Cam bearing replacement - DIY?

[daveb500]

I've just got my block back with new tophat liners but I've just noticed that a couple of the cam bearings are quite worn (I wish I'd checked properly ealier). How difficult are they to fit? I assume they need to be pressed in? Can they be done at home?

[daveb500]

So to do the rear one, do you need to replace the core plug behind it as well?

[spend]

Yes

Chopping an old cam up to make mandrels is a common method.

[daveb500]

Thanks Quinny - I'll give it a go then.....fingers crossed

[daveb500]

Quinny - I'm not sure from the picture why you need different blocks/spacers for each bearing or why they need to be round. Can you not just have a flat piece to go across the whole bearing or does it need to go part way into the hole?

Also, do they need to go in dry?

[daveb500]

Ok, thanks. Chopping board it is then

[daveb500]

Right, new bearings are in. I checked sizes carefully by putting them on the cam first and then putting them in in order. All worked ok but I just wanted to check something. The new cam is in but it feels very tight (I can turn it with a spanner). Is that normal for a new cam with new bearings?

[rev-erend]

Did ypu put some oil on the bearing surfaces ?

[daveb500]

Yes, I did

[adam_rbts]

Hmm that doesn't sound right mate. I seem to remember mine being nice and loose as I had to prevent the cam from falling out the front of the block. Make sure there's nothing obvious causing it to be stiff but for the price of a new set of bearings I'd be tempted to have another go.

I was lucky to have access to a lathe as I made up individual shouldered bungs for each bearing similar to Quinny but longer with an extra smaller diameter that picked up on the bearing below to keep it all square. Hope that makes sense..

[spend]

Sounds like you may have lipped the bearings inserting them, big hammer was it?

Did you check the bearings on the cam journals first BTW (just don't trust parts for granted these days - rocker shafts being a prime example)

[daveb500]

Well, I turned it a few times, pulled it out and re-oiled it and it seems much loser now. May be it was a bit dry somewhere.

[daveb500]

Cam timing in the morning then