"unleaded" valves, guides and seats?

[elanbaby]

Another question arose today as I dismantled my S4SE head a little further:

As I bought my Elan there came receipts for engine work (Oselli England) with it. It has had a complete overhaul and new valves, guides, seat etc. apx. 15000mls ago. The bills don?t mention if the parts were meant to run on unleaded fuel.

The inlet valves (std size, by the way) are magnetic. The valve guides look like bronze ones. The exhaust valves and all valve seats are non-magnetic. Must be stainless steel then? Does anyone know if these are OK to be run on unleaded? Could this be an unleaded conversion?

Or have exhaust valves and seats always been made of stainless steel?

Juergen

[twincamman]

we have non lead gas here and I run all my cars [bug eye sprite-lotus 7 -?lan-and Europa with regular non lead with stock valves and seats with no adverse affects ---ed

[M100]

Juergen, the fact the valves and valve seats are, or are not magnetic is no indication that they are, or are not "stainless" There are many magnetic stainless steels and a great many non magnetic ones!

If it's any help the latest "unleaded compatible" valve seat inserts from QED are not magnetic and the inlet valves that Lotus have supplied for many years that I know work ok with unleaded are magnetic. I don't have any exhaust valves immediately on hand to test.

My head was rebuilt before unleaded commonly became available in the UK and has run on unleaded for many years without any problems. I would guess any head overhauled in the UK since around 1993 would be unleaded compatible. Oselli might still have records of what they used on yours.

+44 1993 849610
http://www.oselli.com/services_engineering

[1964 S1]

I know of no unleaded conversions. Both my S1 and 69 +2 have been driving around fine for years and years on unleaded...I do give them a dose of racing fuel once every ten months...

[elanbaby]

Thank you very much for the fast replies!

I won?t be worried about unleaded fuel anymore!

Still I wonder why my inlet valves are magnetic while the exhaust valves and seats are not. Is it always like this?

Juergen

[types26/36]

Still I wonder why my inlet valves are magnetic while the exhaust valves and seats are not. Is it always like this? Juergen

The inlet valves are usually magnetic due to the material they are made from, the exhaust valve heads need to be a different material due to the higher temps they run at and although the exhaust valve head is not magnetic the stem usually is magnetic.The head of the exhaust valve is welded onto the stem during the manufacturing process as they are different materials.
This is to all do with the lubrication and wearing properties between the valve stem and the valve guide and/or the coeficient of expansion between the guide and the stem. If the harder material were used on the stems it could lead to "scuffing" of the stem in the guide as from what I remember the harder material does not pocess good lubricating qualities.
This was all explained to me by a valve manufacture many years ago so my memory is a bit hazy, the standard test of "is it an exhaust valve or an inlet" was the magnet, if the head was magnetic it was inlet......if non magnetic it was exhaust.
Of course time moves on and as valve materials have progressed I dont know if this test is still applicable.

Just to clarify my post, the inlet valves and exhaust stems are not actually magnetic, its just that they will be attracted by a magnet but the exhaust heads will not be.

[twincamman]

the magnetic valves are a voodoo mojo to counter act the Prince of Darkness thus Chuck Barry wrote---I GOT MY MOJO WORKIN -- -ed

[types26/36]

I GOT MY MOJO WORKIN -- -ed

Hmm, may be the word "Lotus" should be substuted for the word "mojo"

[twincamman]

I think the second verse had some thing ' stuck on you ' ---that was most likely the starter solenoid ----- ------ed

[elanbaby]

Ah, I can see clearer now!

[Robbie693]

"Got my mojo working but it just don' work on you" - Muddy Waters

Seems like he can't fix his Lotus either...

[tower of strength]

Ah, I can see clearer now!

new wiper blades?