Hobbsy

My Feedback: (102)

FNQ, in my roughly 45 minute test today the .65 turned the two Bolly's very well

Engine==older blue and white box, plain .65 Saito
Plug=====Taipan 4c
Fuel =====WildCat 15% with 18% 80/20 blend
Muffler====Davis Diesel SoundMaster in cowl
Bolly 13.5x6========9,775 rpm
Bolly 12.5x8========9,725 rpm

Still no pictures.

Rudolph Hart

Awesome explanation thanks much mate i figured that,but i have a question.Seeing as you are flying those engines pretty hard on an open/no tightly cowled lanzo(yuk yuk yuk bomber how would you go about cooling if it was cowled and working that hard?

FNQFLYER

Cowling??? what's that.  I try to hang tese engines as far out into the airstream as possible. O/T rules with Bombers and Playboys is pretty open in that regard.  My ARF Bomber has no Cowling and a French built one has full chin cowling (It is used with mostly Enya 41 diesel  4 strokes.
The engines are mounted vertical and most definitely not inverted, some guys use side mounting.
These engines can last a long time, they are rugged, and if one handles them carefully and has a good supply of bearings (and later Loctite) they runindefinitely.

FNQFLYER

Hobbsy interesting figures try the following
1/ Ditch the 12 inch prop
2/ Try 20% nitro and 20% Klotz or your preferred equivalent, if you can get the Heli oil try that
3/ Tune the engine on the ground until you get just a trace of smoke from the exhaust
4/ Put about 3/4 throttle (linear) on it (engine running)
5/ Take off at about 75 degrees open the throttle and go vertical.  Be careful to do do the dreaded aerobatic manouvre called "the figure of 9" 

Let me know the model and your thoughts, I am interested.  I do the above with either a 85% Bomber or 105% Playboy and get a mild adrenaline rush.

FNQFLYER

Hobbsy that should read
1/ use 13 inch prop
2/ Don't do figure 9 manouvre

Rudolph Hart

Remember that old song 'love potion number 9'

Rudolph Hart

Hi hobbsy it's pete.That 65 you tested the other day..do the old/new ones have a higher compression rating or different cam? the reason i ask is because they really look like good numbers cheers mate

Hobbsy

My Feedback: (102)

Pete, I have an early high compression .80 that turns a Scimitar 13x6 at 9,900. w8ye may know if there are different versions of the .65. My .65 is perhaps an early 2000s black and gold box.

Hoorah, we have pitchers again. Picture #3 is the day I broke it in at 40 minutes run time not quite peaked.

RH

"The engines are mounted vertical and most definitely not inverted,"

Could you expand on the "Not Inverted" part a bit?

I currently run a Saito .82 and .91 upright and they run great. I recently came on a deal to pick up a .40, .56, and a 1.00 that I couldn't pass up. A couple of the possible applications I was thinking of trying would require the engine to be mounted inverted. No one in our local club that I've been able to ask seemed to have a well founded opinion on whether or not to run a Saito inverted so I was about to pose the question here. Your comment was well timed. Perhaps you can give me some tips on this question.

Rick...

w8ye

My Feedback: (16)

If fuel puddles around the glow plug in a inverted situation, it is hard to get them started.

w8ye

My Feedback: (16)

I've been around several Saito 65's and none have been materially different from Hobbsy's. The differences usually include the throttle arm, muffler, glow plug, length of crankshaft, etc.


There are hints of air bleed carbs, high compression, and low lift cams but I've never seen one or even a picture on here in all the years I've been on the Internet.

The 65 Hobbsy has, will run very well with a lot of torque. People that own them think highly of their possession.

FNQFLYER

Ok in answer to questions and comments
1/ I mount my Old Timer engines (read Saitos) normally (in 99% of cases) because there is less "complications" Simple installation and straight forward rigging and running.
2/ Saitos mounted inverted (and I do in sports / scale models) benefit from being "offsett" to have the exhaust valve at the lowest point, this allows any accumulated oil etc to be expelled when you turn the engine over prior to starting.  When the model is in long term storage I put an old glo plug in the hole and throw it away when I go to use it again..  On initial start up with a regular use model I leave the glo power on for a little bit prior to introducing fuel (at reduced amperage) to burn of any left over gunge prior to starting.
3/ Most of my 65's are like Hobbsy's early ones, in the black and gold boxes.  Good engines though some of the old fraternity think they are over compressed feel the need to add washers at the cylinder base to decompress them.  This comes about because they "throw props" because they are being run to lean
4/ Those RPM with the 13x6 Scimitar are about right but can be fiddled with nitro, and carbon fibre props

Hobbsy

My Feedback: (102)

You'll not find me lowering the compression, my 1.50 has 15.5 to 1 compression and my old .80 has 14.56 to 1. Compression ==torque. I say, why reduce the torque and efficiency just so you can run higher nitro further reducing efficiency and increasing fuel consumption. That's just me though.

FNQFLYER

Re reading previous pages posts, Old Fart on cooling I use the rule of exhaust (hot air) outlet is twice or more the inlet size.  Use air scoops on scale make them real not pretens and have the exhaust air exit under the a/frame.  I've been known to use one of the exhaust pipes on a radial engined model as a hot air outlet and of course you can run the engine a little richer than normal and let the fuel do some of the cooling. Remember the sight of the moisture forming on the inlet pipe during running in???
On props, the 16 x 6 or 8 is usually an APC and we rely on the weight of the prop to give some inertial effect to the engine operation, that is sucking every last mil out of the tank, remember we are running at low rpm.  Different matter when it comes to speed events though. 
Trust that clears up some of the questions.

FNQFLYER

Hobbsy I whole heartly agree but I do not try to disuade my learned collegues from their obvious well founded actions.

Rudolph Hart

Thanks good reading

spaceworm

Hi Dave, the 130T still is in VA, so you still may have a chance to run it for me. Speaking of compression ratio, how does the 130T compare, and how about the CR for the old 120ABC and the newer 100 and the 180? Thanks and hope to see you this summer.

Vbr, Richard/Club Saito #635

Cougar429

My Feedback: (3)

FNQFLYER, I have to agree on the formula, but would add that 2X the inlet area for exhaust would be the absolute minimum I would recommend. The standard rule of thumb is 3X and due to their comp ratio and power I would suspect Saitos would have to transfer a greater amount of heat through case and fin design rather than dump it out the pipe. Therefore good cooling airflow is mandatory.

Hobbsy

My Feedback: (102)

Richard, here is an excellent test on your 1.30. http://sceptreflight.net/Model%20Eng...20FA-130T.html

One test I foind for the 100 lists the 1.00 at 7.9 to 1, that can't be correct. I'll be back

spaceworm

Thank you.

Vbr, Richard

FNQFLYER

Cougar, the figures quoted were minimums, I have been known as I said to use the actual cooling "vents" (eg chin inlets on P40 and the wing root inlets on the Sea Fury) as actual cooling inlets.  But I agree with as big an outlet as possible commensurate with the needs of the model (eg sports v scale) is definitely the way to go.  Have you ever seen the lengths our electric brethern go to to "keep their cool".  In fact they provide good ideas and guidelines for cooling.

FNQFLYER

In the February 2013 edition of the english magazine RCM&E there is an article by Brian Winch about running petrol engines (gas) specifically the Saito FG 20 using glo power.  If you can obtain it it is worth te read.

Rudolph Hart

Personally i'm sick to death of hearing about how electric flyers seem to laugh at fourstroke engine guys because they say they don't have tuning problems and the so called slime that goes with it.Many a good laugh at the local club has been had watching that brand new 200amp speedy smoking up along with the humungous wreakage trail and resulting small bushfire after the crashmind you there is usually lots less to carry back.

Hobbsy

My Feedback: (102)

Pete, you mean that there are actual electric powered planes. Never saw one at my house.

hsukaria

I was made aware of electric negatives two weeks ago when a club member brought his electric plane to fly and the motor sounded louder than expected. Apparently, the bearings on his motor are worn out. So, to him, it was a toss-up whether to replace the bearings or the whole motor. To me, that just demonstrated that motors just don't have the appeal (or soul) that IC engines have. With our engines, we would make a big event about replacing the bearings, debating what type of bearings, talking (arguing?) to people about it, testing them, cleaning them, tuning, etc... To the electric guy, he just tosses it and gets another one.

I think that these engines are a hobby within a hobby. You got the engines and then the plane and radio. The electrics have one big dimension missing. (I confess, I have 3 electric parkflyers, so I am not biased that much).