Best mechanical pump?

[Bravo51]

So I got a 93 k3500 with a mechanical 6.5. My injection pump head is toast so i am looking out there and find pumps of all prices. The question is which one should I get? I got my eye on the kennedy marine pump but after poking around on here it sounds like I might not have my rig setup for that yet nor it being the best option for a truck. I am replacing my head gasket and putting arp head studs in. The turbo was the next item I was going to up grade. I got the oem turbo doing about 15-17 psi right now. Some advice on this would be much appreciated before spending over a grand on this.

[More Power]

Marine pumps are OK if done right. However, if you're using a marine pump you should also be using marine injectors. They have different pop pressures and flow rates.

The stock DB2 4911 can deliver all of the fuel a more or less stock engine can/should deliver.

The factory type head bolts are of the TTY (Torque to Yield) variety. TTY means that they are somewhat elastic and can provide uniform head clamping loads over the life of the installation. Studs are not TTY. As head gaskets compress over time, stud clamping load decreases. TTY bolts are install and forget. Studs may need to be re-torqued at some point.

Studs work great for modified Cummins and Duramax engines making way more than stock power with big boost numbers. The 6.5 doesn't go there.

My recommendation... stick with factory TTY bolts and Fel-Pro head gaskets, installed correctly, unless there's more to the power build.

The factory 6.5 turbocharger is operating well beyond its efficiency range at 15-17 psi. It's making a lot of heat when not efficient. I'd want a more efficient turbocharger when operating at those pressures - a Holset....

[Bravo51]

Marine pumps are OK if done right. However, if you're using a marine pump you should also be using marine injectors. They have different pop pressures and flow rates.

The stock DB2 4911 can deliver all of the fuel a more or less stock engine can/should deliver.

The factory type head bolts are of the TTY (Torque to Yield) variety. TTY means that they are somewhat elastic and can provide uniform head clamping loads over the life of the installation. Studs are not TTY. As head gaskets compress over time, stud clamping load decreases. TTY bolts are install and forget. Studs may need to be re-torqued at some point.

Studs work great for modified Cummins and Duramax engines making way more than stock power with big boost numbers. The 6.5 doesn't go there.

My recommendation... stick with factory TTY bolts and Fel-Pro head gaskets, installed correctly, unless there's more to the power build.

The factory 6.5 turbocharger is operating well beyond its efficiency range at 15-17 psi. It's making a lot of heat when not efficient. I'd want a more efficient turbocharger when operating at those pressures - a Holset....


once I swap turbo's I will be running hopefully over 20psi. If i run my turbo at the normal 7psi I can watch my pyro climb to 1200 in a hurry going up hills. Right now at 14psi it runs between 900 and 1000 unless its a long hill and it might be 1100. If you believe what you are saying then why do you think 6.5's are so noted for head gasket blowouts? Also everything I have ready this far is that he difference between marine and regular injectors are so small that the question must be asked, "whats the point?"

[Bravo51]

It sounds like I might be more ahead if I get a rebuilt pump, turn it up and put a hx35 or 40 turbo on my truck.

[stezloco]

It sounds like I might be more ahead if I get a rebuilt pump, turn it up and put a hx35 or 40 turbo on my truck.

I saw this thread and was hoping to get some pump info from it but it seems to have gone off on a tangent....
these IDI engines will only remain reliable if operated within a sensible boost range and cooled efficiently....it is not as rugged a design as Direct Injection. If you're looking for really big power you've got the wrong engine.
Idi's have light pistons for higher rpm's and a greater area of cylinder head subjected to the combustion heat and run hotter with the small turbo fitted simple as that.Big boost and high egt's will blow a hole in your weakest piston some time or other when youre hauling a load or tanking it up a big hill watching your pyro skyrocket. If you want a reliable motor concentrate on the cooling mods/ big intercooler/hx35/k&n/big bore exhaust route...boost and pyro to keep an eye on everything...that will sap enough cash out of you to get you some more ponies but they will cost you in mpgs. Theres some great advice on here from people who've learned the hard way..... you've just got to dig through and look for it...:)
regarding the pump thing...there are plenty of pump shops out there who can upsize plungers and give you big fuel delivery but you need all the goodies to go with it to get the best out of it..........and we're back at the heat problem.........:(

[Dvldog8793]

IMHO- In order to get that type of boost range, You will have to do ALLOT of cooling and engine mods to remain reliable.
Probably cheaper and easier to get a cummins and swap it into the chevy chassis:rolleyes:....

If you were in the Minnesota area I could give high recommendations to a local pump shop. They can do anything but have allot of experience and can give some great advice. I have been using them for 15 years and have NO complaints. Stanodyne and Bosch factory trained.

[Bravo51]

I saw this thread and was hoping to get some pump info from it but it seems to have gone off on a tangent....
these IDI engines will only remain reliable if operated within a sensible boost range and cooled efficiently....it is not as rugged a design as Direct Injection. If you're looking for really big power you've got the wrong engine.
Idi's have light pistons for higher rpm's and a greater area of cylinder head subjected to the combustion heat and run hotter with the small turbo fitted simple as that.Big boost and high egt's will blow a hole in your weakest piston some time or other when youre hauling a load or tanking it up a big hill watching your pyro skyrocket. If you want a reliable motor concentrate on the cooling mods/ big intercooler/hx35/k&n/big bore exhaust route...boost and pyro to keep an eye on everything...that will sap enough cash out of you to get you some more ponies but they will cost you in mpgs. Theres some great advice on here from people who've learned the hard way..... you've just got to dig through and look for it...:)
regarding the pump thing...there are plenty of pump shops out there who can upsize plungers and give you big fuel delivery but you need all the goodies to go with it to get the best out of it..........and we're back at the heat problem.........:(


You say that and yet the biggest factor in cooling is boost in a diesel. 1300 egt's and 200 degree water equal what? a cracked head. The point of boost is lower egt's. I did buy a used hx40 off ebay that only had 5 hrs for $400. I have a pump in route. Ive been searching for a good intercooler option but haven't seen one yet that keeps the trans cooler. Also with this engine adding a intercooler in front of the radiator adds to the cooling issues. I have often wondered if adding some sort of effective cold air intake system would be more effective. I know where the filter sits it has to be sucking in 100 degree+ air. I have often wondered about adding a Subaru style intercooler mounted on the top of the engine with a hood scoop. Also i have a 4inch straight pipe.

[Hill Top]

Actually the point of boost is not lower egt. The point is to force more air into the combustion chamber. Turning boost way up only to brag about low egt really means your running very inefficiently. The low egt means your forcing way more air into the engine than can be used due to a fuel shortage. Also running high boost pressures on a stock 6.5 with 21:1 compression won't gain much power and will shorten engine life. Buy the dieselpage book on the 6.5 and study the performance project truck, it will help your prospective.:)

[Dvldog8793]

Howdy
I made an intercooler system that was very effective. I ended up using and ARB winch bumper and mounted the intercooler in front and down low. Due to the huge area for the winch I would have had room for fans or a mister or probably bigger intercooler. I have mounted the bumper on my new truck but haven't gotten around to installing the intercooler yet. When I do I will post some pics. It was little intense but very doable. I had an old frame mounted intercooler system from JK but it was pretty small.
That engine was fairly powerful (by 6.5 standards)260ish. At 130,000 the crank let go(it was a NEW 2004 AMG long block). I never ran high egt, maintained meticulously but IMHO it was just too much for the stock design without doing extensive internal mods.
My current truck is pretty tame with minimal mods.
If you want ideas or specs for the IC system that I put in PM me.
Hope this helps.

[Bravo51]

Actually the point of boost is not lower egt. The point is to force more air into the combustion chamber. Turning boost way up only to brag about low egt really means your running very inefficiently. The low egt means your forcing way more air into the engine than can be used due to a fuel shortage. Also running high boost pressures on a stock 6.5 with 21:1 compression won't gain much power and will shorten engine life. Buy the dieselpage book on the 6.5 and study the performance project truck, it will help your prospective.:)

Yes and you either use to much fuel or not enough. To much and you burn your piston. Talk to the N/A 6.2's guys who burn a holes in their piston. I would argue differently on engine life. Heat and friction shorten's engine life. These engines hate heat. Lower compression to raise boost only makes sense if you are trying to push your engine to that last edge. When you raise boost you raise compression. You take a 5.9 cummins running 100psi of boost you get a compression ratio of roughly 108:1. You take my 6.5 running say 14.7 psi you get 42:1. 29.4 psi you get 63:1. If you run 18:1 then your final compression would be 54:1. What else you loose? Egt's and fuel economy. What do you loose by increase boost? Egt's and fuel economy as well but maximize fuel burn. The real question would be what is the maximum compression can these engines take?

[Bravo51]

Howdy
I made an intercooler system that was very effective. I ended up using and ARB winch bumper and mounted the intercooler in front and down low. Due to the huge area for the winch I would have had room for fans or a mister or probably bigger intercooler. I have mounted the bumper on my new truck but haven't gotten around to installing the intercooler yet. When I do I will post some pics. It was little intense but very doable. I had an old frame mounted intercooler system from JK but it was pretty small.
That engine was fairly powerful (by 6.5 standards)260ish. At 130,000 the crank let go(it was a NEW 2004 AMG long block). I never ran high egt, maintained meticulously but IMHO it was just too much for the stock design without doing extensive internal mods.
My current truck is pretty tame with minimal mods.
If you want ideas or specs for the IC system that I put in PM me.
Hope this helps.

I push a lot of snow with this truck so an intercooler down there is not an option for me. I could on my c3500hd.

[Bravo51]

Ha spreaking of egts and cooling, ever seen a overheating 6.5 at -30f? Hahaha I have. Also have seen 300 degrees on the 4l80e in low range. That issue has been resolved now. Air coolers arnt enough..........

[Dvldog8793]

By "down low" I mean about standard bumper height, with all the protection of an ARB bumper. The ARB is the main expense but it works.
We see lots of overheated plow trucks up here(northern MN) most of the time the problem is due to negative air pocket created by the plow or packing snow dust in the AC.

[Hill Top]

Peninsular Diesel is the consumate expert on the subject and they recommend 18:1 compression. Their testing showed the 21:1 compression engine run only about 3 hours at full power before pistons seize. The 18:1 at full power while putting out more hp and torque will run indefinitely. All the testing and results available on the diesel page and in the diesel page books. On page 24 volume III shows a 6.5TD race truck, guess what....18:1 compression.

[Bravo51]

Peninsular Diesel is the consumate expert on the subject and they recommend 18:1 compression. Their testing showed the 21:1 compression engine run only about 3 hours at full power before pistons seize. The 18:1 at full power while putting out more hp and torque will run indefinitely. All the testing and results available on the diesel page and in the diesel page books. On page 24 volume III shows a 6.5TD race truck, guess what....18:1 compression.
Well you do know the fastest 6.5 was running 22:1 compression..... But at 22psi. 22psi at 22:1 and 32psi at 18:1 (which is what the one guy who has a drag truck on this site is running) is pretty much the same compression psi in the end. So then the question would be what is the psi that the piston will lockup at?

[Bravo51]

By "down low" I mean about standard bumper height, with all the protection of an ARB bumper. The ARB is the main expense but it works.
We see lots of overheated plow trucks up here(northern MN) most of the time the problem is due to negative air pocket created by the plow or packing snow dust in the AC.
I would be interested in seeing pics if that every happens. Ya air pockets and a bad fan is a plowers nightmare.

[stezloco]

So.............best mechanical pump then?
just got hold of a spare (needs overhauling) DB2829-4126 4705541 DSS1090DG.....any idea where I can find info on its output/application?
rgds

[Robyn]

4911 pump for the 6.5 was the last word before electronics came on the scene.

These have larger plungers and will gitterdone.