hey, is it possible to get 600#ft of torque from the engine with stock pistons? or would you have to get the compression down to be able to use more boost? or can it be done at all??

 

I went with milling down the pistons to lower the compression ratio.
I will be looking for a dyno here shortly to see what it can do, first I want a few more miles on the rebuild before I run it that hard.

 

i have been following your progress with a lot of interest and wishing the best for you. also, having somebody in front of you blazing the trail as it were, just to see how far you can reliably boost the power in these idi's is great!

 

I am not really trying to go to the max.
I want a bit more power without sacrificing reliability and driveability.
Also I am trying to address the 6.9 weak spots when turbocharging.

As it is set right now I am running about 20 PSI of boost and the EGT's are getting close to 1000 degrees. So far so good.

Sometime this evening I am going to enter all my fuel reciepts and see what I am doing for MPG so far. Initial figures at the pump make it look like I have gained power but the MPG impact is close to the same or slightly better.

I hauled 6 loads of retaining wall blocks last week, the loads were close to 4 tons of blocks each. My trip odometer showed over 200 miles on 18 gallons of fuel which would indicate an improvement hauling that much weight at interstate speeds.

 

do you have any plans for more boost or fuel? or to dyno it to see what you got and enjoy it

 

I will turn the fuel up a bit more after I get a few more miles on it.

Where my IP is set at was running at 1200 plus as far as EGT's went.
Same setting dropped my EGT to 900 degrees after I milled the pistons.
I have increased my boost from 14 PSI to a little under 20 by adjusting the wastegate, but that is all it will make till I add more fuel.

I have noticed my bottom end torque has dropped a bit with milled pistons, but once I have the turbo spooled up I have more power than I did before from about 1500 RPM on up.

I have also noticed that cold starts require 5 seconds of glow plugs in the summer, where before it required no glow plugs at all with temps close to 70 or above. I hope this one does not come back to bite me this winter.

With what I took off the pistons my base compression ratio is dropped from 22.5 to 1 down to 19.5 to 1.
With 19.5 PSI of boost and 19.5 compression ratio that gives me a final compression ratio of 45.4 to 1.

A Power Stroke running 18 to 1 and 30 PSI has a final compression ratio of 54.73 to 1.
5 more pounds of boost will put me at the same final compression ratio as a Power Stroke with a few mods done to it.

 

I have a question for you... My 6.9 was supposed to have been rebuilt 5000 miles before I got the truck, and from day one it has needed the glow plugs for every cold start, whether 20 degrees or 100, it wants glow plugs to fire every time cold. Warmed up it pops right off, be surprised if I have over 1/2 turn before it fires, hardly any cranking. It pulls well, and uses about 1 quart per 800 miles, so I have good reason to believe it is as fresh as claimed. Is it needing the gp's because the compression may be reduced, or just happens to be that way/ Just curious, and looking for an opinion. Not that I am really going to do much about it, because I love the way it runs. No turbo, no money for that yet, but it can hang with the 92 Cummins motor in the 92 F350, I actually had to turn the Cummins up to satisfy me, because the 6.9 has more snap to it. Now the Cummins responds better, but by factory set, it was a pooch in comparison...same rear gears too, only difference is the auto behind the Cummins vs my T-19.

 

my 88 7.3 requires a touch of glow plug on a "cold "engine. it can be 100º out, but if the truck has sat for more than 12 hours it will not fire without the glow plugs cycling first. hot is the same. less than 1 rev to fire off.

 

Good to hear I'm not alone... was wondering when I see so many that don't. Mine starts just like it had been running all day if I use the glow plugs, otherwise, I have to crank for a while on it, and it will fire, but smokes a bit at first if I don't use the gp's.

 

same here, if i don't wait for the gp's to cycle, it cranks longer and smokes more, and idles a little rough until it "clears out".

 

My fresh rebuilt 7.3 engines would start after about 3 revolutions without the glow plugs if the temp was over 70.
This engine will start after about 15 revolutions if I crank it that long.

I just hit the glow plugs for a couple of seconds to make it easier on the starter if it has been setting for more than 4 hours.
With glow plugs it fires on the first cylinder to get to the compression/combustion strokes.

 

Dave, Hope This Isn't A Dumb Question, But, What Do You Mean When You Hit Or Cycle Through The Glow Plugs?

 

Dave has manually operated glow plugs. he uses a momentary contact push button in stead of a gp controller.

 

thank you.