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Harmonics

Speaking of rpm. What limits these trucks rpm wise. And why is every post I read about db2 pumps referencing that they defuel around 3krpm. Or they are bench tested to 3500. Is it the cam that limits the rpm or if given enough airflow can they rev to 5k
 
It's the IP that limits the fuel. Rotary pumps usually peak fuel delivery is around 2500 RPM they generally taper off after that.
 
Will L. said:
You're hitting a few different points here.
Harmonics: crap crank with weak mains and psycho high compression and a mediocre HB. I’ve pushed 6,000 rpm using extreme measures and had the crank hold fine. The ultimate fix for all of it is p400, shy of that optimizer crank or scat crank and fluidampr balancer & Leroys billet pulley. In the fleets we saw many broken cranks and EVERY ONE had bad or highly questionable balancers. 100,000 MAXIMUM imo if the AC Delco or GEP (which may be AC Delco). 500,000 fluidampr
As for firing swap, gains are minimal on engines living at 4,000 rpm max so wasted $ imo on 6.5

The low power issue: they never figured to want over 220 hp or 500 torque even in concept. This is a fuel miser engine with low maintenance costs was the whole plan. Better power is available: big turbo,exhaust, pump/tune, cac, wmi, even if wanted propane works wonders in idi. Pick a target and have a realistic wallet to do it. Diesels are not gassers- no $250 power gains here.

Hot spots: were from coolant flow issues (especially amplified by rear head cooling kits), cheap metallurgy, and thin castings- basically 1 error and profiteering penny pinching. The optimizer fixed the metal and thickness. The spin on fanclutch/ balanced flow waterpump with restrictor fixes much of the overheating-with more help from better fanclutch. Then cheap radiator is the other part. Higher quality radiator with thermal coating to make up for undersized radiator and things can be happier. In fleets we ran hundreds and hundreds of trucks over 1/4 million miles and never suffered heat issues once set up right.

As for your cooling: Leroydiesel.com
What waterpump, fanclutch, fan, and since you have dual stat- what are you running as restrictor?
Click to expand...
Hey bossman. I checked leroys site and only saw 195 degree stats. Can you point me in the right direction for a updated water ump and spin on fan. Maybe 180 degree stats. I did check today in between fixing my drain line and grind8ng my knuckle and sure enough I have a 4 bolt fan
 
Rock Auto. Buy it for the 2000 year model 6.5. You need the water pump, Hayden severe duty fan clutch (or Kennedy Diesel early engagement fan clutch from his site) and the steel fan unless you do the duramax fan.

Don’t forget to use this sites 5% off code if you order anything from Rock Auto.
 
Jaryd said:
Rock Auto. Buy it for the 2000 year model 6.5. You need the water pump, Hayden severe duty fan clutch (or Kennedy Diesel early engagement fan clutch from his site) and the steel fan unless you do the duramax fan.

Don’t forget to use this sites 5% off code if you order anything from Rock Auto.
Click to expand...
I didn't know there was a discount. Where do I find the code
 
Plan your build to never be above 3,000. 3500 takes an act of congress and their funding to boot. As AK mentioned its all in the fuel. A couple of idiots, myself included, added secondary fuel supply systems to get rediculous rpm. Intent by GM backing me to do it was a desired pile of blown engines, which they got. It got me banned from driving the dragstrip here in Vegas, lucky for me ownerships has changed when they went big time. One of those engines was the loss of the old time board that used to be after the traps. The famous right lane dip was another. Guess why I got booted? This was every engine having been perfectly balanced. Just forget the high rpm unless you are serious about a record setting rig and are dumping in over 20k into the engine. Back to what makes sense-

The metal fanblade you want to find is gm#15992650- stamped on all the blades. Ebay or junkyard, maybe your lucky and already in your truck.

The thermostat crossover is a part of the cooling system that has to be addressed in the update also. If you have dual thermostat then get the bypass restricor fitting from Leroy. Guys on the hummer forum (all 96 & newer hummer use dual stat) are having great sucess on it. Otherwise you need a singlestat crossover that has the blockoff thermostat.
Leroy has access to stuff he doesn’t have listed on his website- just call.

You seem familiar with 6.5 to have many if the upgrades you do. But if just learning of the waterpump issue, still some to go. Are you familiar with the balancer issues? How about stretched timing chain issue? Spoked power steering pulley? I ask these because it is easier to do this all at once than pull the same parts off over and over.
 
Will L. said:
Plan your build to never be above 3,000. 3500 takes an act of congress and their funding to boot. As AK mentioned its all in the fuel. A couple of idiots, myself included, added secondary fuel supply systems to get rediculous rpm. Intent by GM backing me to do it was a desired pile of blown engines, which they got. It got me banned from driving the dragstrip here in Vegas, lucky for me ownerships has changed when they went big time. One of those engines was the loss of the old time board that used to be after the traps. The famous right lane dip was another. Guess why I got booted? This was every engine having been perfectly balanced. Just forget the high rpm unless you are serious about a record setting rig and are dumping in over 20k into the engine. Back to what makes sense-

The metal fanblade you want to find is gm#15992650- stamped on all the blades. Ebay or junkyard, maybe your lucky and already in your truck.

The thermostat crossover is a part of the cooling system that has to be addressed in the update also. If you have dual thermostat then get the bypass restricor fitting from Leroy. Guys on the hummer forum (all 96 & newer hummer use dual stat) are having great sucess on it. Otherwise you need a singlestat crossover that has the blockoff thermostat.
Leroy has access to stuff he doesn’t have listed on his website- just call.

You seem familiar with 6.5 to have many if the upgrades you do. But if just learning of the waterpump issue, still some to go. Are you familiar with the balancer issues? How about stretched timing chain issue? Spoked power steering pulley? I ask these because it is easier to do this all at once than pull the same parts off over and over.
Click to expand...
Timing chain I have heard of but have yet to address. Balancer is already replaced with a fluid damper. Never knew of a issue with the power steering pulley. And I already have a dual stat housing from the factory.
I only get Saturdays to work on my truck due to me being in a shitty rental as I'm trying to buy a house so I'm doing weekend projects. So there are items I still have yet to addess but I don't want to tackle something that can't be finished in a day leaving the truck Immobilized.
This past weekend I fixed my dual steering stabilizer setup and oil return drain line. Redid that with 12an line and 3/4 pipe into the block. Then noticed the box was binding because the bearing failed so that got ripped apart and rebuilt and I took a grinder across the hand cause I was in a hurry and careless cleaning up the rusted box.
For now it's one step at a time. Making a laundry list and checking off items week by week
 
So the dsg timing gears that fixed the timing chain problems were no longer made, until Leroy started having them remade- so I would say order that part and do when you do the waterpump. Remember a new front seal while timing cover is off.

Already having the fluiddampr is great. Leroy makes an all aluminum belt drive to mount to the fluiddampr and not have to keep replacing the rubber ones.

The power steering pulley isn’t a problem, just convince thing, and yeah I am a “while your there” guy so all my suggestions may be better left until in your new home- haha. Some power steering pumps are a pain to access, some not to bad. The spokes make access much nicer. Idk which trucks can run this and which can’t (yes different ones by different years), but amazon takes returns. Just hold in place next to yours and see if the belt is correct depth before removing your old one. This is an old screenshot, so price is probably tad higher.
ABCF2078-8C90-4CA5-8D6E-40C3619FC96F.png
Some guys (guilty) just mark a drill and hole using annular cutter drill bits in the solid pulley. If I can’t fit this pulley on mine this next go round, out comes my drill.
 
Will L. said:
So the dsg timing gears that fixed the timing chain problems were no longer made, until Leroy started having them remade- so I would say order that part and do when you do the waterpump. Remember a new front seal while timing cover is off.

Already having the fluiddampr is great. Leroy makes an all aluminum belt drive to mount to the fluiddampr and not have to keep replacing the rubber ones.

The power steering pulley isn’t a problem, just convince thing, and yeah I am a “while your there” guy so all my suggestions may be better left until in your new home- haha. Some power steering pumps are a pain to access, some not to bad. The spokes make access much nicer. Idk which trucks can run this and which can’t (yes different ones by different years), but amazon takes returns. Just hold in place next to yours and see if the belt is correct depth before removing your old one. This is an old screenshot, so price is probably tad higher.
View attachment 52052
Some guys (guilty) just mark a drill and hole using annular cutter drill bits in the solid pulley. If I can’t fit this pulley on mine this next go round, out comes my drill.
Click to expand...
Just out of curiosity can I just slide the gears in and remove the chain. Or will I mess up the timing. Is this a easy enough task for a weekend or do I need a scanner to retime.
 
No, not a slip in thing. Yes retiming MIGHT be required~ before disassembly you bring it to #1 tdc compression, and reassemble to same setting. So a db2 doesn’t need to be touched. Your ds4 will still be same in relation to cam/crank so it could be ok. But sometimes it has move a degree or two and that could be enough to need to be reset. Really a try and see thing.

As long as you do it correctly, it will start and run. So you could drive it ro the shop you use afterwards and have them retime it.

What is nice is it would be the last time you have to sweat it. Because right now as your chain keeps stretching your timing fades and at somepoint the IP cant auto correct for it.

A few times I’vs seen people do a new ip, then sell truck because it didn’t fix the problem. New owner does new chain/gears and problem solved.
 
Will L. said:
No, not a slip in thing. Yes retiming MIGHT be required~ before disassembly you bring it to #1 tdc compression, and reassemble to same setting. So a db2 doesn’t need to be touched. Your ds4 will still be same in relation to cam/crank so it could be ok. But sometimes it has move a degree or two and that could be enough to need to be reset. Really a try and see thing.

As long as you do it correctly, it will start and run. So you could drive it ro the shop you use afterwards and have them retime it.

What is nice is it would be the last time you have to sweat it. Because right now as your chain keeps stretching your timing fades and at somepoint the IP cant auto correct for it.

A few times I’vs seen people do a new ip, then sell truck because it didn’t fix the problem. New owner does new chain/gears and problem solved.
Click to expand...
That' My problem. I don't have a shop to work on it. Diesel places in the queens NYC area are scarce.
 
Almost all 6.5 owners do the work themselves because of this. A ds4 pump is akin to a ferrari- almost no mechanics know it, so having to go to another state for it is just a fact of life. Difference of something worth $15k vs $150k means work on it yourself instead of paying a hauler to get it to the shop for repair.
You seem to be tackling things yourself, getting the scanner or laptop program to diy it should be in your future imo. If not you, you’ll have to pay a mechanic to learn it.
 
John Romann said:
Just out of curiosity can I just slide the gears in and remove the chain. Or will I mess up the timing. Is this a easy enough task for a weekend or do I need a scanner to retime.
Click to expand...

I put gears in recently. Your accessories are different, but, this link is an idea of how big a job that is. You are 2/3 the way there with the water pump off. GM would bolt the rear diff to the water pump if they could... :facepalm: http://www.thetruckstop.us/forum/threads/moose-call.46822/

The steel fan and Duramax fan are said to be the same. The Duramax fan requires perfect engines mounts or it will trim the shroud. (You should trim it before the fan does...) IMO the Duramax fan pulls more air getting better AC performance at idle and then flexes at high RPM. Neither is a bad choice.
 
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