How to build a high-performance Cox .049 Engine

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

microflitedude wrote:

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

Yes but i cheated it was on crazy high nitro and a .020 prop.

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

Yes but i cheated it was on crazy high nitro and a .020 prop.

With what prop do you hope to achieve such RPM? Wonder what an .010 would do with a 2 - 3 inch prop on 40% nitro...

microflitedude wrote:

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

Yes but i cheated it was on crazy high nitro and a .020 prop.

With what prop do you hope to achieve such RPM? Wonder what an .010 would do with a 2 - 3 inch prop on 40% nitro...

I know a diesel 0.006 (0,1cc) that can do 40,000 on a cox .010 prop.

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

Yes but i cheated it was on crazy high nitro and a .020 prop.

With what prop do you hope to achieve such RPM? Wonder what an .010 would do with a 2 - 3 inch prop on 40% nitro...

I know a diesel 0.006 (0,1cc) that can do 40,000 on a cox .010 prop.

A diesel? That's something else!

microflitedude wrote:

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

microflitedude wrote:

nitroairplane wrote:

Cox International wrote:
Paul Gibeault, a world-renown Mouse Racer, has re-written his Mouse Race Program Guide for 2011.

Although, technically, it relates to Mouse Racing, there are page after page of valuable instructions on how to make your Cox engine scream. The guide is located here:

http://coxengines.ca/MRP.pdf

Enjoy!
Bernie
www.coxengines.ca

Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get.

You yourslef said 30,000, right? 4.5"?

Yes but i cheated it was on crazy high nitro and a .020 prop.

With what prop do you hope to achieve such RPM? Wonder what an .010 would do with a 2 - 3 inch prop on 40% nitro...

I know a diesel 0.006 (0,1cc) that can do 40,000 on a cox .010 prop.

A diesel? That's something else!

Not really,
A common misperception is that diesels have tons of torqu but won't rev.
Because of the variable inflowing timin diesels can swing a wider variety of props and at different speed they do have. Lot of torque but the do rev well if they are a high Erving engine most are not designed to be though.
But if need be a .048 diesel could be designed to out rev a tee dee or AMA.

"Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get."

Yep, with a .020 prop and lots of nitro you might see 21k w/ a Sure Start!

A strong mouser with a APC 4.75x4 on 35% nitro will only do 19-20k. If somebodys telling you more, ask them to check their tach.

Mark Boesen wrote:"Good info thank you i wonder how many RPMs can actually be squeezed out of a suretsart i have heard of guys getting over 21,00o but i wonder how many its possible to get."

Yep, with a .020 prop and lots of nitro you might see 21k w/ a Sure Start!

A strong mouser with a APC 4.75x4 on 35% nitro will only do 19-20k. If somebodys telling you more, ask them to check their tach.

Yeah, guess the whole RPM chase is OK, but it doesn't mean a lot under the definition of "Performance" unless when it's held to a standard...like the "Tach Race" you and Chris sponsored a couple of years ago on the Collectors Group.

In THAT case...it was an "apples to apples" comparison...and the results really held some value beyond just seeing how long the crankpin, rod, or piston would survive.

Maybe consider doing that again, with a "Sportsman Class" for those of us challenged with slightly less "Engine Mojo" ? I got a Black Widow with fresh gaskets !

What is that Kim?
Just whenever gets the most out of a 5*3 wins ?

It was a cool deal, coordinated by Mark, and run by Chris, over on the .049 Collectors Group.

Members actually sent their engines to Chris...to be run against other members' engines under conditions as nearly as identical as Chris could control. This is what I meant by "Apples-to-Apples"...the playing field was as level as possible, with the same fuel, prop, and atmospheric conditions for each engines' run.

I'm pretty sure that the rules and results are still archived over on Mark's Group Page, and I'm sure he'll be glad to provide details and correct anything I might have gotten wrong. It was a bunch of fun to see how everyone's engines performed.

I didn't participate, but may take part in the next one if they do it again. If you think about it...it'd be a ton of work for the test guy, and Chris' efforts were really appreciated by all the members.

Further info on the "Tach Race" from a letter by Chris back in 2009. Hope it's OK to reprint...figured I'd take a chance:

--------------------------------------------------------------------------
"It was very fun to receive a bunch of fine high performance engines and run them myself in one afternoon. I was especially excited to get Paul's, because we had known each other through a few Nats and Whittier Speed contests, even though he didn't remember me! Like Paul, I'm a person that believes in the best in people and his gut told him we were real people and those that sent their engines were risking a bit. To all of you that sent engines, thanks for being involved. The participants were the most of the contest, my side was just the time to run them, photograph them and return them.

It is a very good idea to have some kind of a contest. The whole thing came about when a few engine builders were showing their engines on You Tube and one was turning 020 props at real high r's and that started a debate about real power. Then Mark thought up the idea of running engines together in a stable atmosphere, like load, standard fuel, etc, and thought of me in California in the middle of winter 2008. I didn't get them all prepared to run until early 2009, but it went well the day I ran them.

Now, we could make the contest in another format. Postal, You Tube, formula, unlimited, whatever. I think we should keep the dialog going on it and since Nick has retired and brought up the contest again, he should make the decision on which way to proceed as long as Mark, as our fearless leader, has no objections."
------------------------------------------------------------------------------------
Sounds like FUN !

One of the things that Paul emphasizes is what Leroy Cox discovered almost 60 years ago...mix and match for an EXCELLENT piston/cylinder fit. I understand that the original Cox factory had some folks who were specially trained to mix and match sets. My guess is, that went away due to being so labor-intensive.

If you want top-notch performance, you probably should order a dozen or so piston/cylinder sets from Bernie and possibly end up for a few great fits and the rest decent fits. You can use the less than great for practice for whatever event you are pursuing.

We sport flyers don't have to have highest performance. If my TD .049 won't handle it, I'll slap a TD .09 in it.

George

gcb wrote:
If my TD .049 won't handle it, I'll slap a TD .09 in it.
George

There ain't no substitute for cubic inches!!!

While I am a fan of the NORVELs and have replaced a couple of aging BW's with BigMig .061's and had good performance improvements, not all of the increased power is due to the design, since the .061's pack 25% more displacement. It would have been nice to see what a TeeDee .061 could have turned.

Just listen to this one! Turning over 21k with 10% nitro and a 5x3!

https://www.youtube.com/watch?v=Ic2MKSn50Tg

Slightly lower -

https://www.youtube.com/watch?v=LfdvbvlM3YI&feature=related

I'd hide under the table till that first one ran out of fuel.
No mention of the spring in the pickup tube. I was disappointed. I want some of that aluminum tubing. I HATE it when the plastic tube pops out of place and hardens. And loosens over the nipple.

RknRusty wrote:I'd hide under the table till that first one ran out of fuel.
No mention of the spring in the pickup tube. I was disappointed. I want some of that aluminum tubing. I HATE it when the plastic tube pops out of place and hardens. And loosens over the nipple.

I have about 6" of small aluminum tubing. How would you attach it?

microflitedude wrote:I have about 6" of small aluminum tubing. How would you attach it?

The quote in the write-up says:

I bend a piece of 3/32" O.D. soft aluminum tubing & make the pick-up one solid piece. I file a chamfer at the bottom of the pick-up tube so that it fits perfectly into the backplate. Attach it to the tank back with a short piece of tight fitting silicone tubing.

I'll have to experiment with it. I don't know where to get tube that size. Where did you get yours?

RknRusty wrote:

microflitedude wrote:I have about 6" of small aluminum tubing. How would you attach it?

The quote in the write-up says:

I bend a piece of 3/32" O.D. soft aluminum tubing & make the pick-up one solid piece. I file a chamfer at the bottom of the pick-up tube so that it fits perfectly into the backplate. Attach it to the tank back with a short piece of tight fitting silicone tubing.

I'll have to experiment with it. I don't know where to get tube that size. Where did you get yours?

I actually got it from an old kit - it was not mentioned in the plans/manual so I took it out. Probably a throttle cable tube.

I don't think I'l ever use it. If you can help me de-bur a couple .049 cylinders, you can have it. It's 1/10th inch dia. and 5" long.

gcb wrote:If you want top-notch performance, you probably should order a dozen or so piston/cylinder sets from Bernie and possibly end up for a few great fits and the rest decent fits. You can use the less than great for practice for whatever event you are pursuing.


George

You would be suprised at how many professional drag race teams do this. We are talking crates and crates of valve springs, just to get a few sets of perfect matches for all 8 cylinders. Then those perfect sets are tossed after about 4 runs(limited budget),, and sometimes as short as 1 run (unlimited budget), then it all starts over again to obtain the same.

But that's just valve springs,,many more items matched up.

When building a top notch rc car I order 3 engine and keep the best an sell the other 2 for £5 off retail that way I only spend £10 extra and get a great engine (offna or picco are my choice)

nitroairplane wrote:When building a top notch rc car I order 3 engine and keep the best an sell the other 2 for £5 off retail that way I only spend £10 extra and get a great engine (offna or picco are my choice)

I was buying the Novarossi 7 & 5 ports, modified and dynoed my Maissimo Fantini(Maxpower modifieds). I had one onroad modified 9 port that was crazy,,thing was uncontrollable. lightswitch powerband,,either full on or off, no inbetween. 3.25HP out of a 21 sized motor. I caught a track post at full sing and peeled the suspension off 1 complete side of my Xray Buggy and said that was enough with that thing. I was going to get hurt or someone else was.

The craziest rc cr I err drove was the Schumacher fusion .28 1/10 scale rc touting/drag racer this are mad over 90mph. Uncontroalble well that's what you get when you mix a picco .28 with a 1/10 scale touring car that would have been fine with a .18 or even .15

What is the best reed material for maximum high-end RPM?