"wake up shunshine"

man most of this is way over my head but.....look inside a top fuel engine. way more fuel goes thru that than does a diesel. instantly accelerates to idk what rpm from idle. it doesn't look anything like the inside of a diesel and theres a reason why.
spinning all that heavy schidt alotta rpms isn't gonna work very well for long. fuel eng have almost no piston skirts at all. rods are short by comparison by cubic inch. forced induction by engine crank speed.
I built a few gas engine drag engines....to me hp means top end power..by rpms and airflow...torque is the opposite made by mass of spinning weight. light stuff spins fast makes top end. heavy stuff makes low pwer torque?
a 2 stroke can make 75 hp out of 500 cc easy..but has almost no torque..no btm end cuz it has no reciprocating weight
or I could be full of crap idk really


why would anyone need a pump when the f1 are all electronic injectors at 15000 rpm..some way into 18000
 
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Post 136 you were around 5500rpm.

Cat truck came off the line at 6000rpm and carried around 5000 down the
track.
 
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12vchevydually said:
Post 136 you were around 5500rpm.

Cat truck came off the line at 6000rpm and carried around 5000 down the
track.
Click to expand...

I have no way to prove it on this video. We have turned it harder but most of the time we tried to shift at 6,000RPM. You could feel the truck sorta nose over just after that. We never used any fancy fuel except for the stuff the nice fella gave us up at Antrim Diesel days.

All we had in her for fuel that day was good 'ol pump #2. Folks have posted on here and don't quote me, but, I think we as a nation have the worst quality diesel fuel in the world. Just ask the Taiwan boys. Anyhow, I was making good power to 6000rpm's with junk fuel. That sorta fits the piston speed calculation above.

I have no way of knowing what the Cat truck was turning. I know it was much harder than mine towards 3/4 track. Again, I was making my RPM's with a 5.9 crank. Any guess as to the stroke on the engine in the Cat truck?

One more bit of info, I've seen post on here that prove the racing diesel fuel does nothing for adding power. Did anyone ever question what it does for RPM's??
 
Most of it's way over my head too, but I'm hear to learn anyway. Keep going.

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Bodacious said:
I have no way of knowing what the Cat truck was turning. I know it was much harder than mine towards 3/4 track. Again, I was making my RPM's with a 5.9 crank. Any guess as to the stroke on the engine in the Cat truck?
Click to expand...

If it's a 3406b or c it's a 6.5" stroke factory.
 
J-Pipes said:
Inline has more mains, more support. I'd guess over 4k rpms. As long as it's all balanced right, I was told almost 10yrs ago that the pumps where capable of 7500rpm. Was on a truck the make peak power at 5200rpm.

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Click to expand...

Sorry to leave ya back there on this one. You are correct that an L-anything has more mains than almost all V-designs. ...almost. lol

They also only have one rod per journal. As long as the rods and pistons are balanced, once the crank is originally balanced, you no longer ever have to balance that crank again. It doesn't care what kinda bob-weight you hang on it.
 
mfsuper90 said:
If it's a 3406b or c it's a 6.5" stroke factory.
Click to expand...

Lol, it is an LSM 6.7base cummins with billet steel head. I seen it at Scheid's engine shop. Such a badd a$$ truck. ...mechanical injection as well.

I also laid my hands on the most beautiful 6.7 crank I'd ever seen in my life. Even the counter weights looked like mirrors.
 
dieselbeef said:
man most of this is way over my head but.....look inside a top fuel engine. way more fuel goes thru that than does a diesel. instantly accelerates to idk what rpm from idle. it doesn't look anything like the inside of a diesel and theres a reason why.
spinning all that heavy schidt alotta rpms isn't gonna work very well for long. fuel eng have almost no piston skirts at all. rods are short by comparison by cubic inch. forced induction by engine crank speed.
I built a few gas engine drag engines....to me hp means top end power..by rpms and airflow...torque is the opposite made by mass of spinning weight. light stuff spins fast makes top end. heavy stuff makes low pwer torque?
a 2 stroke can make 75 hp out of 500 cc easy..but has almost no torque..no btm end cuz it has no reciprocating weight
or I could be full of crap idk really


why would anyone need a pump when the f1 are all electronic injectors at 15000 rpm..some way into 18000
Click to expand...
See post 123

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Bodacious said:
I quoted ya here Pudge for the piston speed part. I knew something didn't appear correct to me. I went back down and looked on the block wall and I found a faded out zero. lol

So just so you all can check my math and this is a very important part of what I aim to do, here are my calcs.

I need to know how many feet are in the circumference of the crank radius.

4.72441 x 2PI = 29.68434" convert to feet /12 = 2.47370 multiply by crank speed in R/M x 6000RPM = 14,842 F/M

Zach apparently told me 12,000 - 15000 F/M lol

See, I'm the biggest idiot in this discussion. LOL
Click to expand...

I don't think you are using the right equation. You are calculating how fast the pin is moving, which I don't believe will equate into true vertical speed of the piston.
 
zstroken said:
I don't think you are using the right equation. You are calculating how fast the pin is moving, which I don't believe will equate into true vertical speed of the piston.
Click to expand...

You are absolutely correct. That's where Tobin's stuff starts playing into view. This is max speed at that RPM. We know about injection timing. How long after the injector fires, is a good guess to where the piston actually sees the force? I know it is not when the crank/rod angle are 90 degrees. If we set the fuel up to inject at 20*BTDC, the fire has to be starting before the piston gets up there.

Edit: ...in addition, how far down the cylinder before the force on the piston becomes null?? I don't really know myself. I willing to throw out some guesses???
 
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Bodacious said:
You are absolutely correct. That's where Tobin's stuff starts playing into view. This is max speed at that RPM. We know about injection timing. How long after the injector fires, is a good guess to where the piston actually sees the force? I know it is not when the crank/rod angle are 90 degrees. If we set the fuel up to inject at 20*BTDC, the fire has to be starting before the piston gets up there.

Edit: ...in addition, how far down the cylinder before the force on the piston becomes null?? I don't really know myself. I willing to throw out some guesses???
Click to expand...

Wouldn't how far down the hole really be determined by geometry (degrees of separation between firing of one cylinder to the next)? It can only push the piston so far before no amount of force applied to the piston will move it on around in rotation (unless we count acceleration and account for its ability to freespin beyond that point) therefore need the next cylinder to fire to push the crank on around and continue to move the piston on down and head back up. So the physical geometric shape and force angles play a part.

Then the other part is, of course, the amount of time the combustion event has to push on the piston which is controlled by the exhaust valve open time.

Or am I all wet on the general function of a combustion driven engine and what you're trying to hint at?
 
valve timing has alot to do with when the force of the explosion make the most powerstroke. overlap and timing mean a lot otherwise we wouldn't degree cams
 
So does flame front propagation, atomization, fuel plume velocity, induced swirl. All those things I can't quantify because I'm not an enginerd

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biggy238 said:
So does flame front propagation, atomization, fuel plume velocity, induced swirl. All those things I can't quantify because I'm not an enginerd

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Click to expand...

I have lots of buddies now with mud trucks so fast, I will never be able to catch them. They don't have eninerd degrees. lol

Clessie cummins was in his early teens when he build his first steam engine. He only made it to the 8th grade and look at the stuff we get to play with because of him.
 
I think saying it’s because of Clessie, is a bit of a reach.


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OK, to sum up this thread:
- don't know what kind of fuel to go with, still up in the air about gas vs diesel
- possibly owns 1 turbo to go with the build
- debating about V8 vs inline 6
- read one book written by Clessie
- I think the 1st gen is the 'competition truck' entering UCC 2018
- might be on pills, depending on the hour of the day
- thinks moderators on this forum are unfair
- likes multi-quoting himself
- possibility of revgain


Did I miss anything?

My issue is that I have literally seen/been a part of hundreds of these threads over the years on multiple forums. Maybe, and I mean this is a stretch, but 1 out of a hundred actually materializes, and makes it to the finish line. I can't tell you how many times I have read "can I put a DT466 in my F-150?" over the years.

So I'll ask you again, how deep are your pockets?
 
He's sent me some more info in PM's, that I won't divulge, but I think what he's got in mind is doable. Definitely going to need some custom parts, but will be pretty cool when done. He's just playing it close to the chest since it's different.

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