Northstar Engines and System Technical Discussion Discussion, BBob, 2 stroke oil in gas to preserve... in Cadillac Engine Discussion; BBob, I remember in another post, you wrote about adding 2 stroke oil to the gas tanks of your toys, ...
BBob, I remember in another post, you wrote about adding 2 stroke oil to the gas tanks of your toys, to preserve the engines and exhaust systems during the winter months.
I was wondering, what amount of oil do you add? Are there any limitations to this? That is, are their any vehicles you would not do this with? I have two Vettes and a couple of other cars that see limited use during the winter months. I'd like to try this, but I don't want to mess anything up.
They are both running small blocks (350's), one of which is Tuned Port (with full emissions equipment), the other is carbureted (with no emissions equipment).
Yep, that is my favorite trick and it has never let me down. I do it to everything. Bikes, Corvettes, lawn mowers, you name it. Figure about how much gas is in the tank and add enough premix oil to get it to 20:1. I like a nice "rich" oil mix so that it smokes a little an coats everything good. It will not hurt a thing. You are going to only run it for a little while so it is no big deal. I put the two stroke oil in and run it for awhile before storage so that everything gets a little coating of oil. A real simple and lazy way to fog the motors for storage. I just try to plan ahead and put the oil in the gas tank so that it will get run thru in the last drive or use before storage. Personally, I use Bombardier conventional two stroke oil...just because there is usually gallons of that around as I use it in my sleds.... most any good two stroke oil will work fine. It really works well in carbed applications as the fuel left in the carb will have a bit of oil in it so that as the fuel evaporates the oil coats everything inside the carb preventing and varnish or deposits from hardening or sticking to anything. In the spring just put fresh fuel in the tank and drive. I have stored engines for up to 5 years like this and have never had a problem with carb deposits or corrosion damage due to lack of oil on parts. In the fall I keep a 2 gallon gas can of "winter prep" 20:1 premix around to put in all the various engines that get stored for the winter for their last run before storage.
This is a good way to store two stroke engines, also, that are oil injected. Most oil injected engines do NOT run the oil thru the gas in the carb so the carbs can dry out and form deposits (very common failure mode of snowmobile engines...carb deposits, plugged jets, lean out, melt piston...) so it is a good idea to add oil to the gas and run into the carbs and such so as to coat the fuel system and carbs with oil. Many people think that this is unnecessary since it is a two stroke engine and already uses "premix" or oil injection but unless the oil injection puts the oil into the fuel line before the carbs the carbs are not protected by the oil in storage. In any case, most two strokes run much leaner oil mixes (40:1 or 50:1) so the extra oil of a 20:1 premix adds quite a bit for storage purposes.
A quart of two stroke oil in 10 gallons is 40:1..... (40 quarts in 10 gallons vs. 1 qt of oil) so if you wanted to "treat" 10 gallons of gas in the tank for runin prior to storage put in 2 quarts of oil to achive 20:1.
I thought I read the whole 2 stroke thing on the Corvetteforum, and posted there. Then, I realized it was on the CaddyForum. But the cat was already out of the bag. Ooops. These guys are rough.
But I knew that already.
Interesting responses. They seem to misunderstand the idea of using the two stroke oil. It isn't for preserving the gasoline....but as a way of "fogging" the inside components of the engine and exhuast system to prevent corrosion.
For all the folks there that think that two stroke oil is all burned or that it won't "hang around" or wondered what the engine would look like if it was torn down months later..... All I can say is that they must have never taken many two stroke engines apart.... I have. LOTS of them. That is where I got the idea of using the two stroke oil in the 4 strokes to prep them for storage. You can dissassemble a two stroke engine that has been sitting for years and it will still have oil on all the internal parts. 'Nuf said. If they want proof, then tell them to go to a bike/snowmobile scrap yard and buy an old engine for a few $$$$ and take it apart and see for themselves.
I, too, own a Corvette. Have owned one constantly (sometimes two...) since my I inherited a '72 Coupe in 1982 with my wife....LOL (she will drive any kind of car that is any kind of color....as long as it is a red Corvette) and currently have an 02 C5 coupe....red of course. It was prepped last November with two stroke oil, like always, before winter storage.
The two stroke oil will not hurt the injectors or anything in the fuel system. Engine is is recommended for the lubricant to put injectors into the sockets in the manifold and is used by all GM engine plants....so the injectors have been validated for oil contact.
If they are worried about two stroke oil hurting something the I assume they NEVER put any fuel system cleaner or "gas treatments" in the system....the two stroke oil is completely benign compared to any solvents in the fuel treatments as far as the injectors and fuel pump is concerned.
Maybe they are not aware of the fact that for many years Arcticat and Polaris, as well as Skidoo the last 3 years, have built snowmobile engines with port fuel injection. The consumer sleds have the oil injected into the crankcase but the systems will run fine on pre-mix (thru the injectors) as all of them ship sleds with extra oil in the gas tank for added lubrication during breakin and recommend it when any work is done that might interrupt the flow of oil thru the oil injection unit. Those are the same injectors that cars use, BTW.....
I have a fair amount of experience with personal water craft engines....pretty much a worst case situation for potential corrosion as they are two strokes, the cranks/rods/pistons are only lubed by premix in most cases and the exhausts have water injection for cooling as well as the water jacketed exhaust manifolds and mufflers (which are wet exhaust chambers full of water for silencing)....so....on shutdown and in storage the whole exhaust system back up thru the ports and to the crankcase is guaranteed to be 100% humidity....and in storage it takes weeks and weeks for the water to dry out in the exhaust system. I have NEVER seen any corrosion problems with the iron cylinder walls, crank bearings, etc. in those engines and the ONLY thing protecting the critical surfaces is the presence of two stroke oil.
There are many studies on the amount of oil to be used in pre-mix or twostroke situations. Understanding that rejetting is required when pre-mix oil percentages are changed (the jet is for the "gasoline" quantity, as more oil is added to the pre-mix displacing gasoline, the jetting has to be richened to keep the same A/F ratio) usually the more oil the more power up to about 20:1. There are a LOT of racing twostrokes on the market that require 20:1 ratios for max power and protection. 20:1 is NOT that rich of an oil mix for heavy load operations. Snowmobiles with oil injection will run about 80:1 or even 100:1 at light throttle. The oil pumps are staged so that the heavier the load the more oil is injected. At full throttle my 800 REV runs about 20:1 from the factory and it makes excellent power, the plugs currently have about 3000 miles on them (no fouling). 20:1 is only an outlandishly rich oil mix to someone who is looking at the "average" mix ratio of about 40:1 or 50:1 that many manufacturers quote for premix oil. I think a lot of the concerns about rich oil mixes come from people who do NOT rejet when running richer oil mixes and see a loss of power or even engine damage...because the more oil they pour in the leaner the engine is running. Surprise....?????
I have personally taken MANY carburetors apart that were stored for several years with the premix treatment and have always found a nice coating of oil and no deposit formation. The oil coating seems to keep any varnish deposits from the gas drying out from becoming too hard or sticking to any jets or anything. I quite taking my snowmobile carbs apart each fall to check them as I NEVER found any deposits at all...just a nice clean film of oil inside the bowls....in the meantime, guys I ride with suffered burndowns from lean carbs caused by carb deposits on machines not prepped with premix in the carbs. Remember that most two strokes have the oil injection AFTER the carbs so to protect the carbs premix must be put into the tank and run into the carbs and engines. The idea of two stroke premix as a protection/storage method might make the wrong impression unless someone realizes that the carbs do not get the oil unless the premix trick is employed.
The comment from the guy about the turbines and what he thought of the two stroke premix idea was a hoot. I assume he realizes that turbines run on kerosene, not gasoline, and that he could probably run the turbines on the two stroke oil straight...!!!!! LOL Bringing up turbine engines in this discussion just points out the severe need to criticise something that was "not invented here" with no logic to back it up. What a hoot.
I assume you will post this there and get some responses. I don't really want to start dabbling in another forum so if they have questions/comments let me know.