Welcome to Club SAITO !
11-07-2022, 04:49 AM
Big block Saitos do have a more durable valvetrain than the smaller Saitos, namely the tappets.
As mentioned on the other thread on RCG, counter rotation is not required for our model twin engine aircraft or full scale twin engine aircraft. Many twin engine aircraft do not use counter rotating engines.
Keep in mind That when a model manufacturer specifies a 2 stroke gasser 20cc-26cc engine an equivalent 4 stroke glow engine will need to be approx 1.2 times larger displacement to produce the same power. An equivalent 4 stroke gasser will need to be approx 1.4 times larger displacement.
Only you can say.
so
so the 150. or. 180 are the correct choice as to the cc conversion…. what happens when you go radial.
FA-200R3. - FG-33R3. Power Up or down ?
11-07-2022, 04:58 AM
11-07-2022, 06:24 AM
Senior Member
On a Saito 182 twin the distance from the crankshaft centerline to the top of the air bleed screws is 2.1875". I experimented with it on the Rascal 110 and there would have been very little cowl left.
11-07-2022, 06:26 AM
It sure is Dave. I had three of them at one time. Had used one in a Pica 1/5 WACO biplane. Great matchup. Gave them away but don't recall who got them.
Extremely nice engines, many differences from the current big blocks. Most of the design changes in the new engines enhanced top end power and hugely cut costs (and weight).
Multi cylinder engines usually make up for added drag by being able to rev higher due to having smaller, lighter parts. Higher revs give a virtual higher displacement per unit of time.
The rev advantages tend to diminish as engines become smaller.
Extremely nice engines, many differences from the current big blocks. Most of the design changes in the new engines enhanced top end power and hugely cut costs (and weight).
Multi cylinder engines usually make up for added drag by being able to rev higher due to having smaller, lighter parts. Higher revs give a virtual higher displacement per unit of time.
The rev advantages tend to diminish as engines become smaller.
11-07-2022, 08:07 AM
Senior Member
I just ran my Saito FA 30-s with a new RMJ piston ring.
Saito FA 30-s with new RMJ ring and Boca Bearings.
Fuel====S&W 15% with 17% full synthetic
Prop====Bolly 9.5 x 6
Plug====Glo-Devil 4c special
Exhaust==stock muffler
Max rpm after 8 oz fuel===11,200
Max after 10 oz of fuel===11,410 rock steady
Idle=======smooth, steady 2,400
The compression was a little mushy before running, unusual for an RMJ ring, now it is finger chasing snappy. It quit a couple of times at 5,500 while rich, once peaked it never stumbled at any rpm.
Running at 6,800 rpm
A few minutes later it read 11,410 rpm
RPM with a Xoar 10 x 5.
Saito FA 30-s with new RMJ ring and Boca Bearings.
Fuel====S&W 15% with 17% full synthetic
Prop====Bolly 9.5 x 6
Plug====Glo-Devil 4c special
Exhaust==stock muffler
Max rpm after 8 oz fuel===11,200
Max after 10 oz of fuel===11,410 rock steady
Idle=======smooth, steady 2,400
The compression was a little mushy before running, unusual for an RMJ ring, now it is finger chasing snappy. It quit a couple of times at 5,500 while rich, once peaked it never stumbled at any rpm.
Running at 6,800 rpm
A few minutes later it read 11,410 rpm
RPM with a Xoar 10 x 5.
Last edited by 1200SportsterRider; 11-07-2022 at 08:16 AM. Reason: Add picture
11-07-2022, 12:20 PM
My Feedback: (1)
82, 91, 100 Tappet Question.
I had a set of tappets that had slots on the bottom of them, is Saito still making them like that? or is Saito doing something different today?
thanks!
Jim
I had a set of tappets that had slots on the bottom of them, is Saito still making them like that? or is Saito doing something different today?
thanks!
Jim
11-07-2022, 02:10 PM
11-07-2022, 02:18 PM
My Feedback: (1)
11-07-2022, 02:39 PM
My Feedback: (1)
Jim
11-07-2022, 02:44 PM
well I have a set, but they are in my 100 that I moved the breather to the front. when I took the engine apart one of the tappets side was scratched so I ordered new tappets, and these new tappets had 5 grooves cut into their bottoms, the grooves were not deep at all, and pointed outward, the centers of the bottoms were left unmarked. I assumed these grooves helped by holding more oil. maybe there were something Saito was testing, and the excess simply went to market to unload.
Jim
Jim
11-07-2022, 04:06 PM
Senior Member
11-09-2022, 04:53 AM
My recently acquired low time 180 GK ran fine for 2 tanks then started squeling/screeching/chirping. A high pitch metal on metal sound. Thought that maybe the front bearing inner rubber seal had come off or the ring had cracked. Nope, everything inside looks perfectly normal. Hmmmmm.
11-09-2022, 02:56 PM
My Feedback: (1)
I mounted my new cam to the 91's cam housing. it only took me about 3 hours.... 3 hours you say. LOL yes 3 hours.
the first time I mounted the cam to its housing there was a noticeable amount of back & forth lash in the cam. I was thinking that can't be very good for the tappets.
so I had the thought "hey, I have the 100GK shims. let's check them".
so I could see that the 100GK shims are slightly thicker than the 91 shims. so I tried to put the cam back in the housing and use 1 of the GK washers,,,, no go. the cam wouldn't fit in.
hey, I have a brand-new fine-tooth file. so how do you file the thickness down on a rather small washer? very carefully!
so I file down the thicker washer. check the thickness to make sure the washer is flat. Shazam, surprise surpise its flat. so I mount the cam again. but it was kind of tight. I could not feel any lash. yet it turned good and smooth. if I spun the cam it only turned over about 3 times. so I thought "no lash no oil for the shims"
so I removed the cam again and filed on the washer again. check it. its flat. so I mounted the cam again. this time I could feel and see a bit of back lash and it turned even smoother. I must have taken up 1/2 the back lash.
I was able to measure the backlash. it's right at 0.010"~~~~~~~~~ "how did I do that?"
later tonight I will mount the cam housing to the case.
and tomorrow I will mount the cylinder. thanks to our good friend Lonnie!!
EDIT; cam hosing now mounted to the case.
Jim
the first time I mounted the cam to its housing there was a noticeable amount of back & forth lash in the cam. I was thinking that can't be very good for the tappets.
so I had the thought "hey, I have the 100GK shims. let's check them".
so I could see that the 100GK shims are slightly thicker than the 91 shims. so I tried to put the cam back in the housing and use 1 of the GK washers,,,, no go. the cam wouldn't fit in.
hey, I have a brand-new fine-tooth file. so how do you file the thickness down on a rather small washer? very carefully!
so I file down the thicker washer. check the thickness to make sure the washer is flat. Shazam, surprise surpise its flat. so I mount the cam again. but it was kind of tight. I could not feel any lash. yet it turned good and smooth. if I spun the cam it only turned over about 3 times. so I thought "no lash no oil for the shims"
so I removed the cam again and filed on the washer again. check it. its flat. so I mounted the cam again. this time I could feel and see a bit of back lash and it turned even smoother. I must have taken up 1/2 the back lash.
I was able to measure the backlash. it's right at 0.010"~~~~~~~~~ "how did I do that?"
later tonight I will mount the cam housing to the case.
and tomorrow I will mount the cylinder. thanks to our good friend Lonnie!!
EDIT; cam hosing now mounted to the case.
Jim
Last edited by the Wasp; 11-09-2022 at 06:42 PM.
11-14-2022, 07:02 PM
My Feedback: (1)
well guys, I mounted the cylinder on the 91 case Friday. it went together with no problems. and I installed the rockers today. so she has a new cam, new tappets, and new rockers. and the cylinders is very nice.
she turns nice and smooth. I will have to put a plug in her tomorrow and check the compression.
to add. a while back I bought some 91 gaskets off RCG. the guy sent me the gaskets and a BSNIP (Brand Spanking New In the Package) ring. the ring on the piston looked brand new, so I got out my calipers and measured the width of the band in 3 places, and I measured the new ring. the band on the piston's ring was 0.002 larger so I used it.
sO thanks to Capt and Lonnie and about $90 I have a real nice Saito 91 for my son's midget racer.
Jim
hummm. didn't Horizon for a time suggest to burn 30% Nitro in Saito's ? you know I still have 3 gallons of 30% Heli fuel with 20% oil ; ). naa, that won't be any fun.
she turns nice and smooth. I will have to put a plug in her tomorrow and check the compression.
to add. a while back I bought some 91 gaskets off RCG. the guy sent me the gaskets and a BSNIP (Brand Spanking New In the Package) ring. the ring on the piston looked brand new, so I got out my calipers and measured the width of the band in 3 places, and I measured the new ring. the band on the piston's ring was 0.002 larger so I used it.
sO thanks to Capt and Lonnie and about $90 I have a real nice Saito 91 for my son's midget racer.
Jim
hummm. didn't Horizon for a time suggest to burn 30% Nitro in Saito's ? you know I still have 3 gallons of 30% Heli fuel with 20% oil ; ). naa, that won't be any fun.
Last edited by the Wasp; 11-14-2022 at 07:07 PM.
11-15-2022, 02:49 AM
Senior Member
Horizon did that indeed, now everybody thinks that Saitos require 30% nitro methane, nothing could be further from the truth. They run very well on 0%, 5%, I ran mine on 10% for many years, I just recently bought a gallon of S&W 15% with 17% full syn. Good job Jim.
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jamesroutledge (11-15-2022)
11-15-2022, 06:27 AM
Saito suggested the 30% nitro in an attempt to compete with YS power.
Of course 30% is in no way required. Then again, you don't need 20% for YS either.
Of course 30% is in no way required. Then again, you don't need 20% for YS either.
