Any idea what exhaust this is?
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Kinky 
Looks home or custom built cross over considering the header pipes appear to be all different lengths, most production manufacturers go out of their way to make all the headers the same length.
... if you look at other photos of that bike he has all of about 3 inches ground clearance without a rider onboard
Looks home or custom built cross over considering the header pipes appear to be all different lengths, most production manufacturers go out of their way to make all the headers the same length.... if you look at other photos of that bike he has all of about 3 inches ground clearance without a rider onboard
A company like Cone Engineering could make up the header pipes and collector. You or someone you know would need to fit and weld it.
Megs Exhaust Warehouse-Exhaust Systems, Exhaust Collectors, Components, Exhaust Conical, Mufflers, Exhaust Tips
Manufacturer of aftermarket exhaust for automotive, motorcycle and marine since 1970. High quality fabrication of exhaust components & kits. American-made USA exhaust tips.
www.coneeng.com
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I agree that the headers and collector box are possibly custom built. Cylinder three's pipe has been bent to be able to access the oil filter without having to drop the headers, which was a common issue with aftermarket systems of the time. There was a company in the 70's that introduced this concept - but sorry, can't remember their name.
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There was one made by Triple A that looked all bent like that, but that's not it.
May 1972 Cycle magazine did a test of a bunch of CB750 period exhaust systems.
article was "pipes galore for the Honda 750"
May 1972 Cycle magazine did a test of a bunch of CB750 period exhaust systems.
article was "pipes galore for the Honda 750"
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found the article:
May 1972 Cycle Magazine Honda CB750 Exhaust System Test
I got these pages at a swap meet years ago. It covers (most) of an aftermarket exhaust system shoot out between Dunstall, Triple A, Action Fours, Racecrafters and Jardine. Its missing the last page…
piledriverz.com
Hindle have built exhaust for Hondas for decades, they still make pipes for vintage bikes. If you don't want to spend new price you may be able to find a used one. Prices are in Cdn $, take 25% off to get a US $ number.
www.hindle.com
Vintage Exhaust
www.hindle.com
I'm curious just for the ease of maintenance. I do like the Delkevic pipes as well and I see many people like them. I'm possibly thinking about trying a 4-4 set up with some 18" reverse cone style mufflers to keep a bit of my bikes vintage look. The originals are bit large for my taste. Although I'm still a ways out from that part of the build.
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I have a dohc750 and I got the Vance&Hines 4-1 chrome pipes a few years ago and they still look great, don't block the oil drain and I haven't ground them at all. for less than $400. I'm really proud of them. You might be looking for something special? but I have both soch and doch 750s and I think either model looks great regardless of the exhaust. The bike in your picture looks like the suspension is lowered and the exhaust collector is pretty bulky I'm pretty sure it would ground Easily, and I think I would stick with a pipe that offers good ground clearance.
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1/2 and 3/4 share an exhaust stroke, so they can be two different sizes when they go to a collector. Stock, they were four completely separate pipes all the way back.Kinky
... if you look at other photos of that bike he has all of about 3 inches ground clearance without a rider onboard
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So you figure it fires just like a twin cylinder engine
you might want to look at the crankshaft, Cylinders 1 & 2 are positioned 180 degrees apart. & The 2 sets of breaker points are running on the crankshaft which travels twice the rotation rate of the valve camshaft resulting in a wasted spark ignition system. Service manual states the firing order is 1-2-4-3
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The crankshaft doesn’t control the exhaust valves. That’s what a camshaft is for on a 4 stroke. This is from the CB750 fsm. #4 is on the compression stroke. 1/2 are on exhaust.So you figure it fires just like a twin cylinder engine
rate of the valve camshaft resulting in a wasted spark ignition system.
Service manual states the firing order is 1-2-4-3
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You could make it fire and shake like a twin, but you'd need to change the cam shaft and it still wouldn't fire 1/2 then 3/4 unless you also changed the crankshaft #1 and #2 con rods are 180 degrees apart. Take a look at any photo of a CB750 crankshaft.
None of them share a common exhaust stroke, they fire one at a time so it runs smooth.
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You are so fixated on the crankshaft. Their exhaust strokes overlap. They are not totally open or totally closed exactly at the same time, but they are still open on the same stroke. If it's hard for you to get my jive before, I hope that clarifies it a little more. I apologize if saying they are "sharing an exhaust stroke" insinuated I meant they were timed exactly the same. Changing the overlap on the CAMSHAFT is a way we can find horsepower and/or torque. I know you know this, but for some reason you are fixated on proving I am seeing this engine like a twin or that I don't know what I am talking about. I've built plenty of 750s to have a decent idea what they look like inside. Because two exhaust valves are open at the same time, you know like they're sharing the same space, it allows you to run a longer header on 2 and 3 to get around the oil filter when feeding collectors. Man, I struggle to stay active on this site because so many guys like you seem more focused on putting people in their place.
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