Ok I had a head built for my project Y8. The place took it upon themselves to put rings on the head. Well now I am getting the rings removed and left with two options:
A) Remove the rings, weld in new metal into the groves, and plane flat.

B) Remove rings, mill head down to the bottom of the ring groves.

Here is my problem. My motor is alredy built for high compression. 10.5:1. How much will milling raise my comp? I don't know how much for sure they will have to mill, just wondering if it will raise it a substantial bit.

 

They o-ringed the head? Welding the head is going to be a headache.You are going to have to mill the head in the .020"-.025 range would be my guess.About half the thickness of the head gasket.If your at 10.5 now that would make you about 11.2.I would get them to do another head for you.
Glenn

 

Yeah they o-ringed the head.

Well thats the problem. I bought it from a place off Honda-Tech about a year ago when I started to piece together stuff to do the build. It was a good price so I went ahead and ordered it.

Well needless to say we have since wiped the computer clean, moved and lost records, and I cannot remember for anything who did it. With the amount of money in the head there is not a option with starting with a new one.

If they have to mill around .025 and that kicks the c/r up to 11.2 will that make my timing off? How hard will it be to just weld in the ring gaps.

 

To get a good weld the head will need to be stripped and heated.At the very least your looking at milling it .008" -.010" to get it flat again.And there is always a good chance the seats will need to be recut after welding.Maybe milling it flat and getting a custom thicker gasket.
Glenn

 

Ok so if I have the shop pull the rings out, then just run a cometic MLS gasket would it be fine? Do the o-ring grooves really need to be welded up?

 

Also what would happen if I had them make the o-rings that are in the head even with the rest of the head. Just plane them down to be even.

 

I don't know if you will be able to mill the rings flat but it may be worth a try.
Glenn

 

I don't see why it wouldn't work. They would be flat with the block so they wouldn't cause any interference, plus they will still fill the gap so it will not sacrifice strength.

 

Glen is there a way to determine real world compression ratio if you dont know how much your head/block were milled? Like a magic compression tool.

 

ok that idea doesn't work. When you try to plane the rings down they come right out of the head.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Glen is there a way to determine real world compression ratio if you dont know how much your head/block were milled? Like a magic compression tool.</TD></TR></TABLE>

yup, use water to find the CC of the combusion chamber.

 

http://www.smokemup.com/auto_m...o.php

http://www.race-cars.net/calcu....html

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Muckman &raquo;</TD></TR><TR><TD CLASS="quote">Glen is there a way to determine real world compression ratio if you don't know how much your head/block were milled? Like a magic compression tool.</TD></TR></TABLE>

Funny you should ask.There is such a device.Its commonly known as a "Whistler".It's a box about the size of a shoebox that connects to the spark-plug hole and an air hose.It is used for race car classes with a compression rule.You input the cubic inch (or cc) of the engine and it reads out the compression ratio.It is vary accurate.I had a chance to measure every engine in the shop one day and its readout was the same as my calc.s.Katech Engineering used to be the supplier and they were around $1500 many years ago.
Glenn