4BTA cummins in my J10

[mcinfantry]

quick hijack
4l80e/compushift/clocked np241
hijack over

[tndonor]

thats not a hijack......I asked.

That will be a great combo as well. Keep us up to date....Id like to see what you build up

[dusty]

yep. like i say PROVE ME WRONG.

untill someone runs 60,000 miles on 400hp 4bt, i dont care what you THINK will work.

he said 350tq, NOT 350hp.

400hp is a little hard but its been done there are three or maybe four now ... guys in NW bombers who have already played with thier 4BT's in one shape form or another in converted 1970-80's model 3/4 and 1 ton chevys that have crossed the 100k mile point pushing the 250-300hp+ ballpark and i have heard rumors of a few dabling in higher hp ballparks but have yet to see one at a dyno day break the 350hp ball park .....but debating this is pointless if you have a pre set opinion.

If you make the assumption that its impossible before ever attempting it where would we be? This seems rooted in the assumption that the engine is being operated at max power all the time, in that case yes the engine would never last past 60k miles producing 400 hp but if normal driving is taken into consideration then 10% of the time or less you are actually using that full hp potential the load and wear on these engines has been proven to be minimal. i ran a 6bt for over 400k miles that dynod 537-600hp at the rear wheels with no problems, and it the 6bt is 2 more cylinders over the 4bt then theroretically 2/3 of my power level would be between 350-400hp. but then again the conversation about actaul load on the engine and WOt duty cycle ect all comes into play.

Cummins discusses this on thier web page or used to with the old 370hp 6bt marine engines they could handle WOT at 370hp up to 15%-20% of the duty cycle after that potential for engine wear increased.

Kinda funny too cummins offered a few off road and racing versions of the 4bt back in the early 90s outside of the Domestic US market and EPA laws ( military demo rigs ect) the twoi that i saw were rated 290hp & 305hp.... they were pretty trick, they were compact but snappy an attempt to replace the 6.5 in the hummers at the time, the concept never took off but they definately proved themselves, they smoked pretty heavy off the line till the turbo caught up. Sorry all i can offer for proof of this one is seeing them first hand, taking a test ride in one up in missoula at fort missoula NG station, and getting to peer under the hood. but it has always stuck with me.

anyways. cummins rated the 6bt for 160hp/400 ft/lbs for dodge first year out ......................... come a long ways and they are still going strong even with all the mods that guys do.

To each our own but i used to share your sentiments till i saw and experienced otherwise. never under estimate the engineering in a cummins motor.

Cheers

[mcinfantry]

its realy an old arguement. i never said its impossible, but its improbable. i just get tired of the tire kickers who constantly quote "you can easily get 250,350,400 hp"

my point was, im tired of everyones theory. show me. build it, dyno it, and run it.

fyi, a marine engine is constant power, not intermmittant like a road vehicle. (i know you know that, it wasnt directed at you). they have air to seawater aftercoolers (unlimited ocean cooling, for the most part), and some have wet exhaust. i have read, not seen, quite a few marine mechs complain about the total lack opf durability of a 250hp 4bt.

and a military test 4bt is a ringer. im sure they performed well, im sure they held up, cummins had to guarantee it. my 4bt powered m715 totally out accelerated any hummer ive been in.

that was a hijack, im sorry.

now, my m715 replacement?

[dusty]

its realy an old arguement. i never said its impossible, but its improbable. i just get tired of the tire kickers who constantly quote "you can easily get 250,350,400 hp"

my point was, im tired of everyones theory. show me. build it, dyno it, and run it.
.......................
that was a hijack, im sorry.

now, my m715 replacement?

Age old debate you are right.. LOL

No hi jack, good debate and info. i'll have to conceed that the 4bt definately has some draw backs when compared to the 6bt. i still believe 250-300 is an achievable hp for some but not all who play and drive these much over that and the drawbacks of the 4bt may become a factor. i also think the 250hp marine suffers from some of the same issues the 370 marine suffers from people running them at WOT all the time and not having pyrometers on them. i know ive seen a fair number of 370's that were just 100% wiped out and a short period of time and i think had that had pre turbo pyrometers and been told not to go over 1300* they probably would have never chewed up a piston on lost ring tension like so many did. A friend has a 370 12valve in his boat with a pyro and that baby will pin 1300 after a short while of WOT in heavy currents and then temps will keep climbing into the 1400 ball park thats hard on innards for sure

to really make it to 400hp and hope for it to live i think would doll out some serious chinges to the innards, like teflon coated piston skirts and ceramic piston tops and ceramic coated head combustion chamber, valves and exhaust ports as well as a better cam grind ( the 4bt is very aniemic) head studs, a fluid dampener and better internal balancing. probably also would have to consider o-ringing the motor and when you get to that point reliability in my opinion is gone though alot of guys tow for years with o-rings, i felt like with my last set it was every year or so i was putting in a HG.


]
how come you cant be closer to the left coast i want to see that thing up close.
Thats they way the military should have gotten em to begin with.
thats they way to do it right there. I Love it. i want some pictures of that baby when shes done....

[mcinfantry]

i may have it done in 2 weeks. my father is ill, and i would like to take him to cali and washington before he dies (colorado, new york, carolinss too)

ill be making some silly, silly road trips

[crazydog]

yep. like i say PROVE ME WRONG.

untill someone runs 60,000 miles on 400hp 4bt, i dont care what you THINK will work.

he said 350tq, NOT 350hp.

I said 250 horsepower in that thread. Not 400 horsepower, not 350 horspower.

[mcinfantry]

I agree. But, don't let mcinfantry see that, he will tell you it won't work and if it does the engine won't last.

ok, dont let me see what then?

[joe]

That is going to be one sweet adventure touring rig!!!!

[Lindel]

My best to you and your Father, Mac. If you come by way of Dallas, let me know.

[mcinfantry]

ill try and get some pics up taday, and start my OWN thread

[dusty]

but hijacks are so much more fun

[mcinfantry]

ok, pics are up

http://www.ifsja.org/forums/vb/showthread.php?p=606547#post606547

[sgnellett]

Dusty, turbo is a HX30. In stock trim my CPL made 350 TQ at 1300 RPM. Fuel was turned up slightly and added and ATA cooler.

Got the rough fit done. Now I just need to slap some insulation on the backside. Ill probably shoot some hammered gray metalic too.

HOLY CRAP! That is one long-a$$ shifter!

[DieselSJ]

its realy an old arguement. i never said its impossible, but its improbable. i just get tired of the tire kickers who constantly quote "you can easily get 250,350,400 hp"

my point was, im tired of everyones theory. show me. build it, dyno it, and run it.

fyi, a marine engine is constant power, not intermmittant like a road vehicle. (i know you know that, it wasnt directed at you). they have air to seawater aftercoolers (unlimited ocean cooling, for the most part), and some have wet exhaust. i have read, not seen, quite a few marine mechs complain about the total lack opf durability of a 250hp 4bt.

and a military test 4bt is a ringer. im sure they performed well, im sure they held up, cummins had to guarantee it. my 4bt powered m715 totally out accelerated any hummer ive been in.

that was a hijack, im sorry.

now, my m715 replacement?

400+ HP 4bt

http://www.dieselpowermag.com/features/ford/0709dp_1966_ford_bronco/index.html

But note that it was not driveable with that much HP because it had too narrow of a powerband. Now it is detuned to 350. Yeah, surprised the heck of me also because I always called BS on that 400hp number.