Another BRM Cam victim

[James & Son]

In you all's opinion, what do you think of the smaller gear of the BRM oil pump and its potential effect on cam running position relative to the oil slot, and therefore oil flow to the followers? That's the third major mechanical difference between the BEW/BRM other than the injectors and cam.

I agree and it could be causing this( see follower drag on base circle). I think it is the higher oil pressure generated by the faster spinning pump that is causing the problem. The BEW has 30% less pump flow and therefore less oil pressure below 2500 rpm.

 

[James & Son]

This might be a good time to show this issue I found with #1 and #2 exhaust on the base circle. The pickup is exactly opposite to the apex of injection lobe. I caught this at about the same time the black was wearing through on the follower. I have my own theory as to the cause but so far have not been able to solve my follower issue. I tried to solve the pickup by preventing the cam from moving around in the bearings due to the valve spring and injection forces causing what I believe is an up and down movement. But so far no luck.
Edit, Notice how roughly my cam was ground, the pickup highlights this.

 

[TonyJetta]

Got a better pic? Thats a bit grainy for me.

Tony
Sent from my e-diesel fleet

 

[James & Son]

Here is the same thing on exhaust #2.



Basically my thinking is if you have a cam ground rough, more than .4 Ra (Ra=average micrometers), the nose may breakin but the base circle will not and the injection pressure pushes the cam down and squashes the follower against the closed exhaust valve at top dead center of the compression stroke. This constant rubbing would generates a lot of heat. Now a cam with a very smooth grind would have a better change of not rubbing due to asperities not breaking through the oil film on the base circle. Note the scoring is exactly opposite to the top of the injector ramp.


Scoring of #2 Exh Lobe

 

[stacerbob]

Pulled my vc off tonite to have a look, cam lobes feel fine, 2 have what look like copper deposits on them #2 cyl has a circle on one cam follower

http://s830.photobucket.com/compone...albums/zz229/ash_flat_diesel/image.jpg1_8.jpg

What do you guys think?

http://s830.photobucket.com/compone...albums/zz229/ash_flat_diesel/image.jpg2_5.jpg

 

[TonyJetta]

Links appear to be broken.

Tony
Sent from my e-diesel fleet

 

[James & Son]

Pulled my vc off tonite to have a look, cam lobes feel fine, 2 have what look like copper deposits on them #2 cyl has a circle on one cam follower

http://s830.photobucket.com/component/Download-File?file=%2Falbums%2Fzz229%2Fash_flat_diesel%2Fimage.jpg1_8.jpg

What do you guys think?

http://s830.photobucket.com/compone...albums/zz229/ash_flat_diesel/image.jpg2_5.jpg

When is your next timing belt job. I don't think you have a lot of miles left. I am not going by the pictures but your discription of the #2 follower.
You need to run the 15w-40 (it is summer) to have the added advantage of a thicker base oil over the 5w-40.
http://www.schaefferoil.com/documents/222-700-td.pdf and a can of #132. Then prepare for timing and cam job
edit: forget the additive, the 7000 has most of it already. Probably Mobil 1 TDT would be equal as well or ask for suggesions for a 15w-40 wt for your problem on the oil thread