4bt cummins swap

[1972RedNeck]

Originally Posted by 66Submarine

From everything I've read, a 4BT pumped up like that will kill itself in short order if you actually load it up and start up the side of a mountain WOT.

Wow, you must have read all of the same stuff that I read. I'm just too tenacious about some of the hair-brained ideas that I have to listen to reason. I plan to have a 300 HP 4BT that I can tow with. Do I think I can? - yes. If it lasts over 100,000 miles I will be ecstatic.



In case anybody cares, I should have it all juiced up by the end of the month. I had to pull the motor because of a "little" break down after running it at 200 HP for about 2,500 miles.

[66Submarine]

Originally Posted by 1972RedNeck

Wow, you must have read all of the same stuff that I read. I'm just too tenacious about some of the hair-brained ideas that I have to listen to reason. I plan to have a 300 HP 4BT that I can tow with. Do I think I can? - yes. If it lasts over 100,000 miles I will be ecstatic.



In case anybody cares, I should have it all juiced up by the end of the month. I had to pull the motor because of a "little" break down after running it at 200 HP for about 2,500 miles.

Reason seems to suggest that just jacking up a 4BT to 300HP and beating on it will greatly shorten its lifespan; the marine 250HP versions that supposedly have lots of reliability problems also hint to this.

So you ran @ 200HP for 2,500 miles and actually messed something up, but you plan to beat on it @ 300HP and have it last?

Anyway, do you mean you want a 300HP engine you can tow a 500lb 5'x8' utility trailer with once a year, or a 300HP engine you can actually hook something heavy up to and hold it wide-open climbing a steep hill with regularity? Not really the same thing.

BTW, you mention:

If it lasts over 100,000 miles I will be ecstatic.

Well, an old guy from Texas on another board used to run a '59 (IIRC) GMC tandem axle road tractor with an Oldsmobile 371 V8; he said he pretty much ran wide open all day and kept it @ 3,800-4,200RPM. He also said he went 100,000 miles between rebuilds running like that, and it was still a good running engine when he later wrecked the truck.

One last time; I'M NOT HATING ON DIESEL ENGINES!!! All I said is that I think the modern lore embellishes on reality to some degree. I actually do like them, but they are not some kind of magical mechanical unicorns that are beyond human comprehension. Is that not OK? Really?

If you want to have a 300HP 4BT just to say you do/can, great! Nothing wrong with that, and I never said there was.

[1972RedNeck]

Originally Posted by 66Submarine

Reason seems to suggest that just jacking up a 4BT to 300HP and beating on it will greatly shorten its lifespan; the marine 250HP versions that supposedly have lots of reliability problems also hint to this.

So you ran @ 200HP for 2,500 miles and actually messed something up, but you plan to beat on it @ 300HP and have it last?

Anyway, do you mean you want a 300HP engine you can tow a 500lb 5'x8' utility trailer with once a year, or a 300HP engine you can actually hook something heavy up to and hold it wide-open climbing a steep hill with regularity? Not really the same thing.

BTW, you mention:

Well, an old guy from Texas on another board used to run a '59 (IIRC) GMC tandem axle road tractor with an Oldsmobile 371 V8; he said he pretty much ran wide open all day and kept it @ 3,800-4,200RPM. He also said he went 100,000 miles between rebuilds running like that, and it was still a good running engine when he later wrecked the truck.

One last time; I'M NOT HATING ON DIESEL ENGINES!!! All I said is that I think the modern lore embellishes on reality to some degree. I actually do like them, but they are not some kind of magical mechanical unicorns that are beyond human comprehension. Is that not OK? Really?

If you want to have a 300HP 4BT just to say you do/can, great! Nothing wrong with that, and I never said there was.

I'm not disagreeing with you. 401/478 v6's and 637 v8's and 702's were advertised to run 200,000 miles between overhauls. They pull fantastic and drink like an alcoholic.

As for towing, I only tow about 15% of my driven miles. When I do tow, it is always at least 25,000 lbs. I am going to try to make it so I can hold it to the floor and never let up.

[66Submarine]

Yeah, those comments were really intended for the other guys; I was just using that as an example more than anything (sorry if I came across as coming after you--my bad there). You seem like you understand that you are asking for a lot out of the little 4 cylinder, and that it will cost money to get it to live like that. Nothing wrong with wanting to push the limits on a hotrod project to see what can be done/if it can be done, but just be realistic with the expectations--that's the point I was trying to get across.

[truckeez]

"Torque is only a measurement of force, which does nothing without speed; speed x force = HP."

^^^^^^^^^^^
there are -a - mixed up dude (s) here, torque is what gets a truck going from a start, (and also is what delights ricky racers in their 5/0 mustangs with a stick) ,
NOT HP.
hp is ONLY a measurement of what an engine can do up above 2500 rpm, and dosent factor in while getting up there.
the wierdo 4bt craze is just that.... 1000$ i dont think so unless someone is doing some serious inet scrownging and swapping spare junk to get there (but -No , not including a modded pump---NO Way).
you start adding the cost of sourcing the correct back plate you have to have and the flywheel that it didn't come with and ,,,, oh yea that damn outfit called advanced adaptors just wont sell those bits at a giveaway price,

Plus the hemeroid surgery from the butt sore cringing syndrome of not only driving something so equipped after going into that much hock--just to be in with the latest oddball IN crowd. oh and lets not forget The attempts to sell the project off to some new guy to the crazee 4bt thing because you realize its just too damn rough to use in anything,,, there is a durango equipped one someone could get for .....


and last but not least the dentist bill to have the fillings replaced.
hey lets get a s10 frame and an old heap from the farmers tree row and build a _real_ truck!!

[66Submarine]

Originally Posted by truckeez

^^^^^^^^^^^
there are -a - mixed up dude (s) here

I don't think you know just how true that is...

torque is what gets a truck going from a start, (and also is what delights ricky racers in their 5/0 mustangs with a stick) ,
NOT HP.
hp is ONLY a measurement of what an engine can do up above 2500 rpm, and dosent factor in while getting up there.

I think that is one of the dumbest things I have ever read. Really? HP = torque x RPM / 5252. The idea of it somehow not being able to be used as a measurement under 2,500RPM is absolutely beyond ridiculous. It's really basic math that anyone with three functioning brain cells can understand very well. But don't listen to me, just google it for yourself.

I guess parroting the same stupid BS and attacking anything remotely resembling thought is fun though, right?

Low-end power is what actually moves the Mustang you mention, and is why a lot of people cannot seem to grasp this basic concept.

Twice the torque @ 1,000RPM=twice the HP @ 1,000RPM.

You guys are all confusing this with peak HP numbers and peak TQ numbers (etc). Torque is only a measurement of force, not anything more or less, and without motion/HP you go nowhere.

Again, let me make another example. I will put a 2:1 reduction drive between my lame 250 six and the trans tomorrow, instantly giving me 440ftlbs at the new "crank". Will it pull harder in high gear? You bet! But wait...now I need to replace my 4.10 gears with 2.05's. End result? Same damn thing (forgetting about the loss from the reduction gears).

The rest of the driveline needs to be matched with whatever engine you use. DZ302 with 2.56 rear gears and a PG with a tight converter? It's going to suck at getting itself rolling. You'll also be disappointed if you take your 4BT with 5.13's to Bonneville. This isn't hard to figure out.

Anyway, I'm done here. Even I have much better things to do with my time than try to teach basic math to people so hard-headed that they refuse to even consider it. You win, guys. Go take a victory lap...