Complete Rebuild for 2007 Rhino 660 - which exhaust??

[LGustin]

Hey guys, I was on the forum when James made the break from the other forum then due to a change in direction with the career I got too busy to play. The stink of the new position is starting to wear off so now I am ready to play. I am hoping to have James do a complete Hot Rod rebuild on my 660, looking at going with either the 719 or 734 with all of the upgrades. I am not that handy with a wrench so I want to go with something that is very reliable and low maintenance and get the most bang for the buck. I figured if James is willing to do the rebuild he will take excellent care of me. The part I could use some experienced help with is which exhaust to go with? I don't fully under stand the idea of dual exhaust in a single cylinder engine. What is the advantage over say a Gibson system? I am leaning towards the Gibson, I figure that will give me the better flow for performance and I can silence it with a Benz during hunting season. Any suggestions will be researched. Also, any engine rebuild mods to consider or avoid? THANKS!! in advance for the help.

[08Rhino450SE]

ahhhh yes. the never-ending search for the best of both worlds: flow for more horsepower when you want to quench your thirst for speed and quiet for the other 85% of your riding.

flow is a measurement that peaks at high rpm. your engine is basically a simple air pump. the more air it breathes in and out, the more fuel you can mix with that higher volume of air. high flow numbers depend on how much time you spend near the rev limiter…

people love the thought of going faster, but when they put that wide open exhaust on their bikes they (and their friends and neighbors) find out how loud that open exhaust really is and then they have to take some of that flow (and sound) back out of that exhaust.

when designing an engine build you should talk to james and let him walk you through the exact kind of build you want. he has all the go-fast parts you will ever need and has done it enough times to know what works and what doesn't.

also, there is a lot of information on engine theory right here…
http://hotrodforums.net/forums/forum...ne-Performance

[Kenny G]

Very well stated Denny.

[LGustin]

I have an email out to James. I will wait for his reply.

[jimclemjr]

LG- I just got my bike back and am fairly excited about what James did. In consult with James, I too wanted a reliable unit for mostly trail riding and not interested in high speeds or bragging rights, so that considered is what I believe I got. I have only been up and down the block a couple times so have limited testimony. I did a new welded crank out of necessity with CP forged rod, 734 BBK with 11:1 forged piston with JBS head-carving for final 10 or 10.5:1 final compression ratio, Viking cam, Raptor valve springs, Viking injector, MSD mapped for setups and 8000 rpm rev limit by James. New oil pump, chains, bearings, seals etc. for a tight like-new motor. Slugged clutch. Notice Sig that I am still running the Unleashed sheave so may give away a little performance due to that fact. Notice my tire size which I feel is always important in these discussions.
In low range it feels like it is pulling the front wheels from a dead start on pavement and it is instantaneous when you punch it. James said while testing/tuning that it is one of the quickest bikes from 0 to 10 mph he has driven. It is faster too but do not know how much more yet. Guessing +/- 55 mph. All with factory exhaust. I have an Alba exhaust, but not mounted yet, James believes exhaust will not make that much difference with the Viking cam since it does not have the duration of the hotter cams. I will try the Alba soon and let all know the results but not sure that I want anymore noise as I just got Medicare this week and trying to save the hearing I have left lol. The lift of the Viking cam gives it the bottom end power and the idle smoothness and reliability of the OEM at basically the same price, so that is what I chose. More cam duration is where the higher HP breathing and RPMs is going to need the performance exhaust. The Yama engineers obviously use the same basic engine in the bigger bikes but need to provide more getup for these heavier machines, they probably use some lower gearing and they obviously do not care about faster speeds. That bottom end power and reliability is big pluses for me. Ripping along a trail or gravel road at 40 to 45 is more than enough for me. And so with a 734 cc I guess I have more power than a factory Viking VI. Yee Haw!
Hope this helps your decision.

[Kenny G]

jimclemjr, Sounds like you got a beast from the JSB compound. But I'd have to dis-agree about the duals with a less built motor. As I noticed a much more performance improvement with the cam; bored throttle body when I put duals I my bike. Before the duals there was more mellow bottom end and with the duals it's an animal when the peddle is applied. I ran my bike for a year before the duals and there is a big power pull difference. Much like Denny stated before, takes air in and air out to eat fuel and with my experience that's proven true. Once you install the Alba exhaust you might see even more torque than you're experiencing.

[jimclemjr]

I am anxious to install as I do not have the experience in the difference so certainly appreciate your input. I plan to do at least one ride with OEM and then install Alba so I can have a point of reference. Before I go I may also grind the OEM header welds too. I trust you know that the Alba is not a dual so it may not blow as much as the duals, but that may match up better with my cam anyway, we shall see.

[Virgils686]

I just talked to JAMES this week about doing a build for me and he said he is not gonna be doing any for a while.. Said he just to busy down there.

[LGustin]

I just talked to JAMES this week about doing a build for me and he said he is not gonna be doing any for a while.. Said he just to busy down there.

Bummer. I am not a gearhead and don't know anyone that I would trust to open my rhino up. That seems about how it works out for me; always a day late and a dollar short. I was ready to tow the bike from Arkansas to WV.

[jimclemjr]

If you are enough of a Gearhead to take the motor out and strip it down, then think about crating and shipping to a reputable builder. Probably cost about $200 for that and that saves a lot of labor time on the R&R. And a lot of builders are more agreeable to that opportunity. Big challenge is the tuning when you get it back together. Air /fuel meter will cost but simplify the process.....