Looking for parts to convert Novarossi 21 car to marine

[mike the snake]

I'm looking for the parts necessary to convert the offroad Novarossi engines I have.

I need flywheel, collet, cooling head/button, rotary carb, and anything else I might need to run these engines in a boat. I plan to build and race a Whiplash 20.

Used parts are fine too.

Also, I want to add counterweight slugs to the crank of one engine. Does anyone do this modification?

Thanks for any help

 

[Jerry Wyss]

sounds like you have most of the parts, if not all. I did this one from the cheapest Nova Plus-5 buggy engine.

 

[tnrcboatracer]

Water cooled head caps are3 available from Frank Orlic. I just picked up a flywheel off of ebay for $18 from a place in China. I have not received it yet, so I don't know the quality yet. You may also want some sleeve shims the adjust the port timing. I got my sleeve shims from Woods Racing Products. I modified my collet myself. I'll post pics of my EB Mods REX 21 tomorrow.

 

[mike the snake]

Thanks, I have already PM'd Frank Orlic.

Jerry, maybe you misread? I Need the parts mentioned. Sounds like you might have thought I said I already had those parts?

Does anyone know who I might be able to contact to slug my crank? These engines are offroad and don't have the counterweights, and I'd like to add one or two slugs for the extended high RPM's and loads. One is based on the P5, the other based on the R1 On-road Kangaroo motor.

Still looking, Thanks for any help

Water cooled head caps are3 available from Frank Orlic. I just picked up a flywheel off of ebay for $18 from a place in China. I have not received it yet, so I don't know the quality yet. You may also want some sleeve shims the adjust the port timing. I got my sleeve shims from Woods Racing Products. I modified my collet myself. I'll post pics of my EB Mods REX 21 tomorrow.

 

[tnrcboatracer]

It may be easier and cheaper to buy the onroad slugged crank for your motor. I bought the complete EB mods motor with slugged and silicone filled crank with a spare P/L and rod for a little over $100 a year or so ago. Slugging your existing crank is not going to be cheap. I know someone who can do it, but I dont know their schedule right now. The tungsten raw stock is about $40 for the 1/8" dia rod.

 

[mike the snake]

WOW that's expensive material! I can probably get the material, probably even do the job myself (I know a few people with mills and lathes), I guess I thought it would be around $40 or so. The NR cranks I've seen were a lot more than $100, I'll look into just buying another if that's what they cost, Thanks. Maybe I'll slug it with Gold! LOL

IT may be easier and cheaper to buy hte onroad slugged crank for youe motor. I bought the complete EB mods motor with slugged and silicone filled crank with a spare P/L and rod for a little over $100 a year or so ago. Slugging your existing crank is not going to be cheap. I know someone who can do it, but I dont know their schedule right now. The tungsten raw stock is about $40 for the 1/8" rod.

 

[Jerry Wyss]

Sorry Mike, that is the way I read it,, anyway, I like the O.S.VZ-M flywheel (available at Tower), the flywheel

itself didn't need any mods but the ferrule that comes with it needs some shortening. I also used the Aeromarine

SS Flex collet for the 21 O.S. from Rocket City Racing but it needed lathe trimming to enter the front of the flywheel

opening AND to go in further to catch more threads on the SG style crank.

On the crank, "Tungsten Slugs", What?, you mean the off-road motors are running unbalanced over the on-road

motors? I doubt that would be the case,, my Plus crank came with one slug, but it also had 180 degree total open

crank timing! that had to be opened-up. Some of these buggy engines are made for fuel economy and mine "was"

one of them.

My plus took .010" sleeve shim and opened the crank to 210*,, the button was right at .19cc volume and headspace

set at .008" for now.

Back to the crank,, if you think it may not have enough balance weight try removing some of the piston skirt or like

Steve Wood say's "cut a piston port" right in front of the boost port(s),, maybe that will satisfy ya,,,?? Talk to Steve

if you can, He knows allot about this area. Also, Frank Orlic himself told me that he takes the NR 4-21B and mods

it to run with the best Nova's made,, Thats encouraging, yeah?

JW

 

[tnrcboatracer]

Gold isn't dense enough......You might be able to find some depleted uranium, though. Tungsten carbide drill blanks are one souce, but they are hard to cut. I have some tungsten penetrators from a previous life......The best bet is just plain old tungsten stock from McMaster, and carbide tooling to cut it.

WOW that's expensive material! I can probably get the material, probably even do the job myself (I know a few people with mills and lathes), I guess I thought it would be around $40 or so. The NR cranks I've seen were a lot more than $100, I'll look into just buying another if that's what they cost, Thanks. Maybe I'll slug it with Gold! LOL

 

[mike the snake]

Thanks Jerry.

It's my understanding and observation that the higher revving on-road engines generally have the slugged cranks. The P5, 421B, long stroke offroad cranks are not counterweighted. The RB Concepts C5 they stopped including the counterweight on the offroad versions.

I have a Crono Turbo Race 7 port, based on the Novarossi R1 on-road engine, offroad changes were using the non-counterweighted crank, plastic carb, nd large head. It is newish, and I have a spare piston/liner, crank, and bearings, so it's a good candidate to convert to marine and run for a season.

This is the engine I want to convert to marine and add the counterweight/s to. It is THE gnarliest 21 I ever ran. I'll post a couple pics. It's called a "7 port" but I counted 12 ports (I realize the exhaust is 3 of them)

Sorry Mike, that is the way I read it,, anyway, I like the O.S.VZ-M flywheel (available at Tower), the flywheelitself didn't need any mods but the ferrule that comes with it needs some shortening. I also used the Aeromarine

SS Flex collet for the 21 O.S. from Rocket City Racing but it needed lathe trimming to enter the front of the flywheel

opening AND to go in further to catch more threads on the SG style crank.

On the crank, "Tungsten Slugs", What?, you mean the off-road motors are running unbalanced over the on-road

motors? I doubt that would be the case,, my Plus crank came with one slug, but it also had 180 degree total open

crank timing! that had to be opened-up. Some of these buggy engines are made for fuel economy and mine "was"

one of them.

My plus took .010" sleeve shim and opened the crank to 210*,, the button was right at .19cc volume and headspace

set at .008" for now.

Back to the crank,, if you think it may not have enough balance weight try removing some of the piston skirt or like

Steve Wood say's "cut a piston port" right in front of the boost port(s),, maybe that will satisfy ya,,,?? Talk to Steve

if you can, He knows allot about this area. Also, Frank Orlic himself told me that he takes the NR 4-21B and mods

it to run with the best Nova's made,, Thats encouraging, yeah?

JW

 

[Rick Doane]

While depleted uranium would be heavier, unless you have experience in the handling of this material, I would not use it. If you have to machine it, you will contaminate your machines, work area and expose yourself. Tungstun is a better choice.

 

[mike the snake]

Thanks. I'm not going anywhere near depleted uranium.

Now that I think about it, the SG shaft is common among 21's, a CMD or MAC 21 flywheel should work as well as the OS21 flywheel.

I'm trying t contact Blazer Marine to order their Whiplash 20 Hydro, but the phone number on the site is disconntected and they haven't returned my email yet.

While depleted uranium would be heavier, unless you have experience in the handling of this material, I would not use it. If you have to machine it, you will contaminate your machines, work area and expose yourself. Tungstun is a better choice.

 

[Jerry Wyss]

Just a word of caution Mike,, just because that exotic "on-road" car engine is the bomb in a RC car doesn't

really mean that it will perform equaly in a boat. There's an entirely different power curve between the two

applications. With that engine in an I/B, the launch can be the nightmare of your life to get it up and going.

Just remember I'm only trying bring up the "flipside" of what can possibly happen. Boats have a ever changing

load on the engine with the amount of drag changing right along with it,, and they don't need brakes.

The last five word statement can tell you allot if you think about it

 

[tnrcboatracer]

Seriously, I was kidding about the depleted uranium. I only mentioned it because it is about the densest hard material out there. BTW, gold and lead are too soft and not dense enough for counterweight slugs. Chatter free durable tunsten is 0.614 lb/in3 (1061 lbs/ft3). This is about 15% more denser than tungsten carbide and over 2x the density of the steel crank. BTW, depleted uranium is 0.686 lb.in3 (1186 lb/ft3), or about 10% greater density than tungsten. But just try to find some for the home machinist...........................

 

[Richard Dahlheimer]

Just a word of caution Mike,, just because that exotic "on-road" car engine is the bomb in a RC car doesn'treally mean that it will perform equaly in a boat. There's an entirely different power curve between the two

applications. With that engine in an I/B, the launch can be the nightmare of your life to get it up and going.

Just remember I'm only trying bring up the "flipside" of what can possibly happen. Boats have a ever changing

load on the engine with the amount of drag changing right along with it,, and they don't need brakes.

The last five word statement can tell you allot if you think about it

Mike, the CMB .21 inboard black flywheel will work great for converting a Nova with the SG crank to marine. Use the Aeromarine .21 CMB cable nut with the pilot. The pilot goes inside the flywheel, and therefore captures more of the crank threads. You will also need the CMB .21 flywheel cone. No mods needed to the flywheel and cone. You may have to relieve a bit of the engine case with a file, below the carb. Hope this helps. Richard D

 

[mike the snake]

Thanks for the word of caution Jerry. If the engines I have don't work I'll go buy a dedicated boat engine, no big deal. These are special engines that are worth giving a try with, and I have lots of spares.

Richard Thanks for the tips!

I contacted Frank Orlic and should have this engine converted in a bit.

I'll also be receiving my Blazer Marine Whiplash 20 soon as well, I hope to do a build thread for this boat.

I'm looking for the parts necessary to convert the offroad Novarossi engines I have.
I need flywheel, collet, cooling head/button, rotary carb, and anything else I might need to run these engines in a boat. I plan to build and race a Whiplash 20.

Used parts are fine too.

Also, I want to add counterweight slugs to the crank of one engine. Does anyone do this modification?

Thanks for any help

 

[Jerry Wyss]

Thanks for the word of caution Jerry. If the engines I have don't work I'll go buy a dedicated boat engine, no big deal. These are special engines that are worth giving a try with, and I have lots of spares.

Didn't mean to scare you, and it doesn't mean that car/buggy engines aren't convertable, they are,, its just the exotic

timed, million port engines are designed with "wheels" in mind,, high HP numbers @ high rpm's, with very little resistance

to over come. Will not be the same case on water with a prop,,, in a boat.

JW

 

[NITROSNIFER]

I've been running a Buggy engine now for two years. It's a RB WS-7 and it's basically a NovaRossi and is built for RB Products by Nova. It's set up to be in a single speed race buggy that needs low as well as high end power capabilities. I have the pipe set at 7" and it screams on 50%. I don't think you will have any problems with your choice of engine, in fact you'll be surprised just how well these engines work. I think a on road engine may be timed a little different and could cause some issues with set up but then just run a cut down prop and an even shorter pipe and let her scream. Yes the exotic buggy/car engines are designed with wheels in mind but gearing for those also plays a huge roll. They have to go from idle to full throttle as they run a course. it's not all straights, they are running less nitro, leaner and higher clearances than we run.

 

[anthony_marquart]

In my engines I've found that the off road engines seem to have more torque than on road but don't turn the RPMs that the on road ones do. I'm leaning toward the on road engines for my .12s..

 

[mike the snake]

I've run the RB Concepts C3, C4, and a few C5's (Long strokes), and the WS7II (square stroke) (All modified) offroad. All "C's" are based on RB's on-road design. The problems I had was too much explosive power. For offroad my favorite is the MAX M5 (P5), best of both worlds and sips fuel.

The Crono I have is based on the R1, and was completely out-of-hand power wise. Most notably that it revved to probably 45,000 rpm (Really), There's not much that revs higher than the C5, and this crono made my modded C5's look like they were going backwards. LOL, I remember blowing by a factory OdOnnell RB WS7II factory driver on a long straight once, got EVERYONE's attention!

I'm pretty sure that this Crono will work very well. I have the MAX M5 also (P5) that is the best offroad engine ever IMO so if the crono doesn't work, the MAX might, and if that doesn't work I'll buy a CMB or MAC.

Offroad requires torque from near idle, whereas on-road are clutched to grab later, and usually hit harder and rev higher.

For boats, I think the on-road versions may be better suited for marine use.

I ordered my Whiplash Sport 20 Hydro last night!

In my engines I've found that the off road engines seem to have more torque than on road but don't turn the RPMs that the on road ones do. I'm leaning toward the on road engines for my .12s..

 

[Tim_Duggan]

Marine engines usually run similar, if not the same timing numbers as the Car (on road) engines. Buggy engines generally have lower timings in the sleeve and in the crank. Some as low as 180 degrees duration open in the crank window. (They don't use as much fuel if they can't breathe) Nothing that can't be fixed by a competent engine builder B) Most engine builders would aim for at least 213+ open on the crank in a marine application, where fuel consumption and nitro% aren't an issue like in buggies. 215 duration / close at 65 ATDC is pretty common.

Marine engines tend to see a lot higher nitro %. Liquid torque.

Please don't take this as a shot Mike, but very few people on the planet have heard a 45,000rpm 2 stroke engine! (especially from a 21 engine with a car pipe) It's very, very easy to overestimate rpm. Even manufacturers do it - to sell engines.

32,000 would well and truly stand out over engines only pulling 28,000 under load, and is a more likely and realistic number. No mean feat either - still a tremendous accomplishment. Few people in the R/C hobby outside of pylon racing have ever heard 35,000rpm!

Tim