5 replies to this topic

[80sMiniCity]

I just took the valves off my ~1986 998cc (99H) head to put on new valve seals. Haynes specifications indicate a 99H head should only have a single spring with a free length of 44.45mm. For some reason I have 2 springs per valve with a free length of 41.5mm for the outer and 40mm for the inner. Did Rover switch to a dual Copper S type setup on later 998cc engines? Does anyone else have this setup? Can I get away with using them on the 998?

Thanks.

[Cooperman]

Maybe someone has re-built the head earlier in the life of the car & fitted dual springs. If the cam is standard and/or you are not revving it over about 6000 rpm, single standard springs are fine and will cause less wear on cam and followers.

[80sMiniCity]

I first thought that someone who had the car fitted dual springs, but only dual springs, strange. It has a stock rocker and valves. The ones on it are about 4mm shorter than the ones called for on a Cooper. Can I get away with the existing shorter dual spring setup?

[Cooperman]

If it was running OK before you took the head off it'll be OK with the double springs, although they are not necessary really. It won't hurt the running of the engine, just increase cam, rocker and follower wear.

[jaydee]

Have you measured valve size to see if they're actually standard?
Double springs makes no sense if anything else was changed, and bigger valves are essential on a modified A series engine..

[80sMiniCity]

The intake valve size is 27.75mm and the exhaust is 25.3mm. I think that’s the smallest valves you can put in a 998. Strange, strange, strange.