Motus

[ericheath]

Not doubting you, just asking to know, but how do they make more torque down low?? More lift??

[JSBail]

I don't think the fact that it's a pushrod engine has anything to do with it's willingness to put out solid low end and mid range TQ but more so it's bore/stroke ratio combined with the fact that it's 1650 cc's explain the impressive TQ and HP numbers. All in all I like the MOTUS V4 a lot mainly because it adds some diversity compared to other American companies that seem obsessed with V twins. Nothing against V twins but there are other designs to choose from and the pushrod Motus V4 make it unique.

[sunnbobb]

Dang that is a nice bike.

[Sugs]

Not doubting you, just asking to know, but how do they make more torque down low?? More lift??

Yes, it isn't the pushrods specifically that creates torque, I was speaking in a more general sense of pushrod versus overhead cam engine design. Like JSBail said, its more about displacement. Pushrod motors are more compact than their overhead cam counterparts, so they can be larger displacement in the same or less amount of space, so more power. The larger displacement is what helps the torque down low in the rev range.

[ericheath]

Fumbled around the web and couldn't find a definitive answer. OHC tend to be able to rev higher was all I could find. Thanks for the info anyways.

[WingMan71]

Saw one close up at a motorcycle show in Atlanta a year or so ago.

Nice bike, well built, fit and finish is great, plenty of performance.

Price... outrageous!

Market... greatly limited by price.

That said, I'm sure there are some folks, way richer than me, who will have to have one. (Maybe they can get a "two-fer" and give the second one to me!)

***

[Sugs]

Fumbled around the web and couldn't find a definitive answer. OHC tend to be able to rev higher was all I could find. Thanks for the info anyways.

Sorry if I was a little unclear in my first post, it was a bit incomplete. Easiest way to understand the differences between the two engine philosophies is to search google for Chevy LS(pushrod) vs Ford Coyote(DOHC). There are several comparisons that talk at great length about the differences, advantages, disadvantages of each motor. Really interesting stuff.

[JSBail]

An OHC design all by itself whether it's a SOHC or DOHC doesn't necessarily mean the engine is a high RPM engine, it can be right at home and work just fine on a low rpm/big low end torque engine. Generally speaking an OHC design has no need for pushrods and depending on the design it doesn't need the rocker arms either so by not having as many moving parts does tend to help increase power. The design is preferred in a high rpm engine because by not having pushrods or rocker arms it doesn't have to deal with the inertia created by those parts which allows the valves to handle a higher RPM before floating. Every design concept has its benefits and drawback so which design is better really depends on what benefits the engineer designing the engine wants and what drawbacks they're willing to deal with for an engines intended application.

[Whiskerfish]

So I have not had any time to research this but it seems like once OHC engines came on the scene that pushrod design has become obsolete. In general terms what advantages could a pushrod design provide that would make it desirable???

[CYBORG]

So I have not had any time to research this but it seems like once OHC engines came on the scene that pushrod design has become obsolete. In general terms what advantages could a pushrod design provide that would make it desirable???

One thing is a more compact engine. Which in a motorcycle application, makes a neater package. Looks good, which translates to sales. And the pushrods are shorter then you might find in a V8 car. And do you really need more then 180 HP in a bike?

[robin1731]

Pushrod engines are far from obsolete. The chevy LS engine uses pushrods. It is one of the easiest engines made to get big HP numbers from with very little work.

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[robin1731]

Nascar still uses pushrods. Pro Stock cars, even top fuel engines use pushrods. Yes, these are all specialty built engines. And some use pushrods because of the rules package. But, it just goes to show they can make big HP. (although they wouldn't live long on the street at the numbers they produce)

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[ericheath]

Thinking about it with my limited experience, pushrods add a little more weight to move up and down and a little more friction. But both have cams. Their cam weight must be a wash and surely even additional weight for DOHC. Then add weight for the room and strength needed for the head to accommodate cams. Whether using chains or belts, you add at least one more gear and longer belts or chains-- more weight. By reducing the height of the heads you have the possibility of adding stroke- not good for high rpm?? But good for torque? Maybe that's one way they get more torque.

Just asking as a few of these pushrod motors are breaking into the motorcycle scene. I was wondering if there was something new and if that is a direction we might see swing. I guess if quality and tolerances of parts and improved techniques to properly set everything up in balance, maybe it will make a comeback.

As for the Motus, it sure has gobs of torque and hp. Maybe the Goldwing of the future will be a Corvair of the future.

[mcgovern61]

Checking out their website and seeing that they have crate engines available for multiple applications is a great idea! If nothing else, I am thankful that these guys took the leap (and plunge) into manufacturing their own engines and bikes! How many other new American companies are there out there making (manufacturing) their own products here in the States? Their engine is really cool and has merit in my book!

[JSBail]

So I have not had any time to research this but it seems like once OHC engines came on the scene that pushrod design has become obsolete. In general terms what advantages could a pushrod design provide that would make it desirable???

I guess one could argue the superiority of an OHC design over a pushrod but I don't think the OHC has shoved the pushrod into obsolescence quite as much as the pushrod overhead valve as we know it made the previous flatheads obsolete. Engineers have come up with ways to make it more efficient that it's still a practical design and it does have an old school charm to it that many prefer especially bikers. Imagine the cries from loyal HD buyers if HD all of a sudden decided to ditch the pushrod design and go OHC an all their engines.