What truth are you talking about-one word you wrote -you can't support with small bit of legimate info? So everybody are idiots and all reces results over the year was falsificated ? Now god Corex came and open eyes. :lol: :lol: :lol: I am actualy glad that you came across. I was hopping that you will bring one instance which I am not awere of, but now since you just keep talking without any kind of info, that is telling very clear you have no clue in RC. You have no sources or knowoldge to play real RC, you just bashing around RcTech forum ( i read all your posts try to find out how smart you are), insulting guys from Team Kamikaze ( btw, you did take wrong guy there-that one is pretty good driver ) etc. Just keep doing that-it will ruin your credobility more and more. Keep going!!!!!
YOU NOT INTERESTING FOR ME ANY MORE!

WOW now this is fun. LMGDAO

Gettting back on topic...

I couldn't find anything on bore and stroke on the Mega ZX12 or DSII engine line. Anybody have or know where I can find the info? I couldn't find it at the Serpent site.

Quite a number of people have stated that the Mega has good bottom end. Just want to see what the numbers look like for comparision. I haven't seen a dyno graph anywhere.

Thanks! :)

Picco Micromotori makes Mega ZX engines, and also makes LRP engines. The specs of the three are quite similar, maybe a different timing spec on each brand, but the bore end stroke identical, thought this spec sheet for the LRP .12 Spec.2 Team engine might help you

Exhaust: rear exhaust
Displacement: .12 cu in (2.11cc)
Carb: 5.5mm slide carburetor
Crankshaft: SG shaft 12.0mm/7.0mm bore
Sleeve: ABC piston and sleeve
Ports: 3+1 ports. EFRA, DMC, OFMAV, SRCC, IFMAR, ROAR race legal.
Bore: 13.8mm
Stroke: 14.0mm
Piston: CNC machined high silicium alloy
Connecting Rod: New Fork shaped aluminum using special bushings
Rpm: 3,600-42,000rpm*
Hp: 1.11hp @ 34,500 rpm *
Torque: 32.46 Oz.In. @ 34,250 *
Weight: 221g

* Specifications on 30% Nitro fuel using Mugen - Shimo pipe and header at Nitrodyne Systems Dynamometer using corrected SAE factors.

AFM

Excellent! Thank you. :)

When you start reading through the threads for the individuals engines, you start to get a real sense of what these numbers mean and what they don't mean. Just because th LL3 has the longest stroke, doesn't mean it delivers the best bottom-end performance throughout the lower powerband. Similarly, the shortest stroke doesn't mean that it doesn't deliver on the bottom-end. How very interesting.

Anybody have anything else to add to this or comment on?

Thanks! :)

hmm
 

think you could find this info. for mugen x12 or jp x12 :D

Found the info buried here: http://www.mugenracing.com/X12.htm

The other thing to consider in this is rod length, which has nothing to do with stroke. Shorter rod motors tend to have higher piston acceleration as well as having shorter TDC and BDC dwell times. This also affects the so called "low end" response.

Unfortunately, manufacturers don't seem to publish the rod length!

Right, but I am sure that the RCTech readers of this topic could chime in with some responses here.

From what I remember the Picco motors had an ultra short rod, most novarossis a mid length rod and OSs (TRs and before) a long rod, along with the MT12 and CX 12 novarossis. My memory is pretty faulty though!

I just wonder, with my LL3 i always knew it didn't make the most torque out of all engines but it felt really torquey. Is that just the powerband coming on or what? Personally i wasn't a fan of it working like that

This list of engines was published by Dennis Richey long time ago on a post regarding pipe selection based on rod lenght. Of course thera are several new engines not posted, but it's a reference

Very short
HPI 15 FE
Rossi Pixi
Short
RB X12 and all the V12 derivatives
All Novarossi .12 engines and derivatives
STS D3, D3R
RD Logics RRE S3
OS TS & TZ
Mid length
Picco 12
Mega 12
Sirio 12 all
L.Collari 12 all
Long
STS MT12
Mugen MT12

AFM

Great info thank AFM. Seems I was pretty much wrong on everything I said, I'm getting too old!

Cant be getting to old Al, seeing as how you just brought a MTX-4 for some more excitment!!!!

If you haven't already, check out mtveten's posts in the Novarossi thread. That should explain some of what' you're experiencing.

Thanks AFM. That's a good starting point. Now I think I need to get some actual numbers and add it to the chart I started.

iv found the LL3 has a higher power band than the LS3 and to some this may fell like toque i think its more mid power but the LS3 has higher top speed. i think the megas are like this low and mid power. im getin old so idono. what i mean is the LS3 coms on later then the LL3 the sirios are like this to the power comes on later

hi afm.........

interesting.....max torque and peak power at almost the same rpm...........or am I wrong?
BTW: SAE want POWER in kW and TORQUE in N*m :p :p :p .....just kidding man!

Are you kidding? i'm not trying to be a smart ass or question your experience but, my dad and i both run TZ's and have not had one single problem. his, i think has done around 14+ litres and mine around 7-10 litres (its hard to know mine exactly, as we share fuel) and both engines perform like they did out of the box, both have incredible compression and i run mine hard, and its the original conrod in mine, although i believe my dads was replace after a couple litres. so i wonder, how the hell do you blow up an O.S. after
?????

Come to think of it, he still uses both of my old os tr engines and i know for a fact one of them has run about 20 litres! the other around 8 and both go like an OS should!

I'm pretty sure that some of the early tz's had conrod problems, but they sorted them out.

If you break it and run it properly it should run for ages.

ok maybe not one day say about 3 but the two pistons did break the same way.i see guys run them for a long time but there not that fast and it wasent the con rods the pistons in 5 little peaces.

Odd, ive never done that to an O.S.

Found this information that my shed some more light on stroke lenght


"Longstroke vs Shortstroke. Differently to four strokes, a short stroke is not higher power/higher revving in a two stroke engine. The port area available in a two stroke engine is proportional to the the cylinder wall area not the head area. This favours long stroke/small bore The limitation is friction/wear and inertial effects and so the best stroke/bore ratio seems to be between 1:1 and 1.2:1.
Rod/stroke ratios. A rod stroke ratio of 1.75:1 will give a good wide powerband. A rod stroke ratio of 2:1 will give a higher revving narrower powerband."

Dave Marles, Prestwich Model Centre, 1 Mill St., Golborne, Nr Warrington, England.


AFM

If anybody has a new (or relatively new) conrod, could you please measure points A and B as indicated below. Then I can put a engine matrix together for everyone to reference. :D

Thanks!

http://www.nitrokb.com/images/conrodmeasurement.jpg

rmd, I think you should specify "GOOD" conrod or NEW, cause if the conrod is worn, then the data will be inaccurate.

Thanks for pointing that out. ;) Change made. :D

no prob rmd

Novarossi conrod 25 mm between centers of the holes.

hey AFM, you are getting really close to real info. I am aplause to you, and my hat off to you. Now calculate what is conod ration for 25 mm conrod lenght and 14 mm strock and 14.25 mm strock-then here is some answer. Keep going and I am sure you are pretty close to make some seriouse stament and I will support it. Please PM your email and I will send you some programm for help to play around. :nod: :nod: :nod:
BTW, Prestwich posted a lot of valuble info on the web. Just keep diging it-very interesting thing will find there as well as on other sies too..

Good post this is the sort of stuff I was getting at above. This sort of analysis will really allow you to start seeing why certain engines react the way they do beyond merely the stroke/bore ratio.

Thanks Edward

Lots of information available on the web, specially on R/C boating and airplane sites.

This is fun......reserching and learning beyond copying other modder's work.

Do you happen to have numbers on the Mega ZX 12 engine?? rod lenght, timing numbers, etc.???

BTW, I sent you PM

AFM

Yup! This is really awesome! Thanks AFM. .12 Knowledge Base :nod:

Trying to make an informed decision about what engine to get next has been pretty difficult for me. Based on the specs that manufacturers publish, it's next to impossible to determine what the real differences are between each engine and what exactly you're getting. That's why most of us just rely on other people's experience and opinion. Clutch and 2-speed tuning are really big factors in getting the most out of any engine of course, but if you select the wrong engine for the type of track you racing on to begin with, then you're just wasting your time. :eek: :lol:

This can't possibly be this simple. Crank out a bunch of formulas to help people choose an engine? Add on gearing info and then all of this becomes a no brainer.

I must be missing something... :confused:

I just did the rod/stroke calculation for the WASP Rev: :eek: :eek:

:lol:

Thanks Edward. Is the Axial conrod 25 mm as well?

running an Axial
 

We all know that if you put An Axial engine in any of the top ten at the worlds that it would produce the same result. As far as running the motor to 400 degrees in testing is not to see if it can run at that temp, but it was just a test the durability of the materials within the engine. Axial is commited to put the best quality into all of their products. If you had a little business sense you would understand why Axial decided to skip the worlds this time around. Time wil be the judge and those that acually own one.

Id have to agree ,as a Profi 12 user I have gone through some teething problems and have overheated engine a good few times where my temp gauge couldnt read the temp >400deg/c
I have stripped engine and everything is A ok.
Fianlly figured out the problem with engine was the hsn oring got too loose and when running car the hsn was turning clockwise ,leaning out the engine.
If anybody else had these hassles they would have given up on the engine but I had to find the problem.I found problem when I was blipping the throttle with car on the starter box and I saw something move in the corner of my eye,when i blipped a gain saw the hsn move.

I am convinced if I had this problem with any other engine I would have had a different result.Engine running sweet and is not showing any signs of power falling off.

The Palmaris Profi PR 12 rod is 25mm and should be the same as Axial 12RR.

You don't have a clue on what you are talking about, "put an Axial engine in any of the TOP ten at the worlds", :lol: :lol: :lol: What.............. you must be kidding, it is not going to even make the Y main :lol: :lol: :lol: you make me laugh :lol: :lol: :lol:

Enough already