Greg Brillus Racer

[greg brillus]

Well you can run other frames of the era, such as a Featherbed but not an Egli. Some of our boys run Esso and JAP engines in the Norton frames. I asked for confirmation on the use of the 72 Suzuki front brake, and MA (motorcycling Australia) sent me a reply saying that "Yes" it was ok. They had recently changed the rules on brakes, where it used to be that they had to be a Period component, now the ruling says "Any drum brake with a maximum internal diameter of 230 mm" I don't think you are allowed to use strengthened swing arms, but I guess it depends on how clever the scrutineers are........Greg.

 

[timetraveller]

With regards to valves and valve seat angles; I have just had a chat with Roy Robertson who races a 90 x 100 Egli over here, 1272 ccs. He gets 94 BHP at the rear wheel and has tried 30 degree and 45 degree inlet and exhaust valves etc. He found no significant difference and went back to 30 degree angles on both. He uses an exhaust valve head diameter which is one eighth of an inch smaller than standard and a 1.9" diameter inlet, that is about one tenth of an inch larger than standard. I have also seen inside Godet heads, but not measured, and there is a noticeable difference between the inlet and exhaust valve head diameters. Patrick does all his development commercially so we could not expect him to divulge what he had done in his latest two 500 cc racers, but Roy was racing at a recent meeting when at least one of them was there and he tells me that it was going very well. Really nice to see what you are doing Greg.

 

[Bill Thomas]

Hello Greg, Don't think we have seen your pistons ? I am worried about Pockets ! Not your pockets, They must be deep !! You know with standard 9 to 1 and bigger, The valves rub on the inside of the pockets, I take them off to within a nats' of the top ring. Cheers Bill.

 

[litnman]

Greg, your project is a real inspiration to anyone planning to build a Special. It's a real beauty.

 

[greg brillus]

There is a lot more bits finished for it now....the exhaust system is nearly done, and the pipes look slightly unconventional with the rear one following the front of the engine, and the front one swings to the right and around the timing cover, then downward and under to a 2 into 1 collector. This then straight into a hand fabricated muffler which comes out at the left near where the original left side footrest plate goes, and angled slightly upward. It is held on to stubs held into each port by shortened finned coarse thread Norton type bronze nuts, with ringplates behind to anchor the springs to. The seat is painted, tank is near done, just needs more clear coat to finish, the oval number plates look great painted letterbox red with a off white rim around the outside. Sorry Bill, the pistons had pockets on both inlet/ exhaust sides, but we have machined them all off, I still need to check for clearance at TDC and either side of, but I think it should be ok. That's for the info Norman, it is interesting that the valve angles made no significant change. Perhaps with the low engine revs, that it is not a big issue.....I pick the bike back up tomorrow, and will strip the top end again, so as to set up the heads, barrels, valve timing, etc, which hopefully should go to plan, then I will begin the final assembly, which will come together very quickly.....I have just over a month till our next race meet.....I'm back in the shed.....Greg.

 

[davidd]

Photo 54

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Photo 59

David

 

[greg brillus]

Thanks David You always do a tremendous job with the photo's, Ok guys well here is the exhaust......you will either like it or hate it, at the end or the day we had to build it with the ability to keep the noise limit down. At our National championships at Lakeside this September, we were told that if our bikes showed up without a muffler, that we might as well put it back on the trailer and take it home. So to combat this, we had to guess the length of pipes given their 1 3/4 diameter, we wanted to run a 2 into 1 system which will automatically help with noise, and we needed a good enough muffler to lower noise without choking the engine. I can't remember if I told you but the chap who did this system is the same fellow who did the exhausts on the "Britten" motorcycles...He has been doing this type of work all his life, and that was good enough for me....The only way we could have kept both pipes running forward and under would have been to run 2 completely separate pipes and mufflers. I may look at this down the track but for now, I need to start with something. The workmanship is outstanding, and although it is a bit "Out there" to look at...I don't mind the look at all. The hand made stainless muffler is a work of art. Immediately after I took these photos, I stripped it back to the bare bones with only the rods sticking out of the crankcases....it's time to get on with the heads/valves etc., Cheers for now.....Greg.

 

[Bill Thomas]

Looking Good, Cheers Bill.

 

[greg brillus]

Hi there all, just an update to let you know that the racer is progressing very well now. The engine is completely finished, and although I had a couple of issues to sort out, it all came together nicely. One item that had me for a while was one of the rocker tunnels was out of alignment.....that is that the fork in the rocker was not central to the valve stem. I ended up shimming the rocker over to one side slightly, to correct it. I am not sure why this happened, only that perhaps the tunnel was out beforehand. I had to make up special length pushrods at around 143 mm length to compensate for the change in rocker geometry. The change in height of the step on the valves seemed to be only necessary on the inlets....the exhausts needed to be closer to standard. The seats were changed to 45 degrees on account of what was easier for both the valves and the seats, and I had to remove a small amount of material in the roof of the rocker tunnels right in near the upper guides to allow the rocker assemblies to be installed. We ended up using valve spring retainers and collets from a Toyota engine, and machined the outside diameter to suit the Gold Star springs. I had to remove about 1.5 mm from the inside roof of the valve caps just to be sure of no clearance problems. The tappet adjusters are the allen key type, so no fear of them hitting inside the caps. One other issue I had which I was very keen to check, was the exact timing of the magneto. With number one set at 34 degrees, when I checked number 2 it showed 31 degrees......Hmmmmm. Out came the dremel with a sanding barrel attached.....Within two goes taking about 2 minutes in total, I ground the cam face for number 1 to equal the timing so both are now exactly 34 degrees.....I knew I should have been a cam grinder.!!! Anyway I was most happy with that, and yes I did polish the cam with some wet and dry, and I blew out the fine dust, and regreased the cam.....Jobs done. I will now spend the week reassembling the rest of the bike together, hoping for an engine run next weekend. I have decided to leave the exhaust as is for now, and will make changes a little later. I have been taking more photos, so I will organize some for David to post on here very soon. I'm getting quite excited now, Cheers......Greg.

 

[Bill Thomas]

Excited !! So am I and it's not even my bike ! You will have to do a youtube of it, So I can hear it run, Good Luck, Bill.