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Petrol head thread!!!

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

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hermes2015

Thanks for that explanation, billy rubin, and sorry again for introducing one of my obsessions as a tangent to the discussion. One of the artists I admire very much is Eduardo Paolozzi, who was also inspired by industrial processes and materials.

https://www.flickr.com/photos/rogersg/5271369678

I came close to being a student of his at the Central School of Art in London, but that's a story for another occasion. At least I met him once at the opening of one of his exhibitions at the Marlborough Gallery, where I bought one of his serigraphy pieces.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

Dark Lightning

Quote from: billy rubin on April 16, 2020, 10:56:38 AM
lol

im afraid my piston to head clearance problems had to do with the rod becoming detached at the bottom end and not zlowing down at all az it headed north. the issue was a failed rod bolt, down there at tge bottom.

icaruz, i actually do run beehive springs in an earlier head, and im planning on those in the futyee with this one. but on this iteration i ran with the springz the cam people reccommended, and so far theyve held up.

DL, i really hope not to have to do track rebuilds on this thing. LSR is more of an endurance event than all out drags, because the courze length is more than a mile. but we ll see where we go from here. got to break in the new pistons asap.
Alrighty then, that's a different story. I recall the rod bolt part, now.

billy rubin

Quote from: Icarus on April 16, 2020, 12:58:45 AM
Billy the exhaust valve is almost always the culprit. Post mortems almost always find that the damned ex did not get closed soon enough for the piston to get to TDC or a few degrees before. Cams with a lot of overlap is the underlying problem.  We need plenty of overlap if we intend to rev the engine. Tit for tat.

The trick is to make the damned EX close before the piston collision.  This happens at high revs only, unless there was some kind of galling or other problem in the ex guide, a heavy pushrod, etc.  Using a stronger spring on the EX valve is common enough but then that puts an unfavorable load on the push rod, camshaft, and other busy parts.

The drill is to find some bee hive springs that will work in your Trumpet head.  Those springs are progressive in that they get stronger as they are compressed.  Conventional coils have linear progression of counter force.  Bee hives have a curved progression in which the early lift is less resistent and the late lift is much stronger..........so as to get the damned exhaust out of the way when the piston gets there.

Because there is less work done in early lift, there is lessened coincident demand on the output of the engine.  In general, at least a measurable increase in out put is usually seen.

you know , icarus, theres a bit more to say here.  i clay the pistons before i run the motor and i make sure i have a minimum of 080 piston to valve clearance on the exhaust, 060 on the intakes. im running 296 degrees of duration measured at 020, (stock is 272), so az you point out, it matters. my lobe centers are 106/104 intake/exhaust on the current cams, retarded from the makers recommended 105.

my fastezt runs were at 109/106 on the previous cams but unlesz i start swapping out of spec camwheels 106/104 iz as close as i can get.

the beehivez i have in a spare head are reaaly nice, hut the head itself waz mis-cast. ive never gotten more than 112 mph out of it. and this one thats been fixed goes well over 130 in the mile . im reluctant to change whats been working. but i might take those springs out if i need more rpm from the race motor. right now ive geared it to crozs the line at about 7250 rpm, with one 8000 rpm 2-3 shift to keep the engine speed up. piston speed iz way high when i do that, over 3000 fps easy.


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

billy rubin

Quote from: Dark Lightning on April 16, 2020, 05:12:16 PM
Quote from: billy rubin on April 16, 2020, 10:56:38 AM
lol

im afraid my piston to head clearance problems had to do with the rod becoming detached at the bottom end and not zlowing down at all az it headed north. the issue was a failed rod bolt, down there at tge bottom.

icaruz, i actually do run beehive springs in an earlier head, and im planning on those in the futyee with this one. but on this iteration i ran with the springz the cam people reccommended, and so far theyve held up.

DL, i really hope not to have to do track rebuilds on this thing. LSR is more of an endurance event than all out drags, because the courze length is more than a mile. but we ll see where we go from here. got to break in the new pistons asap.
Alrighty then, that's a different story. I recall the rod bolt part, now.

even so, what you suggezt is a real consideration.. i treat the rod bolts as throwaways now. i wont torque them more than once. a news set of four bolts is less than a hundred dollars. not much less, but cheaper than a blow up,

so its new ones every tear down. and a marked set to re-use only for mock ups.


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

billy rubin

Quote from: hermes2015 on April 16, 2020, 05:06:20 AM

Sorry that this is not a meaningful contribution to the technical discussions in this thread, but these are beautiful objects in themselves. I am inspired to incorporate those striations (are they cooling fins?) into a sculpture.

well i was looking for decent shots of radial engine finning as an art form for you, and look what i found



i have spent quite some time just looking through thi stuff

https://www.motoart.com/products

beautiful repurposing


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

hermes2015

Quote from: billy rubin on April 21, 2020, 01:48:27 PM
Quote from: hermes2015 on April 16, 2020, 05:06:20 AM

Sorry that this is not a meaningful contribution to the technical discussions in this thread, but these are beautiful objects in themselves. I am inspired to incorporate those striations (are they cooling fins?) into a sculpture.

well i was looking for decent shots of radial engine finning as an art form for you, and look what i found



i have spent quite some time just looking through thi stuff

https://www.motoart.com/products

beautiful repurposing

Thanks so much. I love this kind of recycling of industrial parts.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

billy rubin

time out for a tri p into the past. did th erear brakes on my little pickup. they were drums. i used to do drums all the time, back when drums were common. falcons, hudsons, old trucks,  now everything has disc brakes, which are vastly easier but less mechanically interesting.most all my motorcycles have drums, which i frankly prefer to discs. not as much stopping power but no hydraulics.

anyway, the little ranger had 10-inch units on the back. springs, shoes, clips, cables, all th estuff that i used to spend a lot of time on.



usual stuff with a wheel cylinder on top



the starwheel had an absolutely needlessly complex tensioner. the old ones just had a blade, no need for sill cables and such.



both sides had suffered either blown cylinder seals or axles seals at some time in the past, and the interiors were coated in goo. whoever did the brakes last hadn't bothered to even clean that crap out.

the most significant change for me going down this ancient mechanical dance with machines was . . .me. even with the truck jacked up on wheel stands as high it would go, i still had to lay down, sit up twist around, and do the drum brake dance that in the past used to be easy. not any more.

but i got to take the number two son away from his school work and teach him how to do drums on the left side.

but only after i did the right side so i wouldn't look like a fool trying to figure out where all the parts went.





"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

hermes2015

Quote from: billy rubin on April 23, 2020, 09:47:19 PM
....

but only after i did the right side so i wouldn't look like a fool trying to figure out where all the parts went.

Watching you figure it out would be a valuable learning experience for him. Good troubleshooting skills are a useful asset to acquire at a young age.
"Eventually everything connects - people, ideas, objects. The quality of the connections is the key to quality per se."
― Charles Eames

billy rubin

damn its time

so i speent yesterday on the triumph race bike, working on the rear brake so it wouldhave the least drag during a run. im more or less happy with that, for the moment.

then i went to the little ninja, the old 2007 250 OHC machinethat the kids race. it needed a new tire in the back and a re-gearing.

ilast time the kids rode it, it gotup to 104 mph and then would bounce off the rev limiter at some 14000 rpm. that was with a 45 tooth rear sprocket.

i just ulled the wheel off to do a new tire and switched to a 43 tooth sprocket. my kids did 104 mph on the 45, and cxouldn't go any faster-- the rev limiter wouldnt let hem past 14000-some rpm.

but with the 43-tooth sprocket, they can theoretically hit 108 at the same rpm. and the record is only 107.

the girls set the one-mile record last spring (it was open, no previous record), but now they have something to beat. this is them



the number 2 son is rqcing as well. he can wear my leathers (with accompoanying comedy) but well hav to buy hinm his own glovses and helmet.


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

Dark Lightning

14k RPM is wound pretty tightly! I could get 105 out of my old Harley, but it bounced all over the place. That was on old highway 126 between Newhall and Fillmore. That road is all grown up and two lanes each way, now. What I did was pretty risky, because back then it was one lane each way, and had few spaces to pass. People took big chances and there were fatal crashes- a lot- several a year. At least if I got hit I would have been dead in an instant.

billy rubin

damn

i blew an ac belt in newhall once. very expensive.

14000 is nothing on a modern OHC with an oversquare motor and pent roof combustion chamber. they all do it.

this little ninja goes 10 000 on thecwaybto work.


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

Dark Lightning

I grew up in Saugus, CA. We used to go to Atomic Auto Wrecking to watch fenders rust as entertainment. That's a joke, although there really was a wrecking yard by that name. There was nothing out there when we moved there in '56(?). Maybe 20k people in the whole Santa Clarita Valley then. It's ca 300k now, and the people drive like maniacs. I have siblings who still live there and I hate driving to visit.

And back on the topic of RPM, I wonder what that old Harley chundered out? 5k? That's probably generous.

billy rubin

probably. so

i have a buell with a 1203 sportster in it and it runs up to 6000 or so. but its newish, onlook y twenty something years.

mthe old stuff wouldnt do that without risking terminal drama


"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

billy rubin



"I cannot understand the popularity of that kind of music, which is based on repetition. In a civilized society, things don't need to be said more than three times."

Dark Lightning

^ I sure hope that the seat is just currently not on and will be installed later or this is a Salt Flat bike, because that looks pretty damned uncomfortable!  :o

Plus if the primary drive belts part, there's going to be pain there, too.