B5252S 10 valve engine vs 20 valve engine parts

kimthepilot · Post by **kimthepilot** » 12 Dec 2013, 07:56

Hi All,

I'm just looking for some info regarding the engine in my 1996 850 wagon (Canadian Bought). It seems as though all part-sourcing websites (IPD, FCP) refer to this car having a B5254S, but mine is very clearly a B5252S.

I'm just looking for some details regarding sourcing parts. Are the timing belts/water pumps/tensioners/etc compatible? Plugs? Distributor? What are the differences between the two motors?

Thanks!

Kim

Post by **cn90** » 12 Dec 2013, 08:22

Last digit is the number of valves/cylinder B5252S.
So the Canadian version is 2-valve/cylinder (or 10-valve total).
Other than that 99% of the parts are the same.

Post by **jblackburn** » 12 Dec 2013, 12:56

Precopster, this one's all you!

Post by **precopster** » 12 Dec 2013, 13:18

Thanks Justin. The heads are different of course with 2 valves per cylinder vs 4. The inlet gasket is different, as is the inlet manifold and the cams of course are not interchangeable. Rear cam seals are unique to the 10 valve and are a weird bowl shaped design. Cam belt is 23mm x 144 teeth. Don't confuse this belt with the 23mm x 143 tooth belt fitted to early 20 valve 960s and 850s; it's unique to the 10 valve. Pistons are unique because they have flycuts for 2 valves and even though compression ratio is shared with 20 valve engines, the combustion chamber in the head is smaller so the pistons are dished. Also the high tension leads are a different length however cap, distributor and rotor are shared.

Water pump is the same as 20 valve versions and the engine block is more or less identical apart from pistons.

Engine management is Siemens and there is no MAF sensor. Power output is 103KW.

I shop for 10 valve parts on eBay UK where many 10 valve cars reside. There was a seller named parts monster. Hope this helps.

Post by **precopster** » 12 Dec 2013, 21:20

Forgot to mention the hydraulic tensioner is the same as the '95 plus 20 valvers but the plastic spacer is a different thickness and comes in blue plastic.

The tensioner arm is the same as '95 plus 20 valvers as is the idle roller.

kimthepilot · Post by **kimthepilot** » 13 Dec 2013, 06:55

Thanks for the info!

Post by **erikv11** » 13 Dec 2013, 09:39

Great that you can provide that info Mike, several key differences there that are impossible to just guess about.

Post by **precopster** » 13 Dec 2013, 14:07

Well I found out the hard way by ordering the wrong timing belt as part of a 20 valve set from FCP for my wife's newly aquired 850 four years ago. Half way through the job on a Saturday had to put it off until Monday when the specialist parts shop opened.

I ended up fitting all new stuff including Aisin and INA brands but had to settle for a Federal Mogul timing belt made in Africa. Still going well though...

Post by **precopster** » 14 Dec 2013, 05:22

Woops another difference is with the oxygen sensor. Not sure if there are two of them but the 1st one (pre cat) is an NTK titanium sensor (NGKs sister company which produces sensors) NOT the same as the Bosch or Denso controlled 20 valvers.

kimthepilot · Post by **kimthepilot** » 08 Jul 2014, 10:23

Reviving this old thread, as I'm about to do a timing belt change on this car. Any suggestions on North American sources of a timing belt/tensioner? Are the cam pulleys the same as the 20v, I'm wondering if I can use the cam locking tool that IPD sells...