I am looking for ideas on what paint to use for my engine. Can't find the colour I want, yellow, so wondering what else I can use. It's for a bike bike engine, what have you guys used?

If you can't find yellow, you've not looked hard enough ...frost's sell it...

http://www.frost.co.uk/item_Detail.asp?productID=8967&frostProductName=Black Engine Enamel (500ml)

Try this

Never thought of frost, looked on ebay and searched yellow engine paint and didn't get much but prices are better than thought, even for a tight arse like me.

Isnt Hammerite ok for engines?

try http://www.classicsagogo.co.uk/

i used yellow hamerite on a block once, it never come off and stayed bright. the trick is to get the engine super super clean before you apply the paint. a combination of gunk and brake cleaner is usually what i use.

I've painted several cast iron engines, but not a alloy one. Are there any considerations such as priming the bare alloy suitably before applying the paint?

Just a thought - I'd hate to see someone spend ages cleaning and prepping only to have the oaint fall off. There was a fairly recent thread where someone had spent ages painting an alloy g/box (IIRC) and the paint simply bubble and fell off.

Never even crossed my mind that I may need a primer, any thoughts anyone?

been told this by a painter you can paint it with any paint as long as you use heat proof lacquer so to burn the paint it needs air no air no burn, cant say it its true or not but sounds good to me.