903 Cummins performance - In the Day

Standen, I drove an 8V71T this harvest, and both the owner and I reckon it is maybe?? 10hp better than a n/a 903. Also, to your question, an old interstate driver told me years ago, that a 290 Cummins will give a 350 GM a hell of a fright, he said it won't quite beat it, but it will give it a fright! I believe his statement to be very accurate. During harvest i was quite aware of a mates 335 leaving me for dead! And, as a comparison, a good 290 will really put the pressure on a 903, there isn't much in it. The 903 is a beautifully smooth engine to drive, not to mention the sound!!!

I believe back in the day there where a few guys that used to run there 903s oil at the add mark to squeeze a few extra ponies out of em.

He also tells of a very special 555 they built for a speed trial in a boat that was rated to 4500RPM. I would love to have seen and heard that.

It may not have lasted long enough to get a photo.

I believe back in the day there where a few guys that used to run there 903s oil at the add mark to squeeze a few extra ponies out of em.

hmmmm....I'd be interested to know how that works!

I believe back in the day there where a few guys that used to run there 903s oil at the add mark to squeeze a few extra ponies out of em.

I also heard that.........

A better method was to totally remove the oil pump and pickup pipe!!

not only did this remove the parasitic horsepower losses of driving the oil pump but also lightened the engines tare
weight.

the oil level had to be increased tho to 1" above the high mark so that the crank bearings could be splash fed.

then you could also sell the oil pump to other 903 owners that didn't know about this hot rodding upgrade and pick up another $600.00 to put towards either a 350hp fuel pump
mod or purchasing a set (+2) of big cam 3-400 "top stop" injectors to put in.

the options to hot rod a V903 were endless.

newto

I believe back in the day there where a few guys that used to run there 903s oil at the add mark to squeeze a few extra ponies out of em.

I also heard that.........

A better method was to totally remove the oil pump and pickup pipe!!

not only did this remove the parasitic horsepower losses of driving the oil pump but also lightened the engines tare
weight.

the oil level had to be increased tho to 1" above the high mark so that the crank bearings could be splash fed.

then you could also sell the oil pump to other 903 owners that didn't know about this hot rodding upgrade and pick up another $600.00 to put towards either a 350hp fuel pump
mod or purchasing a set (+2) of big cam 3-400 "top stop" injectors to put in.

the options to hot rod a V903 were endless.

newto

Is that advice how you got the badge of honor "ex-cummins mechanic" ? haha

I believe back in the day there where a few guys that used to run there 903s oil at the add mark to squeeze a few extra ponies out of em.

I also heard that.........

A better method was to totally remove the oil pump and pickup pipe!!

not only did this remove the parasitic horsepower losses of driving the oil pump but also lightened the engines tare
weight.

the oil level had to be increased tho to 1" above the high mark so that the crank bearings could be splash fed.

then you could also sell the oil pump to other 903 owners that didn't know about this hot rodding upgrade and pick up another $600.00 to put towards either a 350hp fuel pump
mod or purchasing a set (+2) of big cam 3-400 "top stop" injectors to put in.

the options to hot rod a V903 were endless.

newto

Is that advice how you got the badge of honor "ex-cummins mechanic" ? haha

hahahaha.....yep......ex-cummins the company......totally correct.....
nice observation.......you get a newto "this guy's paying attention to detail" badge!

newto

I also heard that.........

A better method was to totally remove the oil pump and pickup pipe!!

not only did this remove the parasitic horsepower losses of driving the oil pump but also lightened the engines tare
weight.

the oil level had to be increased tho to 1" above the high mark so that the crank bearings could be splash fed.

then you could also sell the oil pump to other 903 owners that didn't know about this hot rodding upgrade and pick up another $600.00 to put towards either a 350hp fuel pump
mod or purchasing a set (+2) of big cam 3-400 "top stop" injectors to put in.

the options to hot rod a V903 were endless.

newto

I'm not raining on the parade here, but I suppose they fitted dippers to the rod caps, drilled holes in the rods to capture the oil, machined larger clearances in the bearings for the oil to actually flow through and then went and fit high HP devices to pull more ponies out of an engine with a now compromised lubrication system. Also not mentioning fitment of a different sump to keep all the dippers in the oil at all angles.....

That sounds about as good pulling the oil pump out of a Detroit and running a 25:1 fuel/oil mix

I also heard that.........

A better method was to totally remove the oil pump and pickup pipe!!

not only did this remove the parasitic horsepower losses of driving the oil pump but also lightened the engines tare
weight.

the oil level had to be increased tho to 1" above the high mark so that the crank bearings could be splash fed.

then you could also sell the oil pump to other 903 owners that didn't know about this hot rodding upgrade and pick up another $600.00 to put towards either a 350hp fuel pump
mod or purchasing a set (+2) of big cam 3-400 "top stop" injectors to put in.

the options to hot rod a V903 were endless.

newto

I'm not raining on the parade here, but I suppose they fitted dippers to the rod caps, drilled holes in the rods to capture the oil, machined larger clearances in the bearings for the oil to actually flow through and then went and fit high HP devices to pull more ponies out of an engine with a now compromised lubrication system. Also not mentioning fitment of a different sump to keep all the dippers in the oil at all angles.....

That sounds about as good pulling the oil pump out of a Detroit and running a 25:1 fuel/oil mix

DieselDog you old rascal........hahaha.....can't put one over you I now know......well spotted.....you obviously are up with the program......rain on the parade any time brother....I think you qualify as one of us!!!!

newto

ps...oh...and 30:1 is more gooderer!

That sounds about as good pulling the oil pump out of a Detroit and running a 25:1 fuel/oil mix

But the Detroits are two stroke- don't you have to do that anyway? I know I have to with my Victa

Grant.