4AGE head without cam caps, anything special needed to replace them?

[TERRA Operative]

Nope, when changing a cam, the only clearances that need to be checked are between the cam lobes and the shims on the buckets.

The cam retainers (the caps that hold the cams down to the head) don't come into it at all.

[af300e]

I have a spare bigport head complete (minus cam covers). $200 plus shipping.

[TERRA Operative]

Woooo. What's post to 4113? It's got cams yea?

[af300e]

Yes, has cams. I'll wiegh it and get a price on shipping tomorrow.

[TERRA Operative]

orsum. Thanks.

[LeeRoy]

The cam retainers (the caps that hold the cams down to the head) don't come into it at all.

But cams wear and so do the caps correct?

So when you put different cams in what happens there?

[TERRA Operative]

Dunno. AFAIK, the only measurement taken with new cams is the shims??


Is it totally stupid or insane to bore the caps out larger than required, then install bearings like what's used on the crankshaft?

[af300e]

But cams wear and so do the caps correct?

So when you put different cams in what happens there?

I'm pretty sure you're being sarcastic here but I'll say this anyway.

It's not really a wear issue, more that the tunnel boring of all the caps and the head lines up. Caps bored on one head are more than likely to me misaligned when fitted to a different head. Cause binding or excessive play.

I wouldn't expect it is possible to install bearings, and the cost would no doubt be far greater than just getting another head. If you are going to have the head restored (bathed/shaved/seals/guides/valve seat) then another head is prob most cost effective.

Anyway, I'll try to get that price today.

[TERRA Operative]

Yea, I was thinking cost vs benefit wouldn't be great...

[af300e]

I had a look, not really any room between the bolt holes and the cam to fit bearing shells.
You have PM re head.

[Starfire]

Basically the cam caps are similar to the main caps on the crank. The main issue is that they are all line bored so that the cam sits in them straight.

If you do manage to find a replacement set you can install them, but you will need to have them shaved down a little and then line bored again to have them fit correctly. This will be about $200 worth of machining. It is possible to have them overbored and a set of small shell bearings fitted, but this is generally not required and will add even more expense.

As the 4AG isn't particularly rare or valuable, at the end of the day you can pick up a bigport head for around $100 if you're not in a hurry and are happy to rebuild it, so it's not really worth the effort fixing up one that doesnt have the correct cam caps.

Cheers,
Terry

[TERRA Operative]

Yea. The engine builder where I am getting the gear crack tested pretty much said the same thing. He has the tooling for doing all the boring etc, but the cost of a new head (which should be here soon) worked out cheaper in the end...