Oil baffles

[leaf200]

Hi,

I am trying to fit a set of oil baffles to a early 1926 engine but I am finding the recesses don’t look deep enough. Where the later oil baffles thicker than early ones?

Thanks

David

[Ian Williams]

Not in my experience, but I throw them away rather than fit them

[Dave Mann]

I follow Ian's advice, the science that puts the mixture above the piston also draws the oil through the slot in the baffle.

[Tony Griffiths]

I follow Ian's advice, the science that puts the mixture above the piston also draws the oil through the slot in the baffle.

I bow to Mr. Mann's vast experience and knowledge - all based upon sound empirical evidence. One wonders what, if any, experiments were carried out with baffles by the factory - or, indeed, subsequently by any of us?

[John Mason]

My engine has run without baffles for the last ten years without problems. I have no scientific proof but I think it maybe something to do with modern pistons having the lower oil ring.

John Mason.

[Bruce Nicholls]

First thing I threw away in about 1972. Never missed them.

[Tony Press]

Didn't the factory have great problems with oil burning at start up causing many 'smoking' engines to be replaced at the test stage ? 

The baffles may have been an attempt to stop this.

[Bob Culver]

Somebody must have done a before and after test with no other changes. It is astonishing how much oil a Seven can burn....with baffles. I wonder if supposed to channel downward droplets toward the con rod drillings. Although Ricardo reckons all so hectic that attempts to direct spray futile. Suppose on a racing engine adds slightly to pumping losses. I squeezed them very close on my car but still used 1pint in 300 hot main road running after rebore.

[Ian Williams]

In my experience with good bores, rings, valves and guide's sevens do not burn very much oil at, all certainly significantly less than a pint every 300! Some engines might leak this amount of oil but properly assembled most leaks can be stemmed to little more than the occasional drip

Edit, I should add that the first engine I built did smoke after new rings, it was the last engine that I used oil baffles on! it was rebuilt again without them and used little oil until i broke the crank.

[Reckless Rat]

For what it's worth the engine on my RP with oil baffles fitted was burning/leaking at a rate of about 100 miles to the pint before it was rebored. Now with +040 pistons and no oil baffles it hardly uses any at all. Since running in I did a long run across northern Spain with two crossings of the Pyrenees and over 2000 miles it used a pint and a half of oil. Consumption is still improving as the engine continues to bed in.