GM 6.2 Diesel Questions

maddog411

Well-Known Member
Joined
Mar 22, 2005
Location
Harrisburg, NC
I know the stock numbers on these motors are pretty poor and they don't have a good rep, but is it possible to get one to around 300hp without spending a shitton on mods? Anybody know a good source of info on these engines?
 
6.2 with the turbo pistons and a banks kit is the best bet for HP
Watch for block cracks in the mains and cracked heads
Pic of my failed 6.2 build
ai40.photobucket.com_albums_e223_8379qtj10_2005_0608Image0001.jpg
 
6.5's are alot better than 6.2's but not worth the energy to do a swap. 300hp is alot to ask out of any diesel by just throwing fuel and wind into the hole.

My 6.5 is making 200hp, 500 ftlbs at the wheels which isn't bad. To get 300 out of it i would have to put new pistons in it and lower the compresion ratio get a bigger turbo. i don't think you want to go threw all that trouble with a 6.2.

Why 6.2-6.5's got a bad rep is beyond me, slow, maybe, but cheap to work on, and last forever if cared for, good fuel mileage. and one of my favorite reasons, injectors are outside the valve cover, how archaic.
 
Cperry said:
Why 6.2-6.5's got a bad rep is beyond me, slow, maybe, but cheap to work on, and last forever if cared for, good fuel mileage. and one of my favorite reasons, injectors are outside the valve cover, how archaic.
Click to expand...

slow, yes, by todays standards.

cheap to work on, yes IF you can do the work yourself.

Care and feeding, many owners expected to treat them like OTR semi's, 10k+ oil changes, even longer on fuel and air filter service's.

They have a history of head gasket failure's ( some that would destroy the block) as well as head cracking issues ( which is somewhat paranoia, they crack between the valve seats, an issue if the seat is also cracked, other wise, no problem, reassembled many like this, never an issue) Much of the head and gasket problems were owner inflicted by the OVER use of starting fluid when the injection pump crapped out attempting to start the engine.

there was a year they had some poor block castings, causing " block porosity" where coolant would seep thru the block into the oil, yep, thats bad, wipes out the bearings, but was also warrantied if it happened in a reasonable amount of time (not advertised)

I like the 6.5TD, it's quiet, powerful enough for anything I'd need to do, and, san's the Stanadyne DS4 injection pump is actually pretty damn reliable. Gimma a '93 with a DB2 and I'd be all over it.
 
well there are many ways to build up a 6.2 to handle more power and work better. First are you going to turbo it or non turbo it. IF you aren't going to turbo it you can still put a non egr intake. tune the injection pump and injectors as well as play with the timing. The exhaust needs to be opened up if you trying to help the airflow out of the engine.
If you plan on doing a turbo you can upgrade injectors to 6.5 marine ones along with the injector pump. Then there is the block . You can go a couple of ways on this. You can use a 6.5 short block if you want and then just install the 6.2 heads. No matter what block you use ,you should sonic test the block and it find out if if has cracks or weak.
As far as the internals you want to upgrade at the rod bolts and if you can the rods itself. Then if you want to really get more power drop the compression so you can run a bigger turbo. You can get 300 hp out of it if you want to do all this but if not you can get over 220hp with a normal good running 6.2 and a turbo kit.
I have a built one that has a big turbo and as long as you realize it isn't a big block you can be happy. My cucv runs 54 boggers and still gets almost 18 mph so as a recovery vehicle IM VERY HAPPY.
 
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