African twin with dct.

It was shown on the Honda Show at Tokyo in the past few days. Have a look

https://www.youtube.com/watch?v=rILNEcDyI4U

Did we just fall down a worm hole and come out in May 2015?

dduelin said:

Did we just fall down a worm hole and come out in May 2015?

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I don't know and hope not. I am looking forward to going the International Motorcycle Show here in the next 2 weeks.

Did I get the wrong end of the stick. Not unheard of

Africa Twin has tappets I can adjust, and two plugs per chamber.

Old Can Ride said:

Africa Twin has tappets I can adjust, and two plugs per chamber.

View attachment 27325

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It is a hybrid design with screw adjustment on the intakes and shim under buckets on the exhaust or vice versa.

Thanks Dave, I have never seen anything like that before. This engine and the whole bike for that matter is way ahead of the rest. I am about 1/2 inch to short from touching the ground. Now that is going to be a real engineering problem. You and Fuzzy have completly sold me on the auto transmission.

I got it backwards in post #8. The exhausts are screw tappets and the intakes are shimmed. It is something I've not heard of before either. This picture shows the intake valves directly operated by the camshaft while the exhaust valves have rocker "fingers" similar to the NC's.

Let's see if this link works:

image_zpsdzgx2dea.jpeg Photo by Twmcdono | Photobucket

dduelin said:

I got it backwards in post #8. The exhausts are screw tappets and the intakes are shimmed. It is something I've not heard of before either. This picture shows the intake valves directly operated by the camshaft while the exhaust valves have rocker "fingers" similar to the NC's.

Let's see if this link works:

image_zpsdzgx2dea.jpeg Photo by Twmcdono | Photobucket

Click to expand...

A creative spacing solution on the engineers part. Using a single cam to actuate the intake valves directly and the exhaust indirectly using tappets. This reduced the distance that would transnational be needed for using either tappets or cams on both sides.

Kudos to the genius that conceived this concept.

The bike shown is the DCT version!!

Note the optional "Shift Lever" at the left foot peg!!

This appears to be a well Farkled version but I don't see a Center Stand!!

Oh, , , I've heard it will be shown at the Show in California!!

Alfred

Griff said:

It was shown on the Honda Show at Tokyo in the past few days. Have a look

https://www.youtube.com/watch?v=rILNEcDyI4U

Click to expand...

Does anyone know where the oil filter is on the Honda Africa Twin? Is the oil filter internal or external?

Honda unicam? they have been doing it for a while on dirt bikes. Less complexity, lighter weight and most of the benifits of dual overhead cam, with the greater precision of direct valve actuation where needed most.

The head on the Africa Twin is great tech, but when I am out on the road in who knows where it is not so easy to aquire those shims. And it is a lot harder to change the shims to adjust the valves (remove cam), than to just adjust the tappets. Not racing at or near home, just adventure riding in the middle of no where makes this a hard to accept. Makes the NC7 for me a better adventure bike, even though I would sure love to have the suspension and tire sizes of the Twin. One thing I have learned about adventure riding is keep it simple, as you might just have to fix it in the middle of know where.

Old Can Ride said:

Thanks Dave, I have never seen anything like that before.

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Hey, I expected you should have seen it because it is a solution first applied while you were in your prime years, in the early '70s Triumph Dolomite Sprint car:



Oops, I forgot, no internet back then and you may had got no such brit car over the pond.

The head on the African Twin is like that of the CRF racing bikes. Like Dave said, the exhaust valves are compressed by the tappets that are operated with rollers that contact the cam. These rollers do have wear. Easy to adjust these tappets. The cam itself is hollow. The intake valves are shims under buckets. The buckets contact the cam and compress the intake valves. Here the valve clearance is set by the shim under the buckets. The entire cam has to be removed to replace the shims to adjust the intake valves. Let me say here that because of newer harden metals that the intake valves should only need adjustment about every 60,000 miles. Never seen this used on a non racing bike before. On the racing bike (CRF) all the plastics on the side of the bike and the gas tank must be removed just to get to the valves. Lot easier to adjust the NC7 valves.

OCR, as far as I know all Honda shim under bucket OHC motors require the cams to be removed to adjust valve clearance. My ST1300 has required 5 valves to be adjusted in 150,000 miles. I've pulled the cams before.

Mi_ka said:

Hey, I expected you should have seen it because it is a solution first applied while you were in your prime years, in the early '70s Triumph Dolomite Sprint car:

View attachment 27344

Oops, I forgot, no internet back then and you may had got no such brit car over the pond.

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As far I recall the Dolomite was a home market model and not exported to the USA. During the late 60's and 1970s we got the Triumph Spitfire, GT6, TR6 and the Stag. The unusual multivalve SOHC Dolomite Sprint motor was apparently unique to that car. I was into British cars in the 1970s, owning an MGC then an MGB.

I had a TR3 when I was in college. One night in the hot summer on the beach in Galveston with a date I hit a stump. The stump knocked the floor board on the passenger's side out. Had to drive the date back to Houston with the heat from the exhaust blowing directly on her.