Modern three cut valves shouldn't need to be lapped in............

If you buy an exchange head it'll be ready to go, just bolt it on and start it up. (adjust the valve clearances first, of course)

Lapping valves is pretty easy, before you re-assemble the springs and such......turn the head over, mark the valves so you put them back in the right holes. Buy a lapping tool ( a dowell with a suction cup on one or both ends, available at any parts store) and some lapping compound. apply a little compound to the face of the valve and put it in the guide. Stick the suction cup on the valve and run it back and forth between your two hands, held palm to palm. Every few seconds lift it up and turn it a bit then rub again. After a few times of this pull the valve out and clean the face and the seat. You should see a dull ring running cleanly around both the face and the seat - you only want it to be about as wide as a dime, no more. If you have that, move on to the next one in line. Once they're all done, clean everything thoroughly and start assembly.

But as I said, with modern valve cutting equipment, you really don't need to do this, and in fact it's probably better if you don't.

 

You'll take the head asembled in to the machine shop. They do all the work and you pick it up re-assembled & ready to bolt on. Easy-peasy.

 

I'd arrive with a baggie containing the new guides and seals and everything else, I assume? I can't imagone anyplace would have parts.

What does something like that run, assuming they have to clean up carbon and (possibly) lap the valves? At that point, I'd be ready to reassemble the (completed) head and install a new head gasket, new carb gasket, any new hoses (if necessary due to wear or age) and everything else, right? Would I also have to adjust the tappets or would all that be done already?

 

I would say machine work shouldn't cost more than $200 bucks, its just a stock rebuild. Maybe another hundred bucks for gaskets and seals.

The shop should be able to order in all the parts for the heads no problem.

You will have to do final adjustments yourself.



I'm not trying to "push" these guys or anything, but they are who I go to for all my machine work. Precision Automotive Machine, in Canton. Their number is (330) 456-304.

 

Matt, COMO (Cental Ohio Mini Owners) meets every third Tuesday at Tommy's Pizza on West Lane Ave. You are more then welcome (anyone is more then welcome) to come and talk minis. There is a weath of knowledge there and everyone is willing to help.

I have had my head off a few times and it is not that hard. The only real special tool you need is a torque wrench. Getting the exhaust off is the hard part I think. I am not a expert either but I can lend a hand if you want.

Jason

 

You would have to adjust the tappets, yes. but again, it's an easy job, and if you have a manual it will walk you thru the procedure.

Parts are readily available for the head, but you could certainly order them ahead of time and take them in with you, especially if you have a supplier you particularly trust. They will clean and decarbon the head as part of the work, and have them check it for straightness too, if not perfect they can skim a few thousandths off for you while they're at it. This is all very common work, nothing new about it at all. You might need new valve seats too, and again, they can get them and install them for you. When you get the head back, you do not need to lap the valves in, but it's the perfect time to shoot a nice coat of paint on it and the valve cover.

While the head is at the machine shop clean up the threads and the head studs and decarbon the tops of the pistons. Check for excessive wear in the cylinders (a thick ridge at the very top is a sign of wear) Clean the top of the block - I use a single edged razor blade followed by a scotch brite pad and some WD40. Replace any worn or broken studs for the manifolds, bolt it on, torque it down, adjust the tappets and you're done. While you're in there it's a good time to change the coolant (you did remember to drain the coolant before you removed the head, right?), flush the radiator and change the oil.
Some copper-coat (again, available at any parts store) on the headgasket will help it seal up.

Sounds like you have some good resources in your local Mini club, don't be afraid to call on them, we Mini owners are only to happy to share our hard won learning.

 

Hehe... yeah I know - I've been to Tommy's like a dozen times.

 

It is not recommended to use any sealant on a head gasket. Very Clean (and flat) surfaces are quite sufficient.

Use at your own risk.

 

+ 1..... IMO not a good idea. I knew someone who did that. Two days later he got to clean up the mess he made.

 

I prefer copper spray on the head gasket.

In my experience, boosted cars at least, tend to hold gaskets longer with copper spray.

 

I knew someone was going to say they did that. I friend of mine used to do that, but I never have. Using the right product makes a world of difference. Plus they keep coming with new & better stuff as time marches on.

Better living through chemistry....

 

"Boosted"? As in...? Fiona's as vanilla as a 1275 gets, I think. I wasn't planning on using any sealant on the head gasket. I've put sealant on the valve cover side of the cover gasket, just to make it stick to the cover (makes it easier if you ever need to pull it off to make an inspection I hear), but other than that, nothing... Should I use anything on the OTHER gaskets (thermostat, fuel pump, carb/manifold, etc.?)

 

I started using it when a tech at Honda said thats what Honda recommends. I also use a beam type torque wrench for head bolts because Honda recommends that as well. I have never had an assembly or prep related failure in that area since I started doing that. Just personal preference I guess.

I don't like using sealer where its not needed. If you want the gasket to stick while you are assembling something, like the valve cover for example, I just use some brush on Form A Gasket No3. I have used the High Tack Spray A Gasket before, for holding gaskets during assembly. It works well on just about everything.

If I pull something like a valve cover gasket, I just replace it. I have just about ever gasket for a Mopar on my wall at home in case I need to do something to one of my cars. Piece of mind in the long run, using a new gasket every time.

All the other gaskets, either use the paper gasket, or make the entire gasket out of Great Stuff, its basically the same stuff OEM mfg's use for their gaskets these days. Makes a usuable gasket in 15 minutes.