GB is not OK, again!

[duTch]

 

.....That poses another question. Is the base circle on the new cam the same as the old cam ?...

 Dunno, I wondered the same, and somewhere I have the measurement of my ground 357, and a new (pattern?/ NOS ?) that I can measure to compare with GB's old one

   *edit
 

..........I reckon I've managed to bend both Inlet rocker arms  ; ..........When I can face another strip I'll be investigating.

 If you do, Id expect you'll arm yourself with spares in case, and you need 'em for comparison anyway, but I just had a wonder if it's possible to extricate the rockers without pulling the box off...just pull out the shaft with cam in ideal position and adjusters wound right off  just be careful to not drop the thackeries/shims....it may be even easier than stuffing around withh *all* the pushrods 

 (worst can happen you need to pull the box)

[RoyC]

 

.....That poses another question. Is the base circle on the new cam the same as the old cam ?...

 Dunno, I wondered the same, and somewhere I have the measurement of my ground 357, and a new (pattern?/ NOS ?) that I can measure to compare with GB's old one

IF, GBs new cam has a smaller base circle he would have to screw the adjusters in more to get his .08" gap.

[berger]

i have not been to the pub. all know on the subject wether its worth owt is my 356 cam is 1.250 from base to top, and 357 1.280 base to peak as near as damn it

[RoyC]

i have not been to the pub. all know on the subject wether its worth owt is my 356 cam is 1.250 from base to top, and 357 1.280 base to peak as near as damn it

Want to know if 'A' is different on new and old cams.

[berger]

I have an old 357 in one hand and an srm 357 in the other and now I can't measure them { only jokeing} the old 357 as near as with vernier and not mic cos I can't be arsed . across A the srm is .9335 the old one is .9460,,,,, and from base to top the old one is 1.280 and srm is 1.270. I think I've been done by 10 thou all round.  { BLOODY AUSTERITY} sorry I can't get the decadent point in the middle of the figures because I haven't got a clue how its done, they must be saving metal, tight gets to be more clear and stop jokeing the srm is 12 and half thou smaller across A someone correct me if you feel ime wrong and going round the bend ...... pub tomorrow, back to workshop and the old 356 just to confuse is .9550 across A, about 9 thou bigger than the used 357.... to conclude gentlemen it looks like new cams have seen cut backs, thankyou for listening. over,

[RoyC]

I can't see 10 thou making that much difference to GBs adjuster screws.
Unless GBs cams are a lot more different than 10 thou.

Edit.  GB, can you please strip your engine down again ?   

[Greybeard]

I can't see 10 thou making that much difference to GBs adjuster screws.
Unless GBs cams are a lot more different than 10 thou.

I agree. The adjusters are probably low by about 1/4"

Edit.  GB, can you please strip your engine down again ?   

I'll pretend I didn't read that!

[morris]

If this can give you some peace of mind GB, I adjusted the valves on the SA this afternoon. I noticed that the inlet adjusters sit about 5-6 mm deeper than the outlet adjusters.

[chaterlea25]

Hi GB and All,

GB
Can you remember if the tappets were "more  equal" before all this palaver?
I have a spare set of rockers if you work up the enthusiasm to have another bout with the rockerbox
To my mind having the adjusters wound all the way down upsets the geometry of the valve gear
the over extended adjusters will push the valve to one side 

John

[muskrat]

G'day John.
"To my mind having the adjusters wound all the way down upsets the geometry of the valve gear
the over extended adjusters will push the valve to one side"
That's what I was worried about and suggested the long stroke valve stem caps.
As far as bent rockers I find it highly unlikely. Their strong little buggers, surely the pushrods would bend or the guides mushroom first.
Cheers

[duTch]

 Ok, I located the good quality stone I carved some notes into....(but let's not forget this is only base semantics we're dealing with here, and unlikely to solve anything except our collective curiousities)
 Carving says;
        357 'Lift' ; 0.3455"/ 0.3515"/0.350" / 0.3455"     (Must be ground cam in use- no base circle size here)

          'New' 357 Base Circle dia;  0.951"/ 0.951"/ 0.949" / 0.951"  (4 lobes L-> R)

      'Old' ?     356  Base Circle dia;  0.8985" / 0.897 / 0.894" / 0.884"   (must be an old one I'd forgotten about)

 ** note fairly rudimentary measurements
 
 If I recall most of my adjuster are also wound in far and varied, but Ally head so different game, but have the concerns that Chaterlea John mentioned of geometry, which is why I asked GB for pushrod length measurements  (I replaced mine with 'Dural' rods but can't locate the slate I scribbled those measurements into...tin roof rules that out )

 I took a bunch of photos to figure it all out, but analyzing two pics/valve (Open/Closed) sent my brain into a spin....

[Greybeard]

Hi GB and All,

GB
Can you remember if the tappets were "more  equal" before all this palaver?
I have a spare set of rockers if you work up the enthusiasm to have another bout with the rockerbox
To my mind having the adjusters wound all the way down upsets the geometry of the valve gear
the over extended adjusters will push the valve to one side 

John

Hi John. All four tappet adjusters were about equal. They were well down, presumable due to having the reground camshaft but I could still adjust and tighten the locknut. Currently the exhaust tappets are approximately the same as they were. Both inlet tappets are so far in, I had to thin the locknuts to be able to set and lock them.
If the cause is not bent rockers, I have no idea what's going on!

I was also wondering about the effect on valve geometry. The inlet rockers seem to be meeting the valve tip nice and squarely.

[berger]

hey dutch I've got a feeling in my water that I want your 357 and you can have my brand new but smaller 357 one good thing came out of all this for me anyway ,, cheers greybeard, and that is I used the old 357 which has more lift to set my top end up for spring bind. I now know i'm very safe using the new cam and followers

[RoyC]

If the cause is not bent rockers, I have no idea what's going on!

There must be some longer pushrods around somewhere.
How long were the original pushrods ?

Have to get Julian on it.

[Greybeard]

If the cause is not bent rockers, I have no idea what's going on!

There must be some longer pushrods around somewhere.
How long were the original pushrods ?

Have to get Julian on it.

But the current pushrods were OK for some years.