Rudolph Hart

No no no popey my friend.Pearl3's pic of that cowling is nice and no huge cutouts are needed.These engines run really cool on ice cold metho..which reminds me i need another drink..hic

Hobbsy

My Feedback: (102)

Aww man, I went and wasted a .62.

Hobbsy

My Feedback: (102)

I made a new Saito timing tool, just a piece of Sullivan Golden rod and 2/56 connector cut down. It's very precise.

blw

My Feedback: (3)

I've not heard of the air exit hole size being that small (twice as large as the intake). Usually, it's always around 4 times larger. It's really a 'rule of thumb' as far as I know, so let the 4 times larger be your guide as much as practicable. Just having a big hole in front doesn't magically fix heat issues either. The air has to be directed to flow around the engine to carry away heat.

SrTelemaster150

That's what I have always been told. 4x

FNQFLYER

Re cooling all that has been said above is correct. Re exit "holes" on the cowl consider the following on most a/c fitted with piston engines, radials to be considered here, there were fitted things called gill cowls (or flaps) the actual cowl was usually set up for max cool when the flaps were open and closing allowed the engine to maintain operating temperature. On Russian engines that actually had louvres mounted on the front of the engine that stopped air flowing over the engine, if the place is that cold I don't want to go there. That being said I subscribe to the max airflow through repeat through the cowl. Big inlet smaller outlet will back up hot air in the cowl. Likewise if the air isn't directed onto the cylinders then it is doing little good, use baffles as required and of course have the right oil to fuel mixture and don't run lean.

RC_Fanatic

My Feedback: (1)

When I lived in Canada, the Volvo sedans and station wagons came with a blind in front of the radiator that you could pull up with a chain from inside the car! I don't live there anymore and do not miss the cold.

acdii

Don't be dissin the LT-40. I love flying mine and would not hesitate putting a Saito on it. Then again, mine is no longer trainer worthy, its not as forgiving.

As for cooling, here is a post I made showing the cowl opening for my T-Clips with FG-11 Saito in it, http://www.rcuniverse.com/forum/arf-...l#post12010463

The bottom of the cowl is open all the way across at the back by 1/4", and it is baffled to force air over the cylinder. Not heating issues even on 100* days.

the pope

I dont know why people hate trainers . There cheap ( like me ) , can do just about all that any other plane can do and I also wouldnt hesitate to put a 4stroke on one . One of my all time favorite planes was a phonex classic with a OS55 on it . At one stage I was going to get a Jett engine and put on one . Maybe beef up the firewall and wings a wee bit . That would be a hoot . Sorry OF but that plane needs more cooling and the other posters are right in that baffles are sometimes needed . Maybe lovers on the out let as well . Im speaking generally here . Im not so sure that the outlet needs to be x4 of the inlet though . Perhaps someone can explain why , if its because hot air expands I cant see that it expands that much .Maybe someone will come up with a formula and like a constipated mathematician will work it out with a pencil ! Cheers

Rudolph Hart

Yes you did dave that has to be the ugliest trainer i ever seen with a saito sticking straight up like that..if you had an an old steam traction engine it's probably ok.You'll run an apc prop right?

Popey well tuned saito's with a drop of castor run cool.If the exhaust elbow is out in the air as it is in pearl 3's pic all is good.If you run gas that all changes and you need good suction on the outlet lips and well directed airflow.

Hobbsy

My Feedback: (102)

My most flown plane is an old RCM 40, that has seen a variety of engines, Saito .40, Saito .45, Saito .56, a MERCO .50 and even an Irvine .40 Diesel. The LT 25 wears a Saito .30 and the ancient Joss Stick wears a .90TS.

Cougar429

My Feedback: (3)

For most of us, the exit is generally required to be a MINIMUM of 3X the inlet, but as stated, you should direct the air over the engine to maximize cooling. It will always find the easiest route and that engine in the way is not the direction it will go if left on its own.

NOTE: Some full-size aircraft have louvers to increase the exit area and create that low pressure area during ground ops when minimal forward velocity. This was easily seen on large radial WWII machines and at the back of the scoop on the Mustang, (that could be selected either manual or auto, the first being preferred during ground support since you could see a compromised cooling system a few seconds earlier if the system did not hide it in Auto).

But I digress,...With high power requirements and with low operating airspeeds, such as with piston helis like the S-55, an "Augmenter" could be installed, basically a jet pipe where exhaust was used to create low pressure flow from within the cowl.

Those cowled radials work with the same principle on the front, where the inside lip was used to create a ram effect, yet just aft of that lip the air slowed down and pressure increased.

You can copy some of these tricks to help flow along. One is to try and set up a low pressure area at the exit point, something I did with the cowl on the 'Bolt by adding the fixed lip.Rare Bear seen in the second pic has outlets fit into the fuselage sides aft of the cowl to do the same thing, (it also keeps the rather draggy exhaust within the aircraft profile).

Dave, I will have to try that timing tool trick. As most of us likely have those common items laying around, saves fabbing up a specialty tool and costs practically nothing at all.

Hobbsy

My Feedback: (102)

Thanks Cougar, maybe Dan can check in here and say what size control rod he used for the big block Saitos.

SrTelemaster150

It doesn't work for big blocks. They have a nail head tappet that can't be removed with the cam in place.

For big blocks I cut a rectangular notch in some brass shim stock that just fits snugly into the teeth on both sides. It works on the same principal as the x-acto knife blade, but engages the teeth on both sides & it stays in place until you pull it out.

After the housing is in place you can slip the rear screws into place before pulling out the gauge.

You need a slightly wider notch for "A" big blocks compared to "B" big blocks.

Hobbsy

My Feedback: (102)

Thanks Dan, I keep forgetting that fact.

the pope

http://www.flyinggiants.com/forums/s...92#post2473327

p3arljam

My Feedback: (5)

Can anyone tell me if this small piece of tubing/sleeve comes from a Saito 100?

spaceworm

Google up the " Saito Small-Medium Single Cylinder Manual" It includes the FA-100. An exploded view with parts identifiers is included in the back of the manual. I took a quick look and could not find any similar parts, except part number 26, which is called the crankshaft collar. But, take a look yourself. Good luck.

acdii

I replaced the crankcase on mine and dont recall seeing a piece like that.

Rudolph Hart

Nope but i'd like to steal your longnose pliers.

Cougar429

My Feedback: (3)

Have to concur. Someone may have added it along the way, but with MANY 82-100 tear downs there is no function I can think of for it.

p3arljam, if you have any difficulty finding that manual send me a PM and I can boot it off in .pdf format.


Those pliers are available from McMaster-Carr or Acklands. I find those and a pair of hemostats pretty much indispensable when fingers are less flexible as years, (and injuries) accumulate.

the pope

If it fits on the crank maybe it was used to shim out an oversized prop hole . cheers

FlyerInOKC

My Feedback: (6)

That makes a lot of sense.

the pope

Sometimes but not too often I do . cheers

SrTelemaster150

Need a roach clip?