Oh boy that oughta get everyone riled up! I was following your logic until the JB weld comment. I believe a head gasket needs to allow for some flex between the two surfaces, plus the specific width of the gasket - wait I can't believe I'm even thinking about it! It's funny, had to consider a lot of options and factors. Guy had a complete "running when pulled" motor for sale on craigslist for $200, that was tempting, but I would have to store the remainder, but then I'd have the block if mine is crap. Another guy had a set of "rebuilt" heads with no valve train for $250, and then the local machine shop, good guys, printed a sheet of specs, measured my heads and said they would come in in spec. So for about $400 including fixing the dropped seat, a valve job, and guide seals installed, I went that route. There was plenty of space on the heads for resurfacing. It was a tough decision because the inside of my heads looked like an oven that's never been cleaned, meaning the motor overheated hard enough to bake everything on, or the PO ran crap gas and never changed the oil So I just spent $400 bucks on a $900 car, and I still don't really know why it overheated in the first place, or if the block has problems I can't see anyway! I may regret not going the low budget used motor route, we'll see!

 

So, I guess my phone posted this in another thread about seat kotors or something last night. Here we go again...


These things only make like 9:1 or 9.5:1 compression. There's no reason I can see that you couldn't shave the heads half a dozen times if it's only a couple thou each time. If you wanted to decrease your risk of detonation you could do some work to the combustion chamber to do some smoothing with sandpaper or something. I would check the Piston to valve clearance, but if you're sticking with the stock cam that shouldn't be an issue either. Not sure what the stock ptv clearance is.

Also, I agree that heads dont need resurfaced every time. A good straight edge (I've got a machinists straight edge) and feeler gauges can tell you if you're within .002"-.003". OP appears to already know that, but just for anyone else who may wonder through. If they're within spec, just cleannup the whole surface with scotchbrite and carb cleaner. Doesn't have to be perfect.

 

The biggest issue you come across with taking more and more material off the heads is the associated change in clearances. Pushrods will become too long, the intake manifold bolt holes effectively move closer to the center of the motor, so the bolts wont line up anymore, the intake ports wont line up with the manifold, etc. etc. Not to mention the ever shrinking combustion chamber.

 

Got the heads back, and they are right on the edge of specs, literally. So I will bolt it together hopefully Monday, we'll see if the manifold bolts fit and I'll let everyone know how it goes.

 

I buy heads at the yard for $50.

also another route, instead of using scotchbrite which causes little scratches, use some mothers aluminum polish or cleaner wax and clean the surfaces. When done, spray with some brakekleen to remove the residue.

 

LLamasayswhat:

Do you know at what point all those terrible things, like bolt holes not lining up, happens with Rover heads? In other words, did Land Rover give the specs of .02" off the heads with that in mind?

 

You actually want little scratches. A polished finish doesn't seal as well as a slightly textured one. Even a scotchbrite finish is a little fine, but it works. The typical recommendation is to finish your heads with the equivelant of 360-600 grit sandpaper, depending on the manufacturer, but that's hard to do at home without a surface plate.

 

.002 off the heads wouldn't cause that. I forget what the numbers are now, but I'm betting you can take of .015"-.020 before it becomes an issue. Beyond that, you can also have a certain amount taken off of the intake manifold and it will bring it back to true 1/4 of what you took off the heads maybe? I can't remember right off hand, but the machine shop would know.

 

We'll see, mine have the full .02" taken off of them. Good idea to take some off the intake if necessary, hopefully won't have to.

 

A scothbrite pad is terrible to use on a head or on anything in an engine and a smooth surface more surface tension then a scratched on.

try to slide something along a clean polished surface vs one that's scratched.

I'm not talking about a wash cloth on a waxed car finish either...but, put pressure on your finger and slide it across.

I've never gotten a head back from the shop with any scratches on the surface.