaving the tail bracket off the starter. The starter gets to wiggling around and flexes the bolts until they fatigue and then break.

The bolts will break right at the point where the knurl and the threads join. I have seen many broken ones

Another cause can be from an engine that blew a head gasket and hydro locked.
Someone gives the starter a whizzz and BANG the engine comes up hard and the starter falls on the ground.

In many cases one bolt will break and the starter will simply kick out of the ring gear. Some times both bolts break and the starter falls out on the torsion bar "CLUNK"

AND in some cases the corner of the block breaks out like this one did.

Hard to tell exactly what happened but it was for sure related to that broken bolt.


MGW
 
Cranks are very much grindable on these engines. Its done all the time.

Most bearing manufactures offer all the normal oversizes for these..

Normally the surface hardening is a process (GM calls it tuffdriding) that is done to the forged steel shafts and not the Iron ones. (Although they could have induction hardened journals)

The stocks shafts I have seen never seemed like the journals were very hard as compared to a nitrided steel shaft.
The steel shafts have a hard "skin" that is about 40 or so Rockwell but its very thin and grinding will go through it.

At any rate there are a metric buttload of 6.2/6.5 engines with ground cranks out there.

The 6.2/6.5 cranks have a very large fillet relieve and as long as the grinder pollishes the fillet after the grind, there is no issue.

Myself I prefer a standard crank in these engines but it's still not an issue.

If the industry was not grinding cranks then the major bearing makers would not offer inserts in Undersize. (GM even offers the undersizes for ground shafts)


MGW
 
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