Camshaft cap - sources
Discussion
I was leaning towards pulling the engine later in the year due to what I think is a bearing noise. I've got the interior out at the moment for a recarpet so the shim service was whilst I was waiting for soundproofing to arrive. Bit of a unwelcome surprise....
Any ideas why cap #3, the middle one, would go like that. You'd think it would be the least stressed?
I'll speak to the known experts on what they thin!.
Any ideas why cap #3, the middle one, would go like that. You'd think it would be the least stressed?
I'll speak to the known experts on what they thin!.
The torque setting is 23nm, so not a lot.
I'm just hoping that a previous owner/garage didn't just put it back knowing it was broken. Not saying it is but it is in my mind, especially seeing the cap scoring, in the bearing edges you can see an indentation. Shame they didn't have traditional cam bearings.
Gruffalo - appreciate you asking Jason.
I'm just hoping that a previous owner/garage didn't just put it back knowing it was broken. Not saying it is but it is in my mind, especially seeing the cap scoring, in the bearing edges you can see an indentation. Shame they didn't have traditional cam bearings.
Gruffalo - appreciate you asking Jason.
Spoke to Dom at Powers and shared the photo. To be done properly it's heads off time and then we'll see, he's kindly sending down a cap or two in the unlikely event it'll fit in tolerance. To be honest he said it's never worked for him but I may be lucky, long shot time with plastiguage. He was mentioning tig welding the original but imagine after seeing the cap damage it's not worth it. Perhaps the cam seized at some point to cause the crack but I'm guessing.
My problem is removing the engine/head isn't going to happen overnight due to work commitments and it's not driveable at the moment. I'm probably wanting to do an engine rebuild with Dom, so I can trust it. The problem with our cars are you just don't know what previous owners have or haven't done to the car.
I would like to think a new cap could be made and then line bored in but only time will tell.
My problem is removing the engine/head isn't going to happen overnight due to work commitments and it's not driveable at the moment. I'm probably wanting to do an engine rebuild with Dom, so I can trust it. The problem with our cars are you just don't know what previous owners have or haven't done to the car.
I would like to think a new cap could be made and then line bored in but only time will tell.
t quality.
Update. Waiting for a cap or two to try on the heads with plastigauge clearance of 2 thou.
My neighbour used to work at Aston Martin as an engineer and got his opinion. He agreed to get a cap made and line bored, probably £600. Will have to remove lowered cut from valve tips or shims, looking at around 5 thou.
Will need a new camshaft which is around £350 too as its badly scored on #3. Luckily the head cam journals are very good.
Or.... Just get the whole lot to Powers and get a rebuild done.
Either way the engine needs pulling first, then I'll decide on next action.
Glad I have a chimaera 450 to play with over the summer. I do feel that rover lump is a more hardy engine, trying to get it ready for castle Coombe by fitting an oil cooler.
My neighbour used to work at Aston Martin as an engineer and got his opinion. He agreed to get a cap made and line bored, probably £600. Will have to remove lowered cut from valve tips or shims, looking at around 5 thou.
Will need a new camshaft which is around £350 too as its badly scored on #3. Luckily the head cam journals are very good.
Or.... Just get the whole lot to Powers and get a rebuild done.
Either way the engine needs pulling first, then I'll decide on next action.
Glad I have a chimaera 450 to play with over the summer. I do feel that rover lump is a more hardy engine, trying to get it ready for castle Coombe by fitting an oil cooler.
True, but camshaft bearing shells does make life easier.
I'm prepared to look behind the curtain so to speak on these cars, but others won't and will just sell at the first sight of a problem or not divulge it to the new owner. I'm sure there's plenty of scored camshafts, housings out there that no one knows about as they either don't understand the difference a couple of thou makes when pumping oil or just see money being spent.
I'll be putting it right.
I'm prepared to look behind the curtain so to speak on these cars, but others won't and will just sell at the first sight of a problem or not divulge it to the new owner. I'm sure there's plenty of scored camshafts, housings out there that no one knows about as they either don't understand the difference a couple of thou makes when pumping oil or just see money being spent.
I'll be putting it right.
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?
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.
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.
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
Gassing Station | Cerbera | Top of Page | What's New | My Stuff