SHOUTING IS ALL CAPS

SHOUTING IS ALL CAPS!

Bold is just for emphasis,

A programable system W/only one high voltage circuit will be more compact & lighter.

were they going to run the engines on spark with glow fuel or spark with petrol/gas?

I m doing it for petrol..

The main reason for this project is to develope the ignition system, the gas conversion would be secondary. I would imagine that they would want to do both conversions.

You would still have the option of retaining glow fuel if you liked.

BTW: the E85 experiment is making some progress. I only lost 200 RPM over glow fuel on glow ignition in the FA 150. 7500 RPM W/a Dynathrust 18X8 prop. Lowest reliabale idle was 1400 RPM, the same as glow fuel/sprk, 300 RPM lower than glow ignition.

I found that I could advamce the ignition timing to > 35* BTDC W/E85 & the RPM picked up 300 RPM over the standard 28* BTDC setting.

The carb adjsutments were very touchy & required fiddling w/even slight changes in conditions. Making a more gradual taper on the main needle & installing a demand type regulator should help.

Over all, it seems to be a viable alternative W/less HP loss over gasoline/petrol.

if i was going to run spark i would stick with glow fuel as it means i dont have to change the carb. i also get the best power. the funny thing is regarding your idle rpm numbers on normal glow i can get a laser 360v down to 900rpm, i cant imagine what spark would do to it!

Spark ignition on glow fuel is well worth it, especially when on board glow is being considered.

The weight penalty of EI is probably not any higher than OBG. Since OBG has such high amp draw the batteries required would probably weigh as much as an EI system, 4.8v battery pack & all.

The HP boost is substantial on EI/glow fuel. I picked up about 150 RPM, right in the middle between the FA 150 & FA 180 running glow ignition (7700/8000 respectively) & if the glow fuel on EI responded to more spark advance like the E85 did, the gap might have been closed even more or even eliminated or surpassed. The 28* BTDC initial setting is probably a value that is optimal for gasoline. The much higher octane of methanol would most likely allow more spark advance & more HP output.

There's also the added fuel economy. I gained 23% longer run time & if I had been running a more approprite 16 X 8, I think my results would have been more in line W/the 60% that I remembered from way back when I 1st started running EI in '97.

Last but not least is the increased user friendlyness. If your Laser 360V idles @ 900 RPM now, it would most likely sound like a Harley Davidson Big Twin on EI, & starting would be a dream! I hope to eventually convert all of my 4-strokes W/the possible exception of the FA 91 since the aircraft it is going to be powering might not have the space behind the engine bay.

So, has anyone worked on an FS400AR lately?

I want to paint the front hub/ cover. What other parts would I have to dismantle to take it off ?

Removing the front of the engine would be a major disassembly. There are a lot of parts either inside or connected to it. Retiming the engine would be difficult.

I recommend removing the pushrods and pushrod tubes, then masking off everything except the front cover and then spray painting it.

I am building, well restoring an airframe for my 400! its almsot done :P and i agree with knot, if you are unsure about taking the engine apart then dont do it.

I also bought another airframe that the 400 might go in first. the model is a mahers pacer with 82'' span, but i think the 400 will be way over the top for it....i will see how i feel about it, i may use it for testing the laser 240v thats going in the P39....but i have a 300v that needs testing, and thats same power as the 400...hmm...so many choices. whatever i do it needs new servos as 2.4kg futaba 3001's aint gonna cut it. i may also have to do some ritual sacrifice of the engine that came with it....a 45cc two stroke side intake piston ported petrol engine....blergh i feel dirty just talking about it! quick, find a propper engine....ooh, a V twin, thats better *cuddles engine* :P lol

Thanks guys, I will mask

I have removed the front without taking off all the cylinders.

After I changed the bearings, and assembled everything (which takes a LONG time, and the exhaust collector ring is a B**tch to install) , I could not start my engine.......
I guess that maybe the timing was off, and I needed to check out the timing marks on the timing gears.

I was a bit angry with myself, and decided to remove the rocker arms, and take out te pushrods, then undo the bolts that hold the front cover, and removed the cover.
It came off quite easy.
Assembling it all is another matter, as you have to make sure the gears inside, and the pushrod covers all fall into place at the same time when pushing it all together again........but it can be done

I would not reccomend it unless you have had it all dis-assembled before, and know what is going on inside the engine though....

i managed to retime my engine with relative ease with kmots very helpful photos at the start of the thread, you do however need more arms than an octopus to get everything in the right place!

Im not critisizing anyone just saying if its my engine Ill decide what happens to it. Why dont they say who they are its not rocket science and if they want a engine tell people who they are , im sure thats more upfront and if they get swamped with offers well thats better than getting none . Im sick of all this fan boy B.S. Cheers the pope

Well said pope. If it quacks like a duck, walks like a duck...

Ok play nicely children. I think we should let sleeping dogs lie and get back to talking about engines.

With that in mind i have a question for the masses.

The other day i picked up a Mahers Pacer with a span of 84''. first off i wasnt going to use it for the radial the i dida dummy install and the model just looked really mean, even with the crappy covering finnish its currently wearing. also the c/g didnt seem half bad (the model has a short nose) and exhast routing didnt seem a problem. The only thing holding me back is that the model is designed for upto 150 four stroke, and while im sure it can take it, i was just wondering if anyone had any first hand experience with this model

Ok guys have a look at this..I not to sure if to will run smoothly as it will be getting the blow by past the rings into the crank case that the intake has to fire on..
Its also in French...

http://www.rcgroups.com/forums/showthread.php?t=1630537

Looking forward to seeing it run.
Im guessing it must be more difficult to start, since you will have to fill the whole crank case with the correct fuel/air mixture before it will fire......

My ASP 180 has the blowback oil fed right into the intake, and injested into the engine again, and it runs realy well.


The spark ignition will be nice
http://www.rcuniverse.com/forum/m_11035561/tm.htm

I am not a fan of that concept as you will be taking hot air, probably with some exhuast gasses into the intake. This will not be good for power and it may also make the engine hard to tune as the relative mixture will change with engine temperature. Also the intake of coolair will help cool the cylinder and as a result the engine. On all my 4strokes if i touch the intake pipe when at full power they are cold, and sometimes even covered in moisture or ice (inthe winter) because thepressure drop of the intake stroke has cooledthe air even further.And as pointed out already i think it would make it harder to start. And while my os engines have the crankcase air recycled in the same way as SJN's ASP thats slightly different to having your entire fuel charge in the case.

I do look forward to seeing it run however, it should be interesting to see

*
Well, that system seems to work just fine for the Seidel-UMS-Evolution radials. That's why they only need 6-7% oil mix in the methanol. I believe the Moki radials are the same. They run 32:1 mix.

The fuel-air charge in the crankcase is constantly being drawn in, used and replenished, lubricating and especially cooling the engine from within. Wet sump engines rely heavily on the oil to take the heat from the underside of the pistons and other internal components. The oil is actually part of the engine's cooling system.

Our small engines are not lubricated by "blow-by" as such, but by the oil film on the cylinder wall finding its way down into the crankcase because the ring can't scrape the oil off the cylinder wall and keep it just up in the combustion space (Luckily). If there was blow-by, especially on a multi cylinder radial, the gases would be blasting out the crankcase vent. Usually there's just a drop of oil every now and then.

The opinions being posted don't seem to be based on any experience. Exhaust gases in the crankcase? Only if they forgot the rings! Why should they be harder to start? Every 2 stroke takes the fuel mix into the crankcase first, and manages to run ok.

EVO radials are no harder to start than Saito radials. And if you do it right, they will all fire on the first flick... or so. Just like most engines.

Regards, RossG
radial1951
_____________

Crucially two strokes have clever passges linking the crankcase to the cylinder, a 4 stroke dose not and so the only way for fuel to get into the upper cylinders is for it to go through the inlet valve. Also exhaust gasses will get past the rings on almost all model engines and piston ring blow by is exactly how the oil gets into the crankcase, but the amount blown past is only very small otherwise you are correct in saying it would be blasting out of the breather (although on my radial the rings and valves leak like sieves). On Laser engines there is a 2nd ring on the larger engines, an oil ring, to help 'pump' oil into the crankcase. its very effective and can be seen in operation if you ever take a laser apart and have a look inside the piston while moving it up and down the liner.

andi agree that on wet sump engines the oil is a coolant, and the same is true of a model two strokes and why the heli boys run alot of nitro. All that extra liquid cools the engine from within, but in the large volume of a radial crankcase i cant see that it will have any effect. Also throttle response may be worse due to a reduction of velocity through in the intake. Fianlly, has anyone tried running a 400 on the same oil as the evo engines? because the amount of oil that pours from my breather leads me to think that thr 18% they suggest is over the top. Iknow that the larger laser engines (120,150,180,240v,300v,360v) can be run on 10% oil without a problem (15% is recommended for safety though) and someone has even run a 150 on 5% oil without an issue. When i get time i will build one and run it in with 18% and keep reducing the oil until it dies just as an experiment. If anything will go it will be the big end bushes so it will be quite obvious!

Nice size Corsair for the FS400:

[youtube]http://www.youtube.com/watch?v=di_o6Ali58A&feature=g-u-u[/youtube]

Looks like it flys well in the BHCorsair. I wonder why Top Flite does not recommend a 5 cylinder radial for it's giant scale Corsair, which is just a little smaller.

From Tower Hobbies (www3.towerhobbies.com/cgi-bin/wti0001p):
<pre>REQUIRES: Engine: Gas 2.5-4.1 cu in (41-70cc) Glow 2.1-2.8 cu in (35-45cc) (do not recommend 5 cyl radial)<span style="font-family: Arial;"> Sorry if it's a dumb question. I'm a noob.</span></pre>