Broken Valve Spring

Je pense que le vrai point d'achoppement de beaucoup d'entre nous est la pénurie d'options favorables aux comptes bancaires en ce qui concerne les principaux services et l'affûtage ou l'ennui du S65. Le bore score me fait peur. Après avoir regardé la vidéo du sport automobile H2 sur le processus de rodage spécial utilisé pour exposer la silice m'a donné un aperçu de pourquoi si peu d'options sont là.

Merci d'avoir documenté votre processus de reconstruction.

spammysammich a écrit

Je pense que le vrai point d'achoppement de beaucoup d'entre nous est la pénurie d'options favorables aux comptes bancaires en ce qui concerne les principaux services et l'affûtage ou l'ennui du S65. Le bore score me fait peur. Après avoir regardé la vidéo du sport automobile H2 sur le processus de rodage spécial utilisé pour exposer la silice m'a donné un aperçu de pourquoi si peu d'options sont là.

Merci d'avoir documenté votre processus de reconstruction.

C'est marrant que tu parles de H2. Ils ont raté quelques pas en affinant un bloc d'Alusil. Ils n'ont pas utilisé de plaque de couple pendant le rodage et n'ont pas utilisé de profilomètre pour mesurer la surface du cylindre.
Ce n’est pas si compliqué de réexposer la silice si l’atelier d’usinage en sait un peu plus sur ce qui est nécessaire. Porsche, Mercedes et la plupart des motos «Crotch Rocket» utilisent des cylindres Alusil.
Les cylindres Alusil sont presque comme des freins en céramique de carbone. Tant que vous ne le laissez pas être physiquement endommagé, il ne s’usera presque jamais. Essayez juste de garder tout frais et dans les spécifications et vous devriez être bon.

Oui, les plaques de couple sont à peu près une pratique standard? Bizarre. Ce n’est peut-être pas vraiment difficile, mais l’outillage et la formation ne sont toujours pas bon marché. Je suis toujours envieux des gars qui ont l'espace et les dollars pour faire des reconstructions de moteur par eux-mêmes. Je vais aimer vivre par procuration à travers vous. Désolé que tu aies eu le problème pour commencer.

En regardant les archives de ce site et en ayant eu des Subaru avec des problèmes de ressorts de soupape dans mon cercle social, je suis un peu inquiet.

Sub'd.

How did I miss this thread - interesting, thanks!
(althought sorry that the spring went. Fortunately you're clearly a guy who can sort it...)

Definitely is wear. A little bit above average wear for 130k miles

Time to order new main bearings! Will definitely send it out to WPC.
I believe Main Bearings are definitely a maintenance wear item on these engines.
It seems to wear slightly slower than the RB, but definitely wears.
The front of the engine, at the timing chains, takes most of the fatigue!

130k on MBs
30k on second set of WPC RBs

MBs:
Block Side-All Yellow
Plate Side-GRN, YEL, GRN, GRN, GRN

I don't think the 'mains' look too bad at all for a 130K miles S65, and 8300RPM capable. What does everyone else think?

DrFerry wrote

I don't think the 'mains' look too bad at all for a 130K miles S65, and 8300RPM capable. What does everyone else think?

They’re not terrible but more wear than a typical main bearing at 130k miles. 1st main bearing sure takes a beating. Just like rod bearings, main bearings are definitely a wear item but unfortunately there’s no preventative maintenance for mains. Ay least the main wear rate is considerably lower than the rod wear rate.

DrFerry wrote

I don't think the 'mains' look too bad at all for a 130K miles S65, and 8300RPM capable. What does everyone else think?

There's a bit more wear on the lower thrust bearing than what I'd expect. Pulling the crank was the right move. Visually the wear on #2 lower seems to dispute the theory of excessive chain tension as the actual cause, but we also know nothing about contribution to crank bore concentricity and clearances either.

charliev68 wrote

Time to order new main bearings! Will definitely send it out to WPC.
I believe Main Bearings are definitely a maintenance wear item on these engines.
It seems to wear slightly slower than the RB, but definitely wears.
The front of the engine, at the timing chains, takes most of the fatigue!

Your block shows YYYYY but your crank is GYGGG. Interesting...

Our Main Bearings are made by Glyco.

S85 builder wrote

Your block shows YYYYY but your crank is GYGGG. Interesting...

Curious, what does that mean?

I believe out of three colored bearings, yellow is the thinnest bearing shell. My crank is probably on the thicker side so they decided to loosen the top side to get the optimal oil clearance. Number 2 was most likely real tight, hence the yellow on top and bottom and also the accelerated wear on the number 2 bearing.

S85 builder wrote

Your block shows YYYYY but your crank is GYGGG. Interesting...

How does one tell this intriguing piece of intel from the pics?

DrFerry wrote

How does one tell this intriguing piece of intel from the pics?

Stamp on top of the block, where the head mates. Laser etched on the crank.

DrFerry wrote

How does one tell this intriguing piece of intel from the pics?

Helmsman wrote

Curious, what does that mean?

BMW gauges the crank before install and they laser etch serialize the crank as shown, they print what the bearings should be.

The block is also (supposed to be) engraved with the same information, since a tech needs to know and this is viewable without having to drop the pan.

There are supposed to be 3 different "colors" or sizes for the tolerance band meausred, Red, Yellow, and Green, most are Yellow or Green. I don't know if BMW has ever published the actual tolerance band. dealer service proceedures are to just replace like with like, no measuring, since that actually takes quite a bit of time and skill. This is why blueprinting matters. Also why putting in a differrent used crank isn't ideal, but literally YMMV.

charliev68 wrote

Our Main Bearings are made by Glyco.

what replacement are going with? are you able to measure the main bores in the block? This is quite involved and expensive if you don't have the gauges.

S85 builder wrote

what replacement are going with? are you able to measure the main bores in the block? This is quite involved and expensive if you don't have the gauges.

Can’t find Glyco PNs so I’m just going to order the oem ones from fcp euro. They have lasted me this long with no problems. Another 130k will be fine for me.

Glyco in the US doesn't sell them direct AFAIK, you/d have to get them via BMW OE. King makes a good solution. Only one size there but they are provide a bit more clearance vs OEM as I recall.

If my engine were all GRN, I would consider King. I don’t mind Glyco, it’s an old trusted German manufacturer that Mercedes and Audi uses. I wish I could buy it directly from Glyco because it’s $500 a set from BMW!