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View Full Version : Rebuild vs. long block



jag7720
01-06-2012, 09:07
I'm considering doing a rebuild/build-up. 6.2 Buildup (http://www.dieselpowermag.com/tech/chevy/0554dp_62l_buildup/viewall.html)

My current setup is an 85 M1009 with either 50k or 150K miles (who really knows) and a Banks turbo added about 2 years ago.

The reason I am considering this is two fold
1. For the experience and project aspect (I can get my sons involved and make it fun)

2. To have a new engine that is stronger and will last longer. (who know what was done to these truck before we got them and an 85 with 50k miles is still a 27 year old engine.

I'm not into off road performance. My truck is a daily driver and is the occasional weekend back road trip. I do a little towing with a small trailer.

My truck got 21 mpg at 70mph when I drove it home two years ago... I assume it gets a little better with the turbo but I haven't kept track.

I have already upgraded my cooling, rebuilt my tranny and rebuilt quite a bit of the suspension (still stock)


So, my questions are these...

1. Will the 6.2 parts bolt up to a 6.5 long block? i.e. are they completely interchangeable?

2. Having never "rebuilt" an engine would it be cheaper to buy one of the "Improved" long blocks and do a swap of parts? Skipping the rebuild process all together. $4590.00 for the "Improved" 6.5 long block and $3590.00 for a standard 6.5 long block Improved 6.5 Liter Diesel Engines (http://www.6-5liter.com/ck_pickups-suburban.html) ... or $1500 for something from this place Marshall Engines (http://www.carparts.com/details/Chevrolet/G30/Marshall_Engines/Engine_Long_Block/1995/MEIG35020C.html)

3. Or would it be cheaper to find/buy an old 6.5 engine and actually rebuild it with a local machine shop doing the machine work?

4. I have read some stuff on the different blocks over the years and some having weaker points and using 6.2 heads on a 6.5 block etc... is there a consensus on this?

5. What is the consensus on the DSG Stud Girdle Kit? Is it worth it? Is it necessary on the "Improved" 6.5 block or the GM 6.5 block or any of the blocks for that matter?

6. Serpentine up-grade vs. non-serpentine belt system?


Any other advise???


Thanks

Yukon6.2
01-06-2012, 09:55
Hi
Do lots of reading on this site.Then do lots of homework on the vendor befor you send any of your hard earned $$$$$.There is lots of chinese junk for sale for the 6.2/6.5 family.It may be OK but you still want to know that is what you are buying.Don't rush into any purcase.Good Luck
Thomas

Robyn
01-06-2012, 10:59
Since I see that you mentioned the main girdle, its obvious that you are aware of the main web cracking issues.

Finding a good sound 6.2 or 6.5 can be project in and of itself.

I would stay away from the internet sellers of "Rebuilt engnes"

You really have no way of knowing what your getting.

Doing a rebuild on yours could be a great way to go.

The only caviat is, that once you rip it apart, you will not know what you have.

You can find a perfect block thats good for another bazzzzzziilion miles or a cracked mainline thats questionable at best.

A fresh AMG 6.5 longblock with the new catings is a great way to go as far as getting your $$$$ worth and not having issues later.

I have built many of these and been through everything from complete joy to downright sorrow.

IF is the biggy on these engines.

As far as a rebuild goes, other than the fact that they dont have spark plugs, they are absolutely no different than a small or big block chevy.

The heads are prone to some valve seat cracking and the main webs see cracks in the outer (center) bolt holes.

Its not a sure thing that you will find cracks in the block, but it's something that has to be looked for carefully.

The cylinder block decks can and do errode around the number one and two cylinders where the gaskets fire ring sits. This can be repaired by decking the block and using the .010" thicker 6.5 gasket.

Pistons and rods in these seem to have few issues.

Cranks have been known to break but its not a chronic issue.

Lots of info on this site.

Missy