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Engine basics => Four strokes only => Topic started by: Robin_Holden on November 03, 2016, 01:10:58 AM
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Need some advice please fellas .
Took my Saito 56 out of hibernation. It's a late factory C / L version , which has been bench run in carefully.
It's now in a model.
May I ask your findings please on the following topics :
1. Best prop' ?
2. Launch RPM ?
3. Best fuel mix ? Oil and nitro percentages please.
Lovely engine . Any contributions much appreciated .
Greetings from Harrogate in the beautiful county of North Yorkshire.
Robin.
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Do search on the four stroke list for posts by Bob Reeves, or look up his set up on the Tulsa Gluedobbers web site. It's basically a small diameter intake, large diameter prop with high pitch and low RPM. On my Saito powered Score, I run a 13-6 or 13-7 and have a take off RPM in the 7500 to 8000 RPM range. I discussed this with Gilbert Berringer at Oshkosh several years ago, and it's similar to his preferences and he used a 5 to 6mm ID venturi. Bob's set up uses a screw into the side of the intake to allow you to adjust the choke area and it works out about right where Berringer's numbers were. For props I have used Zinger, Vess, and Rev-Up. Just be prepared for something different! If you go this route you will have to forget a bunch of stuff you have learned and gotten used to over the years! I haven't sold all of my two strokes just yet, but the four stroke is an interesting power plant that you just have to get used to, just the same as taking up electric.
Good luck and have fun,
Dan McEntee
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Need some advice please fellas .
Took my Saito 56 out of hibernation. It's a late factory C / L version , which has been bench run in carefully.
It's now in a model.
May I ask your findings please on the following topics :
1. Best prop' ?
2. Launch RPM ?
3. Best fuel mix ? Oil and nitro percentages please.
Lovely engine . Any contributions much appreciated .
Greetings from Harrogate in the beautiful county of North Yorkshire.
Robin.
Depending on the size of the model a 13" prop may be too large or just too much for the engine. I see 12-6 on most four strokes in that size range. 10-15% nitro is what I like with caster oil blend, 50/50 is most common. Try and keep the total oil content by volume 18% or more, lately I've been using Brodak fuel with 23% oil and it works very well. Also OS Type F glow plugs are the best to use. PowerMaster and Sig are excellent fuels also, lower grade fuels will cause issues.
4 strokes are awesome been using them for years now.
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Haven't visited the forum in a while, recovering from spending 9 days in the hospital with pneumonia.
What Dan said, my experiments and final conclusions are well documented on the forums. Just search for "Saito 56" and you find enough reading to keep you busy for a few days.
This is a link to the Gluedobbers site where my carb mod and set-up are more or less explained.
http://www.tulsacl.com/SaitoCarb.html
I will make a comment about my opinion on using castor in a 4 stroke. Don't.
Run YS-20-20 from Power Master or equivalent, 20% nitro 20% oil all synthetic and use after-run oil.
I've already posted quite a bit on why I say no castor at some time or another on this subject which you will probably run across with the above search.