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2insane’s Random 6.2/6.5 Diesel Projects

imiceman44

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Do you happen to know the dimensions for the hose connection on the CDR valve that goes to the intake side on a 6.2L and also the dimension for the connections on the sides of the intake manifold? I think the intake ones are 3/4" but I'm not sure if the one on the CDR valve is 1" or something different. I'm gonna build a little manifold while at work to redo my plumbing away from the stock style stuff that isn't available.
I was able to find some parts that worked for me last year.
They were not exactly the same, the outlet on the CDR was a different angle but I found a hose the had the right bend for it at NAPA and cut it to fit.
 

Big Ray

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Twisted Steel, I talked with that fella on The Truck Stop forum.
Seems to know his stuff.
 

2INSANE

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Do you happen to know the dimensions for the hose connection on the CDR valve that goes to the intake side on a 6.2L and also the dimension for the connections on the sides of the intake manifold? I think the intake ones are 3/4" but I'm not sure if the one on the CDR valve is 1" or something different. I'm gonna build a little manifold while at work to redo my plumbing away from the stock style stuff that isn't available.

Bottom of CDR nipple going to intake on a 6.2 is 25.5 MM or 1.004” I think the Intake nipples on sides the Lower plenum for the 90 degree rubber elbow boots are about the same dimensions.

image.jpg
 
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2INSANE

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I want to share my method of how I like to bomb proof the lower ends on these motors depending on customer budgets.

Not trying to reinvent the wheel here and beat a dead horse… This “how to” is mainly focused to help those that are new to the 6.2/6.5 diesel world. This knowledge has been around for a long time!

BUT… First one must understand a few things before doing this modification.

As we all know, there are thousands of reports of 6.2 and 6.5 Diesel Engine web cracking. Yes, there are even reports of Optimizer Navstar 6.5 diesel webs cracking as well, just not as many…

My 6.5 Optimizer NAVSTAR/P400 theory:
  1. Starting with my 6.5 Optimizer NAVSTAR theory… Currently in 2022, there has only been a small handful of reported webs cracking. Well, first off, the block metallurgy is said to be of a stronger metal mixture of many different alloys. To my knowledge, no data tests have been published proving this. Secondly, these motors are expensive! Because of the higher cost of this block, there will not be a lot of consumer reports on this block, hence less reports of cracking webs. Thirdly, like the LP5 Duramax, these motors are still relatively new to the general public and there are not many high 200,000+ mile reports yet, so reliability and longevity is still unknown in general. So, in my opinion, the 6.5 Optimizer NAVSTAR block webs should be assumed to crack over time. Bomb proofing the lower end is a MUST IMO.
My 6.5 P400 Theory:

First, let us think for a split second… If the P400 lower end is soooo great and soooo strong and the webs are said to never crack… Why is there a freaking HUGE full Girdle on it from factory? It would not need a HUGE Girdle if the webs were not prone to crack right? Would anyone in their right mind buy a $10,000+ p400 motor and not have a girdle of any kind on it? Personally, I do not think so. Secondly, these P400 blocks are twice the cost of a Optimizer NAVSTAR, so there will be even less consumer reports on this block in regards to web cracking (Because of the Oem Girdle as well) and less longevity and reliability reports. So because of this, without a girdle on a P400, I feel it is safe to assume that even the P400 block webs could crack and the lower end bomb proofing is a MUST if you plan on not installing a Girdle on it!

Web cracking is caused by a lot of things.

Here’s the top 10 reasons!
1. A faulty harmonic balancer and/or crank pulley damper causes the main caps and webs to have micro vibrations from improper balancing (Movement of the webs/caps, which is the second main reason why these cracks happen, IMO).
2. Early blocks have wider main caps/web bolt holes, giving less metal support (The main third reason why the webs crack. Especially with the early model 6.5/6.5 blocks, IMO).
3. Over reving creates micro vibrations.
4. Stress risers/sharp edges that are just about as sharp as a razor blade on the sides of the webs and bolt holes. (This is the number 1 reason for the cracking web issues, IMO) Please refer to this article:

https://www.sciencedirect.com/topics/engineering/stress-raiser

5. Rapid Over heating oil and coolant with rapid cooldowns. (Think cast iron skillet. Turning off a hot motor without letting it cool down so to speak.)

6. Flex plate balance issues causes micro vibrations.

7. Metallurgy. (Least reason why they crack IMO)

8. Worn out crank bearings causing micro vibrations.

9. Owner neglect.

10. Main cap studs stretching.

Here are my 4 best ways to bomb proof a lower end.
  1. Removing the stress risers by Chamfering the web bolt holes at a 45 degree angle approximately 1/32” wide and file all the sharp edges on the webs at a 45 degree angle approximately 1/32” wide.
  2. Install a Girdle. Any Girdle is better then no Girdle at all. Here’s a list of girdles, starting with what I think is the best. A:Twisted Steel Performance 100% full coverage Girdle with full Arp Main Stud kit found here: . B:A homemade 75% coverage Girdle with a full Arp Main Stud Kit as seen here: https://www.dieselplace.com/threads/6-2-6-5l-main-bearing-girdle.378951/ C:Kennedy Diesel’s DSG 50% coverage Girdle with 6 Arp Main Studs as seen here:https://www.kennedydiesel.com/product/dsg-main-stud-girdle-for-6-2-6-5-engines-10mm/
  3. Having just the longer Arp full main stud kit could help but, the stress risers would still be there and without a girdle, it is still prone to vibrate the webs causing movement.
  4. Every oil change, check to see if there is any wobble with the harmonic balancer and if there is any wobble with your flex plate by simply going under your vehicle, with the motor running and use a stick to touch either of the two. If there is light tapping/rubbing on the stick or flex plate, then you should replace either. Visual checks are good but using a stick is a much better method because visual checks do not always show wobble to the naked eye.

So, let’s get started. So easy and does not take long at all. 1-2hrs with most of the time being used for clean up.

With the motor completely disassembled and right side up to let the metal shavings drop. I use a 3/4” chamfer bit and get at least a 1/32” chamfer on each web bolt hole. Pic 1-4

Then I file each sharp edge on the webs as seen in pic 5-7 getting a 45 degree angle about 1/32” wide.

Clean up is easy. Turning the motor upside down, probe all the holes, edges, etc with a magnet, use a shop vac and suck every surface area on the motor and finally using paper towels with WD-40 to wipe the motor clean.

This old school method reduces web cracking about 99.9%. Basically, in 40+ years, there has never been a report of webs cracking after doing this modification.

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2INSANE

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Today I also sprayed 3 coats of gloss black on the ORD motor mounts, refurbished the water pump plate and refurbished the vented valve cover by hand, not sandblasted.

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stump_puller

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I want to share my method of how I like to bomb proof the lower ends on these motors depending on customer budgets.

Not trying to reinvent the wheel here and beat a dead horse… This “how to” is mainly focused to help those that are new to the 6.2/6.5 diesel world. This knowledge has been around for a long time!

BUT… First one must understand a few things before doing this modification.

As we all know, there are thousands of reports of 6.2 and 6.5 Diesel Engine web cracking. Yes, there are even reports of Optimizer Navstar 6.5 diesel webs cracking as well, just not as many…

My 6.5 Optimizer NAVSTAR/P400 theory:
  1. Starting with my 6.5 Optimizer NAVSTAR theory… Currently in 2022, there has only been a small handful of reported webs cracking. Well, first off, the block metallurgy is said to be of a stronger metal mixture of many different alloys. To my knowledge, no data tests have been published proving this. Secondly, these motors are expensive! Because of the higher cost of this block, there will not be a lot of consumer reports on this block, hence less reports of cracking webs. Thirdly, like the LP5 Duramax, these motors are still relatively new to the general public and there are not many high 200,000+ mile reports yet, so reliability and longevity is still unknown in general. So, in my opinion, the 6.5 Optimizer NAVSTAR block webs should be assumed to crack over time. Bomb proofing the lower end is a MUST IMO.
My 6.5 P400 Theory:

First, let us think for a split second… If the P400 lower end is soooo great and soooo strong and the webs are said to never crack… Why is there a freaking HUGE full Girdle on it from factory? It would not need a HUGE Girdle if the webs were not prone to crack right? Would anyone in their right mind buy a $10,000+ p400 motor and not have a girdle of any kind on it? Personally, I do not think so. Secondly, these P400 blocks are twice the cost of a Optimizer NAVSTAR, so there will be even less consumer reports on this block in regards to web cracking (Because of the Oem Girdle as well) and less longevity and reliability reports. So because of this, without a girdle on a P400, I feel it is safe to assume that even the P400 block webs could crack and the lower end bomb proofing is a MUST if you plan on not installing a Girdle on it!

Web cracking is caused by a lot of things.

Here’s the top 10 reasons!
1. A faulty harmonic balancer and/or crank pulley damper causes the main caps and webs to have micro vibrations from improper balancing (Movement of the webs/caps, which is the second main reason why these cracks happen, IMO).
2. Early blocks have wider main caps/web bolt holes, giving less metal support (The main third reason why the webs crack. Especially with the early model 6.5/6.5 blocks, IMO).
3. Over reving creates micro vibrations.
4. Stress risers/sharp edges that are just about as sharp as a razor blade on the sides of the webs and bolt holes. (This is the number 1 reason for the cracking web issues, IMO) Please refer to this article:

https://www.sciencedirect.com/topics/engineering/stress-raiser

5. Rapid Over heating oil and coolant with rapid cooldowns. (Think cast iron skillet. Turning off a hot motor without letting it cool down so to speak.)

6. Flex plate balance issues causes micro vibrations.

7. Metallurgy. (Least reason why they crack IMO)

8. Worn out crank bearings causing micro vibrations.

9. Owner neglect.

10. Main cap studs stretching.

Here are my 4 best ways to bomb proof a lower end.
  1. Removing the stress risers by Chamfering the web bolt holes at a 45 degree angle approximately 1/32” wide and file all the sharp edges on the webs at a 45 degree angle approximately 1/32” wide.
  2. Install a Girdle. Any Girdle is better then no Girdle at all. Here’s a list of girdles, starting with what I think is the best. A:Twisted Steel Performance 100% full coverage Girdle with full Arp Main Stud kit found here: . B:A homemade 75% coverage Girdle with a full Arp Main Stud Kit as seen here: https://www.dieselplace.com/threads/6-2-6-5l-main-bearing-girdle.378951/ C:Kennedy Diesel’s DSG 50% coverage Girdle with 6 Arp Main Studs as seen here:https://www.kennedydiesel.com/product/dsg-main-stud-girdle-for-6-2-6-5-engines-10mm/
  3. Having just the longer Arp full main stud kit could help but, the stress risers would still be there and without a girdle, it is still prone to vibrate the webs causing movement.
  4. Every oil change, check to see if there is any wobble with the harmonic balancer and if there is any wobble with your flex plate by simply going under your vehicle, with the motor running and use a stick to touch either of the two. If there is light tapping/rubbing on the stick or flex plate, then you should replace either. Visual checks are good but using a stick is a much better method because visual checks do not always show wobble to the naked eye.

So, let’s get started. So easy and does not take long at all. 1-2hrs with most of the time being used for clean up.

With the motor completely disassembled and right side up to let the metal shavings drop. I use a 3/4” chamfer bit and get at least a 1/32” chamfer on each web bolt hole. Pic 1-4

Then I file each sharp edge on the webs as seen in pic 5-7 getting a 45 degree angle about 1/32” wide.

Clean up is easy. Turning the motor upside down, probe all the holes, edges, etc with a magnet, use a shop vac and suck every surface area on the motor and finally using paper towels with WD-40 to wipe the motor clean.

This old school method reduces web cracking about 99.9%. Basically, in 40+ years, there has never been a report of webs cracking after doing this modification.

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Good info. I got a 6.5 dually that’s blowing smoke from every orifice. still pulls good but looks like a freight train running away. Lol
If I get that deep in I will apply these mods to mine. Thanks.
 

2INSANE

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Good info. I got a 6.5 dually that’s blowing smoke from every orifice. still pulls good but looks like a freight train running away. Lol
If I get that deep in I will apply these mods to mine. Thanks.

What year is it and how many miles does it have?
 

2INSANE

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Started cleaning up the GM8 turbo. Darn thing is super dirty. It has a jerry rig actuator I plan on replacing.

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stump_puller

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What year is it and how many miles does it have?
93 with ~160,000. truck has had a hard life with not much maintenance done. (Before me). Didn’t smoke until after I was pulling my k10 over a mountain and might have pushed it a bit too hard. :dunno:. Didn’t seem to over rev it. But when I got off the exit, smoke was coming out from under the hood. Not heavy but you could tell.
funny thing is it smokes right at startup. Blows the oil cap off when you turn it upside down to check blowby.
 

2INSANE

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93 with ~160,000. truck has had a hard life with not much maintenance done. (Before me). Didn’t smoke until after I was pulling my k10 over a mountain and might have pushed it a bit too hard. :dunno:. Didn’t seem to over rev it. But when I got off the exit, smoke was coming out from under the hood. Not heavy but you could tell.
funny thing is it smokes right at startup. Blows the oil cap off when you turn it upside down to check blowby.
The 93 should be a good block to rebuild. Does it have a turbo? Sounds like you could use a compression test. Any weird noises like a ticking or thumping? Loss of coolant?
 

stump_puller

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Yea it does have a turbo. No weird noises or anything. The compression test is on my short list to help diagnose. Would a bad CDR valve cause this? Only thing I changed before my short trip.
 

2INSANE

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Yea it does have a turbo. No weird noises or anything. The compression test is on my short list to help diagnose. Would a bad CDR valve cause this? Only thing I changed before my short trip.
Compression test kits are cheap and they only take about 1hr to do. Numbers below 380psi usually causes blowby.

I did a compression test on an amazingly great running 6.2 diesel that had major blow by like what you mentioned and found his compression was very low.

I’ve seen low compression numbers on very low mile 6.2/6.5 motors. I’m talking like 23,000 miles lol.

Blowby could be caused by a lot of things. A bad CDR could cause some blowby but not that much.

Taking 5-10 minutes advancing the injection pump a little might clear up some of your blowby.

Bad injector, valves not opening and shutting when they should and super hot oil temps could cause blowby as well.
 
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2INSANE

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Here’s a couple more helpful tips on 6.2/6.5 motor preventative maintance.

Chamfering the starter bolt holes and filing the edges helps prevent the common starter cracking or breaking the block issues. The outer starter bolt hole is the main focus as it is the one that could crack or break. The starter support brace sometimes gets loose from road and motor vibrations. This is what usually causes the block to crack/break/grinding flexplate teeth and misalignment of the starter.

Also chamfering the intake lower plenum bolt holes and upper plenum bolt holes prevents the aluminum cast from cracking or breaking as well.

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centexk5

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I’ve got a soft spot for the 6.5’s as my dad had one growing up that we put nearly 200k on with only an injection pump at a 100k. But all this makes me glad I always drove a Cummins.
 

2INSANE

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I’ve got a soft spot for the 6.5’s as my dad had one growing up that we put nearly 200k on with only an injection pump at a 100k. But all this makes me glad I always drove a Cummins.
When my mom turned 63 years old, I gave her a 2001 Ford 7.3 Powerstroke that just rolled over 420,000 miles. Just about every part on it has been replaced multiple times, but the darn motor just keeps rolling along like it is still brand new.

Had a 2005 Dodge 5.9 Cummins for about 2 years. I liked the motor but I needed a long bed truck and wanted to get out of the payment because of the house I was building. Cummins is a good motor too!

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Big Ray

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My 1990 6.2 has 385000 on the clock. Don't know if it's the original motor or not though.
R2500 suburban. It was a slug, but I like it.
 
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