STEVESRCWORLD

My Feedback: (23)

i have a new 100cc twin that i want to run some on the bench before i put it in my new plane. what is the proper way to do so without overheating the engine?

tim220225

My Feedback: (4)

When I do a conversion or a new name brand engine I just run it at home to get the needles close. Also make sure all is well with plumbing etc and take it to the field. No real need to break one in like a glow engine.

t_driver

My Feedback: (43)

What tim said no need to run on the bench.

DadsToysBG

My Feedback: (35)

I agree with t driver, I you must run it on a bench, run it just long enough to set the needles. It just seems easier to mount the engine on the plane and do the same thing. Dennis

karolh

Ditto that. The best break-in is done in the air.

Karol

t_driver

My Feedback: (43)

By the way what motor did you pick up?

STEVESRCWORLD

My Feedback: (23)

it's the hh 100t. the engine looks very impressive but being it's a china engine i wanted to run it some before putting it in my new g and l hobbies ultimate.

Tired Old Man

My Feedback: (1)

If you're going to bench run it, all you need to do is provide good airflow through the cylinders. A big fan at high speed will do for longer runs. Keep a heat gun handy so you can track the temps. After setting the high and low needles to where you want them there's no need to run at max rpm. Half throttle for short periods, 80% os so throttle for shorter periods, then a little above idle for cooling periods. It's all about heat cycling and it will take about 3 running hours at varied throttle settings and temperatures to complete the cycle. In the air is the best and easiest way, but on a bench makes some feel better about adjusting the needles. Unfortuantely many engines change once the cowl goes on and you have to start all over again.

The only item that's being broken in is the ring(s). The rest is thermally bringing the casting together.

STEVESRCWORLD

My Feedback: (23)

how many gallons of gas at break-in mix should be ran before switching to synthetic? the manual say's that running synthetic oil before breakin has completed will prevent the rings from ever seating fully but it does not say how much gas or how long to run it. i plan on running pennzoil aircooled at 32:1 for break-in.

tim220225

My Feedback: (4)

I run 5 gallons of Lawnboy oil at 32:1 for my engines when I break them in. Then I switch to synthetic at 50:1 ofter that.

Tired Old Man

My Feedback: (1)

Starting with the first tank of gas.

There's absolutely no reason to run common high carbon oil in an engine. If you feel the need to break the ring in as fast as physically possible just toss some sand in the engine Makes about as much sense as using a lower quality oil than what you can obtain for the same price in high quality.

The ring is not the critical item, it's the thermal cycling. Doing it right and not scraping it down in the first few runs matters, but it's not the most important break in factor. The cylinder lining is a lot harder than the ring and doesn't really wear. If it did the cylinders would have to be tossed at 50 hours or so since the chrome plating is so thin. Oil has no impact on the thermal cycling unless you don't use enough of it. Then any engine will get frictionally hot , ending it's useful life regardless of oil type.

Three running hours is three running hours for a good break in. The number of gallons it takes to get there doesn't matter.

tim220225

My Feedback: (4)

What are you saying Pat? I am confused. DA states in their manual to run an ashless oil such as Lawnboy for 4 to 5 gallons. 3W says to run that oil for 3 hours. I have read others and they all say the same thing regarding break in oil.

PAPE

remember the guy who has his 100 twin spit out a cylinder head? why dont you check the head bolts and the thread that was made on the crankcase and re tighten with locktie.

and the break in and cycles leave that for engines that don,t use piston rings, if your engine poops it will most likely do it on the plane even if you ran it 3 hours on a bench, thats just the way live is.

If I were U I would disasemble the engine and check all treads, the crank pin, and seals.

Tired Old Man

My Feedback: (1)

I'm aware of what DA says to do. I'm also aware that a fair number of people believe that their 50 is a great running engine. Just goes to show that you can fool most people most of the time. There's a lot of people that believe 3W can do no wrong with an engine. Yea, right. The intentions are good, though. Literally hundreds of 3w engines are broken in at one location every year. I've got a pile of run out 3w's that would outfit every member of a well sized flying club and have quite a few left over. That's just where I'm sitting and there's other places that go through almost as many. Everyone of them has been broken in and run on synthethics from the first flip. All are run against a dyno, and every one is well documented for problems. Needles are "tweaked" based on results of a fuel-air flow analysis. They're run out becasue of the high number of hours on them and the fact they are pretty well abused in flight.

The ashless and conventional oils have been tried and tested over many thousands of running hours, both on the ground and in flight. They have all come up lacking. Some of the well touted synthetics do the same. One privately sold 100-1 synthetic has frequently failed new engines in the first 10 hours of running time. One private label, type specific, engine oil frequenlty won't get certain engines through the break in process before the engine fails. Oil ratios all over the chart have been tested at various ambient and internal heat levels. Synthetics have won out every time. I'm not talking abount one or two guys having a few engines over the course of years, but a up to a thousand engines running tens of thousands of hours over the course of a few years in testing and practical flight. Tear down inspections performed to a microscopic level is part of the process on quite a few engines, performed by propulsion engineers. This is a process that continues on a daily basis in order to find the absolute best product that will provide the greatest number of useful engine hours and the highest level of reliability.

I've covered this ground before and I know there's no way all will believe it. Someone will always be out there saying they run the oil that they obtain mail order, used 100-1, have used it for years with two flights every other week or so for ten minutes at a time, and it's works great. Stop and figure how much time is on those engines and guess at the severity of use the engine experiences. Not much and not severe. Then contemplate how much useful data could possibly have been obtained from the flight process when the owenr was concerned more with flying a good pattern or a nice torque roll rather that concetrating solely on the engine.

Go ahead and use that ashless oil on your new engine. Get another engine of the same type and break it in for double the number of hours that the ashless engine was run. Tear them both down and take a very close look at the wear patterns. With one the heavy carbon accumulation will be the first thing you see even though it only ran for 1/2 the time of the other. Not very scientific but looking closer will tell you a lot more.

They're your engines and only you can determine how long they will last and how well they will perform over that period of time. I know what I see and experience every day, 7 days a week, and I'll go with what I know works the best.

t_driver

My Feedback: (43)

Even Bobby at CA will tell you go synthetic from the start . Or atleast thats what he told me..

STEVESRCWORLD

My Feedback: (23)

pat, how do you fell about mobil 1 2t racing oil? it is easy for me to get. i would never run amsoil in anything i own.

Tired Old Man

My Feedback: (1)

Use it, mix at 50-1, and enjoy. 70-1 if it's REALLY cold when you fly.

arobatx

Hey guys, have you seen that Mobil is discontinuing the Mobil 1 Racing 2t? I contacted them, and they responded with the following:

"The Mobil1 Racing 2T was discontinued due to lack of sales and overall intrest for the product. Mobil does not have a replacement or equivalent product at this time."

....Pat, have you heard about this?

Chad

tim220225

My Feedback: (4)

Sounds like you are talking about recon planes and engines. Many oil choices and many engine choices too. DA, 3W, BME, conversions or whatever. Not that long ago there were no synthetic oils to speak of and these things have been running for many more years than the 45 I am old. Like everything there are opinions we all have, good or bad, right or wrong. Make a choice and go with it being the bottom line. Nobody in this hobby has the time or money to test like that, us nor the manufacturers. Only the G Man could underwrite studies like that. We have a few guys here that run the cheapest oil they can get at Wally World or the Dollar Store and they have no issues. Not that I am advocating cheap oil but another example of what works.

Tired Old Man

My Feedback: (1)

Tim,

You are correct in your assessment of where and how the testing is taking place. Lot's of flight hours and big bucks behind the process that involves every day engines. A very large number of the improvements and increases in displacements the hobby industry is seeing are coming from information developed and disbursed by people in the areas you noted. I can't think of any hobby engine manufacturer that has the funds available to independantly obtain the developments that are being incorporated in their engines. That's as far as I can go with that train of thought though.

It's nice knowing that we get to enjoy some of the trickle down effects of that here in the hobby.

karolh

I don't need to try and re-invent the wheel, so if anyone does intensive and well documented oil tests that proves what works best, and shares the basic do's and don'ts, then that's more than good enough for me and my little jewels to go on.

Guess it's downright impossible to convince everyone what's best .... to each his own.

Karol

BBW Walt

My Feedback: (11)

Hey Pat Roy, What oil and mix ratio do you personally use in your engine's. From the postings/information listed here you may just be the guy to ask. Walt

STEVESRCWORLD

My Feedback: (23)

yea pat, i'd like to know that myself. i really like the mobil oil. i have been running it all summer in my fpe 95cc and it is running very clean.

karolh

Pat, though you have said it many times right here on this forum, for the hobby's sake do it one more time. You all listen up and heed his words.

Karol.

Jake Ruddy

My Feedback: (40)

I would bet the answer will be Penzoil or Bel-Ray 50:1 but I have been wrong from time to time