Who all is running S52 cams in their M52 motor?? What valve springs are you using??
I recently read that the S52 uses different (stronger) valve springs because it revs higher and the cam has more lift/duration. That made since to me so I researched a little and according to Realoem.com, the S52 valve spring part number is not used in any m52s except for the E39 528i, which I could assume has a more aggressive cam because it's a 5 series that needs more power. The S52 valve springs are also used in just about every M42/44 engine made. I could assume that the 4 cylinder motors use the stronger springs because they rev higher.
All this said ... Will the stock M52 valve springs hold up under S52 camshafts?? I'm rebuilding my M52 right now, using S52 cams and I would HATE to swallow a valve because I broke a spring!! Also, valve springs are $15 each!!!!! $15x24=$360!!!!!
I did NOT expect them to be so expensive!!!! .... Sooooo let me know if this is the worst idea in the world ... buuuttt I was thinking since the S52 springs are the same as the M44s ... I could go pull 24 of them from the junkyard?? Is that a horrible idea??
Most people do not swap the valve springs when doing the cam swap. I think it is a good idea to swap as the S52 spring is a little stiffer, but also a little bit shorter. You could be more prone to valve interference if you miss a shift or over-rev if you use the M52 springs. All of my experience is from a M52 race car that I rent to customers and I have a lot of experience with bent valves from them over revving the engine. I might suggest this kit as your best option if you decide to buy springs (I use it on my current race engine and have no issues). https://thmotorsports.com/538202-sup...-retainer-kits
Thoughts on re-using the original M52 crankshaft timing gear during a rebuild? It appears to have nylon as a major component which from working on early small block Chevy's I know isn't the greatest idea.
Thanks Tom
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