The Bullet Board

Ah right. Changing the head gasket was going to be a last resort.

I need to inspect the inlet cam of those R cams. They are very noisey compared to Hs and the stock cams.

I feel one of the bushes isn't pressed in correctly and a bit crooked. Setting tappet clearances with the timing cover off can be done correctly. But when the cam has end float outwards to the timing cover, it drops out of tappet adjustment by a small amount and creates about 0.3mm of play at the tappet.

It clacks away quite violently.

Once again. I need to check how true the bushes are pressed in. I'll email Henry and see what he thinks.

Thanks for your advice.

Ben

Cam end float is set with the shims on the shafts.
The bushes are another matter. They may need attention, so please do ensure they are okay before proceeding.
Al the Fireball 535 engines had those Ace Magnum cams which are virtually identical with the R Cams. We did not have clattering issues with them, but these valvetrains are never quiet.
All the Ace Fireball 535 bikes were Ton-Up and had between 35-37hp at the rear wheel on the dyno with a broad power curve.

Yes I've set the end float (I'm a fitter). With that taken in account the inlet cam drops out of tappet tolerance. Which makes me suspect a end bush isn't pressed in true, which will cause the cam to oscillate on the shaft causing the tappet come in and out of tolerance. So its got runout and not spinning true.

If you would prefer to use the H cams, no problem.
Just be aware that they will behave "peakier", with a relatively weaker lower rpm and midrange, and then a rush at the top when it comes on the cam. The max hp isn't really significantly different, but it feels like it because there is so much difference between the lower and upper rpm range in terms of power delivery. As long as you're okay with that sort of lower curve, it is fun to feel the rush at the top.

A friend has a H 3 way tooth on hand so I'll see how they'll behave once they've been retarded 3dgs and monitor the compression. So a cheap, easy experiment.

I do like the power delivery of them. They are a load of fun and the power curve is at the meat of its while cruising at 100km/h. Which around my part of Queensland is mainly all straight main roads and highways. Although the low rpm vacuum is bothering me.

Relatively easy change.

I've emailed Price about the issue with one of the cam gears. I've only done 500kms on them and they've been like that since the get go. I only captured the issue upon removing them for H's cams.

Thanks Ace!

Ben

The Price cams should go in straight on the dots with a normal pinion. It will need some sort of compression help because 100 psi is just not good at all. I never encountered that with an 8.5:1 piston in it.
My concerns with the H cams is too early inlet opening and too late exhaust closing. In other words, too much overlap. So if you advance the pinion keyway, it worsens the early inlet opening issue, but helps the late exhaust closing issue. Using the retarded pinion keyway is the opposite, helping the early inlet opening a bit, and making the exhaust closing worse. IMO, closing the exhaust too late makes a more noticeable weakness in lower rpm tq, and the effect is worse than a few more degrees on an already early opening inlet valve. Also, retarding will lower your compression problem even more.

So I would recommend using the 3-way pinion in the Advanced keyway to give the best likelihood of helping all the issues at once.

Hop that helps.

That advancing would be using the 3-way pinion on the H cams.

The Price cams don't need any advance or retard, assuming they are made right.

Awesome. Yes. I understand that the H cams need advancing to bump that 100psi up and help the idle vacuum and improve the bottom end.
I'm actually quite happy with their power delivery for the type of riding where I live. They are tame to potter around town, but have the boogie for open roads. A smidge more bottom would definitely help.

If above doesn't improve enough, additional to help the H cams further with advancing them with the 3-way pinion. Hitchcocks do have a thinner base gasket on offer listed for the older Bullets which is 0.2mm along with their 0.5mm Head gasket. Or delete the base gasket all together. But I'll do one step at a time. 3-way pinion first and go from there.

The Price cams were fine as is, sitting at 170psi. Although I wish they had a little more top end because they were tapering off in their power delivery at cruising speeds.

I should have a update this afternoon. I'm fabricating out of Stainless steel I've formed up a similar principle to the Ace Canister. Drawn inspiration from the Ace Can and Dettrone air kit for the GT535. It will have a built-in velocity stack/trumpet in the inlet track inside the Canister. Actually out of exhaust mandrel bends and a donut! Haha.

I couldn't get very scientific with the curved stack length since space is limited. But should flow better than the rectangular box and filter and have more volume. Even though I've modified the rectangular box, opened it up internally added a DNA filter and enlarged the neck 2in to the Carburettor throat.

The new Can the inlet tract is 2-1/4" (57mm) to match the Carburettor throat. Then can has a smidge more volume. It's 100mm diameter by 115mm tall. Although some of that volume will lost with the trumpet inside it. Still will run a 4in k&n filter.

Cool.
Strange about the Price cams running out of steam at cruising speeds. We have routinely hit 100+mph at 6000+ rpm with dyno showing peak power(35-37rwhp) at about 6000 rpm with those cams..
Anyway, enough about that.

I always just ran without any base gasket. Just use your favorite sealer. Worked for me.

The Ace canister did have a stack of sorts, which was the rubber hose leading from the carb mouth to the canister and extending thru into the canister about a half inch or so. A more righteous stack design like you plan would be better, but it doesn't need to be much longer.

Cool.
Strange about the Price cams running out of steam at cruising speeds. We have routinely hit 100+mph at 6000+ rpm with dyno showing peak power(35-37rwhp) at about 6000 rpm with those cams..
Anyway, enough about that.

It could be just my engine configuration. I've taken on a half built engine. Originally it was just a steel rod, alloy barrel and Accralight Hi-comp 535cc +20 piton. I haven't got a response about the bushes in the R cams. At a later date I'll order some phosphor bonze bushes from H and give them a rebuild.

Ordered the 3-way pinion, Early bullet 0.2mm base gaskets and the 0.5mm gasket. As discussed I'll just try the advanced setting on the 3 way first when it arrives. Then try the thinner head gasket and/or no base gasket second if it's not a big enough improvement.

Here's some progress of the new can. The stack fabrication didn't go as smooth as I like. The ID of the Donut was a wall thickness smaller than the 60dg bend 2-1/4" mandrel. So it had to be split 4 ways and trimmed to tighten up.

A slow fiddly process. Slowly trimming the bend and length, getting the Can mounted in a good spot so rear guard bolt can still be accessed (I like road side user friendly.

Overall inlet track roughly measuring from the center point on the head where the intake valve is 260mm. Where as the GT535 with the Air Kit (my version( is 360mm). I'm still yet to post that build up too.

Once again I ran out of daytime hours that keep the neighbors happy. They always think my bikes are "broken". Haha

Here's the process so far.











That's the rough mock up. I'll have it done this afternoon and hopefully get it somewhat ride-able. It's having a photoshoot this weekend!

Ben