My second pump gas damage mistake

[Steven B.]

Re: My second pump gas damage mistake

Do all these different blends and requirements actually improve air quality? That's similar to the "what's the best additive package debate" and I'm highly suspicious that we are getting very little return for the cost of having so many blends and other requirements.

Duke

I agree wholeheartedly. When I was fueling with diesel today, I remembered to look at the octane rating and method for the 92 octane straight gas that I use. The rating method is (R+M)/2, or PON (AKI). I do not know where the refinery is but I would guess that it is the refinery in Anacortes, WA, which I believe is a Tesoro company. I know that when I lived in Portland, OR, I worked for a regional short line railroad for a while, and we often spotted cars of ethanol in the tank field in North Portland. All sorts of companies came in and out of that storage facility, and I believe that the main difference boiled down to the ethanol and the additive packages. I am fairly sure that the fuel came to Portland from the refinery up North and I was told at the time, by pipeline and barge. I also had an occasion to talk to a driver delivering fuel to a local Safeway and he said that at the time, Arco was blending a bit more than 10% ethanol, and that a lot of people were complaining about their mileage. Whether that's true or not, I don't know. I do remember that he told me that he delivered fuel to another Safeway that was actually closer to where we lived. I was at the Safeway that the driver was delivering to because it was usually about 2-5 cents a gallon cheaper than the Safeway near us and I would fuel up if I was close. There was just over 4 miles between the two, and the distance from the tank fields in North Portland to the two Safeways was about the same, which made me wonder why one had a lower price while the other had a higher price. Same fuel, same source, same distance from the source. I know that although zonal pricing was often brought up, it was somewhat controversial. At about that time, there was a big tie and rail replacement effort that went on in the late nineties North of Portland in order to facilitate 100 unit grain trains that we were going to handle, and were intended for an ethanol plant at Point Westward, OR. Although the track was improved, the trains never materialized at the time for whatever reason. Apparently, it's now the Columbia Pacific Bio Refinery. My curiosity brings me to wonder what stocks are providing 92 octane straight gas if stocks with an ethanol additive are going to increase the octane rating. The typical rating at most stations providing only ethanol blends is 87 and 91 octane. What are they starting with and where is the 92 octane straight gas coming from?

Steve

[Stewart L.]

Re: My second pump gas damage mistake

Thank you. I am aware of puregas.com and there are two sources of ethanol free gas here on Whidbey Island. I was hoping that all the card lock stations had ethanol free gas but apparently not.

Perry,
Contact Masco Petroleum in Aberdeen, mascopetroleum.com you can apply for credit and get a card for their card lock pump. There are Pacific Pride stations all over. Their map shows 4 on Whidbey.

[Perry M.]

Re: My second pump gas damage mistake

Thank you Stewart. I actually have a Pacific Pride card but it is strictly for company use. I also don't believe any of the Whidbey Island stations carry non E gas.

[Jack H.]

Re: My second pump gas damage mistake

Not sure how up-to-date this site is, but I've referred to it in the past. Here is WA info:

https://www.pure-gas.org/index.jsp?stateprov=WA

[Mark E.]

Re: My second pump gas damage mistake

Dom,

Changing the ignition advance curve may help manage preignition.

With a "performance" map of 26 deg @ 2400 rpm (plus initial), my stock LS5 with 10.25:1 cr pinged all the time with 38 deg total advance. I had to retard initial timing to compensate, and still had pinging during part throttle.

Installing a variable VAC helped, but performance suffered with the retarded initial.

Then I dropped in a distributor with a stock curve for this engine- 26 deg @ 3700 rpm. With initial bumped to 12 degrees it runs like a bat out of hell with no pinging!

I was also able to adjust the VAC for more advance which improved throttle response.

I was surprised the stock lazy timing curve worked better for this engine. With a hydraulic Cam and oval ports, it's a different animal than your 427/425. But looking at this may help.

BTW, we run 93 octane E10 in North Texas.

[Duke W.]

Re: My second pump gas damage mistake

Detonation is the limiting factor on how aggressive the spark advance map can be, and since big blocks have a greater octane appetite than small blocks, I'm not surprised that you had to slow the centrifugal; 26 @ 2400 is actually more aggressive than the 365/375 HP map, and with the smaller bore and much later closing inlet valve those engines will usually tolerate the OE map with up to 16 degrees initial without protest on todays' gasoline.

Duke

[Domenic T.]

Re: My second pump gas damage mistake

Detonation is the limiting factor on how aggressive the spark advance map can be, and since big blocks have a greater octane appetite than small blocks, I'm not surprised that you had to slow the centrifugal; 26 @ 2400 is actually more aggressive than the 365/375 HP map, and with the smaller bore and much later closing inlet valve those engines will usually tolerate the OE map with up to 16 degrees initial without protest on todays' gasoline.

Duke

Duke,
All sounds logical to me.

Dom

[Domenic T.]

Re: My second pump gas damage mistake

Dom,

Changing the ignition advance curve may help manage preignition.

With a "performance" map of 26 deg @ 2400 rpm (plus initial), my stock LS5 with 10.25:1 cr pinged all the time with 38 deg total advance. I had to retard initial timing to compensate, and still had pinging during part throttle.

Installing a variable VAC helped, but performance suffered with the retarded initial.

Then I dropped in a distributor with a stock curve for this engine- 26 deg @ 3700 rpm. With initial bumped to 12 degrees it runs like a bat out of hell with no pinging!

I was also able to adjust the VAC for more advance which improved throttle response.

I was surprised the stock lazy timing curve worked better for this engine. With a hydraulic Cam and oval ports, it's a different animal than your 427/425. But looking at this may help.

BTW, we run 93 octane E10 in North Texas.

Mark,
I will take your advice. This was the first time I saw a bendix loose all it's teeth when turning a flywheel and having the engine fire backwards, not to mention that the fresh engine has to come apart from damage to a piston skirt.
I will get back to you and get all the numbers and have a distributor built.

Dom

[Mark E.]

Re: My second pump gas damage mistake

since big blocks have a greater octane appetite than small blocks...
Duke

Thanks Duke. Interesting observation about big vs. small block need for octane and tolerance for ignition advance.

[Duke W.]

Re: My second pump gas damage mistake

The greater the bore the greater the propensity to detonate. The practical bore limit for spark ignition engines is about six inches although there were a couple of WW II era aircraft engines that were a bit larger.

The Continental XR-7750 was 6.375". It was a 36 cylinder liquid cooled radial - basically four OHC 2-valve/cyl. I-4s radially disposed about a common crankshaft with a two-stage boost system consisting of both a supercharger and turbocharger. Design takeoff power from this 7750 CID engine was 5000 HP. It was designed to power the B-36. Two examples were built and tested, and I believe at least one has survived and is owned by the Smithsonian Air and Space Museum.

By the time the two prototypes were built and tested it was clear that turbines were the future of aircraft propulsion, and the program was cancelled.

The B-36 first flew with four Pratt and Whitney 3000 HP R-4360s, but was grossly underpowered, which lead to the addition of four jet engines that were modified to burn avgas rather than JP-4, but they were usually only powered up for takeoff, climb, and high speed runs over the target.

The problem with SI engines is they are not "scalable". You can't just keep increasing bore and stroke, so you have to keep adding cylinders for more power, which can lead to incredible complexity. Diesels and turbines are scalable with virtually no limit on bore size or turbine diameter. The world's biggest diesel, a two-stroke turbocharged type, has a bore and stroke of about 36" by 84" and can be configured with 5 to 14 cylinders, inline. It's used to power large container ships and tankers.

Duke