Cam Followers - remove with head in place?

[JohnC]

Hi all,

Is it possible to remove the cam followers without removing the cylinder head?

For my lockdown project I decided to replace the stupid cam in my car with an original profile. Last time I worked on the engine I took it out and completely reconditioned it. This time I'd like to remove as little as possible. I've removed the rocker gear and pushrods, but I can't see any way to get the cam followers out without removing the head. It that a pointless quest, or is it possible? Tantalisingly, my old Haines manual simply says "the pushrods and tappets must be removed" in its list of stuff to do in order to remove the cam with the engine in the car.

Any advice?

Thanks

John

[JohnC]

Never mind. I can't even get the new cam followers to fit down the openings in the head where the pushrods go. No chance of getting the old ones out! Would have been nice though.

John

[astontr6]

1 hour ago, JohnC said:

Hi all,

Is it possible to remove the cam followers without removing the cylinder head?

For my lockdown project I decided to replace the stupid cam in my car with an original profile. Last time I worked on the engine I took it out and completely reconditioned it. This time I'd like to remove as little as possible. I've removed the rocker gear and pushrods, but I can't see any way to get the cam followers out without removing the head. It that a pointless quest, or is it possible? Tantalisingly, my old Haines manual simply says "the pushrods and tappets must be removed" in its list of stuff to do in order to remove the cam with the engine in the car.

Any advice?

Thanks

John

It can be done with a round piece of wooden doweling tapered at the end to get an interference fit, forced into the bore of the follower as I have this. I think that the doweling has to be about 15" long but you would have to check that. As for putting them back, I used a length of steel conduit over the doweling to push the follower off the dowel when seated.

Bruce.

[JohnC]

Ooh. Interesting. How did you get the follower up through the head? Maybe I didn't find the right angle of wiggle! Is the head on a '73 car any different from a '71 model?

[Malcolm Tatton]

I think that Roger had a plan to use magnets on strings to hold the followers away from the cam whist doing the swop. Don't know whether he managed it.

I must admit that I always thought that the followers wouldn't draw through the head

 

[RogerH]

Hi Malcolm,

you certainly can't remove the followers on a 4 pot engine without head removal

I never did use my magnet idea to lift and hold the followers whilst insert a new cam because I couldn't at the time get magnets on sticks of a suitable small size.

I now have those magnets and can;t wait to fit a new cam !!!

I would have thought the same would apply to the 6 pot engine. Why make the rocker arm rod holes bigger than need be.

 

Roger

[DRD]

6 minutes ago, RogerH said:

Hi Malcolm,

you certainly can't remove the followers on a 4 pot engine without head removal

I never did use my magnet idea to lift and hold the followers whilst insert a new cam because I couldn't at the time get magnets on sticks of a suitable small size.

I now have those magnets and can;t wait to fit a new cam !!!

I would have thought the same would apply to the 6 pot engine. Why make the rocker arm rod holes bigger than need be.

 

Roger

If it works Roger you should design a suitable tool and patent it!

[RogerH]

I'm not sure you can patent as magnet on a stick

 

Roger

[DRD]

2 hours ago, RogerH said:

I'm not sure you can patent as magnet on a stick

 

Roger

I'm thinking of a device like a long comb/fork with 12 fingers with magnets on.

You clamp it in place and wind the magnets down to pull up the tappets. Then you can withdraw the cam.

Maybe I should patent it then?

Edited June 6, 2020 by DRD
Update

[RogerH]

Go for it - 

 

Roger

[astontr6]

11 hours ago, JohnC said:

Never mind. I can't even get the new cam followers to fit down the openings in the head where the pushrods go. No chance of getting the old ones out! Would have been nice though.

John

To be honest I cannot remember I did this 40 years ago so I cannot remember if I took the head off as I did also have valve seat trouble, as well. But I know I did use the dowel method to remove the followers, the car was a 1973 TR6.

Bruce.

[JohnC]

Well, head is off and cam followers extracted using a tapered dowel (thanks for the tip). Just as well I didn't try to leave the old ones in place - three have very noticeable pitting. Only 25k miles since the rebuild as well. Not great. But I think I had them resurfaced, so I guess that's the problem. NOS this time.

[RogerH]

Hi John,

 

rather than NOS followers try and get the followers recommended by the cam manufacturer.

If a Newman cam they do very nice chilled iron followers.

Roger

Edited June 8, 2020 by RogerH

[JohnC]

Thanks Roger, good advice. The cam I have has the identification SAC DNC 1019. The cam came from a reputable source here in Sydney. I believe that SAC is the manufacturer, and that it's a repro150bhp cam. Before I rebuild everything I'm going to check the profile. I figured it's easiest to install the cam and then check with a dial gauge mounted on the block. Thinking about it, the followers may not be NOS but from the same manufacturer. I wonder if it's possible to tell. The supplier could be excused for not remembering as I've had them for over ten years!

JC