[Mk2] [Turbo] combustion chamber polish

[slipping clutch]

A (long) while back some one posted up a picture of a head that they had polished the combustion chambers on - can any one else remember this? and if so can you find the link to it?
I've used the search function but my approach is to random as I cannot remember if it was posted in mechanical, modding, project cars etc.

[Century Motorsport]

Check my project thread... mine were polished.



edit... page 3

[slipping clutch]

Cheers Nathan

[T.F.S.]

to clean the head i used oven cleaner as per instructions on the carbonised parts of the head and jetted off, i then used fine grade wet and dry (wet) followed by fine wire wool to get a polish...this isnt just done from a cleaning point of view, it makes sure there is no sharp edges/hotspots on the combustion surface and will reduce the chances of detonation in future, the flat part of the combustion face (the bits that stop the head part of the cylinder being round) should also be rounded off slightly to avoid det...the inlet side is more prone to det than the exhaust side







so before clean down we have something like this













combustion face, oven cleaner first then jetter should get something like this














same bit but rubbed with fine grade wet and dry (wet) for about 45mins..maybe less















same bit, polished with fine wire wool for about 30mins













i cleaned the mating surface in the same way...didnt take too much time doing this as i have not yet checked the volume of the combustion areas on the head so it may need a skim if its off but we will come to that shortly, make sure you use a straight edge on top of your cleaning medium to make sure you are removing any material in a uniform manner

doing this polishing is a long process but it really does have great results

[slipping clutch]

Cheers for that as well - I really appreciate you taking the time to write that up I made a start on this last night and have made a couple but not fatal mistakes -the main one being that I have just realised from looking at your picture that as I am putting in new valves I could just put my old valves in and polish away - as it is in a couple of places I have cut down the edge of the recess that the valve sits in to a bit to far ( not touched the valve seat though) - I cannot believe that I have been so stupid not to think of just puting the old valves back in if I can get my digital camera working I will take some pictures.
Thanks again.

[T.F.S.]

its just a copy/paste from a rebuild i done a few years back mate

[Baker]

apologies, but whats the point of doing this?

[T.F.S.]

read the post with the pics in, its covered in the first paragraph

[slipping clutch]

made some progress with this - just need to find my camera

[Baker]

read the post with the pics in, its covered in the first paragraph

Thanks, i didnt see it.

[adam3442]

Here you go!

http://www.imoc.co.uk/forums/viewtopic. ... c&start=20

[slipping clutch]

thats the one I was thinking of - many thanks.

[RyanRs]

Cheers adam you beat me too it!

Slippping... Beware of suveerly sore thumbs by the end of doing this!! i had no prints left on both mine!!

[slipping clutch]

[slipping clutch]

P.S. ryan - last thing on your thread was july - where does the car stand now?

[RyanRs]

Yeah it has been awhile hasn't it! well its running 500bhp & 420 ft/lb (iirc) at the mo @1.6bar on v-power. We had to stop at that point tho as the bosh 044 started dropping ALL its pressure whilst on boost! turns out i had a faulty pump, it was an internal electrical fault. Got a new pump now and will get it back up there for 2 bar + tune soon if all goes well, hope ill break the 600bhp mark ! fingers crossed. Ill update the project thread soon.

[Baker]

how long would this last before it gets coked up again?

[T.F.S.]

how long would this last before it gets coked up again?

what would that have to do with anything?

[slipping clutch]

Cheers Ryan, update that thread asap. Good luck with 600 bhp

[Baker]

how long would this last before it gets coked up again?

what would that have to do with anything?

Um, everything? then you're back to stage one.
You clearly don't like my questions, I apologise if this is so, I'm just interested.