6.2 conversion

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Jims86

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the earlier 6.2 heads with the coarse thread injectors had larger valves and would flow more, but the larger valve heads are also more prone to cracking between the valves. the coarse injectors are only used in the early heads, the later 6.2s and 6.5s use fine thread injectors.

the early heads use a long injector that has an angle that makes it wider and much harder to fit a 6.5 turbo exhaust manifold, but you are not wanting to turbo so it dose not matter.

all 6.2 and 6.5 heads can be interchanged (except for the turbo van and turbo Humvee engine heads)

in my engine I am using the 660 casting 6.2 block with 6.5 turbo heads and 6.5 turbo injectors.

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89Suburban

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Yup, like a boss
 

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Is there any mods you would do to the heads?


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I just ordered the fly wheel , oil Pan gasket one piece, head gasket and ARB head studs came to 380 shipped from summit. I think this will get me started.


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Chuck

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Well I got a complete rebuild kit. Some of the rings needed to be replaced. One main bearing was bad and a couple rod bearings were bad. Cylinders looked good so I honed and ordered standard bore. As I was checking clearances one main cap bolt broke off in the block. I drilled it out tapped in a easy out and that broke. Now I got to go buy a good drill bit to drill out the easy out. Any advice would help and could I replace the bolt with a grade 8.


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Chuck

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help

i threw out the old block and grabbed another 6.2 out of a manual 86 and dropped it in. i got a rad this time. when i mated them together it didn't feel right. i kept the clutch plate and pressure plate that was on the 6.2 on it. the truck with the 6.2 had a hydraulic clutch. can i use cable clutch system. any body got a easy way to explain the wiring.
 

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The 6.5 heads use a bigger opening for the precombustion chamber which is supposed to increase power over the smaller opening in the 6.2 heads. if you swap in 6.5 heads then you can run 6.5 injectors.

if your swapping heads or changing gaskets you can lower your compression with properly sized head gaskets. Ideally to 18.5:1 and then you can safely turn up your injection pump with out running into cracked head issues.
 

Chuck

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i just got the fuel lines run. the lift pump that came with the motor is dead gotta get a new one.can i run with out one. so i need ignition power the ip? whats the best way to hook up the glow plugs. the wires on the motor i butchered but i have complete harness from the last motor. could some one post pics and explain the wiring a bit Please. thats good to know about the heads theres some 6.5 parts forsale with turbo set up. this motor i wana just get running.
 

Chuck

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i hooked everything up to day and turned it over for about 30 min and she fired right up. i ran the distributor wires to the lift pump and one to the ip pump. glow plugs are next but i might wait till i need them. all in all it was a easy swap
 

columnshift

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I didn't read all the other posts (just responding to original post, and more for future readers since it sounds like it was done already) but from researching 6.2's for a past abandoned project the biggest thing i'd be concerned about is the Sudden Death Syndrome they seem to have that other engines dont. :p AKA where even a low mile engine can run perfect one day then just DIE in the middle of nowhere the next.

As near as I can figure out it's related to thermal stresses more than physical use (alot vs alittle, heavy vs light, all irrelevant) which develop cracks in the block. Since they dont produce alot of power they can often keep running even for years with cracks - but at some point they catastrophically fail. What the best way to check for cracks i'm not sure offhand without disassembly... it's mostly a gamble whether a used block will run for a decent long life otherwise.

If you use it as an around town runabout it may not matter but if you want to run into the middle of nowhere or take long trips and a breakdown would be a serious problem you might consider researching the issue more.
 

Chuck

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I've been running it for awhile now. From what I have found the harmonic balancer and flex plate loose balance.


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