Camshaft cap - sources
Discussion
So this is the company that's been recommended to me. Very few companies offer to make a cam cap and line bore.
https://www.hthoward.co.uk/engine-machining-servic...
Still not 100% sure if it's possible until he sees the head. But he sounds knowledgeable and experienced.
I sent the pictures to him and had a long chat, talked about how much thou the lower cam bearings will be taken off and how to offset via shims, shouldn't have to fettle valve tips.
Other issue in lowering cam head bearing a few thou? Chain tensioner is the only adjustment needed, and that already has a 6mm blank in it to create chain tension. Any other considerations?
Will still try an unmatched cap as it's a few weeks before the engine comes out so just want to cross this, then easiest option, off my list.
But secretly looking forward to pulling the engine and taking her apart! Strange right?
https://www.hthoward.co.uk/engine-machining-servic...
Still not 100% sure if it's possible until he sees the head. But he sounds knowledgeable and experienced.
I sent the pictures to him and had a long chat, talked about how much thou the lower cam bearings will be taken off and how to offset via shims, shouldn't have to fettle valve tips.
Other issue in lowering cam head bearing a few thou? Chain tensioner is the only adjustment needed, and that already has a 6mm blank in it to create chain tension. Any other considerations?
Will still try an unmatched cap as it's a few weeks before the engine comes out so just want to cross this, then easiest option, off my list.
But secretly looking forward to pulling the engine and taking her apart! Strange right?
They should be able to "weld-fill" the bored out cam bores in the heads then line-bore them together with the new cam caps.
A strict dimensional control should be performed afterwards to check that the heat generated by refilling the bores did not alter some key functional dimensions. By then the camshafts will still be in their original position.
A strict dimensional control should be performed afterwards to check that the heat generated by refilling the bores did not alter some key functional dimensions. By then the camshafts will still be in their original position.
Edited by Thom on Tuesday 14th May 15:41
Thanks.
Any issues with lowering the camshaft Centre line a few thou? I'd rather make sure I'm not causing problems elsewhere before going down this route.
Shims
Belt tension - will tensioner be enough?
Clearance issues...
I've spoken to a lot of people now, and hope this doesn't happen to anyone else as its a difficult solution and not many people want to do it, hence the specialist.
Any issues with lowering the camshaft Centre line a few thou? I'd rather make sure I'm not causing problems elsewhere before going down this route.
Shims
Belt tension - will tensioner be enough?
Clearance issues...
I've spoken to a lot of people now, and hope this doesn't happen to anyone else as its a difficult solution and not many people want to do it, hence the specialist.
I have no experience working on an AJP so just my 2 pence worth, but tappet clearances should be set the same - have to check before the machining how much shimming is needed to make sure you will stil have room for adjustment post machining, but then if the heads are off it may be worth having new valve seats fitted to "reset" valve seat wear to zero thus maximise unshimmed tappet clearance.
As I understand the cam timing procedure in the manual it is effective regardless of the physical position of the camshafts relatively to the crankshaft, so no worries unless perhaps the heads were skimmed "too much" already in the past or other nasty surprise.
As I understand the cam timing procedure in the manual it is effective regardless of the physical position of the camshafts relatively to the crankshaft, so no worries unless perhaps the heads were skimmed "too much" already in the past or other nasty surprise.
Agreed. I can get back the loss back either through the shims, valve tips or valve seats as Thom mentioned.
Time will tell.
Focusing on getting the old carpet out for new at the moment. Seat, bolsters, rear parcel shelf, helmet trim, door card trim all off in June for reupholstery or repair.
Time will tell.
Focusing on getting the old carpet out for new at the moment. Seat, bolsters, rear parcel shelf, helmet trim, door card trim all off in June for reupholstery or repair.
Chimp871 said:
Focusing on getting the old carpet out for new at the moment. Seat, bolsters, rear parcel shelf, helmet trim, door card trim all off in June for reupholstery or repair.
Anything you can suggest here would be much appreciatedhttps://www.pistonheads.com/gassing/topic.asp?h=0&...
Just to update the thread
I got a few more cam caps to replace broken #3 and if I'm pleased to say one works.
It doesn't bind, plasti guage has the 10, 12 and 2 o'clock positions showing between 2 and 2.5 thou. Not sure what the probability is but it can't be low
Of course it's the reason why I pulled the engine but there you go. Too far committed now
I got a few more cam caps to replace broken #3 and if I'm pleased to say one works.
It doesn't bind, plasti guage has the 10, 12 and 2 o'clock positions showing between 2 and 2.5 thou. Not sure what the probability is but it can't be low
Of course it's the reason why I pulled the engine but there you go. Too far committed now
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