getting the piston rings into the bores

[P. de R. Leclercq]

Thanks Joe for the nice words!

OK, will do - probably in the next two days. Actually I might put it up on my blog. - a bit easier than putting it up here.

I have posted somewhere here the address, if you need it, please email me

Paul

[P. de R. Leclercq]

Tim, I think you are right.

The piston maker is CPS ' Construzione Pistone Speciale (how Italian is that?).

As I wrote above I'll post a snap on my blog. There's no drawing, we mounted the standard compressor in the lathe chuck I think and went at it with a grinder. We used a spare 1600 piston to make the angle - just a couple of easy measurements as I recall.

Paul

[P. de R. Leclercq]

Venolia makes good stuff too.

We (at Evolution) had them make several sets - one was a Fulvia-type set that went into a (now very quick) Aprilia, we also had an 80mm set made for a customer who was building a 1401cc Fulvia. That car has run well for years.

Paul

[Randy Adams]

The conventional wisdom I was taught was that if you have three rings, you set their gaps about 120 degrees apart so none of them ever line up and, at the same time, you make sure that none of the gaps ever line up with the ends of the piston pins. It's not hard to arrange them that way.

[P. de R. Leclercq]

Yes I always used to do this - and indeed still do.

However I have been told that it is in fact pointless, since research has shown that the piston rings actually rotate - at about 7 rpm!

I suppose it would be nice if each ring rotates at exactly the same speed, but I doubt it.

Paul

[Huib]

Interesting (that the rings rotate). And it sounds reasonable.

[john tynan]

The putting the rings in by hand method worked a treat. Block bolted back up, pistons in, oil everywhere, but looking like it might actually run fairly soon. Will stick the head on tomorrow and put on the remaining bits. Might try dropping the engine into the car during the week. Glad I don't do this for a living. I couldn't afford to pay me for the time it's taking to do this.

[P. de R. Leclercq]

"Glad I don't do this for a living. I couldn't afford to pay me for the time it's taking to do this."

Harrumph: it doesn't pay when you DO do it for a living!

Paul

[tim]

Interesting the rotating rings as I suspect that two stoke pistons have pegs in the lands to stop this as ring ends would break in the cylinder ports.

Would have thought this should be a point for 4 strokes to esure the thrust face of the bore does not have the ring gap - but I love the thought of rings rotating at 7 rpm.

Tim