Head Rebuilding

A1ex · Post by **A1ex** » Tue Mar 17, 2015 1:21 pm

Hey Guys,

I'm in the process of stripping down the a8 head in the civic. Once everything has been cleaned and de-coked I'll be building it back up with new valve stem seals, cam end seals & rocker cover gasket.

Are there any other parts I should be looking to replace within the head assuming all valves are straight and nothing is damaged?

Not sure if I should be replacing the retainers & keepers as well or is this not necessary?

Cheers

Post by **Vtecmec** » Tue Mar 17, 2015 1:25 pm

Check the play in the valve guides, I do not think it is much of a cost to have these renewed whilst it is all stripped down.

The retainers and keepers should be fine unless there is some obvious damage.

Post by **NafemanNathan** » Tue Mar 17, 2015 1:27 pm

Spark plug seals in the valve cover?

Shouldn't need to replace the retainers. Just inspect them and replace if there are any signs of damage.

Post by **NafemanNathan** » Tue Mar 17, 2015 1:35 pm

Vtecmec wrote:Check the play in the valve guides, I do not think it is much of a cost to have these renewed whilst it is all stripped down.

Don't you have to heat the head to get valve guide in and out?

A1ex · Post by **A1ex** » Tue Mar 17, 2015 1:40 pm

Thanks for the quick replies

OK, will take a look at the at the valve guides and spark plug seals too.

A few more question;

cams: When I stripped the head down I noticed a fair bit of wear of the exhaust cam lobes, is that normal?

exhaust valves: They're all white, is that normal?

head re-install: Do I need to get the head skimmed before putting it back on with a new head gasket and head bolts?

Post by **NafemanNathan** » Tue Mar 17, 2015 1:46 pm

That is quite a lot of wear on the cams. Do you know what the mileage is?

The exhaust valves look quite caked in white. Not sure if that means it was running quite rich. Most do.

You'd be wise to check the head is flat. Otherwise you'll need it skimmed.

Post by **Vtecmec** » Tue Mar 17, 2015 1:48 pm

NafemanNathan wrote:Don't you have to heat the head to get valve guide in and out?

Yes, to something like +250 degs, not something you can do yourself.

A1ex wrote:cams: When I stripped the head down I noticed a fair bit of wear of the exhaust cam lobes, is that normal?

None of the cams I've seen have looked like that.

A1ex wrote:head re-install: Do I need to get the head skimmed before putting it back on with a new head gasket and head bolts?

It's worth getting it skimmed for piece of mind (cost me £25). It'll cost you more than that to buy a precision straight edge to check it!

Post by **JEBB4** » Tue Mar 17, 2015 1:51 pm

I would definitely get the head skimmed if its been removed and is having new gasket etc..

if not just for piece of mind..
white valves are ok I think, mine were pretty white I did clean the faces of all my valves and lapped them in..

do you plan on grinding/lapping your valves??
Would be a good idea if they are coming out..

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Mar 17, 2015 2:02 pm

That's with the cams fresh out of the head right? (not cleaned up at all)
Looks a bit unusual (a bit 'extreme') but they're overly dirty (black) in general elsewhere tbh. Give them a clean and put a comparison pic up then. The lobes might not look so obvious then.

The biscuit colouring on the valves is fine/normal.

89 UKDM BA4 4WS (resto job!) · Post by **wurlycorner** » Tue Mar 17, 2015 2:04 pm

Vtecmec wrote:It's worth getting it skimmed for piece of mind (cost me £25). It'll cost you more than that to buy a precision straight edge to check it!

I used to check them on the granite marking out table at college/university back in the day, but since then I've just used good quality straight edge steel rules (rules, not tapes!) and that's been good enough.