Hey Alfonso. Come over to LA, we will have some beer, and run couple of motors on Dyno. I have one and if something goes wrong we will call BK (mxwrench) and will make appoitment with him :lol: :lol: :lol: I got all tools you need to work on engines and I have really big junkyard of them.-so you will not be boring for sure.
Reiner what is going on? You are giving up? Man it is sucks. :cry: :cry: :cry: I was hopping that you will go to the end. You need to continue!!!!!!!!!!

Knowledge is a good thing and if we can help everyone get smart, that would be great. I've never seen a comparison chart like the one we've got going here, so some of the comparative numbers are quite surprising to me.

What I think would be beneficial, is a photo reference that explains what to measure and how to measure it - like the conrod photo I did up. If someone doesn't already have the engine photos we need, I do need to disassemble my TZ tonight or tomorrow night. It would be better if someone that knew what they were doing took the photos. :D

I'm not necessarily giving up. You guys are just so much farther along at all of this than I am. :sweat:

Thanks Ed

That would be great......problem is I'm about U$ 1,000 (air ticket) far away from your place...jajajaja......but I will put your invitation on my agenda of "things to do" in the near future for sure.

Maybe we can organize a seminar / congress inviting top engine manufacturers, designers and tuners from around the world...charge an admitance fee to all interested hobbyst, get some sponsors, and make an open discussion about our engines...

Alfonso

Rainer

You are right, the chart we've put toghether is a powerful tool that has enough information for people who can correctly interpret the data in it.
My hat off for you who started it.

So now we have to keep on learning more on 2 strokes in order to make correct use of chart, and what to mod to improve any selected engine we like.

I hope we can collect more information on other engines periodically and keep it up to date with the aid of great and helpful guys like Edward.

Alfonso

Don't worry, you'll catch up sooner or later with your shown interest and dedication...patience my friend...keep up the search and reading...it's taken me 30+ years on an off and on basis to get here....and I keep on learning.

Alfonso

First, I would like to thank everyone that has contributed to this thread thus far, especially Alfonso and Edward. Thank you for your knowledge and wisdom. I have learned a lot over these past few days and this new information has been very helpful.

I think the chart provides a good way to compare engines given certain known specifications. The dyno figures are a good baseline, but IMO, should not be the sole basis for making a decision. Not everyone has Brian’s tuning abilities and individual performance will vary, especially when it comes to environmental conditions, % nitro, plug selection, pipe selection, clutch and gearing. Having said that, given how Brian has tuned the engine, we can at least get a glimpse of an engine’s performance characteristics to help make an informed decision.

It’s unfortunate that Brian’s dyno has not become an industry standard. I see that it has potential for becoming the standard, but it requires some rather aggressive marketing. It would be great, if every new engine that came out on the market came with a certified NitroDyne Systems performance graph. By certified, I don't mean guaranteed performance - but rather that the tests were performed under controlled operating conditions under Brian's supervision.

As I see it, the manufacturers only release the most basic of information to help consumers make a decision – and this information is far from adequate to help make an informed decision. I think the Novarossi LL3 and Orion CRF are good examples of engines that look good “on paper” but have issue out on the track. The only way to determine if an engine is really going to work for you, is (1) buy it and try it – or (2) rely on other people’s experience. While the latter is not a bad way to go, you just have to be sure that the person is running under the same type of conditions that you are – and you are confident of that person’s tuning abilities. I was just talking to someone about the Sirio STI he ran at the IFMAR Worlds last night and he was saying how great it was coming out of the corners. Then I asked him, “Did you have to brake at all?” Guess what his answer was? “No”.

I agree with Alfonso’s earlier statement that, “If you really know how to properly tune your engine, match the right pipe, set your clutch accordingly and choose the proper gearing, you can take advantage of the power and torque of any engine.” – but he goes on to say “90% of the time I've found that people don't know how to properly set their cars, more than a question of who has the most power out there…” This brings up a very good point about engine performance and all of these numbers. They have no value if you don’t know what the heck you are doing.

What I am thinking now, based on the current figures presented in the chart, is that it gives you a pretty good idea of what type of track the engine is mostly likely to do well on, given max torque at a certain RPM, max HP at a certain RPM and rod/stroke ratio. If you are lucky enough to have a dyno graph, then you can get some idea of how the engine will perform at the various RPM ranges. The question is, what are the cutoff points for selecting an engine for a specific type of track, based on layout and traction? Also, what are the max and min cutoff points for usable performance? Maybe determining these cutoff points isn't possible or really necessary.

At this point, the question for anyone out there is, what specific additional information, would change someone’s decision to use a different engine, rather than just basing it on the information provided at present in the chart or the dyno graph? In other words, how would timing, crankcase volume or other information that Edward mentioned collecting, translate into some type of metric or graph, which would help someone make a more informed decision as to what engine to choose?

I could go on forever (as most of you know), but I will stop here. There is so much more to discuss and work to be done, it's not even funny. But for now, I have a race to prepare for on Sunday, with whatever spare time I have available. :D I will continue to work on this project and start a resource Web page for people who want to do research on engines.

OK Rainer

For starters, you are welcomed, it's a pleasure working with you and Ed on a useful data base project and will continue to support you.

I've edited some of your statements on your last post, which in that way are answers themselves.

And regarding the last question / statement before your closing...here it goes, and I'm sure that with this info the picture will be complete to interpret the numbers on the chart, and you should post them at the bottom of the chart as references:

High exhaust degrees duration = more power and rpm at top end
High transfer degrees duration = more power and torque at low end (wacht out because if to high run time gets hurt)
High boost transfer duration =extension of the peak power curve
Advancing Induction opening = more low end (up to certain limits)
Retarding Induction closing = more high end
Bigger diameter on inner passage = more overall power = more fuel consumption past certain limits.

With regards to Induction timing, little changes in opening timing will not produce appreciable changes in performance. The factor that has a considerable effect on an engine performace is the closing timing. Closing 20% later will not affect high end, but will help low end becaiuse it limits "blow back" through the carb....past 20% youll loose low end and increase high end.

Now as an exercise go see the numbers on induction of the ORION and you'll have a technical answer of why it is like an "unbroken horse" at the track when all that power hits the wheels at such high power band, if they reduced induction to 210º and raise a tad the transfers it would be like a Derby winner.

That's all....now the chart makes sense doesn't ???.....have fun

Let's keep on working finding more engines to put on the chart....jejejeje

Alfonso
answer of why it

I get smarter each time you post something Alfonso. :smile: :smile:

oh this is good stuff :)

Just buy a Proven fast reliable engine and get it over with, don't need to talk about induction , bore , stroke meaning people talking about why they are not fast because of the induction , bore , stroke cut that B. S. and go for the best. just remember you get what you pay for, :ha:

its just for fun and is it like that with golf balls too

buying a proven fast engine doesnt mean anything if you cant drive. then you cant complain about a motor, slow or fast.


please take your incorrect opinions elsewhere and stop bothering people. thank you.

Thanks Alfonso... now i understand why they did it. after all the reading from diffrent sources... and most from respected individual/mag... only now i understand.. THE WHY. Thanks alfonso. thanks a lot. :nod: :nod: :nod:

Wow guys, I havent been keeping up with this forum lately and look what I have been missing!

This thread has taken an interesting turn. I might have to get involved in this one.

Ranier, please email me the latest excel sheet so I can look it over and add to it.

Also Eduard, I was thinking about your crankcase measurment std, and I think the best way would be to have a dummy piston with a hole in it and lock the engine at the point of when the transfer port opens/closes. This way you get the full actual volume under the piston and the entire transfer port cavitys included in the measurement.

Ok, well I'll add more later.

See ya,

BK