Another 6.5 bites the dirt

[Missy Good Wench]

Well as they say, ALL good things come to an end.

My 95 dually Crewcab 4x4 "DaHooooley" finally gave up the ghost the other day.

Started loosing coolant but not pressurizing the cooling system.

Further investigation revealed the leak was into the crankcase

Started ripping the beast apart last weekend but not quite done yet.
The weather has been crappy so the engine is still in the truck.

One more nice day and I can get the sucker out and into the shop.

I decided to get a leg up on the issue and scrounged up another block.
Got a nice 929 block in good shape.
The cylinders has a little etching in 3 holes so its getting some new .5mm slugs in 19.8:1 form.

Once clean we found one tiny crack starting in the outer hole on #2 main.
The starter bolt holes had been molested a bit due to bolt breakage but this was easily fixed with a pair of Helicoils.

This weekend I set the block up and installed the "Full Torque" inserts from Lock and Stitch on all six (6) center main outer bolt holes.

This done the engine is now back in the machine shop for boring and having the decks machined.

Should have it back soon.

A good friend brought over a nice standard crank and I had a set of fresh 6.2 rods.

Going to have the rotating assembly ballanced just to make life better.

I will likely install a fresh set of heads from Clearwater to top this build off.

Used a set of these heads on my 94 Burb 3 years ago now and all is well.

Once the engine is out of the truck the true tale will come into view and I can see just what happened.

Will use all that I can off the old engine to finish the new one.

Just not a great time, but at least summer is on its way and the weather will be nice to work on the beast.

All for now

MGW

 

[Gunner0812]

The new engine sounds good.

 

[bk95td]

Any pics of the lock and stitch? I'm curious how they work.

 

[Ratman]

Geez, you sure have some nice friends, -giving you crankshafts and all.

I'm more curious as to the condition of the motor that's in the truck.

Call me when it's autopsy time.

 

[TurboTahoe]

Missy!

Good to see you posting again! Sorry to hear about Dahooley's troubles. You certainly have the expertise to put 'er right, and to improve things as you go! Go girl!

-Rob

 

[Missy Good Wench]

Thanks for the Good wishes all.

Rat
Will do. I hope that this weekend will be better weather wise and the engine can come out.

If your available and dont mind getting dirty I could always use a hand on a wrench.

Getting the hood off is always a two person job.

Here are some pix of the tools and the equipment I put together.

The insert is a full circle with the 10 or 12 mm threads on the inside and the outside has threads that angle up at the outer edge.

The insert is set flush with the surface of the saddle area and sealed with a heat transfering locktite.
Then a hard pin is driven into a hole drilled through the adjoining thread sections between the block and the insert.

I then use a pilot in the hole and counterbore the assembly a few thousands to be sure that things are below the surface.

 

[Missy Good Wench]

Here are the pix

I use the plate shown to sit the mag drill on.

I bolt the plate to the pan rail bolt holes

 

[Ratman]

Rat, Will do. I hope that this weekend will be better weather wise and the engine can come out.

If your available and dont mind getting dirty I could always use a hand on a wrench.

Getting the hood off is always a two person job.

Ok, call me before the end of the week. If the weather is decent, I may go flying in the am on saturday, -I'll be sure to buzz ya. ):h Don't worry, I'll come lend a hand!

Give me a call and we'll hash it out. :thumbsup:

 

[Missy Good Wench]

Sounds good to me.

After yesterdays rain I was thinking more about needing a boat than a dually though.

Late week weather is supposed to be fairly nice again.

Most of the nasty stuff is off the engine already.

LH Exhaust and Xover needs to come off as does the flywheel cover, converter bolts and the bellhousing bolts.

A few wiring plugs and then it will be time to lift the little creature out.

OMG I am sooooooooo curious as to what took that thing down.

Will be nice though to have a Known good powerplant in there.
Really love the truck but have always been a little hesitant about any long trips due to lack of knowledge on the powerplant.

Diiging through my goodies and found the two new oil cooler lines and a bunch of other stuff that will be handy for the build.

Still need to buy a new radiator before things get done too.

Old one sucks :sad:

Probably use a HO water pump and the dual stat Xover just to make it cool better.


Later

Robyn

 

[TurboTahoe]

Hey Robyn,

Bill Heath and the boys up in Washington think the best combo is a SINGLE blocking thermostat, HO water pump and normal radiator. They think that the bypass dual stat crossover is LESS efficient at getting the coolant through the radiator. I actually agree.

-Rob

 

[Missy Good Wench]

Not sure about that one.

This subject has been flogged a bunch on the various forums too.

The Buzz is that using the HO pump with a single stat can lead to popped freeze plugs due to excess pressure.

No experience with this issue at all.

I do like the dual stats idea as it allows more water to flow out of the Xover as the sectionional area of the two stats is greater than the single one.

The issue was to get far more flow rate through the block and keep the stagnant areas churned up better and to prevent the bad hot spots that were causing the heads to crack.

The radiator was not usually an issue.

The HO pump with the dual stat is supposed to give "IIRC" 70% more flow through the block and 7% more through the radiator

Hell I'll guess with you.

I dont always agree with the Heath boys on some stuff but can't say much here.

Heath also does not like the 18:1 pistons but prefers the 21.3:1 ??????????????

Ratman has the dual stats on his rig and loves it.

I happen to have a dual stat Xover that came my way with a broken off heater fitting.

Took a few minutes to coax the fitting out so its now good to go.

MGW

 

[TurboTahoe]

MGW,

You make some great points.

I know that on Bigley's site it states that the dual stats were to prevent popped freeze plugs and excess pressure, but I have never actually heard from anyone who had that problem, on this or any other forum.

Bill's reasoning (which makes sense to me) is that the blocking thermostat, when fully open, forces coolant through the radiator, as the path back to the inlet of the water pump is closed off due to the blocking plate.

With the dual thermostat setup, there are two paths, one through the rad, one back to the pump. The coolant will flow wherever there is the least resistance, and apparently, sometimes with certain setups this means a certain amount goes back to the water pump inlet.

Bill claims that they have had to put a restrictor in the path going to the pump inlet to force more coolant through the radiator on certain installs.

Anyway, it makes some sense to me.

Didn't know Bill doesn't like the 18:1 pistons, but I suppose that's apples and oranges now.

My guess is that either setup will work fine if properly tuned.

Good luck Robyn!

-Rob

 

[Missy Good Wench]

The 6.5 is fine with stock boost pressure and 21.3:1 comp
Adding a Turbo master or some other controls to allow more boost and of course a chip to feed more fuel the added boost makes more intake heat.

Reducing the comp ration allows for a lot more boost without running into issues with the gaskets and heads.

This said, the starting characterisitics of the 18:1 engines can be a tad anoying in cold weather.

I am using 19.8:1 slugs and the block is decked .015" and the .010 thicker gasket added.

This should be a wash at around 20:1 me thinks.

I have my TM set at 12 PSI max under load.

The truck runs great and makes all the power I want.

Pushing the HP levels into the 300 arena can be far tougher on these little beasts and charge coolers and other things need to be done to satisfy the issues.

Radiators need to be in top shape as well as the fan clutch and water pump.

I prefer a 180F stat so the coolant gets into the radiator before the thing reaches 190 or above

The cooling system on these rigs is IMHO lacking in over design and will fall on its butt once it gets a little dirty and a few months of bugs under its belt.

The clutch fan could easily be allowed to come on sooner but GM did not because owners bitch when that propeller howls.

Having the fan come on about 50-75 degrees sooner (air temp at the clutch) would be sweet.

best

Robyn

 

[Matt Bachand]

Robyn heath and Kennedy both sell differently calibrated clutches that just do what you said, kick in alot sooner. I need one for winter only beacause my plow blocks airflow.

 

[midniteplowboyy]

I say the freeze plugs thing is a myth.

My 92 and 93 both have the HO pump and single stat, no problems.

Our water pump is a centrifugal pump, not a positive displacement pump, so there really should not be that much of a pressure rise(just flow, if unrestricted).

Its also a sealed system, whats being pushed in is being sucked back out the other side, so if there is no restrictions(hypothetically) there would only be system pressure(radiator cap). If I wasn't so busy, I'd put a pressure gauge at the rear of one of my heads, out of curiosity.

I also need to get my dual stats installed on the 93 to see if it helps, it cant get the water out fast enough if I really lay into it, maybe I should try a new stat first. The 92 is in stockish tune and you cant overheat it as long as the radiator is clean, with the old pump the temp gauge would rise like a EGT gauge under heavy load.

 

[Missy Good Wench]

I do believe your very much correct.

GM was propagating the story of the freeze plugs popping out from too much pressure.

The only pressure can be from the coolant temp (15 PSI cap)
Hell I have seen the head gaskets go and the coolant pour out the top of these things and the freeze plugs dont fly out.

Just hype me thinks to get mechanics to do the job all the way and not just the pump.

The low temp clutch should have been a standard issue from GM and not necessary to go aftermarket though.

I started off building a Hybrid HO pump with a Horton electric clutch.
I have it sitting on the bench.
The Horton mounts to a Powerstroke hub that I pressed onto the GM pump.
Uses the standard steel GM fan from the 95.

If I can get a good extra electric fan to run out front to help with the AC system I may use the setup I built.

Later

MGW

 

[Acesneights1]

well I can chime in alot on this one. I own both. Single and dual. The single(95) has the HO Pump and no issues with freeze plugs. The 2000(dual) overheats as quickly if not worse than the single. I would lean towards Bill on this but to be honest I still stand by my guns that moving the A/C condensor out from in front of the rad would make a huge difference. The reason I think this is because I know someone who has a k3500 with a 6.5 with no A/C and he pulls large3 equipment with it. It's bone stock other than PMD and he has never come close to running hot. Both my rags overheat on a spring day if I'm towing anything sizable. I really really wanna move that A/C condensor under the truck with elec fans and see what happens. A Condensor off a Mid 80s R Model looks like it would work quite nicely and they were beefy bumper mounted. On my to do list along with scruf top mount I/C.

 

[OregonHorseTug]

Let me toss in another data point.
I've got the single stat (the correct single stat), stock 60 gpm pump, and Kennedy's Super Sucker fan clutch with the steel 9 blade 20" fan.
My big pull comes in August over a 6000 foot pass heading for Burning Man, last year with this setup I declared my cooling problem solved. I was crawling up a 6-1/2% grade at about 8mph with outside air temps in the 80s and the ECT stayed under 210. I was running 19,600 combined so that might be a medium load for you with DaHooley.
That fan will howl at the slightest hint of warm air but my cooling problems are history. One could say it sucks more horsepower, and I would agree, but the 60gpm pump sucks less than the 130 so I figure we're even. Just to be fair, most of my cooling problem was the wrong thermostat and a stock fan clutch. I also put in a fresh rad at the same time.
And, just one more plug for the ATT, I've lost an easy 50 off of my IAT just running empty down the freeway. Can't wait to seee what it does with the trailer on. I don't think you can keep the ECT under 210 if you're feeding it 280-300 air.
Mike
(..okay, a long-winded data point)
ps: still have that 6.5 autopsy scheduled for this weekend?

 

[Missy Good Wench]

The cooling system on these trucks should be able to handle a reasonably heavy load/pull and be able to keep the engine temp in check even in 100F temps.

My DaHooooley would heat up to 230 on a hard pull in 85F temps with the trailer and as soon as the fan came on, cool off to 190 again.

My radiator is well used up and is going to be replaced when I put the truck back together.

The HO pump really does not do much for the overall cooling but was designed more to keep stagnant spots from forming in the corners of the heads and the rear of the block.

This was IMHO a bandaid fix for the issue of cracked heads and other ills.

The new P400 engine from AMG is supposed to have these areas redesigned and the problems eliminated.

A Hummer out in the deserts of the Mid east has got to put the cooling system to the acid test for sure.

Now, my 94 Burb will stay cool even in 100F weather and running hard.

I use 180F stat in it and its seems quite happy


I got the new pistons yesterday and the block I bought to build up will soon be done.

The pistons are .5mm OS and I found stock GM rings to use with them.
We decked the block .015" to clean it. Debured all the holes and will use the .010 Thicker Felpro gasket

Should be a nice engine and run a long time.

MGW

 

[TurboTahoe]

Hell I have seen the head gaskets go and the coolant pour out the top of these things and the freeze plugs dont fly out.
MGW

Robyn, that's funny!

-Rob