I need to resurface my head.
How many mm can I resurface it ?
I don t want my valves touch my pistons.
I use Cp 9:1 and B16A2 head

Thank you

 

.005" (.127mm) is all you need. You just need a little. DO NOT GO to over .030" (.762mm), you're getting too close to service line

 

you can go past the service limit to raise compression if you know what you are doing. but you will need an adjustable cam gear to reset the valve timing

 

The machine shop will know how much need to be removed to turn up the head. Normally .003-.005 is all that is needed.

 

Thank you very much.

Do you know the OEM value? and How to measure it?

 

He's in France... Can't assume the machine shop knows the limits or even the service limit marks on the head.

He won't raise enough compression to make a difference on the combustion chamber on this turbocharged application. He needs to stay simple, go for a resurface, use an OEM Honda headgasket and enjoy.

 

Correct, But I bought a used cylinder head and would like to you if this one is OEM and even resurfaced.

 

I use this Measure tool


and found 2 differents numbers on 2 differents head.
First was 1.85mm
Second 1.45mm

What is the OEM number please?

 

Both of those measurements are WAY past surface limits for usability. Please go by what I stated earlier. DO NOT GO OVER .762mm if you ever need to reuse the head again. You will not gain anything by going to maximum mill, and will extremely limit yourself on future camshaft choices and piston-to-valve clearances. The service limit "*****" on the corners of the head are set at 1mm. you go past that, and the head will not be serviceable.

Last warning.. then you're on your own to take any further risks.

 

How do you know for sure that those marks are indicating the limit? They are not in agreement with the manual and I have never seen any other reference that positively identifies that purpose.

 

Because I've worked with heads at those limits and there are within that manual for a number of years, and have created a number of issues when they are outside those service marks are both forced inducted and naturally aspirated applications.

I'm typically a "manual stickler" myself. This is one of the few cases in which going that far just not a good idea..

Now if steeve_civic wants to push those limits and take that risk, the burden is on him. He asked recommendations of something very simply done in the regular scheme of things. I'm giving a her definitive answer that has been tried and true for many years.

If you doubt me on it, it's quite alright.. We'll let him decide that.

 

The reason I brought it up is because there seems to be a bit of confusion on what the "service Limit" is on these heads. I'm not in front of my manual right now, but I believe mine states .008 max. There is no mention or pictures that I have ever seen that calls out those cast bumps as limit markers, so it bothers me when people state this as fact. I have a suspicion that they are only for casting tooling/locating. Now obviously for us it is normal practice to put many things beyond the oem service limit. Besides cam timing and clearance issues needing to be checked and altered I don't see negative issues arrising from heavy milling. Not that I am condoning that for the OP, just saying.

 

find someone who has had one milled beyond the service limit and see how it worked for them, the limits in the book not only affect compression but things like detonation,emissions etc, they have nothing to do with performance, in a performance setup, going beyond those my be just fine, for an example, on my A20, you can take off 1.5 mm well beyond the service limit and it still works fine, it's been done and proven

 

There is no confusion. This has been known for a bit.. And yes, many of us have tested it past what was in the manual, and as lostforawhile has already noted, there are more than just "performance" issues with going past these limits.

I know you're "just sayin'", but we've known this for a while now.

 

Sorry but things like "this has been known for a bit" don't really mean much. I have also been around for a bit, i'm not new to this. I don't buy that these any any sort of limit markers. If people cut the head that far and can't figure out how to check clearances or retime the cams then they're in for trouble. Increasing squish is good for detonation resistance and also effects NOx emissions, among others. Do any of us really measure emissions, I don't. The shape and size of the chamber play a large role in engine operation...In all seriousness, I'd kindly like to know specifics here not just beat around the bush generalizations. Its good tech talk.

 

Ok. Then, since we've BOTH been "around the block" so to speak, let's just agree to disagree, and let Steeve_Civic decide for himself if he's willing to take that risk. When he goes past it, starts asking a series of questions revolving around why the car is not correct, have adjustment timing issues, limited use of camshafts, detonation, etc.. he should give you a call from France, so you can help solve his issue based upon the manual.

There's what "the manual" calls for, and what's happened when you inadvertently (or purposefully) go against the manual in which true experience is formed from a particular area, whether or not there's "graph" behind the logic or not. Going back and forth like this won't produce good tech talk, it just turns into more of who has the bigger photobucket/flicker file as to who has enough graphs and out technobabble one over the other. Kinda like the whole "backpressure" of the exhaust manifold issue that comes up occasionally.

Good luck, Steeve_Civic. You've got a serious choice to make here if for nothing else, your own edification.

 

Its not a matter of abiding by the manual, I don't expect anyone to do that. Its just clarification of so called casting "limit" indications and what they really are. If there is a seriously negative impact of milling the head too far besides the obvious I was also hoping to clarify that. Colorful charts and graphs not needed. But as a gentlemen on this forum I can respect your viewpoint and we can leave it at that. To the OP, your going to have to do some more clearance checks to determine what you are working with, good luck.

 

Thank you very much guys,
What say the manuel book please?
As far as my head has been already resurfaced how can know the limit Now?

 

iirc tony the tiger's head is well past the service limit. takes a lot of degreeing but it is possible to still use.

 

I saw in the manuel, STD head height is 132mm (5.19'')
But on 2 different cylinder heads I get 142.12 ! (5.59'')

Any idea?

 

Agreed. I respect you input as well, sir. But the negative side effects of doing so have been shown to rear their ugly head (no pun intended) over the years.

Tony is not past the service limit on his heads, as I remember that build. He was strictly using high compression pistons with his builds.

 

TheShodan, do you know why I didn't find the correct height please?

 

Unfortunately, I do not have that tool, that experience has always been with the machine shops in the area that specialize in these engines. Suffice it to say, you only want a resurface, not take the head down to its limits. This is where I think there's a disconnect.

 

I don't either
Hate when that happens