Don Terrill’s Speed-Talk

hey folks tony pascarelli posted here under the name of truckedup. he died this morning in his home in new york, under hospice care for about three weeks now. he'd had cancer for several years, but it came out of remission the middle of last month and progressed pretty quickly. it was not unexpected...

nicholastanguma wrote: ↑Sun Aug 21, 2022 4:31 pm You and I could probably have a political discussion and walk away without hating one another.

more than liklely.

its a complicated world, and the people who look for simplicity seldom find it.

In former times, when two valve head design was the norm, some form of hemispherical combustion chamber shape was the norm, too. Ergo twin plugs provided some real performance benefits, however small or large per application. i race today in the former times, a 650cc triumph vertical twin with two ...

lol thats the best sporster i ever had , too, after you sold it to me. running in modified production though, its a bear to hang onto at its best of 132mph. ive got three front pulleys thst give me some flexibility in gearing. i dont find the vibration excessive, but ive ridden old vertical twins al...

old british motorcycles used aluminum rods exclusively, although probably not a sophisticated alloy. but the newest ones that are left are all pushing 40 or 50 years at this date. most people, including me, swap them out for new steel replacements, reasoning that the aluminum pieces have likely gone...

lol

off-topic is my spirit animal

hard to see what tim joyce was doing to th ehead unless you made a pest of yourself in the pits. but 75 at the rear wheel is pretty rarified territory. https://live.staticflickr.com/4103/5093757337_d92f7b9031_z.jpg stock there's only a slight downdraft to the intake ports, and none at all on the exh...

i don't know whether megacycle dynos anything or not as part of R&D, but i doubt it. they're mostly selling pretty well-trodden paths. i think our similar speeds mean that we're probably near the end of horsepower on these old beaters and are looking mostly for accumulating small gains in aerody...

no, i didn't get any at the time. i know he keeps the records, obviously, because he mentioned flow figures at the time that pleased him. maybe i can get him to answer the telephone. the 510-X2 cam from jim duer was a surprise to me, because he recommended 103/105, and it did so much better at 106/1...

Vintage motorcycle racing engines? Be nice not to have to choose from grinds that are 60 years old... megacycle makes that triumph twin cam, the 510-x2, which is relatively new. 296@020, with 0.375 lift. the rest of their stuff is repro or their own old stuff, like you say i just looked at the MAP ...

i once worked with the grandson of one of henry ford's test drivers. as i was told the story, the early V8 design didn't incorporate an oil pump-- the crankcase was splash lubed. the test driver didn't like that, and whenever he was given a new motor to road test, he would take it out and spend all ...

Better win the MegaMillion. A friend tried to do an aluminum head shadetree. He had a buddy who was a certified professional aluminum welder. The welds were beautiful, but the valve seat bores warped, the valve guide bores warped, the head surface, as expected, warped. He couldn't find any machinis...

i put up a couple way back on page 1 for my 650 https://www.speed-talk.com/forum/viewtopic.php?p=873716#p873716 the pistons are JE slugs cuztom cut to 11.75. the highest triumph ever did stock was in the old TT racers of the 60s at 11:1. there were essentially no changes to the hemispherical chamber...

i dont have the rules with me but for LSR in mine and truckedups modified production venues i believe the motors have to have the same numbers of valves as stock. either way the aftermarket four-valve heads dont bolt on to the stock barrels but come with custom 700cc jugs that cannot be run in the 6...

so there is an initial primary turbulence around a transverse axis between the valve seat and the piston top? always?


anything visual like this available for OHV?


https://www.youtube.com/watch?v=jdW1t8r8qYc

skip to 1:44


kevin