Taking a grinder to Britain's motorcycling heritage.
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BRITISH CLASS

BRITISH CLASS
TRIUMPH GP500

Monday, 20 December 2010

MAGNUM45PETE'S45MAGNUM




This peach belongs to Pete, and it's his sole means of transport so we ain't talking about no wallflower here, take it away Pete;


1942 WLA 45 lower with a 1957 XL 900 top end,
3 years of collecting bits on ebay,the use or abuse of mates with access to mills lathes and welders.there were really only 2 major things to do,
1) Build up the right hand side of the cases behind the Tappet blocks so that the 900 base flange will fit, and reposition the base studs after opening the case holes for the cylinder spigot to fit.
2) I didn't want to over stress the motor, so when I had the Flywheels balanced for the heavier pistons,I also had the piston crown machined to lower the compression,thought Id run it a year or so to evaluate it's potential of going bang....so far so good, no exploding motor......

There were lot's of little things to do,like fitting sportster tappet adjusters as the 45 ones are flat,not designed for pushrods.
I turned the threads off the outside of the tappet blocks for looks and added a seating recess for the pushrod seals on the inside.
Some metal on the barrel fins had to be removed or the pushrod tubes would foul, and not allow the seals to seal.
I took the rocker oil feed from the oil pressure switch mounting hole,here I made an adaptor with a restricted oilway, as the main crank feed comes from the same point and i didn't want to take too much oil from the crank,
I wanted to and still would like to use 57-58 XL 900 cams,they were only made for the first two years of sportster production and are mild compaired to P or P+ cams that came later,but very suitable for the Magnum,
P & P+ are said to be too hot for it and again I didn't want to over stress the motor,so untill I can find some 57-58 cams I'm using std 45 cams,they work well enough but hopefully I will find the right ones eventualy,
the rest was a std build realy,80 spoke ultima wheels,D & A forks,PM rear brake,home made saddle,internal throttle and wiring with a Fairbanks Morse Magneto for reliable running....

1 comment:

  1. Fantastic detail work & solid engineering here.. a show winner for sure in 2011! Congrats!

    ReplyDelete