Converted 7A Heads

[volcano rs]

I'm aware that you can do more harm than good by taking material away from the wrong places. I think just before the exhaust ports meet was the most restrictive part, so it took a little metal away there creating more of a knife edge. Other than that I just smoothed out the rough casting with grinding stones, gradually used finer grades of cartridge rolls lubricating with WD-40, and finally polished up with a Scotch pad. I did all the ports at the same time at each stage to try to keep them all the same.
I'm not really looking for big gains from cylinder head porting, so I wasn't intending to do anything too radical.

I just used a porting kit from Merlin Abrasives with a normal electric drill. They also have a Ebay shop here for example.

It was a very time consuming job, although I was doing a little bit at a time. If I did another I could do it a lot quicker.

head is the heart of an engine thats where all the power comes from .a well ported head can give you about 30%more power

[Jon441cc]

Cool - I'll get the stock 7A flowbenched at Westward, then we can compare those figures with the 16V VW data at cncheads for another data point.

When i did mine it took me about a week .. all i did was smooth out the casting marks
and then polished each (ex) port to a mirror, it made a difference :mischeif:

http://s88.photobucket.com/albums/k170/034quattro/?action=view&current=GTI-chatter.flv

0-60 was 5.64

[dubmeister]

VW 16v heads are the same as the 20v but with 1 less chamber
I have a couple of pics of sectioned 16v heads (1.8 & 2l) which i will dig out and post up to give you an idea of the thickness of the material round the ports.
Quick tip: spray wd40 into the water/oil jacket near where you are grinding-when it heats up and starts too smoke - you are cutting TOO much out!!

[Jon441cc]

Quick tip: spray wd40 into the water/oil jacket near where you are grinding-when it heats up and starts too smoke - you are cutting TOO much out!!

Great tip

[GazzaG60]

ric wood is the man from CNCheads. what he doesn't know isn't worth knowing. if you call him he's good for a chat. he's been race prepping cars for years. his current super saloon is amazing. lapped every other runner at oulton par earlier this year.

i was gonna have a port with extra work on the exhaust and bigger valves in the 16vt. the work would have been around 1400 quid. quite some cash but IIRC he did an audi super tourer (16v) made 304hp NA and 540 with boost at 1 bar. thats some port.

needs a big inlet and throttle body (i got a mustang one) and some good cams (solid) to make it worth while

[S2central.net]

VW 16v heads are the same as the 20v but with 1 less chamber
I have a couple of pics of sectioned 16v heads (1.8 & 2l) which i will dig out and post up to give you an idea of the thickness of the material round the ports.
Quick tip: spray wd40 into the water/oil jacket near where you are grinding-when it heats up and starts too smoke - you are cutting TOO much out!!

Mr Meister - if you can dig up those section photos for the 1.8 16V head it would be great. I know about the WD40 trick - it was something that Dave Walker or that boy Vizard (writers at CCC mag of eons past) told me about that. Amazing what you can remember really

Paul

[Mark Halligan]

Not meaning to hijack Doug's thread any further but.....

I'm looking at making a template for the water manifold modification.

This works well Stu, I'm modding a 7A head right now.

I've used a 9" disc cutter to slice a ready made template out of an old and useless early ABY head. I used this as a guide to bench drill the three extra coolant ports and water manifold bolt holes.

The sliced out template is not pretty, but it works well and with a little care the WM mod is a good fit using this method. Although if I had the money spare I'd probably get it machined by someone like MRC (less risky).

Cheers

[S2central.net]

Ahah - just *the* man - with the wisdom and experience that I need to help me thru this winter

Any chance I can borrow that template when you are done with it Mark ?

Its a daunting prospect, but I think it will be fun. Just had a 1st look at my 7A head tonight - seems nice and straight according to the steel rule test. Cams look great too. I succeeded in removing the old EM studs tonight as the 1st nice job - two nut and spanner trick worked a treat. There does seem to be good scope for improvements with polishing and port shaping alright. I have some pics but I'll create a new thread about this one.

[Mark Halligan]

Paul

PM me your address and I'll post it to you

[S2central.net]

Fantastic - will do - I might need to call in your advice if I get the shakes with that dremel when I start polishing

I was sure you posted some pics of your modded head work before but I can't find them. You had some info on CC volumes as well - must search harder !

Paul

[Mark Halligan]

I was sure you posted some pics of your modded head work before but I can't find them. You had some info on CC volumes as well - must search harder !Paul

Paul there are some pics in this very old thread

Tell you what though, I wont be spending as much time porting this 7A conversion this time, way too much work!

[dubmeister]

Mr Meister - if you can dig up those section photos for the 1.8 16V head it would be great. I know about the WD40 trick - it was something that Dave Walker or that boy Vizard (writers at CCC mag of eons past) told me about that. Amazing what you can remember really

Paul

Here are the sectioned head pics i found on the net years ago, for a 1.8 kr 16v VW head (left) and a 2.0 abf 16v VW head- never cut up a 5 cyl- but they will give an idea of the internals
HTH

[S2central.net]

Great stuff - thanks to dub & markH for this update !