6.2 with turbo build in progress

[bubba_got_you]

How thick is the spacer and do you have one on the driver side?

I just got a complete 6.5td 93 and I plan on putting the Turbo and IP on my cucv. Is there anything
else that would be worthwhile (heads,ext.)? Does the intake off a 6.5 fit on a 6.2?

Amazing build I hope mine turns out half is good. Thanks for sharing this it truly is inspiring.

the spacer is 1/2" and it in not necessary for either side and i ended up removing the spacer in order to get the motor to sit lower and farther back than originally intended. the only reason i made the spacer to begin with was as a feel good part. i wanted the exhaust to be farther away from the injectors. but again the spacer is not necessary and ultimately i ended up not using it. and the 6.5 and 6.2 are almost the same motor so yes the intake and the heads will fit it.

 

[bubba_got_you]

[FONT=&quot]Ok so I haven’t posted in a bit because ….well I finished the build and install in the last few weeks and haven’t had time to post. Ok so here are the pix of taking the old motor out and putting the 6.2 turbo diesel in. [/FONT]

 

[bubba_got_you]

more

 

[bubba_got_you]

and more

 

[bubba_got_you]

ok that it on the pix for now maby after work Thursday i will get some finished pix and video

 

[bubba_got_you]

the camera broke so no vid yet sorry

 

[ralbelt]

Quite an undertaking. Nice work.

 

[WARWAG]

Beautiful!

 

[bubba_got_you]

Beautiful!

thanks

 

[bubba_got_you]

Quite an undertaking. Nice work.

thanks.
[FONT=&quot]There is a bit more blow by than I wanted to see but it runs like a scalded cat so im not going to mess with the rings as of yet.[/FONT]

 

[rango]

did you use regular ring gaps? or did you close them up any?, id go file fit with any boosted application

 

[bubba_got_you]

did you use regular ring gaps? or did you close them up any?, id go file fit with any boosted application

i did not rebuild the motor so i never did anything with the rings

 

[rango]

gotcha that would prolly explain the blowby then, on most NA vs FI motors, the FIs have tighter gaps to prevent blowby, but if its still running decent then it shouldn't be to much of issue

 

[jdemaris]

Clearances

i did not rebuild the motor so i never did anything with the rings

Non-turbo and turbo GM diesels (6.2s and 6.5s) use exactly the same clearances. Same ring-end gaps, same piston skirt clearances, same piston ring side clearances. For all, they vary slightly for cylinders 1 to 6, and for 7 and 8.

When checking over any 6.2 block, checking for hair-line cracks on the main bearing webs is the biggest concern. I have doubt that stud-girdles to anything to preserve block life - but I assume they can't hurt.

When GM finally addressed that cracking problem, they did it by making the oustide bolts on the main caps smaller to leave more iron in the block. If a stud girdle would of fixed the problem, I assume they would of used it.

Cylinder heads is another issue. Big valve heads on 6.2s are very prone to cracking. Small valve heads not so bad. The newest replacement Chinese heads are better yet. - I assume. They are much heavier built.

I also would never run more then 8 PSI boost IF you want an engine that's going to last a long time.

A few specs:

1999 GM turbo 6.5 diesel CR 20.2 to 1
Keystone rings - top ring end gap - (.25-.61 mm) .01” to.024”
2nd ring gap (.72-1.07 mm) .028” - .043”
Keystone rings side clearance - top - .0015” - .0052”
Piston skirt clearance - #1 to #6 .0035” to .0049”
Piston skirt clearance - #7 and #8 .004” - .0054”
Timing chain deflection:
New - .5” used - .8”


1986 GM 6.2 non-turbo diesel CR 21.3 to 1
Piston ring - top ring gap .03-.55 mm (.001” - .021”)
2nd ring gap - .75-1 mm (.029” - .039”)
Piston ring side clearance - top .076-.178 mm (.0029” - .007”)
2nd ring side clearance - .039-.080 mm (.0015” -.003”)
Piston skirt clearance - #1 to #6 .089 -.1145 mm Bohn (.0035”-.0045”)
Piston skirt clearance - #7 and #8 .102-.128 mm Bohn (.004”-.005”)
Piston skirt clearance - #1 to #6 .112-.138 mm Zollner (.004”-.005”)
Piston skirt clearance - #7 and #8 .125-.151 mm Zollner (.0049”-.0056”)

 

[ODdave]

Has anyone used the Low Compression pistons with the turbo yet? I was gonna give it a try but i shoved a 6cyl in there insted.

 

[67_C-30]

Has anyone used the Low Compression pistons with the turbo yet? I was gonna give it a try but i shoved a 6cyl in there insted.

Yes, I've built a low compression 6.2. You can run a lot more boost without the EGT and water temp getting out of control, which makes a lot more power. The negative with them is that are a little harder to start when cold, which where I live, was never an issue. It was still a great mod, and I have 2001 Navistar 6.5 longblock that I'm going to build with 18:1 's and a Holset turbo that will eventually end up my M1009. A low compression 6.2/6.5 will run with stock first gen Duramax and better than stock 7.3 Powerstokes and stock late '90's Cummins , and still live. Now the Duramax, Cummins, and Powerstroke can EASILY be made to make more power, but the low CR 6.5 will run better than they did stock. You can't compare it to late model DMax,PS, or Cummins though - they will blow its doors off! Mine was very impressive, and the guy I sold the truck to is still running it today (I built it in '05 and when I sold it in '08 I had put about 40K miles on it). It was in heavy '91 C3500 service body truck full of tools, pulling a trailer most of the time.

Here's a great article on a low compression build. I used a lot of info from this when I built mine:

TheDieselPage.com - 6.5TD Power & Performance Project

 

[jdemaris]

A low compression 6.2/6.5 will run with stock first gen Duramax and better than stock 7.3 Powerstokes and stock late '90's Cummins , and still live.

If you run a GM built 6.2 with high boost and fuel delivery, at the same power levels as a 7.3 IH/Ford Powerstroke of Cummins 5.9 there is no way it's going to hold up anywhere near as well.

There is no getting around the 6.2's cast-iron crankshaft, and lightweight block around the main bearing webs, and thin crack-prone heads.

All the IH/Fords have heavy blocks and forged-steel cranks -even the older IDI 6.9s and 7.3s. Same with the Cummins.

Granted that in some later 6.5s, GM made the outside main bearing bolts smaller to prevent block cracking.

And there are heavier 6.5 blocks now being made.

And there are heavier 6.5 heads now being made.

And there are now forged-steel cranks availalbe. but they won't fit the 6.2s that have two-piece rear-main-seals. - which is most of them.

 

[67_C-30]

If you run a GM built 6.2 with high boost and fuel delivery, at the same power levels as a 7.3 IH/Ford Powerstroke of Cummins 5.9 there is no way it's going to hold up anywhere near as well.

There is no getting around the 6.2's cast-iron crankshaft, and lightweight block around the main bearing webs, and thin crack-prone heads.

All the IH/Fords have heavy blocks and forged-steel cranks -even the older IDI 6.9s and 7.3s. Same with the Cummins.

Granted that in some later 6.5s, GM made the outside main bearing bolts smaller to prevent block cracking.

And there are heavier 6.5 blocks now being made.

And there are heavier 6.5 heads now being made.

And there are now forged-steel cranks availalbe. but they won't fit the 6.2s that have two-piece rear-main-seals. - which is most of them.

No, they'll never be as durable as the others, but when you lower the CR, there is less cylinder pressure (even with more fuel) at 15 - 16 psi than there is with a a stock CR 6.2 with 8 - 10 psi boost. Lowering the CR helps with the issues you are speaking of. The late 90's - early '00's Cummins and PS's were putting out 210 - 215HP and 440 - 450 ft lbs TQ, and that's the numbers I was talking about. A 6.2 with a Banks set-up is fairly close to those numbers, those engines live, if don't beat them to death. The low CR 6.2 I built has nearly 100K miles on it now, and though it hasn't been beat, they haven't been easy miles. Many people have done it, with great success. Now, if anyone thinks they can get modern Dmax/Cummins/PS numbers out of a 6.2, they are dreaming - as I said in before.

The last 6.2 and earliest 6.5 block (599 casting) is better than the 660 casting, the newer 6.5's (after 2000) are better and the newest GEP P400 6.5 is the best. I have a Navistar casting enhanced 6.5 with thicker main webbing, the smaller outer main bolts, thicker decks. It also has thicker, better flowing heads. It is the next engine I'm going build up because it is a better platform, but I would no issue building and running another 18:1 6.2 if I didn't have it.

 

[jdemaris]

The last 6.2 and earliest 6.5 block (599 casting) is better than the 660 casting.

Yeah, I've heard over the years many theories and claims as to what was the better block. I don't believe, nor do I disblieve any of them. The reality is, there IS no hard evidience to prove any of it - one way or the other.

The first year 6.2s with different color blocks, coarse-theaded injectors and leaky cylinder-heads are often claimed to be the best 6.2 blocks ever - due to a higher nickel content in the block - like International/Navistar does now with the newest 6.5s. I will say, I've never seen an 82 block that was cracked at the main bearing webs. But to be fair, many 1982s got taken off the road at low miles due to blown 700R4 transmissions that could not be repaired successfully. I have three 1982 blocks ih my shop right now. All with less then 100K miles on them. Some day I'd like to do a metal test on them .

The 83 and newer 660 blocks are often called the worst since so many cracked at the main bearing webs. yet, I've got several with 200K plus miles with no cracks and had one that went to 520K before the block and crrank blew to pieces. I think more cracks are noticed with these engine since so many were used and driven high miles.

The next block series that at first was used in both 6.2 and 6.5s, with the one-piece rear main seal is often called the best. Yet, I've seen many crack in exactly the same places as the older blocks. Keep in mind the "new" blocks have not been around as long, nor were as many made.

Then you've got many more subtle changes over the years with 6.5 only blocks - but I'll stick with just the 6.2 stuff.

I've been working as a mechanic on 6.2s since they were invented. I also own over 20 and have been using them for many years. I have seen many, well cared for 6.2s and 6.5s blow to pieces at 200K from metal fatique. Just going by that one fact, adding much more power has to shorten the lives of these engines - on average. Maybe a few get away with uppiing the power, yes. Same can be said for my all -stock 87 J-code 3/4 ton 4WD Suburban that pulled a trailer quite a bit and lasted to 520,000 miles. All it proves is a few can make it . It is also well established most do not.

Now, if I had a 6500 Optimizer heavier high-nickel bloc,k, a forged steel crank, and heavy heads - I'd have reason to be more optimistic.

 

[67_C-30]

Yeah, I've heard over the years many theories and claims as to what was the better block. I don't believe, nor do I disblieve any of them. The reality is, there IS no hard evidience to prove any of it - one way or the other.

The first year 6.2s with different color blocks, coarse-theaded injectors and leaky cylinder-heads are often claimed to be the best 6.2 blocks ever - due to a higher nickel content in the block - like International/Navistar does now with the newest 6.5s. I will say, I've never seen an 82 block that was cracked at the main bearing webs. But to be fair, many 1982s got taken off the road at low miles due to blown 700R4 transmissions that could not be repaired successfully. I have three 1982 blocks ih my shop right now. All with less then 100K miles on them. Some day I'd like to do a metal test on them .

The 83 and newer 660 blocks are often called the worst since so many cracked at the main bearing webs. yet, I've got several with 200K plus miles with no cracks and had one that went to 520K before the block and crrank blew to pieces. I think more cracks are noticed with these engine since so many were used and driven high miles.

The next block series that at first was used in both 6.2 and 6.5s, with the one-piece rear main seal is often called the best. Yet, I've seen many crack in exactly the same places as the older blocks. Keep in mind the "new" blocks have not been around as long, nor were as many made.

Then you've got many more subtle changes over the years with 6.5 only blocks - but I'll stick with just the 6.2 stuff.

I've been working as a mechanic on 6.2s since they were invented. I also own over 20 and have been using them for many years. I have seen many, well cared for 6.2s and 6.5s blow to pieces at 200K from metal fatique. Just going by that one fact, adding much more power has to shorten the lives of these engines - on average. Maybe a few get away with uppiing the power, yes. Same can be said for my all -stock 87 J-code 3/4 ton 4WD Suburban that pulled a trailer quite a bit and lasted to 520,000 miles. All it proves is a few can make it . It is also well established most do not.

Now, if I had a 6500 Optimizer heavier high-nickel bloc,k, a forged steel crank, and heavy heads - I'd have reason to be more optimistic.

Yes, I've seen some headscratchers, too. I've heard of low mileage, well cared for engines have the cranks break, head gaskets blow, and heads crack for no apparent reason. However, in the 7 or 8 of them I've owned, I've had great luck and had none of these problems. I've also heard of a lot of people that jump in them cold without warming them up and complain about "having to put it on the floor to make go" and cranking them with starting fluid when the GP systems stop working, so a lot of problems with these are probably the result of how they are treated.

From my experience, I have seen morre failures of the early 506 6.5 block. I've seen a lot of cracked 660 blocks, but most of them were pulled running and the cracks weren't known until they were disassembled. I had one that I sold running at 330K and another at 280K and I've always wondered if they were cracked, and if so, when they cracked. I have always used the main girdle on the ones I've built, and I'm like you, I don't know how much they help, but they can't hurt. Guys racing Ford small blocks over years swear by them, and I've seen the results of high HP SB Fords that didn't use them, so I feel like they help.