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Discussion Starter #1
I am going to build myself a "low pressure powerhouse" this is my plan, any input would be appreciated!


82 660 "red block" 6.2, bored for 6.5 pistons

new 93 6.5 heads

95 6.5 crank and rods

of course my db 2 ip and propane setup

water to air intercooler with custom built intake manifold, also homemade and tested on my current setup, constant readings within 10 degrees of ambient temp empty and pulling.


Does anyone know off the top of their head what the bore difference is between a 6.2 and 6.5?
 

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Keep the 6.2 bore and lower compression.
 

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Discussion Starter #3
penny for your thoughts

I though 6.2 engines had a higher comp ratio than 6.5? the other thing is this block need the bores cleaned up, so I figured bore it to 6.5, thanks for the input, stock bore and pistons for 6.2 a better deal?
 

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difference in bore is 2mm 95 crank will not fit in 82 6.2 block 82 2 piece rear main seal 95 one piece rear main seal everything else you want to do will work
 

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Discussion Starter #6 (Edited)
Duh!!!!

Thanks diesel pro, I got my thick head wrapped around what you said after I posted, Thanks again!

DUH again on the crank to block situation I also should have known about the seal issue.

I should pay more attention.

Will I have a heating issue if I bore that block to a 6.5? I have done some searches on the subject but not getting a solid answer,

Please bear with me, I am not real savvy on these 6.5 / 6.2 engines, but I really like what I have seen so far after my swap.
 

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The only 6.2 block that can be safely bored to 6.5 is the 91-92-93 interim 6.2L block - it was intended for 6.2 or 6.5 service, but the thick-wall casting was discontinued in favor of the standard wall casting for 6.5 only.

May get more info from the avant bros, at diesel depot.
 

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How does it pull your 30Ft 5er, because i am looking at pulling 5500lbs max with my rig. On the flat it pulls good but on 6% or 7% grades its a dog with 5000lbs. MAybe i just expect to much.lol
 

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How does it pull your 30Ft 5er, because i am looking at pulling 5500lbs max with my rig. On the flat it pulls good but on 6% or 7% grades its a dog with 5000lbs. MAybe i just expect to much.lol
I used to think 7% was steep until I went up a 10% grade in Newfoundland. It was like driving into a wall.
 

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Discussion Starter #10
good thoughts!

Thanks for the info, I wanted to use that red block because of the high nickel but the odds look to be stacked against it, I have a 599 block with a crack in #8 cyl, I think I am going to have that cyl bored and sleeved, otherwise the block is crack free and in good shape.

Mine handles my 30 ft really well, I pulled it through the bighorn mountains in wyoming this fall and we cruised right along, there are some 6% grades and steeper and we never got below 55, the only thing was I had to keep in lockup or else my egt,s would really start to climb, the faster the engine spun the more propane it would pull and that would really heat it up fast. I did shut down the propane and let it shift down to cool it off a touch right at the top, but I still did not drop below 55. I thought It did really well
 

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Wow! You are a brave man with 18psi boost and propane on a 6.5! How long have you run this set up? Just kinda curious. Most of us are a little spooked about running boost higher than about 14 or so if we want the engine to live in these things. Sure does sound good at higher boost though:ro)
 

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I have a 660 cast 6.2 as well, cost me $50, but needs a total rebuild.
 

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The '82 block would be a good builder.

As stated above, it is not advisable to bore a '660 casted block to 6.5L bore, as there is a chance that the cylinder walls will be too thin and crack. It's been done though.

You can lower the compression ratio in a 6.2 in the same fashion that you would for a 6.5. This involves first starting with the .010 reduced height pistons (that allow for a decked block) and then shave the pistons to achieve the lower c/r.

The Red block might be less prone to bottom end failure due to outside main bolt holes cracking.

The only problem with using the 82 block is going to be one less provision for the turbo oil feed. There isn't an oil gallery tap for the turbo feed on the front of the engine, but rather an auxillary port above the oil filter, next to the cooler lines.
 

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The only problem with using the 82 block is going to be one less provision for the turbo oil feed. There isn't an oil gallery tap for the turbo feed on the front of the engine, but rather an auxillary port above the oil filter, next to the cooler lines.

I looked the 660 block over and I'm pretty sure there's an oil tap at the front of the block with a threaded plug in it that looked like the same tap on a 6.5L block. I'll take a picture next chance I get.
 

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Thats awesome that you can pull that noprob so maybe i should quit being a weep. Because i am looking to get a bigger trailer for work and the family but did not wont it to heavy.
Thanks for the reply and sorry to hijack the thread
 

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Wow! You are a brave man with 18psi boost and propane on a 6.5! How long have you run this set up? Just kinda curious. Most of us are a little spooked about running boost higher than about 14 or so if we want the engine to live in these things. Sure does sound good at higher boost though:ro)
Propane for 6.5 has been done check this link for homebuilt unit by MIA from this site for a while; member Howie E http://mysite.verizon.net/vze54tx9/
 

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Discussion Starter #17
power diff?

Thanks for all the great replys,

I thouht about just staying 6.2, but 80 thou per cylinder is alot of bore to give up, Im sure it would lower my horsepower, plus I dont know if there are pistons that will take a turbo let alone the extra boost I want to run with lower compression.

As for being brave, I am likely living life on the edge with this thing, but I watch my gauges like a hawk, I have not done any cooling upgrades but I do not have any trouble with heating, But the warmest temps Ive pulled hard in are only around 80 degrees ambient. A 100+ degree day will likely be a whole nother animal.


But when I am empty, This thing is GONE! when I stand on It, 7.3s and 6.0s cant touch it! OH what fun for being 18 years old and paid off along time ago!
 

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Bill Heath (Heath Diesel) was running a twin turbo 6.2, T400 auto, in early '90s, 560hp, hi 11's 1/4mi in a '78 GMC stepside pickup.

Rig was stolen while he was outta town..............

Peninsular has 18:1 pistons for 6.2.
 
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