camshaft bearings

[Maggie13]

Is fitting camshaft bearings a job for the machine shop? 

Can I just tap them in or will they need honed?

Their is grooves in mine so I take it they are no good.

 

[PeteStupps]

I changed mine, but bought a special tool to do it. Others say you can tap them in and out with a block of wood but I had no success with that.

Tool was from Ebay, fairly cheap but large and heavy. I'll see if I can find a link.

Main two things if doing it yourself: be careful to align the oil feed holes, and also be careful to drive the new ones in totally square. They're easy to wreck if pushed in at a slight angle.

There's some good videos on Youtube showing the process - it's not specific to Triumph engines of course.

[Maggie13]

3 hours ago, PeteStupps said:

I changed mine, but bought a special tool to do it. Others say you can tap them in and out with a block of wood but I had no success with that.

Tool was from Ebay, fairly cheap but large and heavy. I'll see if I can find a link.

Main two things if doing it yourself: be careful to align the oil feed holes, and also be careful to drive the new ones in totally square. They're easy to wreck if pushed in at a slight angle.

There's some good videos on Youtube showing the process - it's not specific to Triumph engines of course.

Did they need honed afterwards?

[thescrapman]

No they won’t.

what engine?

[Maggie13]

1300 spitfire

[JohnD]

For six cylinders and pre 1300s the camshaft bore must be line bored to take the bearings.  I ask the machine shop to fit the bearings.

[thescrapman]

Only FD 1300 Spitfire blocks take bearings. And the FWD equivalent.

[drofgum]

16 hours ago, thescrapman said:

Only FD 1300 Spitfire blocks take bearings. And the FWD equivalent.

Sorry,

This isn't true. Camshaft bearings were introduced during the Mk2 Spitfire production run at engine number FC61023. So most of the Mk2 Spitfire run would have had cam bearings from the factory.

Regards,

Paul

[RobPearce]

16 minutes ago, drofgum said:

This isn't true

That depends on your reading. The Mk2 Spitfire engine was not a 1300, so it is true that "only FD (1300 Spitfire blocks)" had bearings, and your choice to read it as "only (FD 1300) Spitfire blocks" is not necessarily correct.

[thescrapman]

Oh for a bit of punctuation......

The only 1300 Spitfire blocks with camshaft bearings, are the FD ones, the 1300TC fwd blocks also have them, as well as later FC blocks fitted to some Mk2 Spitfires.

🙂

[Nick Jones]

None of the 4 cylinder engines should require line boring to fit the bearings as they are all machined the same size. Bearings are fitted to Spitfire Mk2, Mk3 and 1300TC FWD saloon. The cams for these engines have smaller bearing journals to allow for this.

Bearings can be fitted fairly easily by pulling in with nuts on a length of studding and suitably sized washers. Pete’s comments about lining up the oil holes and making sure all is straight are spot on. Don’t force them, if all is properly lined up they don’t need very much force.

Edited February 7, 2023 by Nick Jones

[drofgum]

Nick,

The Mk1 and early Mk2 Spitfire blocks had smaller bores for the camshaft in them. The cam was the same size as used with the cam bearings. Triumph increased the bore in the block when they introduced the cam bearings. After that the Spitfire blocks all had the same size cam tunnel, but the camshaft journals were enlarged when the bearing inserts  were dropped.

Regards,

Paul

[PeteStupps]

21 hours ago, Nick Jones said:

Don’t force them, if all is properly lined up they don’t need very much force.

That wasn't quite my experience when I did it, they were pretty tight. But I was thumping via a cam bearing tool rather than winding them in with nuts and studding. And I'm a weakling!

4 hours ago, drofgum said:

The Mk1 and early Mk2 Spitfire blocks had smaller bores for the camshaft in them. The cam was the same size as used with the cam bearings. Triumph increased the bore in the block when they introduced the cam bearings

This was also my understanding. I've got an early mk2 block which doesn't have bearings but has the same camshaft as the mk3 (part number is the same, I haven't measured journals), so the bore in the block must be smaller.

[PeteStupps]

https://www.ebay.co.uk/itm/363871412701?hash=item54b86d21dd:g:xdkAAOSwyOxipukx&amdata=enc%3AAQAHAAAAsLpWVQlOGPpoJRz6QGF1eO%2FPHaOvw1ZtC4nMRWkKPv4dhEgFi3%2BzX7P7VvHCaFDaLHvNdv7Kc6olkOt%2FUWv8DAbsLMKg5xi6OjgpKoxZ6kfHJw97x6HmF%2Fl03DzetN8ySxyRVRBkucxU%2FUNwFmKt3ZRSMUQXj0vX5t56CMN6w5MrCbgG9vuQFn51vdgN1KoK7%2FGSaR530WBMy1Xbk%2BM3i%2BpdREubQ%2BV2Hd7pWd1vkpAb|tkp%3ABk9SR-TP3pzGYQ

This was the sort of thing I used. Don't remember paying that much for it though. 

[Nick Jones]

1 hour ago, PeteStupps said:

That wasn't quite my experience when I did it, they were pretty tight. But I was thumping via a cam bearing tool rather than winding them in with nuts and studding.

Ever so much easier to use a screw thread to just wind them in in a controlled manner.  I originally made the tooling do a 6 pot after having the block line-bored (huge ball-ache and expensive) but have done a 4-pot since. Just had a quick look for it to take a pic but obviously put it somewhere safe 🙄

[JohnD]

Wow! For a moment, Nick,  I thought that you had threaded the cam shaft bores, and somehow the bearings too!

With respect, few of us can have used the tool much, or even have one to use.  That's why I ask the machine shop to put them in.

John

[PeteStupps]

1 hour ago, JohnD said:

With respect, few of us can have used the tool much, or even have one to use.  That's why I ask the machine shop to put them in.

It's a fair point John, but I only bought the tool to do it after the engine machinist failed to line the oil holes up accurately