how does the .## system in engins work? for example my tr4 has a .16 engine would a .18 engine or a lower number engine be better or does it not affect it? also i would like to here some suggestions about a good engine to put on my cen tr4 ive been looking at the os .18 cv-r
tell me what you guys think.

the .12,.15,.18,.21,.27.......
is the engine size
the higher the # the bigger the engine

.15= .15 cubic inch
.18= .18 cubic inch

Most of the engines sold in the US are listed by their size in cubic inches as stated above. Some of the folks have started listing the engines by their cubic centimeter size which is a larger number.

As a general rule, larger engine - more power. This in however not always the case. Some of the better .12's perform like much larger engines, etc. It boils down to quality of build, tolerances, porting, compression ratio, etc.

Also, don't fall into the trap of paying attention to the quoted horsepower numbers. Most are pure BS.

If you are racing on a track then it pays to remember that its not always the highest horsepower that wins. If you have not developed the skills needed to put the power to the track all you do is spin your wheels or break stuff, especially on smaller more technical tracks.

If you are bashing in a parking lot seeing how fast you can go then you may want the biggest, baddest, most powerful engine you can buy and feed. And don't rely on the adds, they all say they are the best.

The OS has a good reputation for making useable power so it might be a reasonable choice as a replacement, not familiar with the engine you are running now so I can't comment.

Ed M.

so what your basicaly saying bigger the .## the bigger the engine but bigger isnt always better thnx yal you guys helped me out allot

PS I did some reserch and the engine i wanted to get had just .12 more horse power but now that you tell me not to belive the horse power they say it has il have reserch the engines a lil more.

I think you are beginning to get a firm grasp on the situation.

Ed M.

how much woulda engine with 5000 rpm more than my current engine help my cars speed would it make any difference at all?

what engine do you have?

CEN Racing Inferno NT-16?

look at this site they give you hp-rpm and prices
just click on the engine you want

http://www.nitroreview.com/TheDatabase/homeengines.cfm

If indeed you do get an extra 5,000 RPM's then it will help out top speed a lot. RPM divided by total gear ratio times tire circumference = inches per minute x 60 = inches per hour. Convert 1 mile into inches and do a little division and multiplication and that will give you theoretical miles per hour you would gain.

Ed M.

wow it is to early for math like that lol

wow you totaly lost me with the math and yes it is a nt-16 inferno.I did some calculations and i more or less calculated/estimated it would make it to maybe 65 if my car right now reaches 55.If that right im gona end up buying this engine http://www2.towerhobbies.com/cgi-bin...&I=LXGGP4&P=ML im gona check that website u mentioned earlier now.

Very nice website and it makes me want to get the engine i mentioned earlier even more, it rated it very well.

Wait i just read the rpms on my current engine and the .18 and my current one has more like 29,000 more is that right or a typo and if it is a typo how could the engine i have now have more rpms yet less horse power and a allot lower ratings?

ok i rechecked everything the .18 cvr has 28,000 rpm and the inferno has 25,000 so its only 3000 more rpms would that make any difference?

look in to the fantom .18
41,250 rpm
and 1.95 hp

no 25,000 on the .16 is where the peak hp accures
it has a limit of 33,000 rpm

and the os is 32,000 rpm max but it has more hp

I couldnt find that fantom on tower so il have to look on the web but first heres the engine i was thinking about getin http://www2.towerhobbies.com/cgi-bin...3&I=LXJFY9&P=K its better than both of them (better be costs almost twice as much![:@])

That fantom is nice but the .12 fits better in my car and there isnt that big of a difference in rpm or horse power and i really like how my old os engine has worked so i would have to go with the .12

yeah tower doesnt handle fantoms

don't get too caught up in rpm, they aren't that useful. the quoted numbers are estimates, there is no hard and fast limit for rpm. also, that is assuming you can hit that. wind drag, gear drag, tires all affect top speed by dragging down the engine. doesn't matter if your engine can hit 50,000 rpm if it doesn't have enough torque to overcome the drag.

torq=hp right?

nope, i've never actually seen a torque spec mentioned for any rc engine, ever. horsepower is basically just the power produced X the optimum rpm

o......