2 vs. 4 stroke equivalents
05-28-2007, 12:34 PM
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2 vs. 4 stroke equivalents
I am sure this has been discussed before and if you know of a place to find this type of info, please pass along.
I have recently got back into the hobby & was use to my os max 40 & my Kraft, & Super Tiger 60. After watching the guys at the field & doing a lot of research I stepped up to 4 stroke's. Yeah. I have an Ultra stick 40 that I put the Saito 72 into based on an article I read. Awesome..... I have a Saito 100 for another plane (Katanna 70) I am building. I have a small 3D plane for the max 2 stoke is 40, does not suggest a 4 stroke alternative & it is a no name ARF. It is almost really for the motor & the Saito 72 would be ridicules so here’s my question;
What I really would like to know is what is the 4 stroke equivalent for a 2 stroke 40, 46, 60. Is there a general rule of thumb to help determine this? Of course, what would be a good prop for both or maybe a better question is what prop will do what best on the 2 vs. the 4 stroke? I am looking for more 3D & pattern type stuff, not really speed
Tips, help or suggestions would be great
rob
I have recently got back into the hobby & was use to my os max 40 & my Kraft, & Super Tiger 60. After watching the guys at the field & doing a lot of research I stepped up to 4 stroke's. Yeah. I have an Ultra stick 40 that I put the Saito 72 into based on an article I read. Awesome..... I have a Saito 100 for another plane (Katanna 70) I am building. I have a small 3D plane for the max 2 stoke is 40, does not suggest a 4 stroke alternative & it is a no name ARF. It is almost really for the motor & the Saito 72 would be ridicules so here’s my question;
What I really would like to know is what is the 4 stroke equivalent for a 2 stroke 40, 46, 60. Is there a general rule of thumb to help determine this? Of course, what would be a good prop for both or maybe a better question is what prop will do what best on the 2 vs. the 4 stroke? I am looking for more 3D & pattern type stuff, not really speed
Tips, help or suggestions would be great
rob
05-28-2007, 04:19 PM
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RE: 2 vs. 4 stroke equivalents
Rob, for the Saitos, as a very rough rule of thumb, the equivalents for the .40, .46 and .60 sized models are the .56, .72 and 1.00. These equivalents perform similarly to the very best sport .40, .46 and .60 two-strokes respectively. However, some conditions apply....
Each project should be thought of as its own case. For example, for a .46 sized 3D aircraft where aggressive pullout is desired, the .82a might be a better choice than the .72. Similarly, for an extreme .60 sized aircraft, the Saito 1.25 might be better whereas the 1.00 might be barely adequate.
I tend to go with the larger engine options and use throttle control myself. For example, I have a 5.5lb .40 size trainer with a clipped wing that I use for our "trainer racing" series. It's got a YS 1.10 in it with an APC 13x11 prop. It is mindblowingly overpowered yet is docile enough at low throttle for me to train students on, using a buddy box, if required.
The best bet, when you are assembling each model, is to come back here and get some comments back from guys who have flown the very combo you are planning. Sometimes the old rules of thumb don't apply.
Each project should be thought of as its own case. For example, for a .46 sized 3D aircraft where aggressive pullout is desired, the .82a might be a better choice than the .72. Similarly, for an extreme .60 sized aircraft, the Saito 1.25 might be better whereas the 1.00 might be barely adequate.
I tend to go with the larger engine options and use throttle control myself. For example, I have a 5.5lb .40 size trainer with a clipped wing that I use for our "trainer racing" series. It's got a YS 1.10 in it with an APC 13x11 prop. It is mindblowingly overpowered yet is docile enough at low throttle for me to train students on, using a buddy box, if required.
The best bet, when you are assembling each model, is to come back here and get some comments back from guys who have flown the very combo you are planning. Sometimes the old rules of thumb don't apply.
