Custom Fighters - Custom Streetfighter Motorcycle Forum banner

Looking for an engine recommendation for a SXV

2 reading
7.3K views 11 replies 5 participants last post by  Talon  
#1 ·
Hey guys it's looking like I'm going to finally end up getting that Aprillia SXV rolling chassis that I've been eyeing up for a while now. So I'm starting to think about what engine I should put in it.

I'm not going to put the stock engine in it as I want something reliable that I can ride on the street or highway without having to do maintenance every other week. Sadly there's no race track anywhere near me so this will be an almost exclusive street machine. There's a possibility of it seeing some dirt, meaning I'll be tearing around our fields and down gravel roads with it.
I know going with a more reliable engine is going to make the bike heavier and possibly have less power which I'm ok with. Cost/availability could be a bit of a factor as I'm in southern Alberta which has one of the worst used bike markets ever. Vancouver is only 12 hours away however.

Anyway I'm looking for some recommendations of engines that I should be researching to swap into this thing.

For reference the stock engine is a V twin, weighs 75lbs (It's a dry sump tho so the oil pan is separate), makes 61hp at the wheel (claim 70 at the crank), only 35 ft/lbs of torque, it's also quite compact.
I didn't realize how little torque it made till now.

Here's what I've thought of and read so far.
The 650 ninja engine would work. There's a dude on youtube riding around with one in his bike. It makes almost the same HP as the stock engine, should be super reliable, are easy to get but weighs 60 lbs more (135 lbs).

Smoker's custom motard build is using a RZ350 engine which would be awesome but I want to go with a 4 stroke. Easier to use on the street and I don't know anything about 2 strokes.

I just started looking at KTM engines. An LC4 690 weighs only 88ish lbs, only 13 over the SXV, puts out 60 - 70ish HP?, would be expensive to get and I'm also not sure about the maintenance/reliability. But I think it'd be a good fit. And it's a thumper. ALSO has 60 - 70 ft/lbs of torque.
Now an LC8 is about 50 lbs more but makes 80 - 90 hp. I'd wonder about it fitting in the frame tho.




So what other engines should I think about?

I'd like to have something comparable to the stock engine that's not too much heavier. I could go for a smaller displacement engine as long as it has decent service intervals and is the same weight or lighter and somewhat inexpensive.
I think reliability and light weight are really what I'm after. The less power it has the less trouble I'd get in right?
 
#2 ·
Can you get motors from the states or will that cause a registration problem? Seattle seems closer than Vancouver if you could get US engines. SV1000 and SV650 motors are V-Twins, but heavy. The fuelie SV650s run 74hp and 47 lbs ft of torque. A SV650 motor weighs in at 134lbs if I remember correctly. The Ninja 650 motor is a parallel twin and I can't imagine it would fit in the SXV. I am at work and can't see youtube to find your example.

I can take some measurements of the SV650 motor tonight if that would help.
 
#3 ·
Sure that'd be great. I was thinking about an sv650 engine as well. It seems to be almost identical to the ninja engine only a V twin. I thought that it'd be a bit bigger as the cylinders aren't right beside each other.
I haven't looked into importing an engine from the states yet but I've brought a couple of bikes across the border before. It's not that much of a hassle.
 
#6 ·
It may be. The oil reservoir is back up in the frame so that'll free up a bunch of space once it's out.
MikeGyver is going to get me some measurements of an SV engine once I message him back. I'll papercraft a mockup of and see if it'll fit. They can be had cheaper than the kawi engines, have almost exactly the same characteristics and there's probably more aftermarket support for them.
If that won't work then I'll get a kawi engine.

I unfortunately won't have $3000 to spend on just an engine, I think a KTM engine would do well in there.
 
#8 ·
Derp. Why didn't I look at a DRZ engine before... or would I be totally bored with one of those?

They're pretty light, only 90 pounds, have good service intervals and probably can be found fairly cheap. Only the power is like half of what a stock SXV, until you do some mods.

Or an XR650R engine. 88 pounds, has more potential for power than a DRZ I'd think.


I'm thinking lighter is better. either of those would be almost 50 pounds lighter than an SV engine.
 
#11 ·
I have this bike. The 2007 SXV450

Image

Image



I don't get the hype about it not being reliable. I've ridden 7 rounds of M1GP (over 40 races) with the bike and never had a problem. My motor is stock. I make sure to warm it up before I ride it and I change the oil frequently and it's NEVER given me any problems. I have the fully unrestricted motor as well. I've also done over two dozen trackdays with the motor between race rounds.


If you take care of the motor and check the fluids on time, you're golden. NOTHING out there will match the motor that's in the frame from the factory as far as weight/power. I'd just use the motor that's meant to be in there.
 
#12 ·
I don't quite have $3000 for an SXV engine. I really wish i did. My friend's 550 was the best bike I've ever been on.
Also I was looking for less maintenance as this will probably be my only street bike for a while once it's up.

What's the maintenance schedule on the 450 like? Similar to a MX bike?

Either way I ended up buying that XR engine. Hopefully it fits. If not I'll probably make a crazy go kart with it.