A10 rocker box.

[tdc]

Just wondering if swinging arm A10 rocker boxes are interchangeable with A7's or is the rocker arm geometry not the same .Thank's . R.

[idie]

They are the same.

[tdc]

As I thought ...thank's ....R.

[TTJOHN]

Don't forget to fit solid copper rocker box gaskets when you fit it together, which I just happen to have for sale at £19-00 per set, plus £1-00 p+p.

Kind regards TTJohn

[idie]

As he said. Recommended!

[tdc]

Don't forget to fit solid copper rocker box gaskets when you fit it together, which I just happen to have for sale at £19-00 per set, plus £1-00 p+p.

Too late John will keep it in mind for next time ....R.

[johncarter]

Interesting. Are there forces present in rocker boxes that warrant solid copper gaskets? I understand the need in head gaskets but isn't the rocker box gasket just there to keep the oil in? With properly lapped faces I've never had a problem with the standard type so what's the advantage?

[TTJOHN]

R.
It's just that they are easier to fit also take up any slight gap in between surfaces, the paper type are hard to keep in place when fitting the box on.

[DAVE BRADY]

Hi John,

How many sets have you sold?  I know Ebor do them as well so it would be interesting to get feed back on how good they are.  I suppose that, like with a head gasket, they can be annealed to help get a good seal and reused many times.  Is any 'goo' used with them?  I would think that the mating surfaces still need to be good and flat as with any gasket and I suspect that a modern gasket is capable of taking up minor imperfections of a few thou.  Also, how much torque is needed to get the copper to deform to the minor imperfections of the head/rocker box joints?

Dave.

[TTJOHN]

Hello Dave.

I have gone into this quite a lot and I have found that they are very successful obviously or I would not have invested in getting them manufactured, I have put photos on the site to demonstrate the best method of fitting, using the comb and mole grips, to hold the comb in place, I have so!d quite  few sets and no complaints yet.

Kind regards TTJohn

[DAVE BRADY]

Hi John,

Do you have the link to the photos?

Dave.

[JulianS]

The thicker conventional rocker box gaskets tend to settle in use because the materials dont resist compression sufficiently and the fixings slacken off.

Retighten the fixings means readjusting the valve clearances.

With the copper gaskets there is no settling and the tappet settings stay in adjustment.

This is another advantage of the copper gaskets.

[idie]

The problem I find with the paper gaskets is when you have an engine that suffers a bit with increased crank case pressure due to wear. The pressure finds the easiest way out and that seems to be the rocker gaskets before they have fully settled.

[DAVE BRADY]

Hi,

A trick for alleviating this bit of excess pressure is to put a breather on one of the rocker covers.  It does not have to be of a large diameter but 1/4 is enough.  Run the pipe down to vent below the engine and fit an old valve from an inner tube in the end.  The valve is screwed in the end of the breather tube to make it one way, exit only.  If the pipe is left open it is possible for material to work its way up the pipe and in to rocker box as the engine will draw air back up the breather pipe as well as push it out.  The valve prevents this.

Dave.

[TTJOHN]

Dave.

If you send me your e-mail address, I will send you a copy of the photos I have, I can't seem to post them on here.