Another vintage project from Great Britain, target Speed Week 2011

[thefrenchowl]

Hi All,

Good weekend indeed... It was our national Harley HDRCGB club's AGM on Saturday. Since I'm quite busy with this project, I haven't got a bike on the road yet, so got picked up early by the lads from the Lakes District region in a mini van. On arriving at the location, got approched by John, the rep of the New Forest region, who promply gave me my 1st sponsorship... They had a meeting earlier in the week to see what to say at the AGM and someone proposed that the region helps me. They voted yes so John gave me a cheque for £200, so big thanks to them!!!

Sunday, back in the garage... Finishing the plenum proved harder than anticipated since the Ansin outlet is not perpandicular to the bit already made... So a bit tricky to judge where to cut the bits so they line up!!!















So that was most of the day gone... I will have to trim a few fins on the rear cylinder to give a bit more room for a rubber hose connector in between. I then started to look for an oil tank. I wanted to use a 60s std XL one but they're a bit wide... Looked around and remembered I had an old Pan Head one, already moded beyond salvation on the drive side... Chopped it in half to use the right hand side portion, it fits neatly below the seat and should hold about 2 quarts...





Well, it's late, I'm tired and need a good soak in the bath to get rid of all the grime!!!

See you soon, Patrick

[38flattie]

It's looking good Patrick!

What size is that stainless exhaust? edit- I just reread and see it's 2.5"

That sponsorship had to make you feel good- congrats!

[thefrenchowl]

Hi Everybody,

Bashed about a bit of steel the other night and finished the job tonight. The back finish is not too good, but hey, it's a proper vintage budjet bike, I'll do it as it would have been done in the old days, use whatever!!! Still, it's narrow enough which was the aim and I've seen enough alloy round oil tanks to last me a lifetime... Mostly all bronze brazed except the filling neck which I silver brazed...













See you soon,

Patrick

[thefrenchowl]

Hi Everybody,

Yesterday, Saturday... I received the blow off valve at work during the week, only ordered it on Feb the 7th ... Nobody keeps any stock these days, they had to make it specially to fulfill my order. Fixed setting of 2 bar, 30psi... Soon had a 1" BSP socket trimmed down and ready to be welded later on the plenum...









Brought the pipe hand bender from work and started some rigid oil lines in 3/8 SS. Nylon pipe is temporary!!! I will fit proper oil hose later...





Then started to look at exhaust pipes... This one looks to far away from the engine.



Also found a minute to install the fuel shut off valve on the tank:



More later on...

Cheers from Patrick

[thefrenchowl]

Hi again!!!

Sunday... Found a more suitable piece of Sporty pipe, just 2 welds to do, that's the front pipe done and dusted...





Tried to find a bend to run the rear pipe under the foot pegs, no luck... Then found these 2 bits and there's just enough room behind the oil tank to get the dip. It will just have to be lenghtened to 36 inch total like the front one.





That's me done for the day...

See you soon, Patrick

[oz]

Looking good Patrick almost there eh!

[Old Scrambler]

I've been watching with interest on your build technique..........impressive. I think I met your adopted brother a couple of years ago at the big swap meet in OHIO.......he was picking out the trashed Sportster pipes from the garbage barrel on the last day..........or was that my adopted brother?

[wobblywalrus]

Patrick, about the 36" pipe length.  Tuned pipe length can help pull the intake charge into a the cylinder on a naturally aspirated motor.  Does it also influence how a blown engine scavenges?  Do you tune it to do the opposite?  Is the pipe tuned to push against the incoming fresh charge to keep it from blowing out the exhaust valve?

[thefrenchowl]

Oz: Looking good...

Making progress, yes, but still a lot to do...

Old Scrambler: he was picking out the trashed Sportster pipes from the garbage barrel on the last day...

LOL, nothing wrong with garbage!!! I've built my pipes like this for the last 30 years, usually all bronze welded, that's the set in 1"1/2 when the KHK was roadworthy and normally aspirated... Got a pretty big box full of discarded bends!!!



wobblywalrus: 36" pipe length

I wouldn't know where to start to calculate pipe lenght on a sheet of paper... Just going with the flow here, 36" is the std lenght of pipe H-D had on most of its K based racers over the years, KR, XLR, XR, + or - a few inches to cope with local conditions and tracks

Patrick

[Gimpy Joe]

Is there a way to calculate the correct pipe length/volume or do you just figure it out through trial and error?

[thefrenchowl]

Hi Gimpy Joe,

Found these 2 formulaes on the web, They seem OK...

1) Pipe length in inches = 850 x ED : rpm

Where ED is 180 degrees + the arc in degrees between exhaust valve opening and BDC.

For my engine: 850 x (180 degrees + 50 approx) : 5500 rpm = 35.5 inches

2) Pipe ID area = rpm x cylinder size in ci : 88200

For my engine: 5500rpm x 27.5ci : 88200 = 1"715 area = 0"738 radius x 2 = 1"470 ID

Std K or KH run 1"500 pipes.

Then, usually, smaller length = higher rpm peak torque, longer length = lower rpm peak torque...

My 36" length is from the start of the slip on bit on the exhaust port to the middle of the cutaway at the end, so the true length from valve to end is probably nearer 38"...

Patrick

[saltwheels262]

frenchowl,

just finished reading your build thread. very nice work.
a lot of engineering on that bike.

really like the intake manifold / head intake ports brace.
that should prevent any type of blow-off there.

franey

[thefrenchowl]

Hi, saltwheels262,

Thanks for the nice comment,

But to me, it's just the way I work with what I've got so this built is not that much different from my other builts, just a bit more extreme and with a grail/goal other than just ride about on a special!!!

Anyway, big step today, I phoned Chuck, the BNI man in charge of attributing the Bonneville race numbers so I got a 3 digits one, 405 APS/VBF... Sounds too much like a bad French Peugeot car, just hope it'll be a tad faster...

Also spend some time later calling Jim Haubert in Arizona, that's where I will ship the bike later in the year...

He'll be part of our luxurious and numerous crew of three: Gordon Thompson, whom I met in Manchester in 1985 and a great lover of H-D Iron Heads; Jim Haubert, H-D race dept supa dupa extraordinary machinist and H-D official prototype builder in the 70's (he's the man that built with Willie G. Davidson the original Café Racer in 1974 in downtown Milwaukee...) and meself... Jim will be organizing a few things and sourcing a few spare parts for me on your side of the pond while I sit here doing nothing!!!

All in all a good day, rejuvenating, even if I did not go in the garage to say hello to the bike, too fed up recently with me Tig welding skills or rather lack of them!!!

Cheers from Patrick

[thefrenchowl]

Hi Everybody,

Picked from Brian's the bracket that will stiffen the assembly and hold the excentric belt tensioner, it fits between the 2 pulleys.

Only the crank end is finished, needed a bit of filing on the other end to miss some of the Ansin protuberances. I'll only finish it once the engine is assembled, at the moment, the drive sprocket is only held by its oil seal, so that doesn't garantee its position is dead right!!











See you soon, Patrick

[Gimpy Joe]

Gorgeous! I really like the way you build. Every problem has a clean, elegant solution, but without covering the bike in billet aluminum.
Keep posting pictures