why you can throw stupid power easily at a cummins and have to work at a IDI......

[MIDNIGHT RIDER]

Concerning my mileage statement, I meant that, in my own experience, an average run-of-the-mill 6BT will usually get twice the fuel-mileage of a run-of-the-mill V-8 IDI.

I know some have carefully timed and tuned their IDIs to get decent mileage comparable to a 6BT.

 

[Blind Driver2]

Concerning my mileage statement, I meant that, in my own experience, an average run-of-the-mill 6BT will usually get twice the fuel-mileage of a run-of-the-mill V-8 IDI.

I know some have carefully timed and tuned their IDIs to get decent mileage comparable to a 6BT.

So if I drop in a 6bt, I'll get 35 mpgs? Where do I sign up?

 

[MUDKICKR]

you're partially missing the point. if all your goal is the max in getting air in and out, then throw out the IH 6.9/7.3 and the 6BT. they're overweight. after all, with your line of thought, a GM 6.2/6.5 will EASILY fill your needs. I've built enough of these motors where they can get stupid fast quick. if longevity is no concern to you, a GM will do everything you want compared to the other two. Now if you want a healthy dose of reliability added into your air pump, you will need to take a look at how the bottom end of a engine is designed and spec'd. an inline with large bearing surfaces will take more power thrown at it and stay together longer compared to a V-designed engine. take away the overkill lower block reinforcements and webbing, you now have a hand grenade known as a GM 6.2/6.5. Fast. stupid fast. But don't ask it to work hard. It will tear out its 2,3,&4 main webs and toss the crank out the pan too.
if you can visualize the bearing size differences by the speedi-sleeve comparo, you just understood my point in posting the pic. if not, just carry on. the point of all this was a simple visualization exercise. nothing more.

i dont believe i did miss the point, i believe the title doesnt represent the thread, and also, what i want doesnt matter right now, but seeing the bearing themselves would be a better "visualization" then the seals, due to the seals are always bigger then the bearings themselves. bringing into the thread about gm 6.2/6.5 only brings us more off topic, and the topic has nothing to do with "what youve built" in the past. also another thing you stated ( an inline with large bearing surfaces will take more power thrown at it and stay together longer compared to a V-designed engine.) thats not always true, but i dont want to go "off" subject. by reading the title of the thread i was expecting to see a Cummings in an engine bay with twin turbo on it, since an inline engine will always have more engine compartment room then there " V-designed engine" counterpart.

 

[Goofyexponent]

Just an FYI on the 3208's being 165HP, those are naturals.

The same blocks can produce a lot more HP with the "easy" yet costly additions of turbo's, injectors, aftercoolers, etc... We have customers all day long with 550HP marinized 3208's.

Weight and stuffment would be my concerns with those big ole bricks, although I'd love one in my IDI.

(Stuffment, new term I just made up.... cramming and engine into a space it doesn't fit)

Ever go to Caterpillar for parts? You better have DEEP pockets. I am a Cat man, trust me when I say that. I would LOVE to have a hot rodded 3406 B or C over anything modern today.

But there is a saying...A Cat is worth more dead (in parts) than it is alive (running and burning fuel)

you're partially missing the point. if all your goal is the max in getting air in and out, then throw out the IH 6.9/7.3 and the 6BT. they're overweight. after all, with your line of thought, a GM 6.2/6.5 will EASILY fill your needs. I've built enough of these motors where they can get stupid fast quick. if longevity is no concern to you, a GM will do everything you want compared to the other two. Now if you want a healthy dose of reliability added into your air pump, you will need to take a look at how the bottom end of a engine is designed and spec'd. an inline with large bearing surfaces will take more power thrown at it and stay together longer compared to a V-designed engine. take away the overkill lower block reinforcements and webbing, you now have a hand grenade known as a GM 6.2/6.5. Fast. stupid fast. But don't ask it to work hard. It will tear out its 2,3,&4 main webs and toss the crank out the pan too.
if you can visualize the bearing size differences by the speedi-sleeve comparo, you just understood my point in posting the pic. if not, just carry on. the point of all this was a simple visualization exercise. nothing more.

Precisely. In an inline engine, all the force is being applied to the bottom end (which is larger!!!) in two directions. Straight down, and straight up. This is why an inline's block is going to be (stiffer) because there ar eno real side forces trying to break the block in half.

In a V engine, that load force is trying to tear the block in half. the mains are being subjected to forces that nearly cover teh whole 360 degree circumference of the main bearings surface. They are generally smaller due to clearance related problems in the crank and block.

I would take an inline 6 over a V anyday for longevity, but that's not to say that the IDI is a piece of junk. they are tough motors, and efficent at what they were designed to do.

 

[riotwarrior]

Concerning my mileage statement, I meant that, in my own experience, an average run-of-the-mill 6BT will usually get twice the fuel-mileage of a run-of-the-mill V-8 IDI.

I know some have carefully timed and tuned their IDIs to get decent mileage comparable to a 6BT.

Sign me up, I'll take near 40MPG anyday from a 1to truck tipping the scales at or around 7000lbs....ya ha I will....and My truck is tuned as I bought it from the previous owner! I have no idea where it's at...rofl....

Just sayin....40MPG would be saweet

 

[riotwarrior]

Ok lets look at this a slightly different way then shall we.

V 8 engine usually has 5 main bearings.....and the crank throws for rods share 2 rods per journal....GOT IT? Check!

Inline 6 engine usually has 7 main bearings and one rod for one throw of crank....GOT IT? Check!

... that in and of it's self is substantial in comparison let alone getting into journal diameter differences!

More bearing area supports more load better. IT is simple and that's the lesson of the day folks!

JM2CW

Al

 

[MUDKICKR]

Ok lets look at this a slightly different way then shall we.

V 8 engine usually has 5 main bearings.....and the crank throws for rods share 2 rods per journal....GOT IT? Check!

Inline 6 engine usually has 7 main bearings and one rod for one throw of crank....GOT IT? Check!

... that in and of it's self is substantial in comparison let alone getting into journal diameter differences!

More bearing area supports more load better. IT is simple and that's the lesson of the day folks!

JM2CW

Al

that is a good lesson, but now since we are talking about bigger bearings and more bearings, we must also talk about the added friction that more/bigger bearings will have, and that not always bigger is better, cause, with the bigger bearings, the faster the crank will spin, the more friction load will be on the crank. so if you take something that has 3" bearings, and spin it at 4,000 rpm, that would roughly equal the same friction as a 4" bearing at 2,800 rpm. and if we also add the extra bearing surface into that, how much more friction is added to the crank?


im just saying that more/bigger isnt always better, and if thats true, how many 300 l6 mustangs are around?

 

[riotwarrior]

that is a good lesson, but now since we are talking about bigger bearings and more bearings, we must also talk about the added friction that more/bigger bearings will have, and that not always bigger is better, cause, with the bigger bearings, the faster the crank will spin, the more friction load will be on the crank. so if you take something that has 3" bearings, and spin it at 4,000 rpm, that would roughly equal the same friction as a 4" bearing at 2,800 rpm. and if we also add the extra bearing surface into that, how much more friction is added to the crank?


im just saying that more/bigger isnt always better, and if thats true, how many 300 l6 mustangs are around?

Oh very well versed on the facts you present, and that does come into play, however since we are comparing friction, don't forget there are MORE lifters more rockers more pistons etc to overcome!

Back to why the 6cyl has a stouter bottom end it's clear a support structure of 7 mb and 6 rod throws is stronger than 5 and 4 respectively. Also the load on the crank is such that the the harmonics of a 6 cyl are different than 8 ever notice how a straight 6 or V12 sounds compared to an 8? Just that nice even power compared to a V8...no comparison....IMHO

 

[79jasper]

im just saying that more/bigger isnt always better, and if thats true, how many 300 l6 mustangs are around?

I would say because it takes a bit more work to make decent power vs just swapping a sbf. But have you seen the old school I6 dragsters? They're pretty quick. And Al is right, they do sound sweet! I just don't like the sound of most 5.9 cummins. They usually have some ricer cowboy wannabe exhaust and sound like a fart can honda.

 

[towcat]

I just don't like the sound of most 5.9 cummins. They usually have some ricer cowboy wannabe exhaust and sound like a fart can honda.

I can't agree with you more. Especially when I am home in TX. i have a corner house and get to listen to these brats get on the throttle after they make the turn. Still, the bottom line is stupid power is easier found in a Cummins due to a stouter design.

 

[riotwarrior]

I just don't like the sound of most 5.9 cummins. They usually have some ricer cowboy wannabe exhaust and sound like a fart can honda.

I'm afraid I gotta disagree with you on the sound....this one is damn sweet sounding and I gotta tell ya ifn my IDI can do this I'l be stoked!

http://youtu.be/Fh45CBDc5iw

 

[79jasper]

Towcat: good engine, just in a crappy truck. IMO.
Riotwarrior: I didn't mean ALL of them. Just the majority of them. Basically the one's driving around towing ghost trailers lol. I do like the sound of the 12 valve over the 24v.

 

[icanfixall]

The rods in the cummins is a very differant rod compared to the idi engine rods. Differant design and much heavier too plus they are a longr stroke too...

 

['94IDITurbo7.3]

Riotwarrior: I didn't mean ALL of them. Just the majority of them. Basically the one's driving around towing ghost trailers lol. I do like the sound of the 12 valve over the 24v.

5.9 CR & 5" straight pipe or ****!

 

[Dave 001]

5.9 CR & 5" straight pipe or ****!

5.9 compression ratio?? That ain't gonna' get much done. (I got one for ya'.....AS = acronyms suck)