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SX Viper 1049cc


Lifetime Member
Mar 3, 2005
western Massachusetts
Who is interested in a 4 Stroke SX Viper? Well then, you have come to the right place! I recently picked up a 2002 SX Viper ER, and while the triple 2 stroke is a neat engine, I have not owned a 2 stroke sled since roughly 2006, it was quickly realized that I do not miss the exhaust.... or the oil that helps create it. I just so happen to have a 1049cc Vector engine tucked away, thanks to Barn of Parts @hibshman25. It's pretty much complete, harness, gauge, EPS even! The SX Viper will be its new home.

The engine weight does concern me here, so I'll be looking at ways to reduce it. How sucessful will a diet be? Probably not as much as I'd like... but maybe we'll get silly and go for some titanium rods or what have you? Lighten the crankshaft, titanium valves... it will be all motor, no boost.

There are plenty of other fun ideas jumping around in my noggin, many of which will likely find their way on to the sled.... so as usual, more to come.

I'll add pics asap.

Strapped down tight, just arrived home.
The sled will see plenty of rough trail use, so it will not be too low. Plus a jacked up trailing arm sled just looks downright mean... It will be a balancing act. Ultimately it's just the chosen platform...

Rear suspension will be a 128" Mono II. front may get long arms, maybe I'll mess with some custom trailing arms. Ohlins shocks with PDS all the way around, if I can track some down.
Wow I didn't even know they made those. Very cool. The LS7 v8 uses Ti rods, there is a issue of rod ends having appropriate clearance if they scrap at all you get Ti dust in the oil system and it will take out the whole motor. That is my only reservation on Ti rods. I still might run them someday but just a FYI.

IMO I would get the build done without them. The performance advantage in the LS world is barely noticeable over I beam forged rods and that is using 8 of them compared to 3. If memory serves actual weight savings per rod is around 150-180 grams. So you may save a single lb but probably more like 1/2 lb.

Lets see that thing tore apart and the nytro motor in there!
Thanks for the heads up. A closer look reveals Crower plasma sprays the rods, which should prevent such issues. 450 grams is almost one pound... that's huge at 8600 rpm. Still, maybe I'll simply look into the Crower Maxi Lite billet steel...
Its actually not that huge, sounds huge but it is not. I spent a LOT of time talking myself out of Ti rods. I really wanted them just for the sheer physical weight savings but its not even worth a single HP at 650hp LS engine said to 'rev quicker' but again nothing quantifiable. If cash is no object go for it but otherwise save it for richer days....
It's the reduction in inertia that's huge... and that can significantly aid durability and schmoooovness. I can afford them, but the younger me, which learned to do more with less, always wants to try and underdog it (relatively speaking).
I have always thought it would be fun (and cool) to build and all motor Viper, but despite all my internet searching I have never found anyone who has done it or where to get performance parts for the 1049. I am very interested in watching you as you do this. I know everyone says just turbo it for the most bang for the buck, but I have always loved built Naturally Aspirated motors with their quick throttle response and awesome sound.

I know this isn't naturally aspirated, but you gotta love the sound.
Yes, all motor is fun!

The race Nytro set up is a great place to start for all motor. Ported air box, thinner Cometic head gasket, cam timing 105 intake, 107 exhaust, 2011+ Apex exhaust couplers, custom header and muffler... possibly Hindle? Fuel controller.

The introduction of the 998 in the YXZ1000r brought out a bunch goodies. CNC heads, cams, stroker crankshafts. Unsure if any can be applied to the older 1049.

I'd like to see if the piston oil cooling jets from the 998 Turbo engines can retrofitted to the older 1049. We could probably lighten up the pistons a little.
I have a hindle slip on that I took off my viper if you go that route. Sounds awesome, but it was pretty loud for a day of trail riding.