cylinder head preperation

[timucin]

hi;
will start porting and polishing cylinder heads next monday, is there any comments? do's dont's? any pictures to collect some idea? www?

thnx for help

[Mark Halligan]

Timucin,

I have just been finishing off my cylinder head today (balancing the combustion chambers). I bought a porting kit and followed the instructions that came with it, here .

It was lot of work, it makes you wish that you did not have 20 valves , I spent at least 20-30 hours over a couple of months (mostly evenings) working on it.
Without going into too much detail I opened out the inlets and port matched them to the gaskets. I did NOT knife edge the internal divider on the inlets and left the inlet ports rough, as per the instructions, backed up by what I had read eleswhere and been told.
The exhausts were opened out quite a lot too, much more so in the valve throat area which was particularly rough, especially with the odd casting mark. I really did remove a lot of material from the exhaust side, these ports were polished up to a high degree.
I made sure that I measured carefully throughout the whole process so that I would not go too far, but to be honest the it was all a bit of a calculated risk too. The guides were all pressed out too, to make it easier to work in the throat areas.

The Combustion chambers were also polished up.

After all that the head was pressure tested to make sure that I had not gone too far, and when that was found to be OK that valve seats were re-cut, and the head was skimmed.
Finally today I measured the combustion chambers with a burrette, Luckily I found these to be within 0.2 cc of 45 cc's total, and did not have to do too much other than adjust one of them by removing a small amount of metal.

I dont know if I've done it right or not, and its definatley not as good as a proper flow bench job, but thats it, I dont know how good it will be when on the new engine, I'll let you know, one thing for sure it will definately flow more at the top end of the rev range, not sure how low to mid range will be affected though.

I had a spare head to 'play' with, I would'nt recommend going too mad with your cylinder head though, unles you have a spare, as it is a bit of a risk and they are a bit expensive :eek2: .

Heres how it started off:

[Mark Halligan]

An inlet after some work:

[Mark Halligan]

And the inlet throat after work (guide pressed out):

[Mark Halligan]

An exhaust port before work:

[Mark Halligan]

Exhaust port after work (full of fluff from a cloth ) :

[Mark Halligan]

Combustion chamber:

[Mark Halligan]

Combustion chamber showing throats:

[Mark Halligan]

Phew, and the last one from today, using a burrette to check/balance the combustion chamber volumes. Hope this all helps you Timucin.

Mark.

P.S. I really need to find something better to do with my spare time .

[Paulm]

Mark

thats some amount of work uv'e done, well impressed

Paul

[APNess]

Must have cost a fortune in silver spray paint to cover up all that gungy black stuff underneath

Well done! Hope it does all you need it to do! (And what is that, anyway? 450hp...more?)

PJ

[timucin]

excellent work there, congrats;

does audi engine need gasket matching on intake manifold side of the head?

[Mark Halligan]

does audi engine need gasket matching on intake manifold side of the head?

Timucin, I did with mine, basically i just followed the instruction that came with the porting kit.

Mark.

[Beetie]

Looks like a very good job mate! The exhaust ports look spot on, well cut. Should help flow really well. Cant wait for it to all be up and running, should be awesome.

[Mark Halligan]

Thanks Beetie,
I'll be using 7A inlet and exhaust cams too, so with their higher lifts it will be interesting to see how it goes, when bolted up to the new engine. I finished all the work on it and gave it a final thorough clean up today.

I'll start assembling the valve train tomorrow .

Cheers,

Mark.