M818/ Cummins NA250

[BKubu]

Joe, the only thing they did was add the super singles (in addition to a few other mods like adding lockers and a fording kit). That is how it was brought up to USMC standards. There are no mechanical differences between a USMC truck and a non-USMC truck. I agree with what you are saying about the 1400s. They are about as big as I would go on a 5 ton. Yeah, they do sap some of the power, but it is not that noticeable...definitely not as noticeable as going up to 1600s. It also sounds like your USMC M813 is a good runner! I've had M809 series trucks that were dogs with 1100s on them.

 

[BBuckRacing]

Thanks for the help, ill probably just deal with the lack of power for now and see how it pulls. if you know western pa you know how hilly it really is, and i hope that 10,000lbs on the back wont slow her down too much. the 1600s arent coming off of the the truck though, no matter what the performance loss is i savor the fact of sitting higher in my truck than tractor trailers, the looks you get from other people on the road is priceless, not worth losing just to gain a little power back. if it doesnt pull well ill just go get a 3/4 pickup and save the m818 for fun and shows

 

[BKubu]

Did you get the truck from John Appel? Very nice truck. John is a good guy and he knows his stuff.

 

[BBuckRacing]

Yes i did, he was a very nice guy and had some really cool stuff, i initially wanted a duece and i was shopping around for a while but then i found the m818 he had and he bobbed it and had the goodyears already, for the price i couldnt pass it up. it was definatly worth the money

 

[drgreg]

 

[BBuckRacing]

this is the truck from the front beside my 4 inch lifted 87 dodge ram 150 on 33s. Ill post some more pictures next week i may take it to a show this weekend

 

[CobraChris]

Guys, just a side note, the 55mph speed rating you guys are quoting is at max load. the same tires on an unloaded, fairly light truck are safe at higher speeds.

 

[Rgdl]

Guys, just a side note, the 55mph speed rating you guys are quoting is at max load. the same tires on an unloaded, fairly light truck are safe at higher speeds.

I wasn't worried. I recently drove my M818 on 53" XZLs home approx 550 miles, averaging 105 mph on the interstates, and my tires held up fine.

You guys are right about hills though. There were a handful of small grades in Minnesota and they sucked the life out of this truck with the big tires. But on flat surfaces with the hammer down I cruised at 2150 rpm.

Where I live the land is flatter than Kansas, so I'm not worried about losing power on hills.

 

[drgreg]

I wasn't worried. I recently drove my M818 on 53" XZLs home approx 550 miles, averaging 105 mph on the interstates, and my tires held up fine.

You guys are right about hills though. There were a handful of small grades in Minnesota and they sucked the life out of this truck with the big tires. But on flat surfaces with the hammer down I cruised at 2150 rpm.

Where I live the land is flatter than Kansas, so I'm not worried about losing power on hills.

You do know that in the states MPH = Miles Per Hour. For your M818 to average 105 mph, I think the tires would need to be closer to 153".
I think flat ground would be required then.

 

[Westech]

Umm yeah with 16:00 tires and the cummins drive train at just a touch under 2200 RPM in 5th gear your going 70 MPH.


11:00 is 54 MPH max speed
14:00 is 64 MPH max speed
16:00 is 70 MPH max speed

 

[Rgdl]

You do know that in the states MPH = Miles Per Hour. For your M818 to average 105 mph, I think the tires would need to be closer to 153".
I think flat ground would be required then.

Hahahaha...........forgot to convert.

105 km/h, or approx 65 mph.

 

[drgreg]

See, that's exactly why the rest of the world should stop using the metric system.

 

[OPCOM]

Umm yeah with 16:00 tires and the cummins drive train at just a touch under 2200 RPM in 5th gear your going 70 MPH.


11:00 is 54 MPH max speed
14:00 is 64 MPH max speed
16:00 is 70 MPH max speed

16.00 is 63MPH @ 2100 RPM.

I have never taken the NHC250 over redline. The one I have, it runs like a scalded dog since the PT pump was replaced. The 16:00's don't bother it much as it's an M818 with a 109 body becaue that is a relatively light truck.

I don't want to ever overspeed this engine at all. it does not leak, drip oil, nothing, and had 8k miles. If for some reason I just have to go faster, the only thing that makes sense to me is to have the TC put in neutral and add an overdrive, but the drive shaft is mighty short on an 818.

IIRC
11.00's are for 50MPH
14.00's would get me about 55MPH.

One thing that would help in keeping a reasonable speed is more comfort. air conditioing, etc.

 

[Floridianson]

OK, I hate to hi-jack the thread, but yet I do.
I have a M813 that has what I assume to be the 14.00 xl's it was surplused with from the Marines. I also assume it has the older engine. It seems to run well and will hold in the upper 50s (mph) on most of the interstates around here. I towed a M818 with it the other day and it stayed above 45, so it was legal at least.

So here's the question. If my truck was configured like this by the Marines, has it had other modifications to the engine or anything? It seems to perform well with the 14.00 xl's on it.

Joe

Has your PT been out or can you tell. Without testing the PT how would you even know if it was running up to book specs. When someone that knows the PT works a little mojo it will run much better and will not hurt the 250. Now when you make it spit fire that is when you need a driver. You can put your own gage on them and see what the rail pressure is. 172lb is what the call is.
Some people accept what it is and might not even know what it is.

 

[Westech]

oops you are correct... I had the 5th gear at .76.... its rally .85-1 overdrive.

 

[BBuckRacing]

i am trying to avoid registering my m818 as an antique or classic, are there any insurance companies that wont hesitate to insure one of these for a fair price?

 

[BBuckRacing]

theres the pics...

 

[M813A1]

You might want to consider adding some mud flap to the rear of the bed so you do not get ticketed for throwingdebis out behind you and possibly cracking someones window ?? Just my small $.02 I would consider that a safety issue ??