Topic: Vintage sidecar rebuild - new video

[bear]

I'm not a fan of the Wiseco's either Brian.
After watching your progress with the sidecar rebuild, I have no doubt you will come up with a very competitive and more importantly, reliable motor.

On another note we have just returned from racing at the "Southern Classic" and where lucky enough to come away with the win.
It will hopfully help my confidence a bit heading into the seasons end at Phillip Island in January.
I haven't really been comfortable on the bike since the accident.
We won't be doing the Australian Titles in Perth unfortunately.
Mum has been diagnosed with alzimers and has lost her drivers license.
And it's going to be impossible to get away for any length of time for awhile.

Cheers,
Brian

[Tintop]

Congrats on the Southern Classic win Brian, great news.

Philip Island has been a discussion point with some of the sidecar guys here.  Seems to be on everyone's bucket list, but it's not an inexpensive proposition.  After what happened at the MotoGP, you may want to consider some new skins for that rig.  The new PI surface seems to be a tire killer.

I've been trading PM's with Brent about Wiseco, and will be looking into my options re pistons.  Now that I feel I've got it handling, I'll build a motor to complete the package.  I know the Weber works, it's just the rest that sucks.

Sorry to hear about your Mum.  Mines 93 and passed her test in July, so she gets to keep her license for another two years.  I know from hearing her friends talk, that loosing that mobility is hard on everyone. 

[tony840]

hi from england this is sundial racing the number 10 outfit is a 810cc sohc honda the yellow outfit is a bsa and the last but not least a bmw

[Bill/BentON Racing]

Nice Tony, where was that taken?

Sam.

[Tintop]

Interesting collection of bikes Tony, welcome to the forum.

The BSA & Honda look like they are CRMC P3's, how big is the BSA engine?  What about the BMW, and who's chassis are under them all?

[bear]

Good to have you on board Tony.
Another chair man to help keep these pesky drag racers at bay.
Some details on the bikes would be good.

Cheers,
Brian

[Tintop]

......Another chair man to help keep these pesky drag racers at bay. .......
Cheers,
Brian

+1

[Tintop]

So you engine builder guys, riddle me this.  Was looking at the pistons today, and noticed that there is a small ridge behind the mark on the exhaust pockets (barely visible in photo).  To me it looks like the metal was pulled up as the valve retracted.   Piston rocking in the bore?

Figure I know what needs to be done from the pistons down, and with the trans and clutch.  So decided to consentrant on the head.  Did a rough measurement (using valve marks ), and looks like I have about another .1595 of clearance to the bottom of the pocket.  So it would appear that the pocket depth is sufficient to take a cam with a lot more lift.  Checked out Webcam & Megacycle; both offer a cam with .475/.480 lift, 266/265 degrees of duration.  I can also get thinner gaskets to raise compression (but lose clearance).  Rules require I use the stock valve size, but going to look into alternatives (5mm??).

[bear]

The one thing I do know Brian, is that all sidecar motors like cams with high lift and short duration.

Cheers,
Brian

[Tintop]

The one thing I do know Brian, is that all sidecar motors like cams with high lift and short duration.

Cheers,
Brian

I'll keep that in mind Brian.  Megacycle has cams with more lift (.5+), but also more duration.  Would time any cam with a bias to torque.  Last seasons motor was very good, just fragile.  I used a shorter 5th (.92 vs stock .96), and that really hurt top speed @ Mosport.  Figure with top end improvements I'll go back to the stock 5th.

[scottly]

Brian, are the new pistons scored on the skirts?

[Sam Green Racing]

Hey Brian, (the fat Ausie one)  I wonder how my drag motor would fair in your sidecar.
Only right hand needed to twist the grip and operate the front brake.
Would be slow off the line but once moving it would be a doddle.
Perhaps take your outfit to a local drag race to see how it performs for comparison.

Sam. well it might work.

[scottly]

How does the auto handle compression braking Sam? Does it free-wheel?

[Tintop]

Brian, are the new pistons scored on the skirts?

Haven't pulled the barrel off yet scottly, but with the pistons at the bottom there are some marks on the exhaust side of the sleeves.  Was a fresh bore & hone before the last race weekend, so not a good sign.  New sleeves are on the parts needed list already, as these are max'd out.

[Sam Green Racing]

How does the auto handle compression braking Sam? Does it free-wheel?

Yep,   that's why you only need the front brake.

Sam.

[bear]

Hey Brian, (the fat Ausie one)  I wonder how my drag motor would fair in your sidecar.

Oy!................whats this fat business? 
I'll have you know that the lovely Evelyn considers me to be nothing more than "pleasantly plump".
I've wondered about the auto thing for our application myself Sammy.
The auto's are just about non existent down here though.
If you or Billy spot one over there in your travels, give me a yell.
I have a road going sidecar sitting in the shed I would like to use, but I don't think I could use it on the road attached to a conventional bike.
An auto would probably work though.

Cheers,
Brian

[bear]

The one thing I do know Brian, is that all sidecar motors like cams with high lift and short duration.

Cheers,
Brian

I'll keep that in mind Brian.  Megacycle has cams with more lift (.5+), but also more duration.  Would time any cam with a bias to torque. 

I agree. We usually add about 5deg advance over the timing card.

Cheers,
Brian

[Tintop]

Thanks Brian, that confirms my direction with the cam choice.

I won't worry too much about Sam's comment.  He's just sore because that new hair caused too much aero drag, and cost him at top end.

As for using an auto in a sidecar....it worked for Jim Hall in the Chaparral.   

[Bill/BentON Racing]

I WAS only joking but we do have a motor. You would only need the bottom end but I hate to think what it would cost to ship to Aus.

Sam.

[bear]

I WAS only joking but we do have a motor. You would only need the bottom end but I hate to think what it would cost to ship to Aus.

Sam.

I'm after a complete road going bike. Can't keep racing forever, I'm getting older and slower, their getting younger and faster.

Brian, when I mentioned short buration, l should have said as little overlap as possible.

Cheers,
Brian

[Tintop]

Thanks for the clarification Brian.  When I get closer to pulling the trigger on a cam, I'll post the specs of what's available.

As I mentioned previously the engine rules for the XS in my class (VRRA P2) restrict carb venturi (34mm), and valve size.  The wording of the valve part is 'stock valve size'.  Note it doesn't say 'stock valves'.  I'm already running 34mm chokes in the Weber, so can't do anything more there.  The valve head size restricts the amount of porting that would be viable.  So to get more flow I'm thinking along two lines.  One, reduce the valve seat area to open that part up (thanks Mike & Jay for pointing that trick out ).  The second flow restriction is the valve it's self.  I can't change the head size, but I could reduce the stem.   The stock XS stem is 0.3145, a 5mm valve stem is 0.195+/-.  So I've sent a request to Kibblewhite for a price on custom 5mm valves, guides to suit (shortened for high lift cam), and a racing spring kit (Ti retainers).  About the only other thing I can do to the valve train would be Ti tappet nuts.  Comments??

[Tintop]

Heard back from Kibblewhite today.  Because of the size of the intake valve head (41.5mm) the smallest stem they can offer is 6mm (0.2362).  This would still be an improvement over the stock stem which is 7.9mm (0.3145).  However, cost for the whole package is an issue (almost double ).  The guides would be one-off CNC custom units because of the OD, and would require custom retainers as well.  Ordering more than one set would lower the unit price(s), but significantly increase the initial cash outlay.  Going to have to think about this.

[bear]

Brian,
Have you tried googling the vale dimensions your aming for?
You maybe able to retro fit something.
We have been using Mitsubishi Evo valves for years, cheap as chips.

By the by, a mate just sent me a YouTube link of the P4 sidecar race at PI in 2013.
Tim is the current Aussi Champ and won this event last January.
I'm using my tablet at the moment but I will jump on the laptop shortly and post the link.
It may give you some motivation for 2015.


Cheers,
Brian

[Tintop]

Look forward to the link Brian, although I don't think motivation is lacking.

Thought I would see what Kibblewhite said 1st, but I'll start looking around now.  The bonus from contacting them is I now know that a 6mm stem is likely the minimum for the head size.  As for the rest have to see what turns up.

[Tintop]

Found it Brian

sidecar island classic 2013