Petrol additives?

[FlipDog]

Hi! I have just bought my first BSA! 1952 Golden Flash, and I am getting ear ache from well-meaning friends about how I should take care of the valve seats by using one of the petrol additives which do the metal coating job which lead used to do.
I had a Sunbeam S8 some time ago, and never used additives and had a chance to inspect the valve seats when I did a full strip down just prior to selling, as it happened. -No apparent deterioration!
Could someone more knowledgable than me chip in, please?

[lawnmowerman]

Hi Flip

There is a view that the lead deposited over the years will last for many more years to come - also I think I read on the forum that A10 valve seats were hardened anyway when manufactured. Our forum experts will correct me if I dreamt it!
Being a belt and braces type I use Ethomix from Frost which helps to combat the effects of ethanol and boosts the octane a little depending how it is mixed.
I have used Valvemaster in the past.
Looking forward to seeing some pics of your new ride.

Jim

[FlipDog]

- very interesting!
Many thanks, Jim.

[bikerbob]

Hi there. What you will find is that the cast iron heads did not have valve seats only the alloy heads had seats fitted I have always used Castrol valvemaster but some people have never used anything and never experienced any problems. I did run my Gold Flash for a year some time ago and took the head off and there was no  valve seat reccession but decided to use it just in case also use it on my A65 with alloy head. From what I have learned it is only the exhaust valves that could be affected you could run without as any problems will take time to have any affect. One expert did advise that not all engines would be affected he said set your valve clearances as per instructions then check the clearances every 500 miles and if after 1500 miles if they had not started to close up then you have nothing to worry about.

[metalflake11]

I, like many others rushed off and had hardened seats fitted when leaded petrol was no longer available. However, the ones that didn't ended up having no problems even after high mileages. Indeed, some are still riding around with 'soft' valve seats. My advise for what it is worth, would be to ride it and see if you are having to adjust the tappets more often than normal. If you have no excessive adjusting, harden the seats when the valve guides are shot. Additives are not my thing due to the fact they can bung up the carb.

[wilko]

And all those valve seat replacements are now dropping down and tangling with the valves!

[metalflake11]

Surely not Wilko?..........

[Goldy]

If you want to do high mileage at high revs then you perhaps should be concerned, otherwise don't worry about it.

[bsa-bill]

A bottle of Castrol Valve master plus will last a good while, may not be needed but will do no harm and the plus bit helps pinking on higher compression engines.

Had no problems with my Flash on original valve seats but have a mate who has had tappet clearance decrease on an alloy head, could be other causes though.

I did have on a cast head a valve pick up a bit (track) of seat and resulted in a little whistle, this was however in early 1960s with leaded petrol so make of that what you will

[Triton Thrasher]

Worst case of seat sinking I ever had was inlets and with leaded petrol.

[FlipDog]

Thanks all! -I guess I have my answer. I don't do many bike miles a year (4-5k) and none at high revs! I also don't want to carry a bottle of additive around.
I will check the tappets and record at set frequencies, until I convince myself that the seats aren't sinking at an unacceptable rate.

-Forum is a great resource! Thanks again to all,
Bill.

[bsa-bill]

Don't think it's that much of an issue that you need to carry stuff around Bill, I just put it in when I get home

[BSA_54A10]

All of the stories about valve recesssion are the result of research by the avaition industry and are 100% true,,, if you are doing 25,000 rpm @ 30,000 feet under lean burn conditions.
This is why avgas iis still supplied to air ports.
Naturally those with out any engineering knowledge ( motorcycle journalists ) extrapolated this information to include motorcycles.
And people wonder why I do not rread motorcycle magazines .

Bike Beesa
trevor