E30 the biowaste - metamorphosis to M52

[hasa]

I lifted the boy out


Then I found out serious installation error... fortunately clutch did not work, as this would have led to serious disaster.

[hasa]

Yes this is my assumption. I found old thread from this forum explaining the problem. (30mm vs 25mm high bearing)

[moatilliatta]

There is are 2 different depths depending on DMF flywheel for gearbox's. Maybe try 323 TO bearing with single mass flywheel?

[hasa]

Engine runs nicely, responds very well to throttle with new light flywheel. But I hitted problems with clutch. Previously cluch disengaged very low, almost at level of gear grinding. Now it does not disengage at all no matter what I try.

So my conclusion is that the release bearing might be wrong for this combination. Engine has 528E bellhousing and unknown throwout bearing, very likely from E30 325i. Clutch is Sachs 618 and organic disc. Slightly stepped flywheel made for M20.

[hasa]

[moatilliatta]

Is oem the ina branded units?

You should give genuine ones a go.

[digger]

Febi looks ok, oem not so much

[hasa]

Contact path with Febi rocker

[hasa]

color scratched to reveal underlying pad area. OEM BMW rocker

[moatilliatta]

I just know IE’s pads used to come off. Not sure if a bond issue or wiping the cam clean of oil. But usually would destroy a cam.

[digger]

I don’t like the cheap looking pads on the IE

[moatilliatta]

I’m not sold on the IE HD rockers as the New Genuine BMW ones have been good. I wonder what the 325is group N cars used or even the 325 group A car.

I know they all didn’t have the hot cam you’re looking for, and understand the profiles issue.

Schrick stiff usually just always work. Don’t they have a 308 Cam?

[hasa]

Thanks helping with this issue, digger! I'll try to take even closer photo of the pad when I visit my garage next time.

I currently think that my choise has to be made between these:

1. fall back to Schrick 304. It is proven to work reliably, but perhaps loses some hp compared to dBilas.
2. Take the risk with dBilas cam if I find any rockers that have long enough pads
3. Take the big step and go RHD roller setup. It doubles the cost of the engine but probably is the only viable option. But then I'd be tempted to build new no-compromise bottom end by using S50B30US crank, racetep designed pistons etc... again big $ more. It's difficult to consider where to stop this madness.

I made some measurements of the pad length. It seems that BMW oem rockers have 20mm long pad. Febi might have 20,5mm. But it was difficult to measure reliably. Of course the placement of the pad is important too. And radius of the pad.

[digger]

most recent IE HD vs old IE HD rockers

[digger]

are you able to do a wiping of some colour and show it on the rocker as it can be misleading, i personally think that if there is a little bit of space then probably GTG as the contact area is still a radius not the sharp edge so oil film wont be immediately broken. You could ask dbilas for how far from edge is ok.

This is one of the problems with stock rockers the feet are not long enough so the cam designer profile is limited by velocity else the foot (heel or toe) digs into the cams so you end up needing to use a lower velocity profile which means more duration to get same peak lift numbers. This is why you dont really see 12.5mm lift with 270 degree cams.

Alternatives are

• I believe IE HD may have been changed in last few years as people complained about this issue with even moderate cams. I may have some samples i purchased at various times over last 5 or so years i can dig out.
• Catcams steel rockers have longer pads to address this but uber $$$
• Metric mechanic were developing steel rockers but not sure they have a product for m20 thats available, i think they have m30 ones done though