1.3 exhaust valve

[stevenf]

Just got a new exhaust valve for my 1.3 head but it is smaller than the ones that were in the head to start with. Is this normal or is it the wrong valve or is it possible to get oversized valves? Any help would be greatly appreciated.

Steven

[Royston]

Std valves are 33mm inlet, 29mm exhaust, has your head been worked i.e. polished, ported, atc?

Yes you can go bigger I have 38mm inlets and 31mm exhausts in my SR

[stevenf]

Bought the head second hand so not sure if it has had work. Where can you get the bigger valves from?

[Royston]

Bought the head second hand so not sure if it has had work. Where can you get the bigger valves from?

Local machine shop should be able to help, are the inlet/exhaust ports origonal rough cast or have been polished, a finger in the ports should tell you;)

[stevenf]

They are very smooth on the inside. just measured the exhaust valve and its 31mm in diameter. Where about did you get your valves from?

[garyc]

are they waisted stem? if so try http://www.gsvalves.co.uk/race-engine-components.html

[stevenf]

How do you tell difference in stem?

[garyc]

the stem gets narrower towards the head of the valve.

[Royston]

I bought a polished and ported head many years ago with no valves and worn valve guides, I used a company called Priestleys at Newton Aycliffe (Durham).

They replaced the guides and installed the biggest valves they could get inlol

But any good engine machine shop should be able to help;)

[stevenf]

Well disaster averted. Went to ma mates neighbour and he just stripped a falconer head and guess what. He had a valve the exact size I needed :) now to get the head built back up :)