goldendesign04

Maybe its been asked before, but can you inline two nitro motors like they do with the gassers?

Is it possible, reliable, and practical? Well maybe not practical but sure would be sweet! I was thinkig along the lines of two OS .21s or something with the rear facing carbs.

slivic003

Hi , it is possible to connect to nitro motors . How reliable it will be is hard to say . Both engines will need the exact same amount of fuel going to them and tuned alike . If it is off it will cause the engines to fight one another . As far as pratical ....... probably not . You would get more performance out of a .45 , .46 single engine in the boat rather than inline .21 . Less weight and easier to use . Inlines would look and sound really good though !

goldendesign04

I dont see an issue getting the fuel to flow equally, though getting them tuned alike could be an issue Im just bouncing ideas around in my head an had visions of a twin powered cat like Ive seen in the gassers. [>:]
The heres my next question Ive seen that the CMB .45 is a geared drive on some web sites. How do you run that? does it use a tranny gear like a big truggie an could you set twins side by side with a single final drive? Like I said just bouncing ideas off you guys, I could be onto something or miles away from possible

rcollector

I believe I have seen pictures of a OPS inline twin that was made in the 80's . I could be wrong but I think there was such a thing .
There was a inline marine twin nitro made by taplin , but this was a long time ago. There is a hydro with a taplin in it on ebay right now.

BB Modss

There used to be a inline nitro that was slightly offset like a V twin but far less degrees of separation, Id like to get my hands on one of them myself!

stempak

Mhz had a twin .90 that runs real well and seriously gets with the program but their about 900used

firelite_marine

mhz even has a v6 nitro. i'd love to hear that thing but at around $3k i doubt very few, if any have a video of it to post here. must sound nice though, not sure of the power though.

stempak

Ya it must the .90's sound real good. And the thing is that if one cyl dies it usualy fires right back up because it had a on board ni starter and it didn't kill the other cyl. I believe P.I.P has a twin 1.ci available. I havn't really seen anything small. But 2 of those os 21's that are turboed and run like a .40 size motor would be trick.

I believe they have a triple .90 aswell all the trick stuff is on their german site and british. they also have stuff that's not on the sites!

BB Modss

supercharged .21's? got a model?

stempak

sorry turbo it's on their website it makes the same power as a .46

goldendesign04

could of sworn there was a thread about turbo/supercharging nitros maybe it was in the truggy forum. but to my knowledge you get no performance enhancement from it. something to do with the exhaust ports being higher than intake so all the extra pressure just shoves the additional air/fuel right out the exhaust without being used. wouldnt do it anyway have always like all natural motors. I was orginally just throwing around ideas back when i first posted this an ended up going with a heavily modified CMB .45 by Twisted Liquid (Now if only theyd get the damn motor to me its been a month since it was done[:@])

-Wayne

stempak

possitive pressure does work when done correctly as seen in the #'s of the os21. People try things and they don't know what they are doing. And expect double the hp, Anything less and it doesn't work. But the os 21 is basicly doubling the hp!

goldendesign04

Ive never trusted the "#'s" people claim on many things like how many times has a buddy of yours said "I once caught a fish this big...". I've been around motors my whole life an seen many over trumped hp claims an on the subject of supercharging I will refer to the post of the actual person I gleaned the info stated above from.
http://www.rcuniverse.com/forum/m_57...tm.htm#5796062
now am I a nitro 2 stroke engine guru.....not by a mile, heck MANY miles but I do know motors enough to know what this guy is saying is a varitable fact. If you have other knowledge about overcoming the problems associated with 2 stroke supercharging then by all means... share

still in any practical application i dont think any nitro motor that is 2 stroke can nor should be supercharged/turbo'd/or spray nitrous stick with what is a known power booster MORE CUBES!!

glennb2006

The big problem you will need to overcome to join two nitro's inline is the crankcase scavenging. Somehow you are going to have to join the crankshafts whilst maintaining the intergrity of each cylinder's cranckase. (I hope that makes sense to you all).

To do it, one of the cranks is going to need to be extended and through the backplate, to enable it to be joined to the other motor, whilst still having pretty good air tightness within the crankcase.

It might, as touched on, be an easier twin engine set up to drive them onto a common shaft, so the motors are set adjacent to each other. Alternatively, and this might be easier again, if you are hell bent on two engines, then two complete sets of running gear might be the best solution. IE, two engines, shafts, props etc etc.

As to the CMB .45 engines that are geared down, have a look here. http://www.iansboats.co.uk/
Whilst this one shows the gearbox for the Valvola, (.21) it's the same principle for the 45. http://www.prestwich.ndirect.co.uk/fsrv/gearbox.htm

They do a direct drive one too. The geared ones are typically used in FSRV where the drive is submerged and the 45 engine then drives a 61 size prop.



Glenn

stempak

nx express has a video on there website of there nitrous kit. it works exactly like a car! huge gains! check it out. possitive manifold pressure does work on 2strokes. It is like a car or anyother motor you can't just put a turbo etc. On and expect it too work it won't. I have personaly seen that 21 run and it does what it says. the #'s don't actually know but I would expect os to have very accurate #'s and if you dyno it I bet it would be very close to claimed #'s

2 separet motor's would also be very cool. And 2 motor's alway's sounds cool!

goldendesign04

got a link to nx express?

I decided to goto a very hot cmb .45 done by twisted liquid still waiting for it but i did get a phone call they sent it to the West side of my circle (same road both sides East,West have same numbers on house) got sent back[:@] some days things just cant go right. I guess I'll see it next week. If your interested check out my build it'll be bumped up again here soon as I'll start building once I have my motor in me grubby hands

glennb2006

Good engines, so long as you have a good pipe and the mods are good, then you should get bags of reliable power from the CMB.


Glenn

BB Modss

If its a .45RS motor make damn sure the crank was welded, ask any man that owns one, yes they make a ton of power and lots of usable rpm's, after a good mod and pipe, they break the crank, Iv had 2 of mine re-pinned and welded, no problems after that, the 1 stocker i have let the crank pin go after 30 runs, cheap insurance, also i agree, Twisted cant be trusted at this point, not with my money anyways.


Side note, Where is the website showing the twin OS engine? URL please.

stempak

www.nitrousexpress.com (under automotive!)the cmb should be a good way to go and fast as heck[8D]There should be no shortage of parts. And I've heard good things about them being fast and dependable.

glennb2006

Just to clarify my earlier point, when I stated I was not Au fait with Twisted Liquids work, I meant that I have no experience of them as a company nor of their product, so I am in no position to comment on their products.

If they are a reputable tuner / engineering firm then there should be no worries.

CMB's are quick out of the box.

Glenn

stempak

I have heard some bad things in referance to service of t.l racing, And have actually had my post erased on here for telling someone they mod engines.

goldendesign04

Im not going to say wether or not their motors are as good as advertised only time will tell since a guy i run with just bought 2 motors for his build a stock cmb 45 an one modded by t.l. so we will have a comparison in two different hulls (V an Cat) but their customer service has been top notch always got a call back on the same day of leaving a message on their phone (they apparently never answer the line but Will call back) in regards to the motor im waiting for they just typo'd my address an actually got it in today. Still at work so havent seen it yet but will definetly run home to check her out! Never had any of my messages edited for saying anything about them. I dont work for them nor do I endorse anybody in particular I am an equal opportunity offender but so far theyve been great
-Wayne

stempak

I have never done business with them. But alot of times if someone has 1 little problem they will blowup the whole situation and make it soundlike the company needs to be outabusiness.

Believe It

dunno about a inline 2 stroke...but OS does make a quad inline 4 stroke

http://www.osengines.com/engines/osmg1330.html