Archive through October 06, 2009

[dfrisk]

BRIAN B. - Matt's right, the number of drive pins have absolutely nothing to do with the clutch engaging smoothly and gradually. That's ALL the teaser spring is for. I've had a couple teaser springs break in all the years Ive run CC's and without them those old GD's are a WHIPLASH machine every time You let out the clutch. If the clutch didn't engage properly with the sping in there You didn't assemble the clutch correctly.

I had a NICE long comment about gasoline for Cubbies typed out, but I deleted it. I'll just say that my 25 yr old Champion D-15Y plugs in my tired old never-rebuilt Super H FARMALL still fire well even when I leave it set idling for an hour in the winter. And My Cubbies run fine with the gas I syphon out of the tank of that Super H. If I ran all my tractors enough to burn 200-300 gal. of gas a year instead of 50-60 gal. I may burn something else in them but what I've used for the last 20+ yrs works great. Even when I leave them sit for 6 months without running.

 

[rwilke]

Matt S. / Wayne C.,
Agreed that patience is a key in getting it removed. Rust isn't the issue since the handle is cast aluminum. The issue is the dis-similar metals of the handle and the shaft - they corrode between the spline teeth & it builds up a scale that binds them together.


Brendan B. / Kendell I.,
It isn't about required octane levels, it's simply about the quality of the gasoline and what other 'solvents' are dissolved in it.

Agreed, our Cubs have a relatively low compression and thus, they don't require high octane fuels to run without pre-detonating, spark-knocking, or pinging. Premium-grade gasoline is simply a cleaner fuel.

Do this test: Pour 1/2 cup of 87-octane gasoline in a clean, clear glass. Do the same with 92-octane gasoline. Put a piece of tap on each and mark them accordingly, '87' and '92'. Now place both glasses in the garage window that gets Sunshine....it'll probably take a week or longer to dry them out completely. Once they're dry, which glass has more residue in it? Yep, the low octane glass. That's the residue that builds up in your tank, carb, on your cylinder head, sparkplug, etc.

I agree, Kendell, racing fuel does smell better than pump gas, and I understand the higher octane fuels burn slower, but Wayne S. and I aren't suggesting you use $6/gallon, 100-octane racing fuel, we're only talking about 92-octane premium-grade pump gas.

Yep, considering the results of the above cup drying test, I think because the fuel sits in my Cub carb & tank longer than it does in my car, the benefits out way the extra cost/per gallon.

Let's look: A quality, name-brand, premium-grade 92-octane gasoline usually around 20 cents more per gallon than 87-octane. Now compared to the cost of Stabil (8 oz. @ $11, which treats 20 gallons, figures out to $0.55/gallon) versus the extra cost of premium over regular. I'll take the $0.20/gallon extra for the premium versus $0.55/gallon for 87-octane with Stabil. But that's just my 2-cent opinion....

Ryan Wilke

 

[kide]

Ryan:
Gas doesn't stay in anything around here long enough to worry about evaporation. IF you're going to run higher octane, you SHOULD bump the timing ahead to counteract the slower burn rate..You probably won't see any horsepower increase unless you've raised the compression about 3 points over stock, but you will cool the exhaust back down to where it should be. Like the question on lead that started this, there is more than one dimension to the answer..

Ryan - like the balance gear question, I'm not telling you what YOU should do, just trying to make sure that all the facts are on the table..Why do I care? Because we've got a lot of less experienced people on forums like this who'll take any statement they read on the Internet as God's own truth....Tell 'em to change the air in the rear tires every 100 hours and there'll be a run on Air Compressors..

 

[kmcconaughey]

Kendell, with winter coming should I change out the old summer air for winter air? Wait, should I put autumn air in them first, well shoot, I think I still have spring air in them,

darn, I forget when I last changed the air in them.

 

[rwilke]

By the way, regarding required octane ratings for our 'toys' -
Just the other day I happened to be leafing through the owner's manual for my MS-250 Stihl chainsaw (I think it was new in 2006).
It clearly states to use at least 89-octane fuel to mix with the 2-cycle oil additive...

Ryan Wilke

 

[rwilke]

Kendell I.,
The 'evaporation test' isn't meant to illustrate you only need be concerned if your gasoline evaporates to dryness. It is meant to visually show you that there are non-friendly components dissolved in the lower grades of gasoline that can and will cause deposits in your fuel system & combustion chamber. Such unfriendly gasoline ingredients are responsible for the buildup of varnish in your carb or tank just as it sits. It doesn't need to go to dryness to start this process.

Again, this is only just my opinion....

Ryan Wilke

 

[rwilke]

Kraig McC.,

NO, DON'T DO IT!!!

HAVEN'T YOU HEARD?

NITROGEN IS BEST FOR YOUR TIRES!!!!!

Ryan Wilke

 

[rpalmer]

Kraig McConaughey,

Just make sure it's dry air.

 

[rpalmer]

Ryan D Wilke,
Not sure what you are getting at here: Let's look: A quality, name-brand, premium-grade 92-octane gasoline usually around 20 cents more per gallon than 87-octane. Now compared to the cost of Stabil (8 oz. @ $11, which treats 20 gallons, figures out to $0.55/gallon) versus the extra cost of premium over regular. I'll take the $0.20/gallon extra for the premium versus $0.55/gallon for 87-octane with Stabil. But that's just my 2-cent opinion....

The difference between 87 octane and 92 octane is the amount of time it takes to burn. And Stabil has no effect on that. Gas stabilizers allow gas to be stored for extended periods without turning to a varnish like substance.

92 octane gas burns much slower than 87. So with proper timing you can have more power via burning expanding gas on your power stroke. Where as with 87 you get a poof of burn and the the reciprocating action of the flywheel carries it on.
So 1. Stabilizers have no affect on octane. And 2. Higher octane gas has more power in it.

Also why would you suggest using 92 octane? The manual clearly states 90. 89 is closer to 90 than 92 is and with out changing your engine timing for the 92 octane you will tear up you engine.

I understand you wrote that your comments were your opinion. These are facts. Some newer members might think your opinions are right on. And you don't want to lead anyone astray do you?

 

[kide]

Actually, I DO like nitrogen - less leakdown in the tires on our motorhome that sits more than it rolls and less pressure change on long rides on the Yamaha....
Dennis:
(just looking at the first post on this page....) My first car had something like a 12 gallon tank (Model A Ford pickup), but I was making less than 50 cents an hour working in a Gulf station. After taxes, I don't think I made $20.00 a week, but the owner kind of assumed that it was the hourly plus a fillup. And no, I'm not THAT old, this was the 60's, not the 30's. To keep this on topic, one of the good things back then was my best friend's dad's NEW International Cub Cadet (a 70, IIRC) that we got to use, IF we were careful.

Richard: My sources indicate that higher octane produces more power IF the engine is designed to use the higher octane, I.E. with more compression, higher cam lobe overlap, etc. IIRC the K series, in stock form has about a 7.5:1 compression ratio. There isn't more BTU/H in higher octane, just additives to slow the burn rate down to prevent preignition.

 

[jpatchett]

All gas regardless of octane rating has roughly the same amount of heat energy (available horse power). It comes down to the additives and blending of the fuel to create different octane levels. Most of us who have stock engines will not benefit from octane levels above 90. The stock stroke length is too short for a complete burn and the remaining unburned fuel/air mixture is pushed out into the muffler (wasted $). High octane fuel makes your 4 cycle engine run hotter (not beneficial).

High octane fuel can be made to burn faster than 87 grade. NASCAR and NHRA both use fast burning high octane fuels. An engine turning 9000 rpms needs to burn fuel in a very very short time period, long burns here will result in less HP.

If you are concerned about build up from additives, you can add fuel system cleaners, but those can be corrosive.

I use around 89 octane from a high volume station (less risk of dirt, water, etc.), I avoid the small station with low volume. Name brand makes no difference every station gets gas from the same refinery in my area. US Gov. regulates/standardizes all gasoline. I use sta-bil if the engine is going to sit longer than 3 mo.

Jim

 

[kide]

Hey! Another Michigander!!! Jim, I think all of the stations in our area get it from the same DEPOT, which is Marathon's. A friend, now living out in big sky country, used to deliver for Shell and would be there when the Sunoco driver was dumping the blue dye in the "260" ...

 

[rwilke]

Richard P.,
I don't what to mis-lead anyone nor do I want to start any peeing contest.
I'll respond to your questions and I'll just leave it at that:

#1. "Not sure what you are getting at here: Let's look: A quality, name-brand, premium-grade 92-octane gasoline usually around 20 cents more per gallon than 87-octane. Now compared to the cost of Stabil (8 oz. @ $11, which treats 20 gallons, figures out to $0.55/gallon) versus the extra cost of premium over regular. I'll take the $0.20/gallon extra for the premium versus $0.55/gallon for 87-octane with Stabil. But that's just my 2-cent opinion...."

<font color="0000ff">-- I was trying to point out the cost difference of using premium-grade fuel vs. regular-grade fuel with additives; in an effort to nip-it-in-the-bud any cost discussions.</font>

#2. "Also why would you suggest using 92 octane?"

<font color="0000ff">-- Just as Wayne S. inferred, my personal experience has also led me to prefer using premium-grade gasoline instead of regular-grade gasoline in my "non-daily driver" engines - such as our Cubs - because:
(A) I believe it has less crap in it that will produce varnish over time and,
(B) I believe it will store adequately for months without additives.

My decision to use premium-grade gasoline has NOTHING to do with a NEED for higher octane due to compression ratios nor does it have ANYTHING to do with any belief it will make more power in our Cubs.</font>

#3. And you don't want to lead anyone astray do you?

<font color="0000ff">-- Of course not. That is why I stressed the point that what I was saying is JUST MY OPINION.</font>

I have never claimed to be some sort of Internal Combustion Expert, nor do I play one on TV..........

Later, Guys......
Ryan Wilke

 

[rpalmer]

Kendell Ide,
The higher the octane the more power in it. This is not to say you will have more usable HP. It has been said that you don't want burning gas going past your exhaust valve. The exhaust valve is the least of your (ones) worries. If you have burning fuel (gas) exiting the exhaust that means it was also burning on the up stroke of the piston as the exhaust valve started to open. So you are putting counter forces on the piston, rod, crank ect.. The energy is being used, but not in a way to make the engine run better.

Jim Patchett,

Horsepower as you must know is a representation or measurement of heat. So the more HP you have the hotter the engine is. The trick is to dissipate that heat ASAP.

 

[dfrisk]

KENDELL - Your right about higher octane gas not having really any more BTU/gal. than regular, therefore HP output would be relatively the same for different grades of gas. The octane rating is a "coefficient" of resistance to knocking or detonation. Two methods are used, a "Motor" method, and a "research" method. Just as a side note, Wyatt Compton used to work where the "Motors" were made for the motor method. The two relative numbers are averaged and that's what's on the pump. The Physics and Chemistry of the testing described in the website "FAQongasoline.com" I read about 8-10 years ago was WAY over My head. I printed out about 200 pages off the site and studied it one weekend. Some of the stuff made pretty good sense.

Only way You can get more HP from higher octane is to adjust the tuning as You say, advance ignition timing, valve timing, boost, etc.
My daily driver car is a 2.5L in-line 5 cyl. engine with variable intake & exh. timing, turbo boost regulated up to 10-11 PSI, knock sensors to retard timing if it ever pings, and several O2 sensors to control the EFI which varies air/fuel ratio. Kohlers have absolutely NONE of that equipment.

There's a LOT of bad information and especially opinions about gasoline floating around. Most of Us here that have been around these Kohler's have found a balance that works for Us. And in most cases it's not too far away from what's in the Kohler or CC service manual.

Of anybody here I probably run the most expensive and highest octane gas. I also run only Champion plugs, multi-weight oil, and probably LUG my engines at the lowest RPM when mowing or doing yard work. So what the heck do I know? I break all the "Rules" anyhow!

 

[rpalmer]

Kendell Ide,

One more thing that might start to ring true.

LP. Much less BTU/H than gas. It NEEDS higher compression and much more ignition advance to run in a gas engine. Think about it. Higher compression means more heat in the cylinder. And that is all.

I guess I'm done. Long story short.... Use 89 or 90 octane. And if your fuel (gas) is going to sit for more than a month use a gas stabilizer.

 

[kide]

As long as we're all still friends !!!

 

[rpalmer]

 

[jpatchett]

Richard,

HP we are discussing here is the measurement of work done over a period of time. The mechanical HP made by an engine is not the same as the heat generated during combustion, but is the ability to create torque (mech HP). The heat is the result of energy being released after mech HP was created and dissipating it faster is efficiency. Heat here is the loss of HP because nothing is 100% efficient.

Up for a physics lesson in the sandbox?

Jim

 

[bbrigham]

OK, taken from http://en.wikipedia.org/wiki/Octane_rating#Examples_of_octane_ratings

What I think is most relevant to us I highlighted.

Many high-performance engines are designed to operate with a high maximum compression, and thus demand high-octane premium gasoline. A common misconception is that power output or fuel mileage can be improved by burning higher octane fuel than a particular engine was designed for. The power output of an engine depends in part on the energy density of its fuel, <font color="ff0000">but similar fuels with different octane ratings have similar density. Since switching to a higher octane fuel does not add any more hydrocarbon content or oxygen, the engine cannot produce more power.</font>

However, burning fuel with a lower octane rating than required by the engine often reduces power output and efficiency one way or another. If the engine begins to detonate (knock), that reduces power and efficiency for the reasons stated above. Many modern car engines feature a knock sensor – a small piezoelectric microphone which detects knock, and then sends a signal to the engine control unit to retard the ignition timing. Retarding the ignition timing reduces the tendency to detonate, but also reduces power output and fuel efficiency.

<font color="ff0000">Most fuel stations have two storage tanks (even those offering 3 or 4 octane levels), and you are given a mixture of the higher and lower octane fuel. Purchasing premium simply means more fuel from the higher octane tank. The detergents in the fuel are the same.</font>

Guess we got a good one stirred up huh