ORIGINAL: Jaysbird
How can one get a real world comparisons of how a given engine compares to other engines of the same size? We know that manufacturer numbers are almost useless.
I bought my first 4S engine a few months ago. Its an ASP 65. I did a search on this engine and as usual some say its a strong engine and others say its not. Ive run almost a gallon of fuel through it and its able to turn an APC 12-6 at 10300 rpm steadily with a lot of smoke coming out. I can get it to about 10600 with less smoke but it will not maintain this RPM. But I don't know if this is good for this sized engine or not. Where can I find practical numbers for given engine sizes and props to compare?
Thanks,
~Jay
What are your performance expectations?
I try to get my 4 strokes in this range to be around 9800rpm or so (maybe 9799 or 9801 but you get the idea). 10k rpm is spot on to revving that engine up. No damage or anthying like that, they are likely safe up until 12k (per the instructions I imagin) but there's no need to go that high with a 4 stroke. If you're getting between 9 and 10k rpm you're probably pretty good to go. I would suggest as others have to try a 13x6. My magnume 61 4 stroke pulls that pretty well at 9300 rpm. My OS FS-61 pulls a Zinger (wood) 13x5 prop at 9800 rpm and it's over 20 years old (on 15% fuel).
4 Stroke performance and 2 stroke are very different so it takes a little adjustment in attitude between the two. Since I've been using mostly 4 strokes the last few years I've completely shied away from 2 strokes mainly because of how high they rev. Its just frightening some times...makes me not want to get near them (which is good I guess) but a 4 stroke I'm more comfortable with.