Which Engine?
 

Ive got an Ultima ST GP and the GX-15s died on me.[&o] I need a replacment engine and thaught i might tune it up a bit at the same time. I was thinking of puting either an O.S. .15 CV-X or an O.S. .18 CV-RX w/11J Rotary Carb in it, will these engines go in OK with some minor mods. Or can anyone recomend an engine to me?[&:]

RE: Which Engine?
 

i would get a o.s. .18 bc they are very good


hope this helps


-Ryan

RE: Which Engine?
 

the OS .15CV-X is around $80, is dead-solid reliable and will run forever. Go with that, it's a tenfold improvement over your GX15, and you'll love it:D

RE: Which Engine?
 

yea get the os.15cvr, i seen one run before i they haull *****

RE: Which Engine?
 

not the CVR, the CV.

RE: Which Engine?
 

oh ooppss, i am used to hitting the R when i type and think of OS( cuz ima buy a .18 cvrx)

RE: Which Engine?
 

Are these engins actually more powerfull than the stock GX-15?

RE: Which Engine?
 

The CVs aren't....

They are reliable and easy to start but weak.

Nitro Rustler Racer was right to hit the R... the R engines are much stronger. Get the .18 cv-r [X if ya need it too]... I have one and it is great. It's stronger than the mega-expensive Sirio .18 out of the box and much easier to tune. You can't go wrong with the OS18, Tower still has them for just under ONE HUNDRED DOLLARS BUT THEY WON'T STAY THAT WAY... Definitely get one now...

RE: Which Engine?
 

and yes any good engine (read no RTR engines) will be a BIG step-up from the GX-15. That engine would make a mean paperweight though!!! [>:]

RE: Which Engine?
 

frost, do you have to convert the trans to metal so it wont shread with the .18 cv-r?

thanks.

RE: Which Engine?
 

That is a question with no definite answer... Another reason I can't say is that I don't have a Rusty, so I have no idea how strong their tranny's are... My Epic 18 (before porting) tore up the idler gear in my RC10GT with ease... on the other hand, my cheap Tower ST15 ran the Epic longer, with a tighter slipper, and never got torn up. Amsterdamn's Evader had an idler gear torn up after switching to a Wasp 18...

In all cases a hard gearset is available, but other things too have an influence. We run our slippers TIGHT, because our trucks stay on the street (the Savages are for off road) and keep our diffs tight as well. These things are hard on the tranny and not how you would set up something that runs off-road....

RE: Which Engine?
 

Thanks for the help:D, im gona get the .18, so on a similar note, what manufold and muffler do i get?

RE: Which Engine?
 

not sure about the pipe, but does anyone know who makes metal tranny gears for the rusty?

RE: Which Engine?
 

if i change my idler to metal will the last one in the diff shread?

thanks.

RE: Which Engine?
 

When my Idler tore up the top-shaft tore up too... I bought a titanium top-shaft, steel idler, and an annodized aluminum diff ring gear. When I put it back together I left the stock plastic diff ring gear in and kept the metal one as spare. I haven't needed it yet.

Just run what you have stock, if it tears up, then upgrade, but not before. Like I said, my ST-15 had a tougher tranny and never needed the parts... maybe yours won't either.

RE: Which Engine?
 

If you plan to run the stock gears, make sure the gear mesh is set properly. That's something that leads to shredded gears. The engine makes about 1.6hp. So it's basically like putting in a modded .12 italian motor in your car. Expect a lot of wheelies, fast acceleration, and serious ballooning tires.

RE: Which Engine?
 

Thanks for the gear advice, ill make sure they are all in properly but do i treat the OS .18 like a .15? Its got a .15 crank case so i need to know weather to use a .15 manufold and muffler. I want to use this http://www2.towerhobbies.com/cgi-bin...?&I=LXUN86&P=7, will it work well with the .18?

RE: Which Engine?
 

Frost, i have an rc10gt too, what were the exact gears you put in the trans to replace the stock ones?
what gear ratio are you useing and what is your speed with them?

thanks.

RE: Which Engine?
 

I'm running 18/65 right now... I'm sort of relegated to running that spur, it's a RR steel spur. It is still too low for the ported Epic. I am going to order a 20 and a 22 next time I order parts.

I saw in another thread you were talking about I beleive 18/63 or 62. This is an excellent choice for the OS18. There will be much more acceleration than before, and more top-end too, topping out around 45 with short tires such as Road Rage IIs. Forget speeds people claim, I am working on some video with radar in it...

RE: Which Engine?
 

Is the epic better out of the box than the OS?
i too am runnig with the steel spur but was in doubt that a bigger than 18t clutch bel would fit in corectly
i dont want to change the sput if the clutch bel fits
If i get the titanium top shaft and steel idler will the bottom last gear in the trans shread?

thanks.

RE: Which Engine?
 

...

RE: Which Engine?
 

Out of the box the OS is a tad stronger... they are REALLY close in the real world. From a mod. standpoint the Epic has more to work by far, so there is REAL potential there.

As far as fit, I have no idea, I haven't tried it. The worst case scenario is that you have to make the slots for the mount longer on the front side to let it slide further.

That "bottom last gear" is the diff. Like I said, I had an alloy one, but I put it on a brand new diff. I decided to leave the stock diff in until it dies. It has held up just fine so far though. The ported Epic running 30% Race broke the titanium top-shaft a week or so ago...

RE: Which Engine?
 

you broke the titanium shaft!
how the hell? i know the stock steel shaft wont hold up to the steel idler but the ti shaft was my only hope.
what ti shaft did you buy,HG?
i was expecting to bulletprof the tranny.

thanks.

RE: Which Engine?
 

Yes a 18t cb will fit with the rr steel 65t spur. You have to move the engine mount all the way forward. I am running that set up right now.

I'm ruinning the steel idler on the steel shaft. No probems here...