Building a Performance Marine Engines

StainlessRRA said:
Reducing internal stress on the motor. However they become difficult to start once decompressed to a certain level hence the term "ether baby".
Click to expand...

ahhhhh, UIM rules allow diesel boats to have 8 pounds of starting chemicals.

I 'spect I still don't get it, however.

I thought 15 (-ish) : 1 was a pretty modest compression ratio, but I don't think that is what you are referencing.

I remember piston-shaving back in my hot-rod-lincoln days. ummm ...
 
A stock Cummins is between 17:1 and 18:1.

Down to about 13:1 is what bigger sled pullers do.

you asked for different engines. Thought about the International DT366 and DT466?
 
oldestof11 said:
A stock Cummins is between 17:1 and 18:1.

Down to about 13:1 is what bigger sled pullers do.

you asked for different engines. Thought about the International DT366 and DT466?
Click to expand...

No, I hadn't, and it was a booger-bear to find specs on them, but that 7.6L looks interesting, esp at 700kg.

Does anybody make them into a (mechanical) performance engine? Will heads stay together at 32-3300 rpm and 2-3 Bar.

I come from a Cat/Wauk/DDA world and surely do like wet cylinders, generally.
 
goatskin said:
No, I hadn't, and it was a booger-bear to find specs on them, but that 7.6L looks interesting, esp at 700kg.

Does anybody make them into a (mechanical) performance engine? Will heads stay together at 32-3300 rpm and 2-3 Bar.

I come from a Cat/Wauk/DDA world and surely do like wet cylinders, generally.
Click to expand...

Hypermax is one.
 
TheBigNasty said:
Hypermax is one.
Click to expand...

I have worked on the IH engines a long time. They are going to be heavier than a Cummins engine. The IH 466 is large. You could use a 8.3 Cummins then. They would be overkill.
Nothing about the fuel system would be different than what you already want. I dont see any gains with this.
 
They are built into some of the top tractor pulling engines out there. 200 psi and 5k RPMs is what those guys run
 
I'd put my money on a DT466 holding 800 HP for hours on end long before a 5.9, horsepower is like toothpaste, the bigger tube you have the harder you can squeeze it and the longer it'll last.
 
Can you still get your hands on the 7.3 and 8.1L 4 cylinder cummins? I've always wondered what those could make for hp, although harmonics on a 4cyl are terrible and probably would destroy the boat parts lol
 
EricStaab said:
I have worked on the IH engines a long time. They are going to be heavier than a Cummins engine. The IH 466 is large. You could use a 8.3 Cummins then. They would be overkill.
Nothing about the fuel system would be different than what you already want. I dont see any gains with this.
Click to expand...

Actually, they are about what-and-what as far as dims and mass are concerned, but I agree: I see no apparent, obvious gains.

- The Cummins (marine) 6.7 is 368cube, mass is 1400lbs.

- The Cummins (marine) 8.3 is 413cube, and a tad less than 2000lbs.

- The 466/530 (dirt) 7.6/8.7 is 374cube, and 1425lbs, which would go on a slight diet when marinised.

- A cast iron 5.9 'B' block, with 6.7 internals, is 325-ish cube and a taste under 1000lbs, but 4-5" shorter that any of the others. The same 'B' on an LSM B aluminum is 150lbs lighter.

Since I plan to mount them nose-to-nose on the centerline, shorter is preferred over longer, and all of them are well-acceptable weight.

The I-H are 'old diesels', slow speed & modest torgue. In order to make things work on the drive end, I really need 3000-3300 rpm and carry 4-500# of twist with it. How does the I-H crank work when asked to go faster? Is everything cross-bolted?

I'll talk to Hypermax in the morning and explain (again) why I only want 1000hp, and yes, I know you can make me 3000hp ...
 
company I worked for had a DT466 in a fertilizer spreader truck that turned 3200 at 45mph, it got driven everywhere like that with the pedal on the floor, last I checked it had been going 20 years like that.
 
cumminsman315 said:
Can you still get your hands on the 7.3 and 8.1L 4 cylinder cummins? I've always wondered what those could make for hp, although harmonics on a 4cyl are terrible and probably would destroy the boat parts lol
Click to expand...

The short version is yeah, and yeah. BT & CT, 4 & 6hole are plenty available: cores and remans.
 
TMONEYDIESEL said:
A duramax would be a great engine for that boat, they have been putting a few in some of the bigger poker run boats and have been doing well.
Click to expand...

WAIT ... you're not thinking of that red Cheetah that MillerMarine in Havasau demoed a couple of times in 2010, are you?
 
cetanefreek said:
company I worked for had a DT466 in a fertilizer spreader truck that turned 3200 at 45mph, it got driven everywhere like that with the pedal on the floor, last I checked it had been going 20 years like that.
Click to expand...

Yep, that's the kind of boring engine I want to build.

Cetane ... speaking of, what are you do when the greenies finally get Cetane lowered to 5, from 20?

Bosch (for one) is going nuts over it.
 
cetanefreek said:
I'd put my money on a DT466 holding 800 HP for hours on end long before a 5.9, horsepower is like toothpaste, the bigger tube you have the harder you can squeeze it and the longer it'll last.
Click to expand...

Yes, and no, I think.

In what I'm wanting to do, 80-85% (with a reserve) is what you set-up the transmission & prop (and run WOT when you can without causing snapping sounds) and HOPE you are tougher, meaner and have better kidneys than your competitors, who have to pull the sticks back at put on their kneepads.

Like any other hp event, 'outside' is fueled with ego and testosterone, but the worst thing you can do to a diesel is lope it: a 1000hp engine run hard at 800 will love you; a 1500hp engine run at 800 will soot in your Fruit of the Looms, and unless you change gears and props, there is no way to drain the engine, anyhow.
 
I love how Wade and Greg come in here trying to measure their peckers and get owned, multiple times, by the new guy and then they just faaaaade away out of the thread...


Epic win my friend, if I ever meet you, drinks on me!
 
Last edited:
You must log in or register to reply here.
Back
Top