Outdoor Power Equipment and Small Engines - a oil question

Okay, last winter i got a barely used snow blower, it has a 6 hp tecumseh horizontal engine. It is somewhere from the early 70's era. It looked and ran like a new one, engine clean, tight, and what seems in excellent condition. I lubed it up, changed oil (10-30 castrol) and started using it. Used it twice in near zero degree temps. Halfway thru second use it slowed, engine stopped, and locked up. Fast forward to the present, i just took the head off and what happened was the piston was stuck near the top in the cylinder, 2 light smacks with a nylon hammer and it was free, engine then turned over by hand easily. There was no score marks in the cylinder at all, none... So i decided to put it back together and it started and "seems" to run fine. I ran it with 10-30 in it for a hour at almost full throttle in 90 degee temps. no problems.
Okay, now the question, i have just found a tag saying "USE 10 WEIGHT OIL ONLY" was it the 10-30 that let it lock up, to thick? and since i cannot find 10 weight, what would be a good substitute? thanks

you might need to get an engine oil that will not freeze during low tempuratures like -20f or something like that. most people recommened 10w-30 oil in small engines. i know that there was a guy that could not turn his lawnmower blade and all he done was remove the sparkplug to let the pressure out. you might not have enough oil pressure or you might have a warm weather oil. go to a place like advacne auto parts that have a wide selection of oil and ask them for cold weather 10w-30 oil. you may need synthetic or something. good luck and hope this helps.

Hello Johnn!

No, the 10w-30 didn't cause any problem. I can't say what did though. Could it have been low by any chance at all? Has the engine been rebuilt? Is there any marking or stamp on top of the piston? 10w-30 oil is 10 weight oil. It starts out as 10 weight, and warms up to 30weight when it warms up. In cold temps, the engine won't get hot enough to destroy the viscosity index improvers in the oil that make the oil viscosity change, but on warmer days, the engine will break down those improvers and revert the oil back to it's original state of 10 weight. That is why nothing but 30 weight oil should be used in small air cooled engines that will be running in temps over somewhere around 20 degrees F. Colder than that, and 10w-30 is fine.

Littleworker, oil does not freeze in any temp found on the planet. It does get thicker though. Synthetic oil is influenced less than dino oil by temperature. I don't know who is reccomending that you use 10w-30 oil for small engines, but they are not correct, unless you are in a very cold climate. Here is an example thread on this forum of why: http://forum.doityourself.com/showthread.php?t=171477

No, the oil wasnt any lower than maybe just touching the full mark on the stick, the enine had never been apart, piston standard, no markings, It all seemed very tight and "new" like.
I am not disagreeing with you but i found a spec sheet from Tecumseh that says:
Recommended oil viscosities for Aluminum Engines:
Above 32 degrees: 30 weight or 10W30 or 10W40
Below 32 degrees: 5W30
Below 0 degrees: 5W30 or 10W

Recommended oil viscosities for Cast Iron Engines:
Above 32 degrees: 30
Below 32 degrees: 10W
So there must be some truth to 10w30 being to heavy for a engine in near zero temps right? Maybe just my luck i got one that just was a bit to tight for zero degree startups with 10-30 i dunno. And as for oil pressure, what oil pressure? arent these 6 hp engines oiled by a slinger?

I checked around last night and found Valvoline 5w20 full synthetic, i might try it this winter in the snowblower. Oh, ran the numbres and it seems to be a 1978 engine.thanks for the replies

I know that there is a lot of controversy regarding using 10W30 oil in small engines. Let me paraphrase what B&S says about the subject. 10W30 oil was primarly developed for use in larger water cooled engines. Small air cooled engines run hotter. The multiweight 10W30 oil can be used at all temperatures but if you're going to use it check your oil more often, especially in the summer. If you inspect the operator's guide for the newer B&S engines you will find that the synthetic 10W30 oil is recommended for use at all temperatures. That's because of an inproved viscousity index. That is, the oil doesn't thin as much with an increase in temperature, nor does it thicken as much at reduced temperatures as the non-synthetic based oils. I use the 10W30 synthetic oils in everything I own and I haven't had a problem yet.

Johnn,
Quote: "Okay, last winter i got a barely used snow blower,". Now, you don't know any history on this since it's used and therefore you don't know if the previous owner(s) had ever run this engine low on oil. I would say they did. Quote: "i just took the head off and what happened was the piston was stuck near the top in the cylinder,". You mentioned the cylinder had no scoring once freed up. Maybe not, but the engine seized elsewhere, likely the connecting rod journal to the crankshaft. This being the case, you will be lucky if the engine runs more than 15 minutes under load come this winter. As far as oils go, here is what the newest Tecumseh service manuals say: "For Summer, use SAE30, period. SAE10W30 is an acceptable substitute." "For Winter, use SAE5W30, period. SAE 10W is an acceptable substitute. SAE 0W30 should only be used when ambient tempurature is below 0 degrees Farenheit." Now here is what petrolium based oils are available from Tecumseh - SAE30 and SAE5W30. Based on this, you can clearly see which oils to use in given seasons. If you choose to use synthetic oil, 5W30 should be used in the winter and 10W30 should be used in the summer.

Well yes i do know the previous owner, he bought it new at Sears. He is very aware and cautious of his machinery, he said it never had a oil change and the whole time he owned it, he only used it a couple times. See he was in bad health and had gotten worse so he hired someone to clear snow all the time with their own equipment, namly a truck with a plow.
This blower sat in his garage the whole time, so long in fact that the exposed drive chains , one to wheels, one to auger both rusted solid and i had to replace them.
And i dont believe that anything was stuck except the piston, reason i believe this as the piston was up as near the top without going over as it could be, you could while it was stuck feel movement in the flywheel when you tried to turn it by hand, grant you only a tiny tiny bit, but it felt loose like the only thing was stuck was the piston to wall. I may be wrong, i dunno, but i did run this thing at near full thootle after i put the head back on for about a hour on 10-30 sitting in near 80+ temperatures and never so much as i hicup, so i guess we will see what happens when winter gets here and it gets loaded up. Id just like to keep the thing all stock cause its in nice shape and faily old but if the engine goes, well i have a 12 hp sitting here doing nothing :)

I've got my fingers crossed for you and hopefully the oil info will help you in deciding which to use. As for the potential for using the 12 horse if the six fails, you will find difficulty in adapting this to the frame unless the original engine is attached by way of thru-bolts rather than weld studs. The mounting plate (engine sump) on the 12 is alot thicker and if weld-studded, you will have to modify these. Also, the crank diameter is likely a 1" as opposed to 3/4" on the 6, along with different crank centerline height (from the mounting surface). In other words, best of luck with the six.

Well, putting a 12 hp on it wouldnt be much of a problem really. I just finished converting a 69 Massey Furgeson lawn tractor from a 6 hp horizontal to a 7 Hp vertical. I also put dual wheels on it, 155x80R-13's to be exact, built dual wheel tire chains for it too. The front tires were swpped out and i used the original 20x8's from the rear on the front. Between the engine and the transaxle is a 90 degree convertor with removable pulleys. i changed them around so it is actually running about double the engine speed to transaxle than before. Hmmmm, that doesnt sound right, anyway, it is "geared down" so low in 1st gear now it barely crawls, you either go over what you are against at idle, or it will sit and dig those duals in. It will be a snow plow when i get my blade welded up to fit.
The darn thing is pretty cool, you can hook to a heavy load from the hitch, and if it cant pull it, it will stand up.. LOL like a mini pulling tractor.. And i dont care if i break it, it was free :)

Hello Johnn!

No, the 10w-30 didn't cause any problem. I can't say what did though. Could it have been low by any chance at all? Has the engine been rebuilt? Is there any marking or stamp on top of the piston? 10w-30 oil is 10 weight oil. It starts out as 10 weight, and warms up to 30weight when it warms up. In cold temps, the engine won't get hot enough to destroy the viscosity index improvers in the oil that make the oil viscosity change, but on warmer days, the engine will break down those improvers and revert the oil back to it's original state of 10 weight. That is why nothing but 30 weight oil should be used in small air cooled engines that will be running in temps over somewhere around 20 degrees F. Colder than that, and 10w-30 is fine.

Littleworker, oil does not freeze in any temp found on the planet. It does get thicker though. Synthetic oil is influenced less than dino oil by temperature. I don't know who is reccomending that you use 10w-30 oil for small engines, but they are not correct, unless you are in a very cold climate. Here is an example thread on this forum of why: http://forum.doityourself.com/showthread.php?t=171477

hey cheese, i ahev about gone crazy and i know that oil doesn't freeze i just wasn't thinking at the time if you know what i mean. i am sorry for the mistake and i admit it. on the other hand my friend reccomended using 10w-30 oil and i even checked the briggs and stratton website and they said it so that is why i did. if i have been misleading to anyone i full apologize.

No problem...and no need for an apology...I just want to clarify for those who don't know. 10w-30 is an option that is acceptable for use by most manufacturers, but sae30 is also reccomended and makes all the difference in the world in many engines. Some manufacturers even make note that using 10w-30 will result in oil consumption. I don't use it or reccomend it unless the engine will be run in cold environments.