flyerdave

My Feedback: (212)

Just got this engine and the previous owner has been using bel ray @ 50:1 with mid grade gas. Just wondering if I use penzoil air cooled, will this be as good. Also, I was told that ZDZ's liked 91 octane better than 87 or 89 because of higher compression ratios. Is this correct? Thanks

flyinrazrback

My Feedback: (69)

Pennzoil will be just fine. If I remember correctly ZDZ does not recommend any leaner ratios than 40:1, at least that is what I remember from my ZDZ days. Yes the ZDZ's are a bit higher compression so I would use premium, but that is just me.

ec121

My Feedback: (2)

I have a ZDZ80. I run it on 40/1 Pennzoil 91/93 octane(whichever I can get). No problems. I just use the same gas on all my gassers,( 26cc to 85 cc) and let the loose ends drag.

captinjohn

If you change to Pennzoil ,find the for"air cooled" engine type. Not the outboard. You can mix it 32-1 for more power & protection. Remember to retune your engine after changing oil brands or ratios. Let it run for a bit and get new fuel in...old fuel out. Then tune. Capt,n

karolh

It is suprising how many switch oils, ratios and even props but keep the same old engine tune.

Karol

captinjohn

Karol
I know what you mean about that retunning. Did it get kinda wind near you the last few days? Capt,n

jack19345

My Feedback: (1)

Please explain how an engine internals can tell what is being used to cool it? Have asked this question many times with no answers that were definitive.
Regards

w8ye

My Feedback: (16)

Not what cools it - but how cool?

Tired Old Man

My Feedback: (1)

Feeling arguementative again Jack? We both know an engine is cooled a multitude of ways. It doesn't care how so much as how well or how quickly. Oil carries btu's out the the exhaust, along with all that nasty wear and carbon stuff. More oil passing through an engine carries more btu's. Now oils designed for air cooled engines break down at higher temperatures than oils designed for water cooled engines. Water cooled engines depend more on a water jacket for engine cooling than an oil mixed with te gasoline.

As for altering tune, oils have different viscousities and differnt combustability so they affect the tune. Of course a change in oil ratio would affect the state of tune.

jack19345

My Feedback: (1)

No arguement, Just asked a question, Assume, from your reply, an engine does not know how its being cooled, which must be the correct answer. Thanks for the input.

Cheers

karolh

Yes it did Capt,n but was not quite as bad as was predicted.

Karol

Kweasel

My Feedback: (29)

It not about how its being cooled but all about the peak temperature of the head and piston. Outboards dont get hot enough to vaporize the oil so they use an ashless detergent. Aircooled engines often get hot enough to vaporize the oil on the combustion chamber, piston face, and ring lands. Particles are added to "aircooled" oil that form ash after the oil vaporizes. The ash that is left behind keeps carbon from sticking to the surfaces. Aircooled oil also use lighter base so it tends to produce a dry exhaust soot where outboard oil makes a greasy mess. You will see high performance watercooled engines, like snow machines specifying aircooled oil. Marketeers are forced to do the best they can with simple words.