Don Terrill’s Speed-Talk

Some of you wanted a report on the double vintage engine Triumph bike's first land speed racing runs....My friend and rider took the bikes to Loring Maine to run the standing start 1-1/2 mile.....I was not able to go because we are moving.. On the first run he held back to feel out the bike and ran 142 MPH....The second run was full throttle but the rear engine starting misfiring so he backed off, the carb was flooding .......Also noticed was the front engine had only 30 psi oil pressure rather than the required 75 psi at speed...He pulled the side cover, checked oil flow and the oil pump..all ok so it must be a connecting rod bearing issue....But my home built junk ran straight down the track and the drive line functioned perfectly...And nothing fell off
And the good news...The other bike, 650 modified production Triumph did what it always does, set a speed record...He ran a 133 plus MPH reclaim the track record which I believe is the fastest time ever for a stock framed 650 cc push rod bike on gas at any LSR track....Being nothing more than a retired electrician working from a home shop I would like to thank the several guys here who gave me tuning tips...

Really cool Truckedup, well done! Any pics or vids?

Awesome result!
Without looking back, did you end up making a cam/cam timing change? Some exhaust tuning?

I shortened the two straight pipes to 34 inches,and changed the exhaust cam timing from 105 to 107.5.....I also fabricated a fuel tank allowing the rider to tuck better....
The dual engine bike is a pig on the track... The cams are all wrong for my type tuning...
The bike was run with no megaphones...


My friend on my hillbilly special..

Very nice, congratulations! My triumph is a 79 boneville

Looks like he was having fun!

What I admire most about 'the motorcycle people' is the courage; I can only imagine what your bikes feel like with no fairing at those speeds...

-must be high pressure areas forming on various parts of the rider's body... a true aerodynamic/physical test of how a human should hold on to the bike?

(no wonder why you made the frame hugger gas tank!)

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I expected to see a much smaller rear sprocket on the back... but that pic shows a sprocket that I think would be for urban use?

I'm self educated on chains -all the info I've read says big links with larger diameter rollers can handle more load but smaller roller chains with multiple rows can handle higher rpms better...

I threw a chain on my '72 Yamaha only going about 50 mph; that was scary like crazy... very violent surprise! (glad it didn't break my leg)

IMO, it's worth it to do some research, on chains, so you can have two legs to walk around with... (the chain is wicked dangerous)

Surely the price of the best new chain you can put on your bike is cheaper than buying a new left leg?

Please at least keep your chains in tip top condition when doing the top speed runs -as perfect as possible.

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More power to you man! -I like these old Triumphs; great looking vintage engines/super cool -thanks for posting

Triumphs have a 2-1 primary ratio, the secondary ratio is 2.14 for a 4.28 overall gear ratio...133 mph at 6950 rpm...The 530 and 520 chain used on the back is very common on many bikes with a lot more power and speed....Broken chains on the street are generally from lack of maintenance...I use high quality Tsubaki, DID or RK chain...

Alright good to hear you are keen about keeping your chain in excellent condition -I just really admire the courageous personalities of motorcycle racers.

Nice job!

twl wrote:Nice job!

Thanks, I changed the exhaust cam timing to 107 as you suggested.cut two inches off the pipes and a lower fuel tank to give the rider a better position..Geared the bike to run 133 because I thought it could do it.....The BSA that took the record from me two years ago blew his engine trying to beat us..
Not bragging and not fair to compare different events, but no 650 push rod bike on gas in a modified stock naked frame class has ever run this fast in LSR...

Truckedup wrote:

twl wrote:Nice job!

Thanks, I changed the exhaust cam timing to 107 as you suggested.cut two inches off the pipes and a lower fuel tank to give the rider a better position..Geared the bike to run 133 because I thought it could do it.....The BSA that took the record from me two years ago blew his engine trying to beat us..
Not bragging and not fair to compare different events, but no 650 push rod bike on gas in a modified stock naked frame class has ever run this fast in LSR...

Awesome!

I'm super happy that it all worked out for you.
That was a really great record.

Congrats! Nice work, guys.