Topic: yoshi exhaust

[754]

I know of a 4-2 equal length pipe exhaust used on a production 4 cylinder motorcycle  before 1969.............

[kos]

When you say Triumph used a 3-1 , when and on what..? are you talking the racers?

 Partial quote from Kos, got me confused..

" I should have used the proper defining term, "merge collector" type systems. Hooking two pipes together without having the head pipes of equal length and into a merge collector is what we are talking about."   posed at 11:06

 Then I listed examples, not all had a collecter, some did...

754..

It is time to reconstruct this thread on collector exhausts systems and hwen they were first used. My mistake for the wordin. By the  standard of the industry definaition...


Singles have one cylinder and are known as, singles
Twins have two cylinders and are known as, twins
Anything over two cylinders are called, muti's

So lets keep this thread about multi cylinder machines.


KOS

Damn, I spent 5 hours this morning trying to trace relatives of my late racing buddy to see if they have any pics of us racing the Benlys with the Siamesed pipe..... and now you don't want to know

Sam.

Shoot...keep'm coming if you like...it is all very interesting and fun!


KOS

[Sam Green Racing]

 

[turboguzzi]

When you say Triumph used a 3-1 , when and on what..? are you talking the racers?

 Partial quote from Kos, got me confused..

" I should have used the proper defining term, "merge collector" type systems. Hooking two pipes together without having the head pipes of equal length and into a merge collector is what we are talking about."   posed at 11:06

 Then I listed examples, not all had a collecter, some did...

754..

It is time to reconstruct this thread on collector exhausts systems and hwen they were first used. My mistake for the wordin. By the  standard of the industry definaition...


Singles have one cylinder and are known as, singles
Twins have two cylinders and are known as, twins
Anything over two cylinders are called, muti's

So lets keep this thread about multi cylinder machines.


KOS

Damn, I spent 5 hours this morning trying to trace relatives of my late racing buddy to see if they have any pics of us racing the Benlys with the Siamesed pipe..... and now you don't want to know

Sam.

Sam, it's the sohc4 forum, not the sohc2, you've got the wrong url

[voxonda]

Pop's probably was the first, but George Kerker always claimed he was first, but so did Russ Collins of RC Engineering. Also Jim Dickerson on of Action fours was talking like he did it first. Here is a picture of Gary Fisher's bike at Sears Point, Ca 1971...lookes to me like a hand bent, four into one!

I'm pretty sure Dave Degen's was not the first. They did not even sell CB750's in Europe until 1971.



Also, look at the craftsmanship of the bike...NOT!  Look at those welds! Can you say, arc welder!!! Yikes, I can't believe it made it thru tech?


KS

Nice to see the Yoshi bikes with their Seeley style seat instead of the Daytona 'Aero-style' seat. And the long megga's, probably in order to gain mid-range?

Rob

[Phil]

We are very fortunate to have guys like Kos who look after these legendary bikes like the Fisher/ Yoshimura 75! I agree with Kos - back then these bikes were not pretty at all! It was about speed ... I worked for Bel-Ray from 1978 - 81 and that brought me into contact with many of my real heroes - Crosby, Cecotto, Sheene, Baldwin, Roberts, etc. I was told to take oil to Le Mans 24 Hour (think it was 1978 or 9?) for Pops Yoshimura himself! A Yoshimura GS1000 was entered (Cooley/Baldwin?). I got there early and the Yoshimura team arrived in a rented van. A very battered GS1000 was unloaded and a few boxes of tools. The bike looked a mess, rider's leathers were scuffed and taped-up! I could not believe the ramshackle outfit - I was more used to working with Cecotto's F750 Yamaha team! The bike really was rough, by anybodies standards. More like a low-budget club racer!! It was just functional. I guess it was the AMA Superbike with lights! But did that GS go... It was unbelievable fast but, sadly, did not last more than a few hours (think it went up the road at least once) so I helped chuck the bike in the van, had a few beers, and went home! I can't remember what won - a Honda probably! Can't remember much about Pops - I recall him being short, very skinny, old and smoking all the time. He looked as weather-beaten as the bike! But I did shake his hand!

[kos]

Pop's was a dirt guy. I was pitted next to him at Daytona, back in 1974 or '75 when he was there with Wes Cooley and they were racing that awful handling but POWEFULL Z1 Kaw and he was the only person I ever saw that I thought could catch on fire from his ciggy butt! Every time the bike came in he would drop the oil in a pan and while the oil was hotter than hell itself... Pop's would put his hand down in that oil and search for metal fragments, put to nose and smell it, then he would pull the spark plugs, not even look at the tips, but get a flashlight to look down into combustion chamber to see how close he was to melting the piston dome! Once bike was on track, he would not look at it as it passed by, but would stand there next to fence, with eyes closed and with hand cupped to his ear....and listen to his engine rip all the way round the Speedway.

I felt Lucky to be there at that time of bike racing history.

KOS

PS: Kinda like what real medical doctors do....that have not come to rely on fancy machines, gadgets etc., to diagnose patients problems. Called, "laying on of the hands"   Something this world needs to get back to very soon or we all are doomed.

[lordmoonpie]

Clive Padgett is almost the same in the UK but with 2-strokes. I remember rebuilding an RS250 honda in the Manx GP - new crank, pistons etc. We started her up and wheeld it round to Clive to check over while blipping the throttle. He was messing with another bike stood by the back of his van. He just glanced up and said - nice job, but the left carb is 2mm out of sync! I laughed, not believing he could know that from the sound alone. We pulled the tank and sure enough, the left carb slide was cracking 2mm earlier han the right. I was dumstruck!!

[754]

OK, looks like no one wants to play the quiz....


 Munch Mammoth had equal length 4-2 exhaust....back in 1967..


 and they were freakishly expensive... I think 3700.00 in 68...2wice the price of a cB 750..

[hotwire]

that was a interesting read. i can bend pipes guys!!! but then i run wire through them

[Phil]

I have just spoken to Dave Degens (Mr Dresda). He confirmed that he supplied 5 Dresda Frames and 5 4 - 1 exhaust systems to Japauto in 1970. He is adamant that he built 4 - 1 systems before anyone else - confirmed by Honda! CB750 were sold in the UK in 1969, I think.

[kos]

Pictures?

KOS

[Ricky_Racer]

Kos, I can't help you with shots of the exhaust, but here's a Dresda-Japauto. BTW, when I last spoke with Dave he said he'd be happy to make more Dresda-CB750-Japauto type frames. All it takes is money...    RR

[voxonda]

Mark, have to dig in my, rather big, archive where I have a special about the, first, Japauto with a pic of the exhaust.

Rob

[voxonda]

Found it:



Rob

[voxonda]

While we're at Dresda, here my all time hero, Tonny van Schijndel, on his '74 Japauto engined Dresda, what a wonderful bike/rider combo:

[Phil]

I asked Degens if he would make a frame: he said yes, if I wasn't in a hurry. Richard Peckett also said he would make me one - but when? Both are not exactly searching for work. He wants to borrow my Dresda GL1000 so maybe I have some leverage!

[voxonda]

Hey Phil,

Send Mr. Degens a mail about a week back ask about the fairing on this '74 Dresda to see if it is still available. No answer yet, think he's a busy man.

Rob

[coneeng]

We have lots of cones and collectors if you are trying to make you own pipes.

[Phil]

I went to see Dave Degens this morning (to collect a fairing for my GL1000 Dresda - yes, available, Rob - let me know if I can help). He is a fascinating chap and guess what? He supplied 4-1 pipes to none other that Pops Yoshimura in 1970! Apparently, these were ordered by the (step?) son of Pops after he saw them on a Japauto and shipped to Japan and later in the year to the US. Degens said he got the 4 - 1 idea from a nearby workshop that race-prepared Ford racing engines. He was doing development work for Honda France (Endurance Racing) at the time and thought they would provide greater ground clearance and be much lighter. The race-car shop explained to him the optimum length of the four pipes before they were collected. He tried the prototype and he was surprised that it improved mid- and top-end engine performance. He said he supplied several pipes to Yoshimura but stopped because they were bad payers - they then made their own! Honda Japan conceded to him that the Japauto bikes were quicker and handled better than their own bikes (he said they probably didn't realise they were close to 1000cc!). They said they were impressed with his efforts to tune the CB750 and liked his 4 -1 pipes! So, another interesting turn to the story of the 4 - 1!!! Oh, and he said he would make me a frame if I wanted one.

[voxonda]

Hey Phil,
Great story and shines a new light on the whole "who was first........" matter.
If you could ask Mr.Degens about this particular fairing, when you meet him, you would make me a very happy man. Thanks in advance.

Cheers, Rob