boost vs. egt

[Clb]

88 banks c-6 4.10's
finally got the bugs out, put a 6x10 dump trailer w/ an 8k(make it 9100#) loadmaster on scales said "about 6k" load(gross total at 15080#) on the bumper hitch,,, yea I know
7° grade +- ...round bout a 1/4 + mile pull
Eng temp at 200° egt at 800-825 boost at 7 psi topped out egt/ spool.
and the eng pulls flat out smooth no hiccups or weakness
looks like it is able to take some more fuel?
Any thoughts?
Mileage looks like 6-8 mpg. 50/50 pulling/town. sumpins wrong here!
gunna run some more fuel thru it (first 1/2 tank) and see where its at on economy

rookie question... how do ya know when ya need injectors and an i.p.?
odometer is unknown,i.p.has ben done ? Used spare in the bed when I got it.
I know I need to do returns and probably g.p.'s
still scouting for a reputable injection mech reported to work around here(napa ca) till then I'll keep polishing away.
thanx in advance cb

 

[idiabuse]

if it runs good, starts up consistent everytime when warm, then most likely ur in good shape.
when it starts to act up and runaway on you, or chuggs along or stalls out but you have no air
leaks and a good filter then you know the pump is on its way out.
I alway's use fuel additive every tank, worth the money. that keeps the pump lubed.
Even when using WMO I have to use additive or she gets lathargic on me and smokes alot.

 

[icanfixall]

Yes from what you posted you might be able to add some fuel. Is the injection pump and injecters painted gery.. If so they are probably originals and any injecter and pump usually lasts for around 125,000 miles give or take a few. As for installing a pump that was "found" in the bed of the truck.. Nope.. No telling how much dirt is in that. Now if it was wraped up and clean maybe I would try using it but thats after I looked it ove closely. Please read up on how to remove and install an injection pump. Way too many newbies come here after they did it wrong and now the truck wont start. Its a tuff job to fix a mistake too. Either typ4 or agnem wil sell you a great pump and injecter better than any ebay or other shop out there... Many members here ahve nothing bad to say about there prices or work.. Its well above anyone...

 

[Clb]

thanx... ?whatcha do for 15 psi onna banks? Early non gated I supose?!

 

[Devon Harley]

Get a rubber intake boot from silicone intakes.com an put a 3in exhaust pipe an filter on end. Then turn up your fuel you wanna run around 900-950 egt loaded . The intake will help quicker boost an lower egt by increased air flow.

 

[kc0stp]

thanx... ?whatcha do for 15 psi onna banks? Early non gated I supose?!

Turbo cal IP + adjust wastegate = 15psi boost out of any of the 3 current bolt ons.

 

[Hydro-idi]

Easy does it now......especially if you are running that engine without arp head studs. That much boost may pop a head gasket if you still got the stock gaskets/bolts on your engine in my opinion.

 

[idiabuse]

RCFA

Easy does it now......especially if you are running that engine without arp head studs. That much boost may pop a head gasket if you still got the stock gaskets/bolts on your engine in my opinion.

What actually blows the gaskets is not the boost, it actually is the water content in the cooling system.
Just like a racing engine that just uses water to kkep cool I/E drag racers they constantly pop head gaskets even using studs and 3 layer steel gaskets, why? the head warps because of the intense heat and the inability of water to control that.

Now with our trucks most all of us use proper levels of coolant to keep from having any issues while towing, and this is the most common method.

Yet just like you stated you have to be careful! Well the truth is that coolant at it's best is good to 240F at best!
We try to keep it under 220F or we are sweating bullets.

Now this is only coolant temps and not inner coolant jacket temps that nobody measures, yet they are much higher
than coolant temps, this heat wiggles the head around and bingo the gasket lets coolant seep by wich torches the head gasket.

Now the studs help squeeze down the gasket but how many 6.0s with studs blow gaskets?

At 240F coolant temp how efficient is the coolant at transfering heat from the cylinder head ito the radiator @ 16psi?

Not very efficient at all.

Coolant choice makes a huge impact when operating a diesel.



Javier

 

[Hydro-idi]

What actually blows the gaskets is not the boost, it actually is the water content in the cooling system.
Just like a racing engine that just uses water to kkep cool I/E drag racers they constantly pop head gaskets even using studs and 3 layer steel gaskets, why? the head warps because of the intense heat and the inability of water to control that.

Now with our trucks most all of us use proper levels of coolant to keep from having any issues while towing, and this is the most common method.

Yet just like you stated you have to be careful! Well the truth is that coolant at it's best is good to 240F at best!
We try to keep it under 220F or we are sweating bullets.

Now this is only coolant temps and not inner coolant jacket temps that nobody measures, yet they are much higher
than coolant temps, this heat wiggles the head around and bingo the gasket lets coolant seep by wich torches the head gasket.

Now the studs help squeeze down the gasket but how many 6.0s with studs blow gaskets?

At 240F coolant temp how efficient is the coolant at transfering heat from the cylinder head ito the radiator @ 16psi?

Not very efficient at all.

Coolant choice makes a huge impact when operating a diesel.



Javier

Very true but I do believe that increased boost on an idi that has stock gaskets and head bolts (especially 6.9's) can and will blow out a head gasket. It has happened many times with these engines. Remember, when you add more boost, you are adding more air pressure, heat, and energy in the combustion chambers.

 

[towcat]

got some reading for you to do.

www.oilburners.net/forums/showthread.php?4911-Let-s-Talk-Intercoolers

 

[Clb]

Devon harley.... Fresh air intake being fabbed up and rest of hood mod finished up soon. thanx cb

 

[Clb]

Thanx guys...
the intake mod to hood was done rather shoddy, I plan on opening the thing up to get some air thru to the eng.
the used pump in the bed looks to be the orignal(grey paint) along with a vacc. punp a couple of injectors a glow plug relay. So I'm thinkng the eng could be at around 170k or 270k....no real records ,just a log book that sometimes had a date or mileage noted but never both at one entry.
so far on the rear tank aprox. 70 miles and a half tank of fuel looks like this thing is exessively suckng fuel,yet no noticable smoke (need to get some mirrors on so i can see the tailpipe)it pulls ok but at 6 mpg I could use my 1 ton 4x4 quad cab mouse powered utility, so any help is greatly appreciated. thanx cb

 

[PwrSmoke]

Coolant is not going to help when your combustion pressure increases due to increased boost and the fuel to go with it. It's purely mechaical. The head bolts simply don't have the strength to hold the pressure, they stretch and that loosens the clamping ppressure on the gasket and combustion gasses start to leak, eroding or blowing the gasket outright. Even with stronger studs, there is a limit to what the head gasket fire ring can take. The coolant and the cooling system have a part to play here, but it's indirect.

There are some mind numbing calculations you can make on combustion pressure. These are based on the amount of air and fuel, cam timing and so many other things. Just to show you how the dynamic (running, which is controlled by when the intake valve closes) compression ratio changes with boost, go the the Wallace Racing site and find their dynamic compression ratio calulatorhttp://www.wallaceracing.com/dynamic-cr.php. You'll need rod length, which is 7.31 inches, and inlet closing spec (stock cam) which is 42.8 deg. ABDC. I used the most common 21.5 compression ratio. Enter 0 for the first boost number and 0 for altitude. You will find the dynamic compression ratio to be:

NA= 19.44:1
7psi boost= 28.7:1
10 psi boost= 32.66:1
15 psi boost= 39.28:1

This is one reason why it can be beneficial to drop the compression ratio in high boost situations, or limit boost on high compression engines. If you drop the CR on our engines below 20:1 you can have cold start issues... some thing Ford had trouble with on the first low compression 6.9Ls in early '83. Changing intake valve timing can also add or detract from the dynamic compression ratio. Bear in mind that when you add fuel to all the extra air in the chamber, you get a bigger "boom" and that increases combustion pressures. And, yeah, it's a lot more complex than this too but the bottom line is, you now have the availabity of studs for this engine and if you plan on running it the least bit hard (NA or turbo, consider studs one of your first and most important mods..

 

[Clb]

Coolant is not going to help when your combustion pressure increases due to increased boost and the fuel to go with it. It's purely mechaical. The head bolts simply don't have the strength to hold the pressure, they stretch and that loosens the clamping ppressure on the gasket and combustion gasses start to leak, eroding or blowing the gasket outright. Even with stronger studs, there is a limit to what the head gasket fire ring can take. The coolant and the cooling system have a part to play here, but it's indirect.

There are some mind numbing calculations you can make on combustion pressure. These are based on the amount of air and fuel, cam timing and so many other things. Just to show you how the dynamic (running, which is controlled by when the intake valve closes) compression ratio changes with boost, go the the Wallace Racing site and find their dynamic compression ratio calulatorhttp://www.wallaceracing.com/dynamic-cr.php. You'll need rod length, which is 7.31 inches, and inlet closing spec (stock cam) which is 42.8 deg. ABDC. I used the most common 21.5 compression ratio. Enter 0 for the first boost number and 0 for altitude. You will find the dynamic compression ratio to be:

NA= 19.44:1
7psi boost= 28.7:1
10 psi boost= 32.66:1
15 psi boost= 39.28:1

This is one reason why it can be beneficial to drop the compression ratio in high boost situations, or limit boost on high compression engines. If you drop the CR on our engines below 20:1 you can have cold start issues... some thing Ford had trouble with on the first low compression 6.9Ls in early '83. Changing intake valve timing can also add or detract from the dynamic compression ratio. Bear in mind that when you add fuel to all the extra air in the chamber, you get a bigger "boom" and that increases combustion pressures. And, yeah, it's a lot more complex than this too but the bottom line is, you now have the availabity of studs for this engine and if you plan on running it the least bit hard (NA or turbo, consider studs one of your first and most important mods..

this thing will probably never get to the point of getting turned up that far as to need head-studs and cam/rods..good to know the tech is out there,,, I have a hunch this thing has mismatched injectors in it,,, I need to do returns so then glowplugs are on the hit list .... where can a guy get the calibration codes for db2's? gunna try standynes site.
I am one of those picky guys that like order in mechanics and this lil truck seems outta order,lol
thanx again, time to go read some more.

 

[Hydro-idi]

Coolant is not going to help when your combustion pressure increases due to increased boost and the fuel to go with it. It's purely mechaical. The head bolts simply don't have the strength to hold the pressure, they stretch and that loosens the clamping ppressure on the gasket and combustion gasses start to leak, eroding or blowing the gasket outright. Even with stronger studs, there is a limit to what the head gasket fire ring can take. The coolant and the cooling system have a part to play here, but it's indirect.

There are some mind numbing calculations you can make on combustion pressure. These are based on the amount of air and fuel, cam timing and so many other things. Just to show you how the dynamic (running, which is controlled by when the intake valve closes) compression ratio changes with boost, go the the Wallace Racing site and find their dynamic compression ratio calulatorhttp://www.wallaceracing.com/dynamic-cr.php. You'll need rod length, which is 7.31 inches, and inlet closing spec (stock cam) which is 42.8 deg. ABDC. I used the most common 21.5 compression ratio. Enter 0 for the first boost number and 0 for altitude. You will find the dynamic compression ratio to be:

NA= 19.44:1
7psi boost= 28.7:1
10 psi boost= 32.66:1
15 psi boost= 39.28:1

This is one reason why it can be beneficial to drop the compression ratio in high boost situations, or limit boost on high compression engines. If you drop the CR on our engines below 20:1 you can have cold start issues... some thing Ford had trouble with on the first low compression 6.9Ls in early '83. Changing intake valve timing can also add or detract from the dynamic compression ratio. Bear in mind that when you add fuel to all the extra air in the chamber, you get a bigger "boom" and that increases combustion pressures. And, yeah, it's a lot more complex than this too but the bottom line is, you now have the availabity of studs for this engine and if you plan on running it the least bit hard (NA or turbo, consider studs one of your first and most important mods..

Finally a response that is more accurate and not someones theory lol. Thanks for the input.