JD 4010 Enhanced Output Testing Results (INTERESTI

FJ40 Jim on Re: diesel ?"s:

> put a real exhaust system on it soon, and do some work w/ the air filter, and
> a cold ram-air system. To buy all that from "Gale Banks house of turbo" costs
> $695US. No, thanks. I"ll do it myself.

The exhaust system will be a real help, but only after a turbo or hotter cam is put on. It *does* help a stock engine, but not a large amount (unless the stock exhaust *really* sucks). Most of the pieces that you need can be found on scrapped 5-tons etc.

> The turbo set up from HyperMax is $1975US. It"s expensive, but it will pay
> for itself, eventually. The truck only has 80K miles on it, and I am sure I
> can get at least double that from it. If the turbo improves MPG by 20%, I"ll
> recoup investment, and have 50% more torque. I"d like to intercool also, but
> it is an $1195US option, and it only picks up another 5% of fuel economy.

Turbos are wonderful things, but if you just slap a turbo on and that"s it, it will do very little for you. The whole point of a turbo is to allow you to pack more air into the cylinder, meaning that you can turn up the feed pump to pack more fuel into the cylinders without burning rings. That"s the beauty; you can overfuel without killing the engine.

> I am not sure about the LPG overfueling trick. Has anybody tried this with a
> pyrometer installed? Diesel pistons get weak above 1300F. A stock engine
> usually runs about 1000-1100 at full fuel (factory setting). Propane burns at
> a high temperature, so it might only be a quick burst of power thing, like
> nitrous on a gas engine. Melting pistons is a messy deal. We did it on my
> brother"s VW TurboD. Don"t turn up the governor speed, and the fuel curve,
> and advance the timing, and then go climbing long mountain grades. It was
> fast around town, but 20K miles later, it was new engine time. Never had that
> problem w/ my diesel rabbits, but they weren"t turbo. Though somebody did
> mess w/ the tamper resistant screws on the injection pump. ;^)

Coincidentally enough, I just found an article on just that question in the Grain Grower the other day. They were comparing various hopping-up schemes (overfuelling, LPG injection, turbo) to expected engine life. They took a John Deere 4010 tractor (I think it was a 4010.. anyway..) they ran the engine for 300 hours, 10 hours per day, with each setup and monitored fuel consumption, and tore it down at the end of each test to see how it was doing. The gist of it is this:

Four engines tested. A standard, normally-aspirated engine setup to factory specs as a control, the same engine overfueled by cranking up the injector pump 20% (that"s a lot, eh?), the same engine LPG injected at a constant rate of 1.8 gal/hr, and the same engine with an M&W turbo, overfueled 16.7%.

Many aspects were measured. The oil was sampled and tested every 25 hours. Coolant temperature vs. intake temperature was monitored, and it was found that the LPG gas engine ran much *cooler* than normal, which is not good. The turbocharged engine ran a bit cooler, but nothing scary. The overfueled engine ran way too hot.

The standard engine was 98.4 hp, the overfueling made it 106.7 hp, the LPG injection raised it to 112.5, and the turbo (which was also overfueled, but not quite as much) raised it to 124.4 hp.

Oil consumption was radically increased on the turbocharged engine. Roughly double the rate of the control engine. LPG injection had the lowest consumption, but that was largely because a ring has broken which allowed blowby to infect the oil; this causes oil thickening in a diesel. The SAE 30 that they had poured in at the beginning of the test was the same viscosity as 140 weight gear oil by the end of the 300 hours. Yowza! The broken ring might have been a coincidence; the turbo engine had two cylinders with stuck rings.

Turbo-charged beats LPG injection on the fuel consumption versus power output chart, but that"s to be expected.

As far as exhaust temperature and smoke is concerned, the temp was taken at the pipe and at the manifold with thermocouples. Smoke density was measured with the Hartridge smoke meter. Both smoke and heat increased with power output (duh! 8-) The turbo engine had the lowest exhaust temperature when pushing out more than 90 hp. Overfueled and LPG injected engines smoked a lot. To be expected. The LPG engine basically has the same amount of smoke as the standard engine up to the point where you pass the HP of the original engine, then it skyrockets. The turbo engine had very low smoke. The overfueled engine was up in the rafters even at idle. LPG injected engine had the highest exhaust temperatures, turbo had the lowest, though the overfueled was set to pass the LPG very soon.. another 5 hp or so and it would have been there.

Standard engine had the most trouble with injectors. Lots of flow in injectors keeps them clean, so the overfuelled, turbo and LPG engines had significantly fewer injector problems (chatter, etc.). The LPG injected engine had the best injector condition, then turbo then overfueled.

Here"s an interesting tidbit: Actual engine wear. There"s a chart with a whole bunch of measurements of the 0.000023 variety, the bottom line is: The overfueled engine was a mess. The LPG injected engine had numbers about the same as the standard engine (some a bit higher, some a bit lower). The turbo engine had a startlingly bad top ring wear (0.0030.. equivalent to the overfueled) but the rest of the rings and the valve guides and piston skirt polish numbers were great; significantly better than standard. None of the engines showed abnormal bearing, cam lobe, or lifter wear.

So there you have it! The turbo *is* the best long-term solution, however I"d like to point out that the LPG injected engine in this case was a *constant* injector. It was getting the LPG at almost two gallons per hour for the entire 300 hours. I only advocate "pushbutton" LPG as a "boost". Going by these numbers, I don"t see pushbutton LPG causing significant wear.

> > If you get a chance to copy/scan/post on the "net, that article out of "Hot
> Rod farm tractors", I"d like to read it.
> > I"ll let you know if I get a chance to drive this truck, how it does fully
> loaded. My calculations indicate a 6700# truckw/ fuel & gear, 2000# camper,
> and 3500# cruiser w/gear. That"s 12,200 pounds of metal, rolling down the
> backside of the Appalachian mountains on the way to GSMTR. Oink, oink, comin"
> through! After I do the turbo, I"ll have to figure out how to get the train
> stopped.
> > Thanks,
> Jim Chenoweth
> TLC Performance
> Lancaster, Ohio, USA