Z320 Posted September 25, 2021 Report Share Posted September 25, 2021 Hi there, on my old spare egiine I always wondered about the valve springs, they are much wider than the collar... Yesterday I dismantled one of them and found both springs do not fit to the collar at all. the springs are too wide - or the collar too small... Also T found a not expected small metal ring slack on top of the valve guide and a hardened washer below the springs. I don't find them on the catalogue of the typical suppliers? Any idea? Marcco Quote Link to post Share on other sites
Lebro Posted September 25, 2021 Report Share Posted September 25, 2021 TR2 / 3 / 4 valve springs are a larger diameter than later TR4A springs. your collars are probaly TR4A, & the springs earlier. Do the springs fit nicely into the recess in the head ? - they should. Bob Quote Link to post Share on other sites
Z320 Posted September 25, 2021 Author Report Share Posted September 25, 2021 Hi Bob, thank you very much for this info. There should be a recess in the head? I'v only seen a steel washer laying there.... Marco Quote Link to post Share on other sites
Lebro Posted September 25, 2021 Report Share Posted September 25, 2021 Your steel washer is in the recess, which is only as deep as the washer thickness, probably to allow the larger springs to sit flat. I would guess that you have a 4A head, with 4A collars, but TR4 (or earlier) springs. Bob Quote Link to post Share on other sites
Andy303 Posted September 25, 2021 Report Share Posted September 25, 2021 The part that is circled looks like a valve guide seal that has hardened over time. it is not supposed to be there, but with the mix and match of parts I guess the previous owner also worked on MGs thought it to be a good idea to add them. Quote Link to post Share on other sites
Z320 Posted September 26, 2021 Author Report Share Posted September 26, 2021 (edited) Hi Andy, you are right, what I thought is a metal ring was a hardened rubber ring, it broke in pieces. I cannot imagine how this ever worked as a seal...? Bob, the recess is about 2 mm deep (?), it's mainly the cast iron leveled to give the spring a flat surface? its diameter fits exactly the diamater of the spring, the washer is smaller (as visible on the photo above) and does not fit to any diameter of both springs? I decide what to do when I have the other springs out but tend to let the washer (s) out. Ciao, Marco Edited September 26, 2021 by Z320 Quote Link to post Share on other sites
Andy303 Posted September 26, 2021 Report Share Posted September 26, 2021 16 minutes ago, Z320 said: Hi Andy, you are right, what I thought is a metal ring was a hardened rubber ring, it broke in pieces. I cannot imagine how this ever worked as a seal...? The seal would work when the valve was fully open and prevent the oil that collected on the valve stem from being sucked through the valve guide and into the combustion chamber. The simple "o" ring style were replaced by the better "umbrella" style. Better explanation here: https://mgaguru.com/mgtech/engine/ch202.htm Quote Link to post Share on other sites
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