Honda Blackbird Cam Timing

[Laurence Wilson]

Before I go ahead and order a spare pulse rotor from Lings — they don't appear to be expensive — does anyone have any advice for how to accurately set the cam timing on a CBR 1100 engine, given the Nova dry sump weld-on scavenge pump drive gear conceals the original timing marks?

 

I'm just about to bolt the cylinder head back on and I assume the marks on the pulse rotor identify number one cylinder at TDC? I'm also assuming Mr Honda stamped them onto the rotor because this job requires a little more accuracy that just sticking a probe down the spark plug hole

[bluenose]

Laurence

 

Not sure how accurate i needs to be but if you need to borrow a standard cover with the timing hole cap then let me know and you can borrow it. When I was stripping down my spare engine I thought the marks are not all that accurate from what I remember, although it was some time ago. If you need either a Haynes manual or Honda Manual I have both.

 

Nick

[Richard Price]

Laurence,

 

I've no idea about Blackbird cam timing, but if you do need to determine where TDC is, then rather than "just sticking a probe down the spark plug hole", then using a DTI fixed into an adaptor made from a tube welded onto an old spark plug works well.

 

I've been using this on K series engines for a few years.

 

 

[Laurence Wilson]

Courtesy of BoSS:

 

... if I needed TDC accurately I'd use a dial gauge (DTI). This is what I did when setting up verniers, you need a bracket to hold the DTI and a welding rod extension that touches the piston crown screwed into the DTI nose. This gives you far better accuracy than a spot on a crank pulley or camshaft. Good luck.

 

Now why didn't I think of that Evidently, I'm lacking in common sense today

 

And Richard, too

 

Nick: I have an original cover. It's an unmodified pulse rotor I would require. You wouldn't happen to have one of those left over, would you? But I'm looking through the Haynes manual now, to see if I can confirm my assumption that it is TDC on cylinder number one. A dial gauge would be the way to go if it is.

[Laurence Wilson]

And for anyone tackling this in the future, the relevant paragaph in the Haynes manual, page 2•14:

 

The engine must be turned so that No.1 piston is at TDC (top dead centre) on the compression stroke ... Turn the engine until the line next to the 'T' mark on the timing rotor aligns with the static timing mark, which is a notch in the inspection hole rim, and the IN and EX marks on the intake and exhaust camshaft sprockets respectively are facing away from each other and are flush with the cylinder head top surface.

 

Thank you all I think I'll be making myself a nice tool like yours this week, Richard 😬

 

Nick: Once I have my engine back together, I'm going to begin cutting tubes out of the chassis Would it still be okay for me to pop round and take some measurements of your car in the near future?

 

Edited by - Laurence Wilson on 19 Feb 2012 19:30:46

[bluenose]

Laurence

 

Any time just blatmail me and we can arrange a weekend you can come up. It would be ideal at the moment because it is up on stands so easy to get to everything.

 

I probably have a spare pulse rotor or two lying round I will check.

 

Nick

[Laurence Wilson]

I will be in touch, Nick