moppedog said:
The 270 degree crank layout of the NRE, and now the new Triumph, engines, plus the literature I have ploughed through, convinced me. And this against the recommendation from Steve Maney himself, claiming there would be no improvement in the vibration department. I am stubborn and I could just not believe what I heard, so there we are,
270 degrees it will be.
I am ready to listen to you guys out there. I just want power , lots of it.
Then we come to power versus or with good handling and rideability. This project is first an exercise to satisfy my desire to use my long ago aquired engineering knowledge for something that I am really interested in. I know for sure that I will not be able to keep up even with the slowest when going around bends, even though I will go fast enough to scare the hell out of myself. Handling will therefore be of secondary importance, although I am doing what I can to build the bike to be a good handler. BUT, and that is my point, since I will lose time against everybody in the corners, I need an engine that will make up for that, and more, when going in straight line between the corners. Hence my obsession with power. And, I am pretty sure I have the brakes needed to reduce the end of stright line speeds to something that my very limited cornering ability can handle. Keep on following my progress and do not stop offering your advise! I will listen carefully before deciding ..........
Well, no I won't agree with most of this. My recent experience is returning to racing after a VERY significant break. My return to the track was initially with track days and with a bike that makes much more power than you will get from any Norton twin, a GSXR750 SRAD, dynoed with 120 rwhp. A bike that handles well in the modern sense and stops as well as it accelerates which is enough to frazzle your mind when used to the full! But racing is not track day work and classics are not rockets, you won't ride one that way and it won't help your cause to build this 'missile'
If you want to get around a track in less time, and to pass others whilst doing so, you will need a different tool and to develop your basic skills. You don't know how fast the other guys are compared to you, you imagine that they are faster, that will not help, you have beaten yourself before you even get to the start line
My suggestion would be to build the chassis, gearbox, set up wheels with single front disc and a double disc set up, and build two engines, because I suspect you will only in the end accept the data you collect, not the opinions of guys on forums.
So put in your order for 920 barrels and another cranks etc, and build this missile, in fact build a 1007....
But with your 750, get the head work done if that pleases you, but perhaps you will complete the build sooner with a standard Fullauto, choose a race cam that gives good rideable power, and don't go much above 10.5:1, use a set of cheap and chearful 34 Mikunis, with long inlets.
BTW this is the engine in my Rickman, which gave me 22 race finishes out of 24 in 2015, and 2nd in the CRMC 1300 twins championship and 6th in the 1300 National series (twins and multis) with a best of 4th overall in a wet race at Brands, where that smooth power delivery meant everything as more powerful bikes slid around....this was the 2nd race meeting on the bike and it did wonders for my confidence, this is so important.
BTW You have no choice apart from 2 into 2 if you insist on the 270 crank, 2 into 1 simply won't work. (No I wouldn't bother with the 270, but it has been done sucessfully, though the margin to a 360 is minimal, and with lightweight long rods and pistons I think even less benefit, Dave Watson built one fr Gary Thwaites and he was successful on it, but Dave said he wouldn't do it again)
Fit this engine into the frame with a single disc front wheel and learn to ride it. I think you will also enjoy it more than any missile you might build. A well balanced bike like this will be a good testament to your engineering skills. What you will find is that you will be able to brake deep into corners, turn the bike, and get onto the power early to keep the bike balanced and comfortable and you will build confidence. If you want to know why Marc Marquez beats clearly more powerful bikes (Ducatis) most weekends you need to recognise he has extreme confidence in his own ability. If you want to go quicker, find a way to build your confidence, don't start out telling yourself you will be beaten by corner speed, develop some. And please don't think that the guy with most horsepower wins!
(my approach to this was to run a second bike, a 500 with around 43hp, but capable of much higher cornerspeeds, to develop my confidence, it works, at a tight track I was faster on this bike!)
Now fit the rocketship engine to your chassis and spend some time on the dyno, make sure you understand from the figures just when this extra power is going to hit, fit it to the bike, fit your megastop front brakes, and most likely destroy the confidence you were developing as this thing bites your arse everywhere!
Even if you achieve smooth power delivery in this engine by compromising on max power, it is unlikely to be as rideable until you develop the skills to use it, and the extra power will challenge the basic handling of the chassis and tyre combination, you will spend more time fiddling with set up than 'racing' your competitors.
