50:1 vs 40:1

[FixNstuff]

I was wondering if anyone had ever experimented with a copper alloy (bronze or other) cylinder head?I would think it would be more efficient at heat transfer out of the cylinder, and run cooler altogether.

Copper absorbs heat faster than aluminum but gives it off more slowly. This is from my experience with heat sinks on electronics. It's fairly common to see a heat sink with copper against the hot surface with aluminum cooling fins mated to it.

 

[redheadwoodshed]

Found some British bikes in the 30's that had bronze cylinder heads (just the heads).

Just took a quick look, but it seems that the copper alloys are not in the same league as pure copper (or aluminum) for heat transfer?

I know copper head gaskets get brittle, and need to be annealed to be reused, would that be an issue? Seems like roughly 3 times the mass too, so that's probably why they stick with aluminum.

Yes, I was thinking mainly of the heads myself.I wonder though, what mixture of bronze they used, bronze describing such a wide variety of alloys.I had in mind myself aluminum bronze, I'm not sure they even made that in the 30's.As far as being brittle, I don't think a chunk big enough to make a head would get the fatigue like a gasket does.At least in the lifetime of the machine itself.I think the main concern would be weight.Even aluminum bronze is heavier than iron.I don't know what the heat transfer properties on CuAl are, but I would think it would be better than pure aluminum.I do have a chunk of pure copper about 5" around and 3" thick if some machinest/chainsaw nut would like to give it a whirl.I don't know how you could measure results inside the cylinder without a pretty, maybe shoot a heat gun in the plug hole.Just idle curiosity, but wheels have started turning.
And of course, aluminum is way cheaper and lighter than copper, so commercially speaking,it would be crazy, but just for the heck of it I think it would be worth trying.


As far as the original question goes, since I barged in with all these random off topic ,off the wall comments, as long as the oil and gas being mixed are good, and I am speaking from a operators point of view, not a mechanics.I haven't ever noticed a difference.And like I stated earlier my own mix is usally somewhere in the middle.

 

[aussie2]

Aussie2, our octane ratings are different to the USA, we both use numbers that sound the same, but it is a different rating system. AFAIK there is ethonal in all our unleadeds, both normal and premium. The one I am fairly sure doesnt have ethonal is BP Ultimate 98 octane. I have been told by Kart racing guys that the Shell Optimax 98 (or what ever it is) does have ethonal. They had problems with it at a race meet and when engines were stripped done they could trace the problem back to moisture in the carb.

Now I recokon ethonal would be worse than running at 40-50-1.....Nothing wrong with changing the fuel oil ratio for what ever a person wants, that is their choice. But it must be retuned to that new mix.

Are all your dealers telling you to retune with the new mix or is that just taken for granted?

what blown huskies does he have haha :hmm3grin2orange:

BTW I run BP Ultimate 98 and a blend of maxima 927 with Husky xp oil (50/50) @ 40-1 in all my saws, blower and string trimmer. By the sounds of it, I would not do any where near the work on my stuff as you, nor in your heat...

interesting yeah mate i have heard the ethonol can cause burnt pistons in our older cars ! yeah this bloke has a fair few huskys and some old stihls mainly smaller homeowner saws that people have abussed but everynow and then he gets some older relics.i see u like your huskys have you had a go of any autotune saws yet??

 

[aussie2]

Up here I use premium ethanol free gas with a little octane boost. Never had any 2-stroke ever burn down on me from oil issues. I've run 50:1 in everything from dirt bikes and snowmobiles to trimmers and saws. Our premium fuels in Canada so far are ethanol free.:msp_thumbup:

yeah we are starting to get more ethonol fuels over here its a little cheaper then the other stuff where i am.
cheers bud

 

[aussie2]

interesting yeah mate i have heard the ethonol can cause burnt pistons in our older cars ! yeah this bloke has a fair few huskys and some old stihls mainly smaller homeowner saws that people have abussed but everynow and then he gets some older relics.i see u like your huskys have you had a go of any autotune saws yet??

burnt pistons meaning melting??

 

[genestar]

I'm thinking when the govt pays for my saw they can tell me how to blow it up early.
Till then I will run Klotz super techniplate at 28:1 and remove the limiters from my saws..
They prob think autotune will solve this...I'm guessing its a matter of time before we see an aftermarket computer with tunable fuel ratios and timing...they have had them for dirtbikes for a while now.

 

[Brushwacker]

I'm thinking when the govt pays for my saw they can tell me how to blow it up early.
Till then I will run Klotz super techniplate at 28:1 and remove the limiters from my saws..
They prob think autotune will solve this...I'm guessing its a matter of time before we see an aftermarket computer with tunable fuel ratios and timing...they have had them for dirtbikes for a while now.

Thought it was only I using 28:1.

 

[genestar]

Thought it was only I using 28:1.msp_thumbsup::

:msp_thumbup:

80% synthetic and 20% castor ....smells soooo good

 

[KiwiBro]

K.i.s.s.

Canola oil for the bar and and also for the fuel mix at something like 50:1 but buggered if I'm getting anal about the exact amounts. The way you fellas complicate life with this or that brand of this or that oil at this or that ratios makes me wonder how you ever get any actual work done. . If you run out during the day, drain some out of the pickup's sump and keep cut'n.

Heck, it ain't rocket science.
:cool2:

 

[genestar]

Canola oil for the bar and and also the fuel mix at something like 50:1 but buggered if I'm getting anal about the exact amounts. The way you fellas complicate life with this or that brand of this or that oil at this or that ratios makes me wonder how you ever get any actual work done. . If you run out during the day, drain some out of the pickup's sump and keep cut'n.

Heck, it ain't rocket science.
:cool2:

I have been build helicopters for the last 15 years....not rockets...tho we do make rocket parts in house...