I've never changed an engine before...

[Igman87]

I have never changed an engine before but i want to get something much more powerful than the one i have. I found a .15cxp from smartech but it just doesn't cut it. When I am choosing a new engine what are the possibilities? Can i pretty much use any .15 size engine? I've also heard of different shaft lengths, what do i have to have? Will a .18 engine fit? I'm running the .15cxp on a smartech winner pro - I got it just to supe-it-up. anyways, I know someone knows these answers. thanks

 

[olds97_lss]

What's the vehicle? You gave an engine, and if it's like other engines there are different styles to suit different vehicles. Post the make and model of your car/buggy/truck and it will make it easier to get info back.

There are plenty of .15's out there. I use the OS .15 cv-r(x) on my xxx-nt and it has more than enough power to shoot that thing around. It's more of a point and aim -----> fire!

 

[Igman87]

Originally posted by olds97_lss
What's the vehicle? Post the make and model of your car/buggy/truck and it will make it easier to get info back.

"I'm running the .15cxp on a smartech winner pro" as I said before. It's an offbrand, but i just wanted a project to work on and see if i could make it into something.

 

[kwong2001]

You have a choice between threaded cranshaft (shorter )and SG crankshaft (longer)

Also, you gotta know if you want rear exhaust or side exhust.

And gotta know if you want slide carb or rotary carb.

Your manual should say what kind of crankshaft you have. Or you could take out the engine, take off the clutch assembly and look for yourself.

 

[olds97_lss]

Sorry, but you said:

I found a .15cxp from smartech but it just doesn't cut it.

This made me think you bought the engine from smartech, not that it was on a smartech vehicle.


Do you have a link for the manufacturer? I'd like to see the engine diagram and engine spec sheet if it exists to let you know what you need to get better performance.

 

[Igman87]

sure, i think its smartechracing.com however that site is kinda slow. i sure appreciate the help. thanx

 

[Candyman]

Unfortunately there's little information on that ride on their site. So I think you're going to at least have to pull the engine. If you have a digital camera, strip the flywheel and clutch off and post a pic of just the engine. That will give us a better idea of what shaft is needed. If it's a standard .15 size, you have a lot of replacement options. Any .12, .15 or .18 size should drop right in. The OS is a good choice for sure. Again, just want to make sure you get the same shaft...

 

[aciddream]

:bow:
I doing an engine swap for the first time also, guess I'm going for a .18 (putting one on a HPI RS4 Nitor MT)
Hardest problem is finding correct type of shaft:flaming: :flaming: :flaming:

 

[kwong2001]

not really, it's either SG or threaded. two choices. The real killer is the exhaust since that determines your header and in some cases, the exhaust. Get the wrong one and that's more $$$ out the door.

 

[Igman87]

thanx for clearing up some of those questions, I'll have to find my digital camera. I still dont know the difference between the two kinds of shafts. I bet there's a thread about that but i can't find it.

 

[SlingItX]

Difference in Shafts

Here you go:

SG SHAFT-

THREADED SHAFT-

-SlingItX

 

[olds97_lss]

Just an addendum to the pic post... some of the threaded shafts are long and some are short. Typically, you can cut a long one to suit your application. But, you cannot make a short one longer without a new crank or some sort of an adaptor.

The long threaded,short threaded and SG are normally posted on the sites you buy engines from so you can make an educated purchase.

 

[Igman87]

oooh, now i understand. thank you for taking those pic's. I think i feel confident to make a guess now. thanks again.

 

[aciddream]

Thanks for the pics/help
I kept the pilot shaft off my old .15 FE (HPI) and have ordered a OS .15 cv-r with a standard threaded shaft. Along with some aluminum engine mounts hopefully I can keep the flywheel and other parts (clutch bell - pinion) and etc. so the swap won't be such a headace. Rest assure if I run into some problems I'll search and post for help
:shrug:
Can't wait till it get's here
Does anybody think there would be a problem breaking the engine in (idle) with 15% 2-4 tanks + slow drive 2-3 more at 15%, then re-tune and run with 20%. I won't really RUN/bash the engine untill about 6-8 tanks have been through it but I want to use 20%. I don't see any problems with doing this. Give me some opinions.
Thanks

 

[olds97_lss]

I had the OS 15 cv-r(x), 2 of them actually. One is going to start gallon 7 when it warms up. The other is a replacement that i tried in my maxx. Not enough juice for the maxx. But works well in my stadium.

I broke it in like this:
temps to 125-150
1st tank, high idle
cool down to ambient

2nd tank drove in figure 8
temps around 150
cool down to ambient

Had to start leaning it out a bit here on out to get the temps up. You want to get to 200 as soon as you can after the first couple of tanks without overrevving it.

3rd tank drove in figure 8
temps around 180-200
cool down to ambient

4th tank drove in large circles gunning it to 1/2-3/4 throttle periodically
temps around 200-220


5th tank drove in large circles gunning it to 1/2-3/4 throttle periodically
temps around 220
Shut down, let cool to ambient.

6th, 7th, 8th, ran as rich as possible but keep the temps up over 200. Prefferable 220-230. This is my good running range. Also, i never shut it down after tank 6 for a cool down.
After 8, i killed it and let it cool down to ambient.

9th-6gallons, tuned for performance while trying to keep the temps around under 240.

Each time i shut it down for the cool down period and after ever time i killed the engine through all 6 gallons, i always put the piston at bottom dead center.

To do this easily, pull the glow plug, look inside at the piston while rotating the flywheel by hand. When the piston is at the bottom of it's stroke, mark the flywheel with fingernail polish so you don't have to pull the plug again.

Like i said, this is what i did and still do. Always BDC and always use after run oil. I will be starting gallon 7 when it warms up and there is still plenty of compression and power in that engine. I really haven't noticed it get weak yet.

I wouldn't recommend breaking in an engine unless the ambient temps are above 50 outside.

Good luck.

 

[aciddream]

:worship: :worship: :worship:
Thanks this is exactly what I was lookin for, Unfortunately it's still in the 30-40's temp here so It will probably be weeks b4 I can break it in. Thanks for the BDC tip I have only heard that once before and forgot it. I guess I can get a gallon of 20% instead of worrying about abusing the engine any. When you say after run oil I've been told wd-40 and/or 3 in 1 oil. I was told wd-40 was better due to it's water displacement (hence the WD) are these safe to use any prefference/amount.
thanks again

 

[olds97_lss]

You should use after run oil. WD-40 from what I've read, isn't a good every day substitute. It's ok if you have nothing else. But I would suggest getting some real ARO. Or, use automatic transmission fluid. It's $1.50 a quart and is pretty much the same stuff as ARO.

When using ARO, I let the engine cool completely. Pull the glow plug, put the piston at top dead center and put drops in until it's level with the top of the threads for the glow plug hole. Then, I lean the vehicle at about a 45 degree angle with the exhaust port on the high side. Then I slowly pull the cord, slowly... if you rip on it, all the ARO will blow out in your face. I then put the piston back at BDC, put the plug back in, and leave the truck sitting with the exhaust side of the engine up still at an angle and allow the ARO to flow into the crankcase.

This is what I do and my engines are lasting. I'm sure others have other recommendations as well.