Dodge 760 PM ??????????

Nice brochure bigcam.I think they mean short stroke piston instead of low piston speed.I wonder what ratio diff its got,pretty low i imagine so you can cruise comfortably at 75km's

Bigcam you have out done your self thats a great article,is there such a thing as a decent diff ratio for one of them? i think not! i will just have to tie my 6 11R22.5 tubeless wheels to the top of the Daewoo,there worth 10 or so K,s per hr

cumminsv8 - Short stroke piston and low piston speed are the one and same thing. Piston speed is basically the direct multiplication of RPM x stroke.
More RPM, higher piston speed. Same RPM, but longer stroke - higher piston speed.

Piston speed calculator .. www.csgnetwork.com/pistonspeedcalc.html

High piston speeds result in more friction and higher levels of wear. As a result, modern engine designers seek to keep piston speeds down.
Unfortunately, truck engines develop better torque with longer stroke.
So, the struggle is to balance the equation between wear, satisfactory torque, friction (and therefore heat) levels, and power.
Most short-stroke engines develop high HP at higher RPM, but lower levels of torque.

The Cummins V8 185 had a bore of 4.625" and a stroke of 3.5", for 470 cu ins (7.7L) .. making it severely oversquare.

This makes these little engines high HP for the cubes, but they need to rev, to develop the power, and to produce a satisfactory torque level.

The Cummins V8 185 was not a successful engine. Plagued with many design faults, they cost Cummins a lot of money, as Cummins produced modification after modification.

The original engine was labelled the V8 185, then came the V8 185-B, as an upgrade. The upgrade still didn't address basic weaknesses, and warranty claims came thick and fast on these small V8 and V6 engines.
They were rushed into the marketplace too fast, without adequate testing and refinement, and bug-finding.

The engine design originated in the early 1960's, when Cummins were desperate to compete with big petrol engines in the light-to-medium-duty end of the market.
Cummins rushed these engines out at any cost, to meet a corporate deadline.
These engines cost Cummins vast sums of warranty money .. and Cummins ceased building them, when it became obvious that increased future liabilities, for an increased number of unreliable engines, would sink Cummins.
The warranty claim payout figures on the little V8 and V6 Cummins engines, were more than FIVE times the warranty costs on the 6 cyl Cummins engines.

Cummins withdrew from the light-to-medium-duty end of the market by the late 1970's, to concentrate on the new V-903 and the highly successful, 6 cyl series of heavy duty engines.
This came about after Cat produced their new lightweight 1100 series V8 diesel for Ford, in 1967 (later to become the 3208), and International produced the DV-550 V8.
When the refined and more reliable 3208 appeared in the early 1970's, Cummins small V8's couldn't match it for reliability, even though the Cummins engines had a weight advantage.
Of course, both the early lightweight Cat and IH, V8 engines, were plagued with problems, too .. but Cummins wasn't to know that, at that time.

The single greatest problem with all these engines, is that they were up against weight. They all tried to build a lightweight diesel engine that would compete with a big petrol V8.
No matter what the engine designers did, the little V8 diesels always carried a huge weight penalty over the big petrol engines.

Weight is death to truckies .. and Cummins, Cat, and IH, all pared their lightweight V8 diesels to the bone.
The design problems compounded, when a lot of the engines were put to work, hauling heavier loads than recommended.
All truckies like to load up to the max .. and the little V8's suffered as a result.

The maximum gross load recommendation for the Cat V8 was 70,000 lbs (31,760 kgs). The recommendations for the little Cummins V8 and the IH V8 were similar.
Users started installing them in bogie drives, and hauling tandem and tri-axle trailers .. pushing gross loads up to 38, 40, and even 44 tonnes.

At these loads, the little V8's started developing major problems. It's not in the least bit unusual to see one of these engines with a broken crank, a leg out of bed, or a heap of other disastrous broken components.

These engines are designed for light-to-medium duty, and should be kept there. If you treat them carefully, they will perform O.K. If you work them to the max, expect major problems.

Juan Trak
GuddayM8

Gr8 info
N th@'z where the screemer fits right in
the Detroit/GM 71 series would B the most reliable deezel engine of th@ era
they love revs (2100rpm) all day, day in day out

Cya
[ch9787]

And we have left out the 6V53 here Ronnie, is that not a light wieght , reasonably high revving diesel?

the 318 and 361 V8 petrols in the dodges blew away the cummins for reliability & on paper matched them with hp-torque. . . maybe thats why the last of the aussie dodges had the 6V53 as the ultimate diesel option .. and the D3F (cabover dodges) had the turbo perkins and 318s in the larger versions

Hmm i think you saved me an outback adventure,now if i could find a Dodge D5N with a screamer and 10 speed

The 6V-53 Screemer certainly was the pick of the small, lightweight diesels for reliability. Their only drawbacks were the dreadful noise, poor oil seals, smokiness when worn and idling, and the heavy fuel consumption.

If GM could have found some way to quieten the 6V-53 engines down, seal them better, reduce their emissions, and improve their fuel consumption, they would have run away with the market.

However, the Detroits always had inherent problems in their basic design, which no designer could ever overcome.
Many operators shied away from Detroits purely because you had to drive them pedal to the metal, to produce any output. However, no-one could ever question their reliability and long life.

Another hidden factor in Detroits popularity for a long time, was GM's cheap parts for them. You could always overhaul a Detroit for half the cost of any comparable motor, and that went a long way to ensuring that Detroits always had a neat sales clincher up their sleeve.

Unfortunately, the parts prices for Detroits aren't what they used to be .. you can look at paying nearly the same price for Detroit parts, as any other engine part nowadays.

Ron, there are a few motors I can think of that the rebuild kits are cheap. A rebuild kit for a 6V53 is around $1500, a rebuild kit for an 855 cui Cummins is a tad cheaper. I am of course refering to the "will fit" parts suppliers, as opposed to the, would you mind bending over as you walk through the door, genuine kits. While parts for most Detriots are still relativly cheap and easy to obtain at the moment, no doubt it will change. Try buying parts for any of the less popular Cummins motors, C160/175/180, any of the V8's, even the will fit mobs don't stock to much for them.

Cribby i dont know how much you want to spend but ive got a lead on a D5N lazy axle (22ft+ tray) detroit powered with a 10 speed O/D RR ..(top speed 85ks on the redline) the truck is at mildura ..i seen it a few years ago he wanted around 10K for it then ..now it may be a bit cheaper or a bit dearer?