I am pulling the head off of my spare block (b18a) and I found these unnatural looking holes. They’re very rough and it seems as if they weren’t meant to be there. I don’t know how well this motor was treated before I bought it so I’m not sure if they came from it having been abused/neglected.
This is the distributor side.
This one is in between cylinders 2 and 3.
This one on the timing belt side.
thats normal, my GSR head has the same looking holes, i noticed that myself a long time ago. i dont know why their so rough but thats just the way it is.
Thanks for the quick response, I was so worried since the head is going to the machine shop tomorrow.
They are oil drain holes and they are ruff because of the casting process. They are not grinded down after making the head. Does not hurt anything just saves $ in the log run for the company. Plus it would be a little bit stupid for a company to do an extra step of grinding and polishing for a stock engine.
Yeah I could see why they would do that, I just got worried because it looked like something had blown a hole in it and I was wondering where the rest of the metal had gone. Also, I found it strange that there were 4 spaced out throughout the head. Thanks for the info.
Since you have the head apart, you might as well grind out the casting “flash” yourself. I’ve heard of others who do this after they get the head back from the shop, but I did mine before sending it to the shop so the burr chips get cleaned out when the head is washed at the shop.
i have been wondering the same thing for some time now. i was just to lazy to take the VC off and take pics again :D. thanks though–good to know 
why would you want to grind the oil drain holes smooth?? you would see no gain in this…just a waste of time.
Well the head got dropped off at the shop today so it’s too late to do before it gets cleaned. There wouldn’t be any power gains but when I barely touched one of the drain holes a small piece of metal broke off, makes me think it’s possible for it to happen once I put the head back on the block. I doubt I’ll grind it down though once I get it back, too scared shaving will get into the valvetrain.
Not all modifications are done for HP gains. Some are done to avoid potential problems, like casting flashes dropping into the engine internals and screwing up the motor. If you do the grinding/de-burring yourself it’s not going to cost you an arm an a leg (probably just the cost of buying that de-burring tool or a grinding stone). Actually if you look up some of the old books on hot rodding V8s most of them suggest investing (I think that’s the right word to use) the time to grind out those casting flashes, not for HP gains but for more practical things like avoiding cuts to the skin when assembling the engine and the issue I mentioned earlier, among other things. I don’t think it’s a waste of time but money well spent.
My point exactly. You’ll have to clean the head and block anyway before you assemble the motor so you could grind those flashes just before you clean the head prior to assembly.
that’s true i never thought of it that way…i always thought of it like if it lasted as many miles as it did, and if honda made it like that, it won’t hurt anything, but I guess yeah, if someone does it theirself it’s a good time investment