Thinking of going from 6.5L to 6.2L, thoughts?

[Pipeline Mechanic]

Hi ALL,

I am an experienced Diesel field service mechanic that specializes in
Caterpillar heavy equipment. I own my own service truck and have a
small shop. I work on most anything that is interesting or pays well, enjoy
a good challenge. I am posting this here to get some insight on a new
project that I am stating this weekend or first of next week, I am hoping
to get some insight from the most knowledgeable site I have come across
on this subject. Thanks in advance!

I have a 1995 Chevrolet K2500 and its 6.5L is in the bed of my 2001 K2500
6.0L gasser. I have been doing quite a bit of research and have decided the
stronger block of the 6.2L is the way to go. I will be reusing the electronic
injection pump and all related parts from the 6.5L Turbo for this swap. I am
curious if anyone here has ever done this? I am more concerned about
reliability rather than performance, another engine failure will make this truck
ready for the scrap yard. I will also be rounding up the necessary parts to
convert to the dual thermostat cooling system as well.

[Robyn]

FIRST OFF WELCOME TO TDP
:D:D:D

OK, The first thing to speak on is the Block issue.
Absolutely any 6.2/6.5 block can crack and any 6.2/6.5 crank can break
There are no magic bullets and no perfect casting numbers.

Now this dirty laundry aired, there is usually a reason for the cracks and breakage

Failures of the harmonic ballancer and or the dampened serp drive pulley is to blame for many iisues. Dual mass flywheels may also have been a contributor in many cases (Failures causing tortional vibration)

I personally would not seek out a 6.2 block for a replacement but instead would find a 6.5 block with the casting numbers ending in 929 or 599

Stay away from the 506 blocks that have the oil squirters in the mainline of any model year.

Some late engines would also crack the #8 cylinder radially around the top about and inch down from the deck in the rear (looking from the RH side about 7-8 oclock)

Now, the center main cracking issues are easy to fix as long as the cracks are in the bolt holes and do not originate from the corner of the register fit.

Cracks in the center bolt holes that are not more than about 1/2" or so long (within the hole) can be repaired with the Lock and Stitch thread insert.

I do many of these repairs in my shop.
The tools (drill, tap and installer tools are available from Lock and Stitch)

Once done these holes wont crack any more and wont break either.

Some folks go the splayed main cap route, this is good but expensive.
Requires that the mainline be remachined as well as the outer holes in the center mains be filled and new angled holes drilled and tapped. (Plus new caps)

Another biggy on any of these blocks is to debur and break all sharp edges and corners in the lower end.
All bolt holes need to be lightly chamfered to remove the sharp edge (1/32" wide) EVERY MAIN BOLT the pan holes are ok as is. Even chamfer the cap holes.

Just a touch with a counter sink is all thats needed.

All the main web edges that are sharp need to be hit with a file and the edge broken and smoothed (1/32" wide) you can do the main bore edges but be careful there and use a round stone or abrasive paper roll.

Make sure there are no nicks or dings in the lower edge of the cylinders too. If so debur and smooth.

The 929 and 599 blocks will have 12mm bolts at all main locations.

Bore and hone per standard practice.
Set the piston to cyl wall clearances at .004" for cyls 1-6 and .0045 for cyls 7-8

Bearing clearance is fine at about .002-003" no tighter than .002

A late model 98 or so oil pump will give you oil pressure to die for.

(The later pumps had to feed the oil squirts and were higher volume and used on a non squirt block gives better delivery)

Replace the cam bearings per standard practice be sure to use a set that has the notched front bearing and install like factory.

For most NORMAL uses the stock type piston with 20:1 or so comp is fine.

Check the crank with magnaflux for cracks and if still in good shape just pollish.

Ballance the rotating assembly to race specs. (Helps a lot with the vibes :D)

Stock cams and fresh lifters are the real deal (good used cam thats ok will be great with new lifters)

Cam and crank timing gears rarely wear and normally I only install a fresh chain.

Any stretchy rod bolts need to be tossed. Torque about 5lbs more than spec and if they wont hold at that toss the bolts and get a new set.

Heads

I would not spend a thin dime on a used set of GM heads as far as machining them. If they need machine work I would toss the heads and get a fresh set from Clearwater in Florida.

These are $670 to your door for a set. New castings and they have a great reputation and good warranty.

************ Top ends hints**********

The pushrods have a copper color on one end, this may be easy to see and maybe not, copper color always goes to the Rockers.

If this is not done the rockers and push rods will wear quickly and fail as the one end is hardened and the other is not.

The TTY head bolts are a bit tweeky.

I go throough the first torque step to 30 Pounds then to 55 then 55 again and then do the 1/4 turn then go back through the pattern and take the bolts up to a point at which it just starts to turn and then note the torque. I then make all the bolts the same (using the pattern)

After the 1/4 turn step many of the first bolts will loosen a little (gasket mashes down more.

Having all the bolts even is very important.

Felpro head gaskets are the best choice.

The deck of the blocks do errode around the fire rings. If this is noted the blocks can be decked .010"

Be sure that the pistons do not protrude above the deck more than the .010 if the block is decked and flush if the deck is stock.

Cometic makes special gaskets if you have to deck beyond .010"
They will make gaskets thicker as required (MLS type)

This should help with the touchy spots.

Just finished a 6.5 for a 95 Dually truck recently.

There is a thread in the 6.2/6.5 tech forum on the build.

The other mods you spoke of are spot on for these engines.
HO water pump, dual stat Xover is good.
A good free breathing exhaust is a must have to get the heat out
I would probably invest is a fresh radiator if the old one has loads of miles on it.

Hope this helps

Missy Robyn

[Pipeline Mechanic]

Missy,

I really appreciate your taking the time to type all of that. I am in the process of moving and am wanting to get this project behind me. I am
already to the point of spending more than the old truck is worth. I found an outfit here in the Nashville area that has warrantied rebuilt 6.2 for $1495.
I am about to give up a 141 casting block that is in good shape, 2 sets
of heads (everyone cracked between the valves), a crank that needs turning on the main journals, and the cam is still in the block.

Here is what I come up with, well first of all I have OCD when it comes to overhauling an engine. My 6.5L failed from overspeed, I sold this truck in pristine condition and bought it back for scrap. I had a rod failure on the #2
cylinder and it ruined the crank when it lapped and locked between the block. By the way, I wasn't the driver!

I rounded up a busted block 6.5L for the donor crank and rods, basically
in my world I have a big pile of scrap metal.

Ok, by the time I pay for machine work on my block,
buy the master overhaul kit, a set of heads and assemble all of this is
getting close to the $2500 mark. The truck is only K2500 by name, it is what we used to call a "heavy-half" since it has 6 lug wheels. So it's only useful qualities are going to be fuel economy and 4X4. Since there is not a lot of value in the truck, it is not a classic, I have a hard time doing my usual and going "all out" on the overhaul.

Now my reasoning for the 6.2 is anytime you bore an engine .080 over
you are asking for problems and that 22cu in just doesn't seem worth it to me. If I can improve the cooling, make use of the Turbo from the 6.5L, reuse the electronic controlled injection pump, and save on parts cost, wouldn't that make sense?

Seems there could both a durability and fuel economy gain here, or am I way off base?

Thanks again! I really enjoy chatting with people who are knowledgable for a change! :D

[Robyn]

I fully understand the dilema.

The parts swap from the 6.5 to the 6.2 will work fine.

Use the timing sprocket with the reluctor off the 6.5, the timing cover that has the port for the crank sensor.

The heads for a 6.5 (need the proper injector angle to work with 6.5 TD fuel lines)

Use 6.5 head gaskets (Felpro) along with new TTY head bolts

All the rest bolts right up.

The only thing you wont get with the 6.2 is the hard coated piston crowns like the 6.5 has.

The 6.2 and 6.5 are the same engine with only some minor changes.

Mix and match sort of :)

For a driver it will work fine.

The real late 6.2 Blocks (599 castings) could be bored to stock 6.5 diameter the older 6.2's can't

Have fun and keep us posted.


Robyn

[Pipeline Mechanic]

I went to Diesel Fixer LLC in Hermitage,TN and give them the core parts for inspection. I will be picking up my freshly rebuilt 6.2 conversion engine
on Monday. They are installing the 6.5 timing cover and custom building me
an oil pan for it as well. We will probably start Monday afternoon with
assembly for installation. Hope to have black smoke blowing by this weekend!

These guys are cheap on prices so I will be the test mule for anyone else who
is thinking about using them.

Here are some pics for entertainment purposes! After all thread is useless without pics. ;)
http://i38.tinypic.com/2emq490.jpg http://i37.tinypic.com/ka1gdx.jpg http://i37.tinypic.com/119yt6p.jpg http://i38.tinypic.com/why3cl.jpg

Also towing in no problem with a a 6.5L Turbo Diesel, at least not when it is ON the trailer! Our intended recipient of this transplant is
on the back of the trailer. The old Chevy 350 did a great job of hauling this 20K lb (gross) load 3380mi avg 9.1MPG. The 36x12.50 tires in the
bed may end up on the diesel if the transplant goes well.
http://i30.tinypic.com/10rpxxu.jpg

[Pipeline Mechanic]

Pics added!

[Robyn]

Tweeked the pix a bit so we can see them better. :)

Missy

[Pipeline Mechanic]

Thanks, I am bad about just point shoot and link! :D

[Pipeline Mechanic]

Missy,

Do you still have that dual t-stat housing? I posted in your "garage cleaning" thread. email me longjohncalls yahoo com

[Pipeline Mechanic]

Okay, we have been busy with other projects so I haven't devoted the time to this that I had intended on.

So here are a couple of pics of progress thus far;
http://i35.tinypic.com/2h7281g.jpg

http://i35.tinypic.com/2eds409.jpg

[Pipeline Mechanic]

Babysteps got us a little further along today, tomorrow is slated for the push to the finish, thought you "followers" may want to see how we handle "outdoor" installs.

http://i33.tinypic.com/znwql0.jpg

http://i34.tinypic.com/2e5ie5f.jpg


http://i34.tinypic.com/25qr9di.jpg

http://i36.tinypic.com/2m607bl.jpg

[Pipeline Mechanic]

For your viewing pleasure;

http://i33.tinypic.com/195w0.jpg

http://i34.tinypic.com/2i70n74.jpg

http://i33.tinypic.com/2dm8h8w.jpg

http://i35.tinypic.com/mtutti.jpg

http://i36.tinypic.com/27xqslv.jpg

http://i33.tinypic.com/15e7hp0.jpg

http://i37.tinypic.com/2hywaq1.jpg

[6.5 Detroit Diesel]

wow, nice looking setup. that "lift" would come hand for my r&r. want to take a trip up to canada? :D

engine looks pretty good too. i just would have done something with those manifolds. powder coating maybe? :confused:

[Pipeline Mechanic]

I would have blasted and painted them if I was going for show quality and put up with the smell of burning paint for awhile. We had a little time waiting for a parts delivery I started playing with paint! :lol:

On the trip to Canada, can't do it. I read where a truck driver was fined $305.00 for smoking in his OWN truck, sited as "smoking in the workplace"
I would be in a Canadian jail over shoving a ticket book in their 4th point of contact. ;)

You are welcome to come down though!

[6.5 Detroit Diesel]

LOL, that was out in Ontario. the laws out there are a little whacked, like most of the lawmakers out there. come on up to bc. and if you go through ontario and shove that ticket book, gimme a call and i will come bail you out. would do it for the laughs. :D good luck on hooking everything up. it will be nice to get that truck rumbling again.

[convert2diesel]

I would have blasted and painted them if I was going for show quality and put up with the smell of burning paint for awhile. We had a little time waiting for a parts delivery I started playing with paint! :lol:

On the trip to Canada, can't do it. I read where a truck driver was fined $305.00 for smoking in his OWN truck, sited as "smoking in the workplace"
I would be in a Canadian jail over shoving a ticket book in their 4th point of contact. ;)

You are welcome to come down though!

Would love to get a copy of that article. If it was his own truck, and he wasn't driving around with a kid under 12, then thats a court case I could wrap my head around. Lots of nonsense around here since the "nico-terrorists" decided to re-write our constitution.

Having said that, how about sitting on a park bench in Malibu, CA in 1984, enjoying the sea breeze and scenery, and of course having a smoke. Some obsequious by-law enforcement officer accosted me for "smoking in a public place". That has to take the cake and thought it could only happen in California. Think again Bill :confused:. Brings to mind the line "everyone should live in California at least once in your life...but leave before you start to think like them".

Bill

[Pipeline Mechanic]

bill,

Here you go on the article;http://www.theprovince.com/Ontario+trucker+fined+smoking/2079342/story.html

Also I wont go to Komifornia either, a friend called me out for a pipeline
job that crossed into California and they could emit no smoke, no oil leaks, and under 85db.
Nothing I owned qualified, also if you were idling with the A/C on you had to put a catch pan to contain the water from the evaporator core so as not to introduce foreign moisture into the desert.

CARB can shove it far as I am concerned!

[6.5 Detroit Diesel]

waterpan for the a/c? wow, that's all i can say

[Pipeline Mechanic]

Do I still qualify in the 6.5L forum with my 6.2.5TD? :lol: It is actually
a 6.35L which would make a very interesting thread 6.4L in a Chevy!

I piddled with it some more this evening, I need a coolant sensor, the 4x4 oil filter o-rings, heater hose fitting, and waiting on a used downpipe to show up
courtesy of eBay. I gotta finish it, I am tired of pushing it around the shop!

[Pipeline Mechanic]

Well I didn't have to push it out tonite! Runs good and sounds good. Still waiting on UPS to deliver the downpipe to be able to take a drive around town. Hooking up the vacuum lines and a transmission service, also a good interior cleaning, will round out the punch list for a highway trip.

Does anyone have the vacuum line diagram for this truck? I can figure it out I was just curious if it was here.

[Pipeline Mechanic]

Bump for a recent question..