flaminia

[chriswgawne]

To add to (my ) confusion, in the 1990's when good quality new spare parts were not readily available, I had a set of good used Flaminia cam followers ground down (they are slightly larger o/d than Aurelia) to use in a B20 engine as the cam followers I had recently bought new then were rubbish. The original can followers were, I think, 'cold cast'(?) whereas the new ones I had bought seemed quite soft on the face which runs on the camshaft.
And as their internal profile was different to that of Aurelia cam followers, I used a set of Flaminia pushrods reduced in length slightly. Quite a good solution I thought at the time but now I cant remember which engine it was!!!! Other than it went in a car straight away and ran well.
Chris
PS Todays new cam followers from bone fide sources seem to be fine

[Richard Fridd]

Aside from pushrods and back to carburettor mixture, I have this info.
Could anyone tell me if these are good figures please, which would give clean, tan coloured plugs?
I assume the top line has a slight misprint.

Richard

[Richard Fridd]

New tool for valve spring work with head in situ. Also the suggestion of a wire through the spark plug hole succeeded  in holding the valve up when tried on my spare engine.
I have made the fasteners large enough to avoid them falling down any oilways etc, marked them numerically for posotioning and also the brass part which fits the spring cap doesn't interfere if i use my magnet to retrieve collets which don't always locate fitst attempt. I thought light grey would be good for any part which needs to be seen if it has fallen into a dark area of the workspace.

Richard

[Richard Fridd]

Additional brackets

Richard

[Richard Fridd]

In situ

Richard

[Richard Fridd]

Thankyou for mentioning that Geoffrey. 0.5mm difference in this case. I have one spare to shorten, and will try that.
I do need to keep a long set for my spare engine which has the different rockers. Both 2.5 litre capacity though, I think.
Richard

I have shortened a pushrod. Mild heat was enough to loosen the end from the tubular push rod, same method to refit the end once the rod had 0.5mm removed.
The damaged rod was not only bent but also cracked.
I would like to source alluminium tube to make some rods, if anyone knows of a supplier.
Also does anyone know the purpose of a tiny hole in each rod?

[Kevinlincs]

Fantasically, innovatively engineered and thought out tool 

[Mikenoangelo]

I wonder if the hole is to relieve pressure due to temperature changes?
Mike Clark

[Richard Fridd]

Fantasically, innovatively engineered and thought out tool 

Thanks Kevin, the tool can be configured to fit all valves on both heads. The U bolts fortunately have flats which assist in securing the cross bracket. The ally spacers are necessary for the perimeter frame to clear fasteners protruding beyond the rocker cover gasket face.

Richard

[Richard Fridd]

I wonder if the hole is to relieve pressure due to temperature changes?
Mike Clark

Could be Mike.
Anyhow three pushrods starting to crack now, but a visit to  Harris Performance Maidstone has led me to a retired engineer who is going to make some more for me.
Just wondering if expansion in length will be different if the material is different.

Richard

Richard

[Mikenoangelo]

Aluminium expands more than steel but whether this is significant would depend on the length of the pushrod, and whether the cylinder block is cast steel or alloy.
Mike Clark

[Richard Fridd]

Thanks Mike, thinking on, it is probably the only the valve stem which lengthens significantly when hot. I was concerned about valve clearance reducing once the engine warms up.
  Regarding coil bind thanks for your comment that space between spring coils could be regarded as cummulative.
  Also it was suggested yesterday that the tiny holes in the rods are to ease pressure when the hard rod ends are installed.
  Another thing mentioned yesterday was using solid steel pushrods. These would not be sacrificial in the event of something else failing though.
  As it happens another secondhand push rod from elsewhere is also bent. Are these prone to bending slightly with service over time or a coincidence I wonder?

Richard

[simonandjuliet]

Love the valve-spring tool - Ingenious !

[Kevinlincs]

From what I believe the pushrods bend when the engine gets over revved, often on downshifts as no rev limiter can stop a gear being selcted too soon, unlike on acceleration where the revs can be mechanically or electronically limted.
That's often where engine damage comes in with racing anyway...same probably applies here.
There's a lot of inertia going on within the valvetrain, that rod moves in one direction then back again at tremendous speed whilst having to come to a dead stop in each direction, and it does it every 2 crank revelotions. So at 4,200 RPM it has to move back and forth 2,100 times a minute, or an incredible 35 times per second! That's the cam lobe pushing it up and the valve trying to resist and pushing back via its' spring, that's a harsh environment and a reason why direct cams above the valve will always be able to survive higher revs.

[Richard Fridd]

Thanks Kevin, new pushrods to try now

Richard