Are Side-by-Side Engines more Reliable than V-Twins?

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mgold · #1 Post by **mgold** » Mon Oct 26, 2009 4:29 am

I was wondering what people's experiences here are with Side-by-Side Engines vs. V-Twins? I've heard Side-by-Side mounted engines and single piston engines tend to be more reliable than V-Twins. Is this true? Are Side-by-Side Engines more Reliable than V-Twins?

Johnj · #2 Post by **Johnj** » Mon Oct 26, 2009 5:10 am

When you say side-by-side I'm guessing you mean twins like old Triumph, BSA, Honda 350/360/400, and all the rest. Triples like Yamaha XS750/850 and modern Triumphs, and the in-line 4's from everybody.

It depends on many factors. The older bikes aren't as reliable as the newer bikes. Go figure.

What kind of bike are you thinking about? I'm pretty sure somebody here has rode one, at some time or another.

jstark47 · #3 Post by **jstark47** » Mon Oct 26, 2009 5:30 am

"V twin" is too broad a category to assess reliability. After all, V twins can run the gamut from air-cooled long-stroke pushrod narrow-angle single-pin crank units like a traditional Harley, to liquid-cooled oversquare DOHC 90-degree units. And you can find the same design variation within any other broad category like vertical twin.

bandit600 · #4 Post by **bandit600** » Mon Oct 26, 2009 10:57 am

And on behalf of the BMW folk, don't forget the boxer twins

At first based on your question I thought you meant reliability between V-twins vs parallel twins but after reading the others responses I see there are many ways to interpret your question so please elaborate, we love to talk about motorcycles

I'm partial to V-Twins so you might not get an objective answer out of me...

But the short answer is that as johnj & jstark said it's too difficult to pass judgement on cyclinder arrangements alone. There are so many other factors that influence a bike's reliability so bike to bike is the easiest comparison to make.

Also with current manufacuring tolerances and build quality, barring running an engine without oil or coolant, it's more likely you'll run into issues with electronics, fueling systems, clutches, transmissions, etc... before your "engine" fails you in IMHO.

#5 Post by **Wrider** » Mon Oct 26, 2009 11:34 am

I've seen HD, Suzuki, Kawasaki, Yamaha, Honda, and BMW twins, both performance and standard cruiser V-Twins last over 100K. I've also seen CBRs and GSXRs last that long too. With the right maintenance and such just get the kind of engine you want and don't worry about it.

paul246 · #6 Post by **paul246** » Mon Oct 26, 2009 12:49 pm

I suspect the OP is thinking along the lines of the rear cylinder of a V-Twin (aircooled) not getting cooled as readily as the front cylinder might. Just a WAG.

Lion_Lady · #7 Post by **Lion_Lady** » Tue Oct 27, 2009 11:42 am

paul246 wrote:I suspect the OP is thinking along the lines of the rear cylinder of a V-Twin (aircooled) not getting cooled as readily as the front cylinder might. Just a WAG.

One of the reasons I like my flat twin (boxer) engine... they may look kinda odd, but in almost 60,000 miles, I've not had the two cylinders on my BMW get far out of sync with one another.

Sticking out each side, they're equally exposed to temperatures, etc AND its a piece of cake to get inside either one without having to take the rest of the motorcycle apart.

P

#8 Post by **storysunfolding** » Tue Oct 27, 2009 1:57 pm

Lion_Lady wrote:Sticking out each side, they're equally exposed to temperatures, etc AND its a piece of cake to get inside either one without having to take the rest of the motorcycle apart.

Isn't that just the best reason to add upgrades though? New suspension, new brakes, new electronics etc while you're in there. Bada bing, bada boom your bike is 100% improved from what should have been only a two hour valve job.

Lion_Lady · #9 Post by **Lion_Lady** » Fri Oct 30, 2009 8:23 am

storysunfolding wrote:
Lion_Lady wrote:Sticking out each side, they're equally exposed to temperatures, etc AND its a piece of cake to get inside either one without having to take the rest of the motorcycle apart.
Isn't that just the best reason to add upgrades though? New suspension, new brakes, new electronics etc while you're in there. Bada bing, bada boom your bike is 100% improved from what should have been only a two hour valve job.

R1150R/Rockster:
Electronics: (under the seat). Suspension upgrade: check. "New" brakes: not needed (ABS). Um. What was your point?

P

#10 Post by **storysunfolding** » Fri Oct 30, 2009 9:44 am

Oh Pam you need to ride more! I've already worn out a suspension, a few sets of brakes and decided that you can't have enough farkles to not want to redo the electronics to best accomodate them.