Hobbsy

My Feedback: (102)

Saito fans, the 1.50 doesn't look so big on a 12 Foot TeleMaster, It looks like an 18x6 will be the prop of choice. The 16x8 Mejzlick looks kind small on there. I'll need a longer exhaust pipe, easily done. The Pull-pull for the tail wheel is already rigged up and very precise.

Rudolph Hart

A nice neat looking installation,did you consider an inverted mount with a short shotgun pipe out the bottom now that the 150 has been tamed a bit with a cdi ignition ?

That looks like a trickle charger hooked up to your bike,personally i like the colour scheme.The lams (learner approved motorcycle scheme/power to weight ratio) is so big world wide harley could not ignore it.The 500 is being made in asia so we read.

Thanks fnq i'm onto it.

acdii

Looking towards the future, what would be a good pair of engines for a 1/7th scale P-61? I have been leaning towards a DLE 40 twin, but the sound of 4 chainsaw engines going is bugging me, and would prefer the sound of 4 strokes instead. I like the economy of gas though, so fuel efficiency it tops of the list too.

Hobbsy

My Feedback: (102)

Thanks Pete, no, I am not a fan of inverted engines, I did consider a side mount but it looked like the cowl cheek would fall right where the Turboheader screwed on. The space behind the firewall is huge, plenty of room for the tank and the ignition system. The receiver can be about a foot from the ignition.

Yes the bike always has a Battery Tender Plus on it, the security system is a constant drain. The Tender Plus charges the battery to 15.6 volts and float charges it at 14.4 volts. I never connect it the day I ride, connecting a charger to a hot battery doesn't seem like a good idea. I give it a night to cool.

acdii

Well I flew my P-51 with the Saito 100 GK, and what a nice engine. Really good running engine. I flew without the cowl, and plan to put it on before the next flight to hopefully put the CG just right, it was a touch tail heavy with the gear up, but with gear down and flaps it flew nice. Once I install the cow is there anything I should do tot he mixtures, or just fly it? I have it on the rich side now, lots of smoke and a healthy dose of slime on the wing. Not a single burble, stumble or falter, just smooth running on 15% Wildcat.

Rudolph Hart

Two fg57's would go well in the p61.If you post a pix of the mustang with and without the cowl you would probably get more helpfull comments and suggestions.Sounds like you are having good fun with it and fitting the cowl without changes would be the way to go.

Anybody seen sammy ? i was wondering whether he has pulled his saito 50 out of the bath and reassembled it or has the f4 qualified jet tech wife taken over?
I hope he has'nt upset her because she's capable of hotting up chainsaws i bet too.Imagine the last sounds you ever heard were made by a two stroke !!

jeffie8696

I want to see photos of the cow after its fitted,,,,,,,,,,,,,,,MOOOOOOOO

slamn sammy

LOL... l'm still here OldFart! l had to run the streets yesterday. Wen't to Walmart, Hobby shop, (Dang! Hobby shop closed! Forget it was the 4th of July) Washed my truck and trailer, cost me $10.00! Trying to kill ant's! I don't know why they like model airplanes? Spent two days unloading the trailer, four days killing ant's, today I'm planing to reload trailer so l can get into my shop!! Seen one of thaw's Ryobe four-cycles in a Focker IV? (biplane not try plane) and it was a dog! He said that it was a 34cc gas. Sounded cool, just not the power I liked. Hope all is good and all is having a good Holiday! P.S. I asked the little woman about putting the Satio back together. She asked me "If she had to go out side to do this?" When l said yes! She just wen't back to her Facebook games. No answer? Guess Not? LOL.... Got to be nice to her, Hopping to go flying sunday and I also spent $212.00 friday for airplane junk at the hardware store (Bolt, Nuts, Etc, for a build. + Filling up the truck and washing things) Watching new season of Top Gear USA. Fixing to get off my duff & get to work before it gets HOT! later guys. Have a good weekend-holiday.

acdii

Well I dont have one without the cowl and its too much a PITA to take off.

Rudolph Hart

Acdii that looks really neat and tidy.Lots of air thru the engine not that they need that much when tuned correctly.I would'nt be worried about the engine overheating can you post a pix of the whole aeroplane?

Dave i've been thinking about that upgrade kit you mention above.If it cleaned the midrange up do think there may be a difference in the lsn seat/taper?

Fnq would you believe it's been so windy today i can't get the shed door up safely.Pouring rain,howling winds and freezing cold man,i'm mixing my scotch with hot coffee.

Rudolph Hart

Would it be in an old post somewhere here,a link to a discussion on how much air an engine sucks in through the carby for a given displacement and rpm ?? i ask because i study the way baffling works around our saito engines and people quite often have cooling questions they put forward.In relation to gas saito's it becomes more important and given the position of the carby behind the engine i would like to have a figure i can calculate(how much air it sucks ) when you sit down and design a baffling! system because i like to do them simply and effectively without overthinking things to much.cheers

Hobbsy

My Feedback: (102)

Pete, unless I'm completely around the bend on this, I came up with a figure that may be in the ball park. Lets use a Saito 1.00 and give Saito credit for having a pretty good induction system. Now, lets give it a Volumetric Efficiency rating of 95%. I think that's close to reality. OK, 9,000 rpm sounds like a reasonable rpm at full throttle. 9,000 rpm equals 4,500 intake strokes per minute. That's 4,275 cubic inches of air per minute, but we need to knock off a certain percentage of that which is displaced by the fuel. Am I all wet,

slamn sammy

Acdii, Man that looks good! I have been installing baffels for years. Make sur that the exit is bigger then the inlet hole,, the exit hole will make a vacuum and suck the hot air out. I had a rash of overheatting on some aircraft, T6, F4u, Su 26, ETC. l found that the hot air was just going around & around & not cooling the engine at all. Did you ck, the temp, before & after? My wife has a RCAF Chipmunck & l installed a Magnum 120 in it and cowled it up before l ran the engine (BAD MISTAKE) Burned up the engine, DUA! Now l got a DLE 20 RA, have not ran it with the cowl on it yet. First flight was a tune up flight & l fluw it without the cowl & on landing the left landing gear block came out and have repaired it, not flown it yet. It's a old Fly Boy Model. The cowl has a small hole in the front and the hole bottom is removed, hope it will cool??

AeroFinn

You may end up with troubles unless you create an arrangement such a lip on the leading edge of the hole in the bottom of the cowl or preferably a louver to cover the hole to ensure a venturi to pull out the hot air. This is as important as is baffling the engine to force the air go through the cooling fins.

This is a good source learning more about engine cooling:

http://prme.nl/forum/viewforum.php?f=18

-Artto

slamn sammy

Ya, l have seen that dun before, may try that! Don't need to trash a new engine. Thanks! :-O

SrTelemaster150

Fabricate a cold air intake to get fresh air from outside the cowl.

blw

My Feedback: (3)

The exit hole ratio varies, but you probably can't go wrong if the exit is 4 times larger than the intake size. Maybe even smaller if you have good cold air like SrTelemaster says.

blw

My Feedback: (3)

The link that Arto put up is Pe Riever's work, and is excellent. Well worth looking at. Thanks, Aerofinn!

acdii

The baffles I installed run from the engine mount all the way to the bottom of the cowl, so the air coming in the front opening of the cowl is forced past the cooling fins. Only the rockers stick out of the cowl, and the rest of the cowl is opened behind the engine, so it should cool just right. I may throw my T1000 telemetry unit in it and hook my iPad up to check temps. Provided of course I can find the correct harness for it, I think it got damaged in the wreck of the 4*120 a couple years ago.

AeroFinn

I think we all miss Pe and his contribution to this hobby..I remember having spent one whole evening just reading through the material published in that site. It was a time well spent!

blw

My Feedback: (3)

Yes, he was friendly, interesting, and tolerant. He is very much missed. I became used to being able to PM him and get a reply quickly on many, many issues. His knowledge base was broad and I don't remember him ever stating anything that wasn't accurate and correct. He could come up with some interesting things!!!

SrTelemaster150

I was speaking of a cold air intake for the carburetor.

acdii

If the P-51 is converted to an A model, the cold air intake could be the scoop on the top of the cowl. Would make an interesting project.

Rudolph Hart

Thankyou dave that's good arithmetic,that is a lot of cubic feet per minute being sucked behind the cylinder.Thank you everyone for your interest and answers it is always something worth getting right when you cowl an engine.

Arrto thanks for the link to pe reivers site i've been reading it for years.I still re read it to better understand what he was saying.You are right he is sorely missed.

Rudolph Hart

Acdii would you make a special venturi on the cowl to suck air in or do you think the sheer amount of air the carby sucks would nullify that or even improve the situation if you just cut a ragged inlet hole into the cowl ? and what effect if any would that have on the tuning at different aircraft speeds.Not trying to complicate anybodies enjoyment re tuning just thinking out loud.A cold air inlet is easy to make and some silicone tubing is easy to bend onto a saito carby mouth,especially if you have the trumpet fitted,or something like dave's copper pipe extension fitted to the carby throat,easy to fit some flexible fuel tubing over that.

Is cold air that desirable on a methanol engine anyway? as the mix is damn near frozen when it hits the combustion chamber anyway ?

Would you rather have the carb suction work for you re baffling and draw incoming air tighter around the cylinder and aid cooling ?