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Discussion Starter #1
Well I've got the bug for a new motor in my truck, partially because the 6.2 I have now has a nice rod knock in it. So This last Wednesday I went out to a guys place and bought an 86, 660 Casting, 6.2 diesel with what appeared to be 57,000 miles. I cant guarantee the mileage but opening it up will tell me for sure if I got a lemon or not. Pictures of the motor soon and I'll keep this as a running turbo build post. But today I'm here for information mostly, especially from the turbonator crew.

A little background on the planned motor build. 6.2 Block with 6.5 turbo setup using an HX35 or HX40 turbo run through a front mount intercooler into an F code intake. Go through and re-seal the whole motor with new gaskets and put a new FelPro +.010 headgasket in. From here is where I need some advice.

Head studs, worth it or a waste of my time and money?
Main studs, can I use these without a stud girdle and not worry about block cracks or use a stud girdle as well? Also what studs for the bottom end as I have not yet seen a kit for it.

I'll probably have more questions down the road but this is for starters. I should have pictures up later this evening of what all I am working with! I appreciate the help gentlemen!
 

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Discussion Starter #2
Well, up until a couple hours ago it was a good weekend! Got the motor torn apart and found on cylinders 4 and 8 the heads had a small hairline crack between valves (going to pressure test and use if they pass) and the bottom end has every main bearing web cracked a little. Going to weld those up carefully with my MIG and hope for the best, throw ARP studs in and make a stud girdle then start putting the motor back together! Turbo manifolds have been sourced, just need to find a serpentine belt setup, figure out my gauges (EGT and Boost), and get a lot of parts ordered up, including a turbo.

BUT! Not to bore anyone here's all out favorites, the pictures! More to come as progress continues. In order;

1. The way I picked up the motor with everything attached on my stand.
2. Stripped down to everything but heads and covers off.
3. Heads off and block flipped with pan off to check for cracks.
4. Just one of a good handful of cracks in the bottom side to be welded up.




 

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well if you plan on welding up those cracks your going to have to do a few things. first off you can't weld them up with a mig welder. when welding on cast you need to use nickle rod. i would recomend using a stick welder with an electrode no larger then a 3/32" rod. also you will need to drill a hole at the end of the crack to keep it from running and grind a groove in the crack to get good penatration. when welding on anything that is cast you need to preheat the casting to atleast 600 deg F. after you weld the cracks your going to have to keep it hot and bring the temprature down slowly which means keeping a torch on it. bring the heat down to about 400 deg after about ten minutes and then down to about 200 deg after another 15 minutes. after that you can let it cool on its own if the air temp is above 60 deg.the best way to do the heating if availible is to use an old oven.
though to be honest with you i would search for another block to use. good luck
 

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Cracked main webs will not make a good turbo motor. I doubt you could effectively weld that back into shape. You should scrap it and get a different block.
 

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Diesel Technician, Formerly zland76
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Ditto, keep all the parts and scrap the block.
It will go boom especially with a turbo on it.
 

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Ex- 6BT Square Body Man
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Scrap that block, it would be a big bummer to get it all together and have it grenade a few miles down the road.
 

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I thought 6.2 blocks were supposed to be stronger than 6.5 blocks?

Either way, sounds like a fun project.

I am planning on using an HX35 too, sold my HY35 as I needed cash, :mad:
 

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660 blocks are boat anchors.
The other 6.2 blocks make great turbo motors.

I had a 660 block.

The heads on that motor are great non-cracking fuel economy getters.
 

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Discussion Starter #9
Whole motor is scrap. Machine shop wont touch em cause they found a crack between the valves. Not going to waste my time on the block either, aint worth it. Probably gonna dump a 6BT in it or something. We'll see in the end. I'll keep this updated as I go with whatever I end up with!
 

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What year are 660 blocks?
 

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Diesel Technician, Formerly zland76
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I bet the heads are still good, there can be cracks in the HEADS, not the blocks.If they tested them then they would know for sure.

Bet you can get a good 6.2 but i understand the dismay with them, helps keep them cheap for the rest of us.
 

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it would be sooo much cheaper to get a replacement 6.2 vs fitting a 6bt. you can get one from teds trucks n stuff delivered and you would still be miles and dollars ahead. the 6bt would be cool... well i used to think so until i looked at what it takes to do it right.

getting a decent cummins engine is tricky for a good price (at least around here, people always want at least $2k for a junker) then you will probably want to mate it with a dodge tranny for ease (and an overdrive!) you have 3/4 suspension which would probably work, but its still recommended to go bigger to handle the extra weight. then dealing with the mounts and on and on...

if it were me, i would just keep an eye out for another 6.2. worlds easier. plus, everyone has a cummins, the really unique people have 6.2's :cool:

side note, you are in washington? where about? im in boise and have 2 engines that ive been meaning to tear into. one im keeping for a replacement when the one in the truck has issues. i havent inspected either yet, but if you are still looking when i get around to it i will pm you.
 

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R.I.P. Sam
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took me 3 blocks till i found a crack free on. found an 82 red block by just taking my time and keeping an eye on ads
 

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The rods likely aren't scrap, I bet some one would buy them

A nonrunning cummins B serries demands as much as $2000 for a non-running rebuildable one. New ones are worth up to $7000. Used and rebuilt fall some where between those 2 prices.
 

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A nonrunning cummins B serries demands as much as $2000 for a non-running rebuildable one. New ones are worth up to $7000. Used and rebuilt fall some where between those 2 prices.
it would probably be cheaper to buy a running early cummins truck (i see them from $3800-6000 here) and then you have just about everything you need. still is a very expensive and time consuming task.
 

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Ex- 6BT Square Body Man
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Love the sound of a 6bt but man they are not cheap, just saw an ad for a motor $1800 with 188k on it. yikes.
You could have a collection of 6.2s and hop one up with the money left over.
 

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plus there is something to be said about how EASY it is with the drop in replacement. not spending tons on custom engine mounts and weld/cut/weld it again to make the cummins align properly. im not trying to discourage anyone from doing it, and if you have the money and skills to pull it off, more power to ya. but for the price of the conversion, you could get a good 6.2 block, nice paint, custom upholstered interior and still have change in your pocket :)

I wish the 6.2 members lived closer, instead of spread out over half the world. :(
 
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Discussion Starter #18
Well the big issue I'm having is a 6.2 is just such a weak motor in comparison to a 6BT. I do a lot of heavy work with my rig and need the grunt without worrying about destroying a bottom end, etc. So thats the big reason I'm leaning towards a 6BT. I also do all my own work so I can fab up the mounts, do the electrical, plumbing, and so on and so forth. Not a big deal at all. And really, who doesnt like a Cummins (any of em).

Yes money wise it's more expensive, I'll admit that. I'd end up spending about 1500 on a cummins swap, or about 800 on a 6.2 swap because I would be studing the motor and doing turbo stuff and all that which arent cheap to begin with. If I was going for a mileage king, 6.2 all the way but I'm going for OK mileage but reliable power is my aim.

But not really sure what the end goal will be, going over all the options right now.
 

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or keep the 6.2 for fun and light duty and get an early 90's dodge for the heavy lifting. least amount of work involved all around :)
 

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it would be sooo much cheaper to get a replacement 6.2 vs fitting a 6bt. you can get one from teds trucks n stuff delivered and you would still be miles and dollars ahead. the 6bt would be cool... well i used to think so until i looked at what it takes to do it right.

getting a decent cummins engine is tricky for a good price (at least around here, people always want at least $2k for a junker) then you will probably want to mate it with a dodge tranny for ease (and an overdrive!) you have 3/4 suspension which would probably work, but its still recommended to go bigger to handle the extra weight. then dealing with the mounts and on and on...
My bosses old 99 Ram was hell on the front axle and suspension, even with a stock cummins in it. I always envied his "big" diesel and D60 front axle...but I guess I just haven't tried a kingpin 60, because I was definitely not impressed with any part of his truck.

It would make a good long hauler though, that's about it.
 
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