Hi Guaire.
Not planning to use the cams, I just want a bit more all round and a safe engine.
I read sometimes the std valves last for ever and others fail at very low miles. I would have thought if the valves were 1mm bigger that the seats would need opening out the same amount which could mask one side of the valve more in the combustion chamber.
As the ECU cuts off about 5200rpm ish I would have thought the original springs would have controlled the valves at that. Its not revving very high but it only has one spring. Did you use the Beehive springs for more valve spring pressure with the upgrade cams ?. I have no plan to rev mine to the maximum so may just put better valves in while the heads off for a skim.
Thanks for the reply. Tony
Hi Tony - That's sounds like a reasonable plan.
"...bit more all round and a safe engine."
ACE can tell you more about how stock valves have failed, more experience there. But, I know they are a 'friction welded' set up. ACE told me that fails have come from an overheating exhaust valve that separates.
Only the intake is 1mm oversize.
Since I have owned my B5, it has had three successive heads. One, was stock.
Two, was our Clubman Kit 1. The head was re-conditioned. Either parts were checked and kept, or made new. Yes, the intake seat was modified for the new valve.
Third, Clubman Kit 2, Beehive springs, new valves. ACE cams. Oil seals. Retainers. Guides were replaced if needed. Seats mated to valves.
Cams; ACE's performance design were installed.
Also, I was running a modified Harley Davidson Sportster 'silencer'. The coil was replaced by one of our 'Ignition Kit' specials.
The PowerCommander V was set up using the AutoTune device. It attaches on the header to monitor the exhaust gas. The profile was changed as per the AutoTune trims.
Yes, the beehive springs make sure there isn't any problem controlling the valves.
I don't like bouncing off the rev limiter myself. The two valve big single motor is supposed to get power from torque, not revs. This bore & stroke two valve responds well to better head flow design.
I really like this set up. No, you don't have to do everything I did, but I believe your approach to mods is a good one.
At the first start of the day, I like to use the kick starter. One kick to get some gas and the second kick starts up. The strong spark helps the first start. Its idle is steady and sure. I did not mention I use an iridium plug, Nippon Denso, an NGK zero ohm cap, zero ohm plug cable and a super coil.
As you would expect, the torque is strong on take off. But, instead of tailing off as the revs climb, the power keeps on coming more, but evenly. It's like having one big giant mid-range from off idle to the top rev.
My local dealer is Cycles of Silver Spring (Maryland). Rush Branson is chief mechanic and co-owner. Once I got my bike set up, he did a test drive on my Bullet. His comment was 'good mid-range'. That's what we were after.
Not weak off idle, no 'where's the power?' in the mid-range, while you wait for the big hit off the radical cam. One big mid-range throttle means there's strong power all through the gears.
Well I just wrote the whole biography of a B5!
Cheers,
Bill G.