ULSD Tutorial

[philip]

I ran across this Ultra Low Sulfur Diesel tutorial.

This powerpoint presentation contains the sort of consumer and retailer info "we" want to know. Watch for the exceptions given to California and Alaska fuel. Hmmm.

[exsimguy1]

Philip,
Who would have ever thought we would have to worry about a cetane rating that was "Higher" than we would like. This may be like running "regular" in a "premium" engine. Less energy content and higher cetane will create interesting compromises in early diesel engines, particularly in high (22/1) compression IDI engines such as SD Nissan's. The fun's just beginning. On a positive note, upon lowering the compression on an IDI engine for turbo installation, at least it will start OK with the higher Cetane fuel!

[philip]

Philip,
Who would have ever thought we would have to worry about a cetane rating that was "Higher" than we would like. This may be like running "regular" in a "premium" engine.

An early discovery with this engine was the effect of PowerService mixed in the fuel. The last thing this engine likes is raising the cetane rating. That discovery is why I selected the Stanadyne fuel additive ... lubricant with no cetane raise. I've even looked for substances that would lower cetane.

Less energy content and higher cetane will create interesting compromises in early diesel engines, particularly in high (22/1) compression IDI engines such as SD Nissan's. The fun's just beginning.

It would be of academic value if someone could put some new BTU numbers to the ULSD vs. B100.

On a positive note, upon lowering the compression on an IDI engine for turbo installation, at least it will start OK with the higher Cetane fuel!

You believe this or .... do you have a studied example where this modification has been carried out?

[exsimguy1]

Philip,
Lucas Fuel Additive will supply lubricity w/o cetane rise. Non-detergent motor oil was added in the past for more "energy", even drain oil was OK'd by Cummins in surprisingly high percentages for fleet use. (Stanadyne is a great product also.)

I cut .050" from top of pistons on 6.9 litre Ford (International) V8 to lower compression for safe (sustained) 15 psi boost. (a fairly common practice with IDI engines for decent boost). It dropped compression approx. 1 point. Starting was OK, but noticeably slower(40-45 cetane). The starter on a 6.9 spins the motor at 300 rpm, wish the Nissan would. Sold truck with 117K miles after above mods, no detrimental side effects, still ran, pulled great.

I think it may be time to take my SD25 down to about 19 or 20/1, fit the pump timing gear (minus the timer assembly) to my spare VE pump (from 4D55), reset the injectors to pop at 1600psi, and have a turboed 2.5 litre. With a mill and a lathe, and spare parts, you can build anything.

[philip]

Philip,
Lucas Fuel Additive will supply lubricity w/o cetane rise. Non-detergent motor oil was added in the past for more "energy", even drain oil was OK'd by Cummins in surprisingly high percentages for fleet use. (Stanadyne is a great product also.)

I have not tried the Lucas product. It is widely available. The diesel shop I visit sells Stanadyne and for all the help he's given me ... I buy his stuff. Tried ATF and later, engine oil. Both resulted in MPG loss and no power gain. But ... both tests were during warm-hot weather (Speaking of which, we're experiencing a warming trend. 67 degrees was the LOW last night. This in mid February!)

I cut .050" from top of pistons on 6.9 litre Ford (International) V8 to lower compression for safe (sustained) 15 psi boost.

Just yesterday at the above diesel shop, he had a 1997 Ford E350 diesel van in for new injectors ($325 each!). There are a fleet of these vans delivering restaraunt food across socal 7 days a week.

The engine ... still the original ... is still running strong. (cell phone camera)

-SNIP- I think it may be time to take my SD25 down to about 19 or 20/1, -SNIP-

Or ... find a TD25 and call it a day. Entirely different engine that came with and w/o turbo.

[exsimguy1]

Philip,
Love to have a TD25, but just as when I swapped the SD25 into the D21, "It's what I Have". I also have a NIB Rajay turbo that maps perfectly to the parameters I want to run the SD25 at. The VE pump will negate the pneumatic governor issue, while also utilizing an internal advance system. Piston pumps are preferred, but adapting from the pneumatic governor is not worth the expense.
Running realistic 5-10 psi boost levels (intercooled of course, they all should be) will allow me to run this engine in a slightly heavier vehicle (the next swap) at performance levels at or above what I have now. If it will approach or equal the performance of a Mitsubishi 4D55, (which I have one of going into another vehicle) I will have met my goal.