Cerbera Manual - Valve clearance procedure
Discussion
Wolvesboy said:
I think Ive got a problem or two. The exhausts are all good at 0.3 everywhere.
The shims for my inlets are already pretty thin:
Actual clearance (mm) Shim thickness (mm)
1 0.17 1.75
3 0.2 1.91
5 0.08 1.51
7 closed 1.53
2 0.17 1.52
4 0.2 2.54
6 0.25 okay
8 0.25 okay
I'm wondering what to do now. Does this mean new valves are needed?
New valves required yes.. Much thinner and you risk them shattering.The shims for my inlets are already pretty thin:
Actual clearance (mm) Shim thickness (mm)
1 0.17 1.75
3 0.2 1.91
5 0.08 1.51
7 closed 1.53
2 0.17 1.52
4 0.2 2.54
6 0.25 okay
8 0.25 okay
I'm wondering what to do now. Does this mean new valves are needed?
Aw jeez, I didn't want that. FFS really frustrated now.
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
Wolvesboy said:
Aw jeez, I didn't want that. FFS really frustrated now.
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
What year is it?I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
The other issue is valve seat wear. I'm waiting for my engine rebuild to be done (1996 4.2 v8, done 83k miles when a leakdown test revealed the intake valves weren't sealing properly). After reassembling my heads with new valves etc we found that shim thickness was just over half of what it should be in a new head, so new valve seats were required.
CerbWill said:
The other issue is valve seat wear. I'm waiting for my engine rebuild to be done (1996 4.2 v8, done 83k miles when a leakdown test revealed the intake valves weren't sealing properly). After reassembling my heads with new valves etc we found that shim thickness was just over half of what it should be in a new head, so new valve seats were required.
Conversely.. I just had my heads rebuilt and was told the valve seats were fine and just needed a fresh cut (well I was having them cut anyway).Jhonno said:
Conversely.. I just had my heads rebuilt and was told the valve seats were fine and just needed a fresh cut (well I was having them cut anyway).
Interesting. I'm led to believe the valve design and material changed at some point in the AJP's life which might explain the difference wear types.gruffalo said:
I had my 1998 4.5 rebuilt a few years ago now covered 27k miles since that rebuild and never needed the valve clearances changing yet.
Saves so much time on a 12k service!
That must mean that different materials were used for the rebuildSaves so much time on a 12k service!
No way could intake valve clearances remain the same with a standard AJP8
ukkid35 said:
gruffalo said:
I had my 1998 4.5 rebuilt a few years ago now covered 27k miles since that rebuild and never needed the valve clearances changing yet.
Saves so much time on a 12k service!
That must mean that different materials were used for the rebuildSaves so much time on a 12k service!
No way could intake valve clearances remain the same with a standard AJP8
Aw jeez, I didn't want that. FFS really frustrated now.
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
Wolvesboy said:
Aw jeez, I didn't want that. FFS really frustrated now.
I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
Where have you been for the last 20 years? (and don't say Australia! lol) .. it's not like the valves closing up is a recent discovery I'm thinking this must be a trait for every Cerb that has any decent miles as the valves WILL stretch to the point where shims can no longer be adjusted. MIne has about 104k miles (not sure as the mileometer stopped a while ago on 99k!).
If I were you I'd be looking at it in one of two ways ..
either :
You're going to use your car a lot and it's well worth the investment to rebuild the engine and enjoy years and years of driving safe in the knowledge that you're probably not going to have any more engine issues*
or
the car is going to enjoy only occasional use, and you can risk skimming the shims down just enough to give you enough clearance to get the job done, say 5 thou as a minimum on inlets. And start saving for when the inevitable does happen in the future when you DO need to change everything.
- bearing in mind it's a cerbera.
spitfire4v8 said:
say 5 thou as a minimum on inlets. .
You meant 50 thou presumably as a minimum thickness..Or then again did you mean 5 thou as the minimum clearance?
Either way I would suggest you stay away from the red line on the tacho
I wonder whether it might be possible to get some custom made out of something less likely to fail - titanium perhaps?
Worth mentioning that they are usually called Lash Caps in other other countries
Edited by ukkid35 on Thursday 22 November 09:03
ukkid35 said:
You meant 50 thou presumably as a minimum thickness..
Or then again did you mean 5 thou as the minimum clearance?
Either way I would suggest you stay away from the red line on the tacho
I wonder whether it might be possible to get some custom made out of something less likely to fail - titanium perhaps?
Worth mentioning that they are usually called Lash Caps in other other countries
I mean clearance, which is why i used the word clearance Or then again did you mean 5 thou as the minimum clearance?
Either way I would suggest you stay away from the red line on the tacho
I wonder whether it might be possible to get some custom made out of something less likely to fail - titanium perhaps?
Worth mentioning that they are usually called Lash Caps in other other countries
Edited by ukkid35 on Thursday 22 November 09:03
Wolvesboy said:
Just an observation really and I’m pretty disappointed with yet another item beyond expectation needing repair. I don’t need to have been in the Cerbera scene for 20 years to feel that way!
No, but the information was out there when researching the car before purchase..Therefore it wouldn't be beyond expectation for the mileage.. Gassing Station | Cerbera | Top of Page | What's New | My Stuff