Cylinder head close up

[Chad]

Bought a new toy, make life easier to build motor. so thought I’d start practice rebuild of engine, from bare block up, crank back in, rods N pistons, next job lap in valves on head, cure them leaky valves. Got to say ring compressor is crap. Made the job to slow, and I chipped oil ring so left it out for now , know better next time don’t buy crap .anybody recommend a decent one???

[Chad]

If of interest to anybody, After my water version leak down test ...valves out of 3and 4 cylinders just to take a look,,, inlet look almost spotless, exhaust looking pretty crappy on the valve face. , But no obvious lapped or ground angel on exhaust valves, this was a new cylinder head that was fitted by bmw, at about 70 k, I’m really not sure if when they supply a new head, it comes completely assembled, Or they assembly in workshop with original valves etc ,,but no obvious sign that they ever got lapped in on rebuild, Or even did a proper job on shimming, as they were almost all, way out from memory, It did run ok ish , but could have been a lot better if done properly imo, but fair play to the lads ,am sure they don’t get much time to spend on this type of head rebuild,,... my local Nissan dealers outsource head rebuilds shame on them,, , But lad being what he is, went and bought a new brand new motor from bmw,,leaving this one to play with... few pictures. Inlet porting looks ace...

[Chad]

All valves out. Will give ports a clean and re lap valves in, See how they turn out

[Chad]

Couple of pictures before and after hopefully worth the time , Lapped area should be 1.2. Inlet And exhaust 1.4 mm

[uncle benz]

Definitely worth the time mate! Looks like a nice job

[Chad]

Originally Posted by uncle benz

Definitely worth the time mate! Looks like a nice job

Cheers. Very time consuming , just keep plugging away at it. Spent a couple of hrs cleaning up exhaust ports, bit more to do. Then give it a good clean up see how it looks then will refit valves, probably temporarily fit camshafts and do shims just to get them in the ballpark,

[Chad]

If of interest,,,Taken a few measurements of 100k piston and rings csl motor to compare with spec sheet, Top ring just on outer spec, ...2nd ring look like it takes the biggest hit, and found 2nd worn outside bmw spec, So for me,this says a new rings wouldn’t hurt . Wonder how typical this is on higher mileage motors?? ..... top ring end gap 0.35 ....2nd ring 1.0 Even piston ring axial play near to max wear on 2nd ring , Piston Ring height in spec. 1.2 and 1.5mm .. a new ring set wouldn’t do any harm putting motor back in ballpark.... be interesting to know how much Bhp these motors have lost with time/use ???

[Chad]

‘Anybody’ been brave enough to have a Csl dynamometer tested recently, to see how the old girls are doing , or are they all rapped up in cotton wool now?????

[alexk]

Originally Posted by Chad

‘Anybody’ been brave enough to have a Csl dynamometer tested recently, to see how the old girls are doing , or are they all rapped up in cotton wool now?????

I did a dyno run a few years ago but mine at 109k km is still going strong.
Acceleration times are spot on, so performance has not degraded

[Chad]

Originally Posted by alexk

I did a dyno run a few years ago but mine at 109k km is still going strong.
Acceleration times are spot on, so performance has not degraded

All still sounds good Alexk. Did you keep any figures .