HPI RS4 3 Engine options

[crxman91]

What would be the best engine for my car? I am new to the R/C world and curious what would be the best options for me. I am not going to race it, just mainly play around the neighborhood and parking lots.

 

[JESSE G]

If I was you I would get the original motor your hpi came with its a .15 I've heard they are good motors and parts are easy to get for them plus it will drop right in with no modification. I had an Hpi for a couple months and only ran it once sold it and bought a T-Maxx anyway it had the .15 engine and it fired right up and would move the car right along nicely. I think that would be a good way for you to start then later on you can drop in a more powerfull motor. good luck getting your car going. The Rs4 is a sweet car I sometime wish I still had mine I just diddnt have anywhere to run it around where I live thats why I bought the 4x4 Maxx.

Jesse

 

[olds97_lss]

OS 18 baby!

I agree with JesseG though. Get familiar with the car and learn with the stock engine. When it dies, you will have a little more experiance under your belt and can surf the net in the mean time to see what other people run.

I think most guys stick with a high end .12 to get screaming RPM's for on-road purposes. The larger engines tend to have more low end torque and are suited better for off-road applications. But the extra torque means you can gear it higher...

Either way, take your time and read what others have done. That's a popular rig and there's a lot of info on it all over the net.

 

[AC48]

If you want a cheap, reliable, powerful engine go with a O.S. 18 CV-RX. I have not heard anything bad about this engine. In a RCCA article it was the best out of like 10 .18s including the Sirio .18.

 

[Revo Rancher]

You did not mention if you had the SS kit, but the SS kit I just picked up has the .12 and it is supposed to be a pretty good motor for it's size. The JUST released SS kit has an .18 and it is supposed to really pull some power at the lower end, but with a 2-speed trans I was not too worried about low end on teh .12 as gears can be changed. No big changes between the two kits other than motor size.

I am about halfway through building the kit. Can't wait to run it. The build step I do tonight is the motor and clutch.

 

[AC48]

The low end on the .12 in the older SS kit sucks major. That engine absolutely no low wnd at all. Once it got past like 15,000 RPM or so it had some okay power, but is defientely lacking on the low end.

 

[crxman91]

it is the ss kit with the .12

 

[Revo Rancher]

crxman:

I just finished building mine tonight except for gluing the tires and installing a receiver. I was thinking that if the .12 was not doing the job, after I got used to the car, that I would consider the O.S. 18. I might see what the specs are on the new HPI 18 and if it is close and cheaper might even go that route. I note that they upgraded the shafts and power take off ends for the extra power.

 

[c3racing0082]

Is the plain OS cv-x .15 engine decent compaired to a Fe or a T-.15 engine?

 

[crxman91]

If you want a cheap, reliable, powerful engine go with a O.S. 18 CV-RX. I have not heard anything bad about this engine. In a RCCA article it was the best out of like 10 .18s including the Sirio .18.

which 18 cv-rx should i get there is several of them ie...
OSMG2102 .18 CV-RX ABC
OSMG2104 .18 CV-RX ABC
OSMG2105 .18 CV-RX (S)ABC

 

[AC48]

For the HPI RS4 3 cars you want the rotary carb version, which is OSMG2104 .18 CV-RX ABC.

 

[crxman91]

For the HPI RS4 3 cars you want the rotary carb version, which is OSMG2104 .18 CV-RX ABC.

what items will i need to purchase also to put this in my car? HPI RS4 3 12ss

 

[AC48]

That engine will be a direct drop in. Just swap over your flywheel/clutch over to the new engine and attatch your throttel linkage to and mount it.

 

[NCNitro]

Hey any of you guys actually have an RS4 3 with an OS engine in it? I am trying to put a cvx .15 hyper with pullstart in mine, and I am having a hell of a time. The pullstart assembly hit the upper deck, so I dremeled it down, now it hits the rear diff. I can't get the engine to mount up properly, or get the two speed gears to line up correctly. The OS pull start is just too deep. What engine mounts are you guys using? What the hell am I doing wrong?

 

[AC48]

I had a similar problem with my XTM .18. I had to dremel away part of the diff case for it to fit. If the pull starter hits the chassis you can put some washers under the mounts, but those are a PITA when you take your engine off or put it on.

 

[crxman91]

i bought the os 18 engine broke it in and man it screams. What would be a good wheel tire combo to get so i can get some traction? also what would be a good pipe to get for this combo. (RS4 3 .12SS converted to an OS .18)

 

[AC48]

For tires I really loved my HPI Super Radial tires. They gave me great grip. http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=000542896&I=LXM984&P=K As for wheels any 26mm wheel will do the job, its your preference on those.

For I tuned pipe, I loved my THS pipe for the RS4. http://www2.towerhobbies.com/cgi-bin/wti0001p?&W=000542896&I=LXCPX4&P=K