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GM 6.2/6.5 Bore and Stroke

I've got '93 3/4 ton Chev. pickup with the 6.5 L turbodiesel and about 212 thousand miles on it. Still runs real well and very little oil usage, but she's long in the tooth and it's my everyday driver. I've got a 6.2 L diesel that is also high mileage but ran good when I pulled it out of my son's '85 pickup that was wrecked. I'd like to overhaul it over a period of time and put it in the '93, along with the turbo from the 6.5. Was wondering if anyone knew how GM got the 6.2 block to 6.5? Was it bore or stroke? I can't seem to find the specs. on the internet anywhere. I'd like to bore it to 6.5 if that's how the increase was accomplished or maybe find a used 6.5 crank that could be turned if it was a stroke deal. I know the heads are different. I believe the 6.2 was 21:1 c.r., and the 6.5 is 19:1 c.r. If anyone has done something like this, I'd sure like to hear of it.

Thanks, Garrett Fulton

Reply to
gfulton
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Greetings,

If you go to

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and hunt around there is (or was) an article about putting a turbo from a 6.5 onto a 6.2. You may also be able to ask a question on their forum and get an answer about the cylinder dimensions. BTW - I don't know what the compression ratio for the 6.2 was, but it was over 21:1 (21.5:1 I believe) for the 6.5, not 19:1.

Cheers - Jonathan

Reply to
Jonathan

the ford power stroke is low in comparison at 17.5 to 1 as is the Duramax line. reason for difference is injection, the first two are indirect injection, the powerstroke and duramax are direct injection engines

Here's a nice little trivia page, test your knowledge

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I've heard a lot of bad press about the 6.2, but never believed it. I did a stint running newspapers what they call 'single copy", newspaper racks, newsstands etc. the trucks ran that 3rd shift 7 days a week, and 1st shift they were used to deliver sales flyers to stores and such 5 days a week. In the single copy crew we knew to modes only, throttle to the floor, or hard on the brakes, 3 ton step vans, Sundays the back bumpers would be dragging. I cant ever remember in the two years I did that three nights a week any truck losing an engine. The only problems with diesels are usually owner induced. Not changing oil and filter, dirty air filters, and not changing fuel filters. I still see quite a few Olds diesels, but they are all in the hands of people who know how to take care of them. I wouldn't worry about your 6.5 being long in the tooth. I might worry about the timing gears and chains as well as the chain that drives the injector pump, but if you have serviced as it should be, the rings and bearings probably have another 80 k before I would worry.

Whitelightning

Reply to
Whitelightning

Thanks for the website reference, and the specs. I needed fellows. The 6.2 on the engine stand in the garage has 234,000 m. on it and was running fine when the truck was wrecked. I'm a little anal with maint. as I changed the oil in both engines approx. every 2,000 and use the 2 qt. purolator filter. I did the timing chain on the 6.2 at about 110,000 and it's a lot more involved than a typical small block chevy type installation. Good engines, no complaints.

Reply to
gfulton

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