Good deal ?

[evoe46m3]

I found a guy in my area selling an s50 for 500 bucks. He said he mis shifted it and broke valves. These are the only components that he is aware of that are broken. Also it has 200k on it. If the bottom turned out to be OK I was thinking this could be a good deal. I would just rebuild it and get some m50 valves. What do you guys think ?

[e30s52]

Its going to need an over-haul. And if you do get it dont use m50 valves. Rebuild the head s50 but that will cost around 2 grand.

[surebimmer]

What's your budget for rebuild?

[evoe46m3]

whats the difference between the s50 head and the m50 head? I looked at the part numbers for the valves and they were identical. I thought only the cams were different

[evoe46m3]

What's your budget for rebuild?

probably 1500 to 2000

[mooseheadm5]

The crank is worth about $250. The head and pistons could be FUBAR if any of the valves broke off. It is a crap shoot unless you but it already apart and know what you are dealing with.

[flyboyx]

its probably worth 500 in parts without any problem. instead of spending the money of a full rebuild, you could probably find a nice 100,000 mile motor in a junk yard for 2 grand or less. that would be cheaper than going through this one and you wouldn't have to deal with the head ache. i think i would go over there and take off the head to see what you really have there before you put down any money. before you tear into it, try to spin it over with a breaker bar. if that works, do a compression check if it is still in the car. if not, you can still get some idea of a compression check by spinning it over with a ratchet or breaker bar with a compression tester in each cylinder. that will give you an idea how many cylinders are f-ed up without pulling off the head.

it is possible to bend valves on an s52, but the cam is connected to the crank via a pretty tough chain. not easy to skip teeth. the engine is rev limited, so the sellers explanation is a bit hard to swallow. could be another problem unrelated to the valve train. maybe (likely) a thrown rod.

[mooseheadm5]

You have obviously never heard of the "money shift" wherin the driver downshifts from 5th to 2nd or 3rd to 1st or accidentally shifts from 4th to 3rd on an upshift. No rev limiter on earth can save the motor from that. It happens. Quite a bit in E36s, actually, particularly at the track. THe cams might be worth it but you would want to find another M50 or M52 as well in case one or more rods are bent or pistons are toast.

[Uber E30]

I would say buy it, you can easily sell the cams and the crank for 500 total if it turns out to be junk.

[etxxz]

think about it. an s50 is usually that much and its likely to be an old high mileage engine.. this engine can cost the same as a used s50 and be freshly rebuilt. i'd do it if you can diy it.

[evoe46m3]

Motor has 200k. Ya the kid was red lined in 4th and then mis shifted into 3rd. Valves floated, pistons hit them, valves got bent and then the motor had no compression. Anyways I borrowed a bore scope and looked inside the spark plug holes. there were some gouges in pistons but none were very deep so I bought the motor. Anyways when I got it back to my house and took the head off I found all of the intake valves were bent, some of the exhaust and a few of the valve seats gummed up. I still have to take out the cams (which are fine) and make sure the valve seats are still straight. Also I need to tear appart the bottom end and see if the rods are all ok.

So my plans are to get used m50 valves, valve seats repaired, new valve springs retainers etc and keep the old tappits. On the bottom end new rings , bearings, gaskets etc.

I know this is not a cheap engine to rebuild but since I am doing 90% of the work myself and I get parts at cost I dont think it will be that bad.

What do you guys think?

[weaksauce]

i'd think you might want to spring for new valves.
Also the lifters have a tendancy to go bad on those motors and cause a ticking sound. i'd get the lifters checked while they are out, along with new valve seats for all the valves, and inspect all of the valves with a dial indicator and replace any that are anywhere even close to being out of round.
Also install head studs and the best head gasket you can afford.

I spent $2k on rebuilding my head after a schrick cam install that i didn't time right.