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Petrol head thread!!!

Started by billy rubin, October 29, 2019, 10:41:33 PM

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Icarus

The Brits had words for that aluminum erosion: "The mice have been at it"  A sure sign of detonation. It appears that the detonation areas are isolated.  That may be caused by hot spots in the head.  In the head photo the intake valve is much cleaner than the exhaust valve.. That may be because the intake valve runs cooler than the exhaust.  Try using a wider seat on the exhaust to help cool it a bit.   The piston pic looks almost like the dome is oiling. If not oiling, something is really amiss about the way the flame distributes itself around the chamber.   This is not an uncommon situation. Advanced tuner guys use wet flow flow bench equipment to identify the path of fuel distribution after it passes the valve seat.  That has lead to some valve, seat and port mods that lose some flow volume.  But dyno testing has shown that there is, or at least can be, a net increase in output despite lower flow volume.   

We are not getting anywhere near the potential heat energy output in piston engines.  That has been the subject of much study and experimentation so to discover the ways to increase the fuel utilization (economy) of automobile engines.  Basic specific fuel consumption (BSFC) runs in the 0.5 pounds per horsepower hour for ordinaru engines.  The likes of NASCAR engines have BSFC figures in the mid 0.40s.  Note that fuel is measured in pounds, not volume, when calculating this characteristic. 

The bottom line is that pistons of that shape are not very friendly to even distribution of air/fuel and thus tends to uneven burn characteristics. There are reasons for such a shape of course. The main reason is to avoid clashing with the valves during overlap periods. And so all that plays into the head design....valve angle and such.

The whole deal with street bikes like the Triumph is a matter of space limitations. That the carbs and inlet tract are nearly horizontal with the world allows the carbs to not interfere with the tank bottom and on and on about design characteristics.  Better the inlet tract angled downward so as to change the valve seat location to a more efficient location.  But what the hell,  the Triumph, Norton, BSA bikes were not intended as race or ultra high performance machines............despite their claims to the contrary.

All things being equal, or nearly so, you are competing against other people's machinery with similar design characteristics. 



billy rubin

here's the answer i've found to these 1930s cylinder heads



you're correct about th eflame distribution. i have 11.75 to 1 compression, so at TDC there's a giant lump in the combustion chamber that prevents the flame front from reaching theother side. so i've drilled my heads for extra spark plugs, and use an ignition that fires them both at the same time. this works well both on the street and at teh racerack, but the restoration people don't like it because it doesn't look "original . . ."



QuoteThe whole deal with street bikes like the Triumph is a matter of space limitations. That the carbs and inlet tract are nearly horizontal with the world allows the carbs to not interfere with the tank bottom and on and on about design characteristics.  Better the inlet tract angled downward so as to change the valve seat location to a more efficient location.  But what the hell,  the Triumph, Norton, BSA bikes were not intended as race or ultra high performance machines............despite their claims to the contrary.

with this triumph, the inlet port is tipped up about 15 degrees, and the exhaist i s completely horizontal. i'v ehad the inlets raised a bit and filled in below with epoxy, but you cant go very high without cutting into th ebottom of the intake valve spring seat-- there just isn't enough metal there. some peopl ewith lots more money and knowledge than me completely weld up the heads with new luminum, and then cut new down-draught ports into thehead. but that's pretty rarified territory.

asyou say, these motors weren't ever designed fo rhigh-performance. they were working-class commuter machines, something that people used beecause they couldn't afford an automobile. but that's what makes them an interesting puzzle.

that's good, because with the money and effort i've expended i could have bought at least two 200-mph hayabusas and gone lots faster. but with lots less interest, you know





News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

Icarus

You have done a good job of trying to fix a design problem.  I salute you for that along with some of the other clever things that you have done.

I agree that you could go a damned site faster for the same or less money had you gotten a Hyabusa or other fearsome rice burner..(no offense to Japanese genius intended)  But that does not do much to cause our creative juices to flow. Some of us are compelled to make silk purses of sows ears. .............I take that back.  The Triumph  or Norton are not sows ears.  They were pretty good machines in their day.  The new Triumphs are pretty much equal in sophistication to any of the modern competitors. Some models are really Bad Ass machines.

If you could get your paws on a Cosworth head for the Triumph, game over for the competitors.  Alas I suspect that even if you could find one of those the price would be out of sight.  Back in the day when Battle of The Twins was a hotly contested class the top guy in the southeast had a Cosworth Triumph.  I am pleased to say that my much massaged KZ750 Kawasaki was his equal.

My rider was plenty skilled but he was a peculiar personality that would sometimes fail to show up at a race venue. I think that he was into "snort" or other high liner substances. I finally gave up and sold the bike to another good rider who also had a personality disorder.  He had a death wish or something like that.  He would drive far too deep into corners and then curse the escape routes that sent him back to 10th or 20th place. He finally blew up the Kaw and I do not know what became of it after that.  Rob Muzzi once saw the bike and approved of the odd ball choice that I had made.  After all, one is not expected to try to make a fast bike from what was generally regarded as a road toad. Muzzi recognized the potential of the engine.

Keep thinking Billy.

billy rubin

Rob Muzzy is Famous.

i think a cosworth triumph these days would be snapped up by the museum collectors people.

and riders are weird. i think lots of them are wired differently in their heads from ordinary people in order to have the skillz to go so fast. im not strange enoughto be really successful.

but id give up a lot to be succezsful at the isle of man.



News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

billy rubin

#244




dragged the middle children outbto the airstrip to make surevthry are comfortable on the little ninja. thryll be fine

i climbed on my triumph too and it seems that i can bend my knee enough to ride it if i get set up on that side in advance

so its a go




News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

Dark Lightning

I'm guessing that these are just posed shots, and that the high speed stuff was done with helmets? I personally couldn't ride over about 40 MPH without a bubble on my helmet, as my eyes would tear up, even though I was wearing specs. I'd hate to think about hitting a bug at speed without eye protection.

Good luck with your speed runs!

billy rubin

no i was just making them ride around in circles at walking speed, and do start/stops. they need low speed practice as much as speed runs

when they went out on the runway they put on the hat.

the rules require a full leather suit, a recent helmet (mine is on its last year), leather gloevez, and boots.

i hit a beetle once at about 60. exploded against my left eyeball and a leg got lodged under my eyelid. not a happy moment coming to a stop.


News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

billy rubin

left the house in the morning and drove some 500 miles north and east. the races are at loring air force base, limestone, maine.

500 more tomorrow and we ll be in caribou.

safety inspection the day after. still have a chain adjustment and taping the lights on the little ninja before its ready.

we ll see how we do. im so close to the edge of the envelope that for me it all comes down to the wind-- where is it coming from, and how do i hide from it


News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

Tank

If religions were TV channels atheism is turning the TV off.
"Religion is a culture of faith; science is a culture of doubt." ― Richard P. Feynman
'It is said that your life flashes before your eyes just before you die. That is true, it's called Life.' - Terry Pratchett
Remember, your inability to grasp science is not a valid argument against it.

billy rubin



500 more moes, of which 350 werr in maine and oooked )ike ^^^this

tech inspection tmorrow


News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

billy rubin

we are back fro maine. did some 200 miles the first day, because the wife wanted to start early. then 610 miles the next day, and i had to stop. then an easy 300 miles the last day, and we are here.

there was lots going on

there is plenty of space



we set up by the flowers, where we could drop the tent if it rained



and raise it when it cleared



the triumph looked good, but alas, it had a failing wheel bearing



while the little ninja was going to do very well



there was another ninja 250 to compete with, but she was running in modified partial streamlining, and wasn't as fast as us anyway



the daughter ended up setting a record in the mile at 108.338



while the son set a record in the mile point five at 108.023



we snagged a nice set of leathers for him too, which were donated and put up for sale. the y were a good fit, and so he doesn't have to wear mine.

when you run, you have th ewhole 13,000 feet to yourself until its over



there were nortns\


bsas



whizzers



harleys



corvettes with dual controls because the driver is blind



ancient weird stuff, like this 52 cunningham



classic hot rods



and on and on.

tyhe fastest car was running 269 until it blew the bottom end out of the engine. i have a video of that illl put up when i find it


News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

billy rubin

and maine was beautiful



the potatos were in bloom



the old air base still had the storage bunkers for the atom bombs



and the machine gun pillboxes



but we all did well





News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

billy rubin

except for my rear wheel bearing. i did 131 mph on this, twice





need to do some improving here, i think


News has been received from the Punjab that the Amritsar mob has again broken out in a violent attack against the authorities. The rebels were repulsed by the military and they suffered 200 casualties.

hermes2015

Your posts are truly wonderful and a joy to read.  :clapping:

Quote from: billy rubin on July 22, 2021, 01:31:57 AM
except for my rear wheel bearing. i did 131 mph on this, twice




I can see some sculptural or jewellery possibilities for this.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

Bad Penny II

Quote from: hermes2015 on July 22, 2021, 04:29:08 AM
Your posts are truly wonderful and a joy to read.  :clapping:

Quote from: billy rubin on July 22, 2021, 01:31:57 AM
except for my rear wheel bearing. i did 131 mph on this, twice




I can see some sculptural or jewellery possibilities for this.

Reading the lines of your palm I can see a second wife, two children, too many, many too many cats
I see you moving fast, too fast, you should stop that and take up a slow activity, origami maybe.
Take my advice, don't listen to me.