Anthoop

Even having a CDI that will cope with 20k RPM in a small package is not ready "off the shelf" for our application....peak torque is nice but power is where the money is...unless you are into haulage.

1QwkSport2.5r

No horsepower without torque. Torque is the twisting force and horsepower is work done over time. Both quantitative measurements and either factor is useless without the other. Moot anyway, but I don't think it would matter because I don't think a small glow engine will last long with all of the OPs intended "hop-ups". Especially in a Redcat car and an SH engine. RTR sport engines work fine in that kind of application, but pushed too hard.... Not sure how it's gonna hold up. I expect if the hop-ups work, there's gonna be a broken crank or rod in the engines future. But we'll have to see. I'm skeptical at best.

Maj_Overdrive

My Feedback: (11)

I guess you haven't seen Losi's LST XXL2 and 8ight series buggies and truggies with the .31 gas 2 stroke engine (same footprint as a nitro big block) with a CDI powered off the 2s lipo also used for the receiver. I forget the exact max rpm quoted by the Losi rep on another forum but it was right around 30k rpm for that engine and the CDI box is about the size of (likely a bit smaller than) one of those old school 4 AA battery holders. I can't say with any certainty but no indication was given that the CDI box couldn't handle more rpm, I believe there was no reason to spin the engine package faster as it wouldn't make any more power.

I agree with quicksport about the benefits of converting to a spark plug. I also think starting with an engine like this already intended for gas offers some benefits. Instead of varying nitro content and dealing with glow plug heat ranges you could just up the octane of the gas used in the premix to ward off detonation. Or if you wanted to go further you could alter the flywheel to accept a new key way to retard the ignition timing, probably easier than machining a new head with more chamber volume, although adding head shims would be even easier.

Anthoop

Yes I am more than skeptical to be honest....over the years we have all seen the dreams come and go.....

I did actually hear about that before launch...and read how it was bad from many sources at launch....but had totally forgotten about it....maybe I should research that again...thanks.

1QwkSport2.5r

It's hard to not be skeptical when someone tries to use full scale engine technology on something 100th the size. Unfortunately, not everything scales down proportionately and the fit/tolerance level must increase substantially because the losses (friction) are realized so much quicker. I'd shoot a guess the turbocharger must be fitted such that there is a tolerance level of .0001" or better. Perhaps better than that. Roller bearings will skid; phosphor bronze bushings would suit better. The RB Innovations gimmick supercharger has a single radial ball bearing. Hardly suited for the application!

The poor OP is gonna find it hard to realize power gains due to not having a dyno of his own and anyone who does likely won't test the engine.

supertib

The OP contacted me, I said I would dyno test it if he built it, I haven't heard a peep from him since ! too bad I wanted to test a RB supercharger.... I also contacted RB Innovations and offered to test their supercharger but sadly they have no responded back

1QwkSport2.5r

I'm quite surprised you'd test the engine, but I can appreciate your willingness to do so. I hope the OP gets it together and we can get some definitive information on those gimmicky power adders once and for all. I have a RB supercharger that a friend gave me in a box of spare parts, but I've yet to do anything with it. The only parts that are missing is the induction tubing. I bet some surgical tubing and zipties would do the trick.

supertib

I am always willing to test something new ! thats why I built the dyno to begin with !

I am now working on a second dyno system that wil allow me to run canned load cycles and measure runtime... will give me the ability to compare runtimes of different setups doing the exact same amount of work over time.... Obviously this one will be a lEddy Current brake dyno not a inertial dyno like my current one..

1QwkSport2.5r

That's good to know! I look forward to seeing the results of the OP's engine build if it materializes. I'd like to be proved wrong.

Maj_Overdrive

My Feedback: (11)

The Losi/Dynamite .31 gas definitely has its issues. They couldn't get the recommended needle settings right and there were lots of issues with broken connecting rods too. The tuning issues helped kill a few spark plugs but I don't remember reading anything about the cdi boxes being an issue. Supposedly they're finally on top of the issues with improved connecting rods and much better recommended needle settings for the engine though.

supertib

If your willing I would test that Supercharger ! I would find a suitable big block and do a before and after

1QwkSport2.5r

I'm guessing this one came setup for a smallblock engine based on the flywheel that's with it. I don't know if all of the mounting brackets are present or not, so you may have to fabricate brackets and sort out the flywheel. Let me weigh the parts and find a suitable box so I can determine shipping. If you'd pay to ship it back to me, I'll send it to you for testing. PM me your address and I'll get a shipping quote.

Anthoop

I was not meaning to say that the issues were due to spark ignition...but quoted rpm and actual are often different...as you know.
I have seen you say that you will test that SC three times at least...( btw why are you trying to imply that you developed the dyno)..many know who "made" the dyno you use....nice that you have learnt the differences between dyno types though...good work.

supertib

I dam well built my own dyno... in fact I have built 3 versions of it.... who do you think built it ?

And of course I want to test the Supercharger...why wouldn't I ?

And of course I know the differences in dyno systems, I have been working with them for 2 decades now....I have been involved in motorsports for many years before I started modifying nitro engines.....

be as disrespectful as you want because at the end of the day I am the real deal and you are just a jealous little forum troll !

cbaker65

That's ok ,we all still love you!.....

Nitrovein

That's a great idea! Back in the days when I worked with dynos it had a digital scale to measure the weight of the fuel flow.
It's easy to see if something is wrong then, but also as you say, it's great to compare and fine tune the engine with this.

Anthoop

I replied to your PM Neal. I will try not to bring out anymore truth here in the open.

supertib

I have nothing to hide here.

Falcon_F7

Id stop feeding the troll if I were you. They have a habit of multiplying or getting out of hand if you give them too much attention.

but I too would like to see a SC setup ran on a dyno.
From what I know a SC on a glow 2 stoke engine would only cram more air into the engine and no/little increase in psi. But what I know about SC is very little.

Tanque

I'm aware of the annoying aspects of bumping old threads but I'm doing it anyway. Since the OP seemed to drop out of the discussion when the senior
members took over in the last third of the reply thread and there was no follow up post I assume it was a failure as most everyone expected. The
pie_in_the_sky aspirations of a young fellow ( reference 'after spring break').

While the original post was amusing I was hoping to see a reference to a Dyno build thread since dynos were discussed at one point. That's something I wouldn't mind doing if it's a practical, useful thing.

Jerry