Rebuilding an M50 check list

[Aatos]

Removing/installing head and especially cams requires quite a few pricey special tools.

[e30serg]

Yeah, no seals for each bolt. I thought it did.

In short, you're 99% there if you get both the head gasket and bottom end kits. It would allow you to take the engine down to the block and head, and put it back together using new seals and gaskets.

If this is going to be a track-only car though, and the leakdown comes out good, you may want to save your cash and just throw it in after replacing the gaskets. You really don't want to mess with replacing them once the engine is in the car, especially the front and rear main.

[e30serg]

Without opening up the bottom end kit, I can see:

Oil pan gasket
Oil filter housing gasket
Front main crankshaft seal
Rear main seal
Timing cover gaskets
Oil pump gasket?
Sensor washers (cps, etc)
Water pump
Thermostat

[golde30]

oh and it does NOT include all the rubber seals for each bolt on the valve cover.

[e30serg]

Yes, it does include the head gasket.
Ok, this is for a Victor Reinz Head Gasket Set

Valve cover gasket
Spark plug seals
Exhaust manifold gaskets
Vanos gasket
Valve oil seals (24)
Intake manifold gaskets
Throttle body gasket
Exhaust header to downpipe gasket
Seal washers for temp sensors, cps, vanos oil line, etc
Rear coolant flange gasket
Injector o-rings (12) <-that's what they look like anyways.
Some other washer-looking seals, not sure what they are for.
Thermostat housing gasket

[Jean]

is the head gasket included?

[golde30]

the top end gasket kit includes everything except the front crank housing gaskets if i recall correctly. the oil pan gasket also doesnt come with that kit.

[Jean]

Ditto. I'm sure to replace that little guy.
You should really do a leak down test though. If the head gasket is fine, leave it alone.

Btw, what plans do you have for this motor now? Have they changed since you started the thread?

Have not changed, it's for my 89 325i autox car. I have to check the rulebook to verify if I can under the rules increase it's displacement etc though.

[e30serg]

Ditto. I'm sure to replace that little guy.
You should really do a leak down test though. If the head gasket is fine, leave it alone.

Btw, what plans do you have for this motor now? Have they changed since you started the thread?

[Jean]

-Hard to get your $$$ back out of a rebuild, but them again you can have a zero-miles m50, something that you can't just find anywere!

-What you seem to be describing is a "refresh", not a "rebuild", tho
-And yea timing parts are wear items, they just wear long

Sorry, I am still a n00b when it comes to engine rebuilds or refreshes.

Give me a couple days and I can tell you what's in the head gasket kit and the bottom end gasket kit. I have both in my garage right now. I just got the engine/head back from the shop and I'm getting ready to reassemble.

Great, thanks! Please do and any info on exactly what you recommend a shop do and not do is appreciated.

[PiercedE30]

If you pull the head, PLEASE, PLEASE replace the oil check valve in the bottom of the head. It just unscrews with a flat head. It is what causes the valve tick that many M5x motors are plagued with on start up.

[e30serg]

Give me a couple days and I can tell you what's in the head gasket kit and the bottom end gasket kit. I have both in my garage right now. I just got the engine/head back from the shop and I'm getting ready to reassemble.

[SpecM]

-Hard to get your $$$ back out of a rebuild, but them again you can have a zero-miles m50, something that you can't just find anywere!

-What you seem to be describing is a "refresh", not a "rebuild", tho
-And yea timing parts are wear items, they just wear long

[Jean]

If your replacing all of that, it would be wise to do a refresh its deff worth every penny to know what condition your motor is in!! (not much if you can do some of the things below yourself)

Replace the above mentioned along with:

fresh hone
piston rings
wrist pin clips
main/thrust bearings,
main bolts

Going slightly OT but the Machining that should be done:

acid bath (important to be properly cleaned)
checked block cracks..magnafluxed
check bore specs
check block/ cylinder head mating surfaces. resurface/plain if needed.
bore/hone cylinders depending on clearances..
align hone the main bearing bores (if needed)
check all threads... repair/rethread or just clean!!
crank inspection for cracks or worn journals....polish/grind or replace if needed
rods spec'd and reconditioned
pistons cleaned and checked, check ringlands extra close!

The list is not in the correct order and will continue to $$$grow$$$ but I don't know how deep you want to dig into you wallet..by the sounds of it not even this far.

For a ballapark ..all of this locally ran $900 assembled on the Supra's 7mgte (shortblock)..friend of a friend did the work..yah yah its not a 1j, or 2j..who cares...

Did you leak down test the motor by chance?

See, I am hoping I wouldn't have to deal with pistons/rods/crank at all though. Engine is at 129k, it's a 95. Basically I am trying to figure out if this is all worth it if I am paying only $500 for the complete engine.... or if it makes more sense to pay more upfront and try to find one with lower miles..

[Jean]

So the timing chain, guides, rails are a wear item huh?

Just did a quick run down through real-oem for the most obvious things (hoses and belts can be done after).

Timing case - http://www.realoem.com/bmw/showparts...57&hg=11&fg=10

04 SHAFT SEAL 48X65X10 1 11142249532 $15.74
05 GASKET ASBESTOS FREE 1 11141720638 $3.17 See SI 110691387
06 GASKET ASBESTOS FREE 1 11141720639 $5.36 See SI 110691387

Oil pan http://www.realoem.com/bmw/showparts...17&hg=11&fg=10

03 GASKET RING 40X4 1 12611277129 $2.01
08 GASKET STEEL 1 11131437237 $35.71

Seal http://www.realoem.com/bmw/showparts...61&hg=11&fg=10

09 SHAFT SEAL 90X110X12 1 11142249533 $46.59
10 GASKET STEEL 1 11141432240 $2.64

vanos gasket http://www.realoem.com/bmw/showparts...82&hg=11&fg=15

06 GASKET ASBESTOS FREE 1 09/1992 11361740840 $4.85
11 GASKET RING A14X20-CUSN 4 09/1992 32411093596 $0.20
14 GASKET RING A14X18-AL 1 09/1992 07119963200 $0.22
17 GASKET RING A12X15,5-AL 2 09/1992 07119963130 $0.10
19 O-RING 18X2 1 09/1992 12141727220 $0.49

valve cover http://www.realoem.com/bmw/showparts...83&hg=11&fg=15
03 SET OF PROFILE GASKETS 1 09/1992 11120034107 $???

valve train http://www.realoem.com/bmw/showparts...06&hg=11&fg=15
need to review

head http://www.realoem.com/bmw/showparts...07&hg=11&fg=15
04 GASKET ASBESTOS FREE 1 11121738963 $2.46
06 CYLINDER HEAD GASKET ASBESTOS-FREE 1,75MM 1 11121726617 $101.56
06 CYLINDER HEAD GASKET ASBESTOS-FREE 2,05MM(+0,3) 1 11121726620 $101.56

07 SET BOLT CYLINDER HEAD M10X95 1 11121721938 $38.78
09 TORX BOLT M6X50 1 11121726397 $1.40
10 TORX BOLT M6X70 1 11121720729 $1.40
11 TORX BOLT M6X100 1 11121720731 $1.67

what does this include exactly?
12 GASKET SET CYLINDER HEAD ASBESTOS FREE 1 09/1992 11129064467 $332.57

-----------------
rod bearings http://www.realoem.com/bmw/showparts...19&hg=11&fg=20
05 BEARING SHELL, BLUE 45,00MM(0) 6 11241284850 $14.62
05 BEARING SHELL, BLUE 44,75MM(+0,25) 6 11241284852 $20.09
05 BEARING SHELL, BLUE 44,50MM(+0,50) 6 11241284854 $10.94
06 BEARING SHELL, RED 45,00MM(0) 6 11241284849 $14.62
06 BEARING SHELL, RED 44,75MM(+0,25) 6 11241284851 $10.94
06 BEARING SHELL, RED 44,50MM(+0,50) 6 11241284853 $10.94

------------------
valve train http://www.realoem.com/bmw/showparts...85&hg=11&fg=25

01 TIMING CHAIN 1 11311432176 $59.99
05 GUIDE RAIL 1 11311726480 $17.52
07 CHAIN TENSIONER 1 09/1994 11311703717 $61.38
13 GASKET RING A26X31-AL 1 07119963418 $0.22
14 SCREW PLUG WITH GASKET RING 1 11311722674 $4.18

-----------
oil pump
http://www.realoem.com/bmw/showparts...76&hg=11&fg=30

17 SPROCKET 1 11411719935 $32.92
18 HEX NUT M10X1-LH 1 11411735137 $0.21
19 CHAIN 1 11411719936 $30.41 See SI 110592504

http://www.realoem.com/bmw/showparts...88&hg=11&fg=30
02 SET OIL-FILTER ELEMENT 1 09/1992 11421730389 $9.60
08 GASKET 1 09/1992 11421719855 $5.19

---------
water pump/ t-stat stuff http://www.realoem.com/bmw/showparts...03&hg=11&fg=35

02 O-RING 68X5 1 11511711484 $8.26
06 O-RING 60X3,5 1 11531265084 $1.62
08 PROFILE-GASKET 1 05/1992 11531740437 $1.62

intake manifold http://www.realoem.com/bmw/showparts...24&hg=11&fg=40
02 GASKET 6 11611717259 $10.38
04 PROFILE-GASKET 1 11611716174 $9.26
09 CONNECTOR 1 02/1992 11611738629 $3.28
10 O-RING 24X3,5 1 11611730725 $2.85
11 CONNECTOR 1 11611735800 $3.46
12 O-RING 9,12X3,53 1 11611735859 $0.62
14 WASHER-GASKET 1 11611735736 $0.60
15 GASKET RING 1 11611735735 $0.61

fuel stuff http://www.realoem.com/bmw/showparts...69&hg=13&fg=15

intake stuff http://www.realoem.com/bmw/showparts...81&hg=13&fg=15
03 RUBBER BOOT 1 13541738757 $21.32
03 RUBBER BOOT ASC+T 1 09/1993 13541703694 $32.92 +core