Low buck Diesel power tips

[Versatile]

These tips are for Cummins Cats and others.

http://www.freewebs.com/nevrenufhp/index.htm

A sampleT466

You can also use a 3000 rpm gov spring kit from a 12 valve Dodge/Cummins, they are usually under $150, keep in mind the valves start to float around 3400rpm. Another option(free) is to just tighten the original springs 3 or 4 clicks. After you read the article linked above, the "clicks" will make more sense. Just make sure you tighten both sets of springs. Each click will be roughly 100 more rpm you can use before the pump starts to de-fuel(most stock trucks will only hit 2700 on a good day). Last tid bit, if you want to turn your 466 into a 530, all you need is the 530 inframe kit. You can even go all out, and get 2pc steel pistons for major EGT protection. The steel pistons add $1000 to the kit price(IH dealership prices), so you know.

[cadillackid]

the service shop manuals i have for the DT360 and DT466 both state that the engines can be run above their stock RPM but you will shorten the life..

my DT360 is stock set to run 2700 under load, 2900 RPM no load.. but it can be "safely" run up to 3200 load (3400 no load).. which coincides with where the valves float..

BUT the longevity of the engine is reduced quite a bit if run at those RPM's

I dont know if the same applies to the cummins or not as far as life..

the more i drive my bus the more I realize these 'DT' engines are MUCH happier at lower RPM's..

I started out running my bus against the rev limiter all the time at 2700-2800 RPM.. which netted me 65-68 (slower on the hills) MPH..

then I started running the bus at 60 which meant I was off the limiter a bit moire except on hills.. and the engine was Much happier..

lately ive started running at 55 MPH and the engine runs at 2300 RPM most all the time, is quiet, not nearly as much doghouse heat coming through.. oil pressure runs at 55 instead of 50,

the coolant tempo always stays 180-190 all the time but driving at 55 I rarely ever have my fan coming up to high speed...

so im convinced to not turn my engine screws up.. and I'll likely have an engine that lasts a long time..

-Christopher

[Versatile]

Thanks for your post. I pretty much agree with you. Unless you have hugely deep pockets or a very good mechanic then don't mess with what is already good. I think there ia a lot of educative value for anyone wanting to learn more about their engine. Before i read this i didn't understand what a P PUMP was. I only knew it was a injection pump.

[cadillackid]

its very educational.. I only posted mine as there's lots of info on the web and youtube aboutcranking up a DT360 or DT466 to make more power but hardly anything about what those consequences might be..

ivedone my fairshare of cranking up an engine.. though not a diesel... I rebuilt one years ago in a car...

alot of the conversations on the forum seem to revolve around "making busses go faster".. i was in that camp originally.. all ready to twist the screws wide open on my DT360.. until I sat down and had a talk with myself about why I was travelling by school bus instead of 400 horsepower Silverado or 200 Hp fiat.. and I realized it surely wasnt to get anywhere fast...

I know some do have the need to go fast.. and maybe they dont travel enough miles in a lifetime to come up against the longevity of the engine.. but just want to make aware that there is often consequences to cranking up an engine without actually rebuilding it with parts engineered to make more power...

yes you *CAN* build a small block chevy to put out 500 horsepower with cast pistons and crank... it just might not last very long... but if Built up with forged pistons and crank you have a lot better shot at it lasting a long time

-Christopher

[turf]

i've read lots about turning up the power on diesels, i feel like maybe i will go down that path.

i have a '93 cummins 5.9 spec'd at 190hp. after 25 years of running, 320,000 miles, im not sure if turning it would break it or help it.

according to the interweb the first gen motors arent capable of huge horsepower but they can be tweaked up. the pump limits them to a max of about 500hp.

then there is that pesky AT545, that runs out of clutch around 250hp.

i don't think that i'd change the governor, i dont want to see my motor running any higher than the 2500rpms or so its governed at. so no extra speed.

i tow frequently, and in the mountains with the bus. i'd like to give it a bit of umphf, and maintain my speed better climbing hills.

by that article or many others, i can change, or rotate the fuel pin, in the Air Fuel Control (AFC) and add about 40hp. if my truck still puts out 190, then i'd push up to 230hp, or the limit of the transmission.

i can rotate the stock pin for free, or buy a performance pin for about $100. it looks like a pretty simple modification.

the only other forum member i recall saying they turned up the screw was guy named Lapeer, he wholeheartedly encouraged it.

on the down side, i have asked 2 different diesel shops to do it for me and they both declined. saying it was illegal and shortens the motors life.

i recently added an oil cooler and that helped out the power of the truck. that kind of gave me a taste for more power.

at 320,000 miles with a strong running engine, not sure if i should let it be or try and squeeze some life out of her. the reading of diesel forums i've seen attitudes that the engine doesnt care if its 30k miles or 300k miles when you turn it up. that the power is there.