Race Engine Forum UK

Hello everyone.
This is my first post in this forum and my first request for help.
Currently I preparing to repair engine for my Fiat Coupe 20V Turbo.
I have a question for the cylinder head. On the pictures you can see the condition of exhaust and intake ports. For me they are terrible!
I did not find any advice for Fiat 20V cylinder head in this forum.
Anyone know how much material is safely removed from the ports?
Thanks, Krastyo

Porting Fiat Coupe 20VT head is a real pain. I'm on my way to do mine, and i wont remove more than 1,5mm.
Will post my pictures latter when ready.

hi Krastyo,

Our host Guy did one of those about a year ago -maybe two- and there was quite a detailed write-up about it on the site. Interested me plenty since I have the related 1.8 engine. It's mentioned in his second book as well.
Seems not to be here any more though. I found traces of it through Google, but even their cache says 'the discussion does not exist any more'.

Might be Guy has good reasons for taking it down, or it got lost when there were some problems with the forum last March and so far it has escaped repair?

regards
Tom

In the 20v you can comfortably remove 2mm thick anywhere you want!

I took that topic down along with a load of stuff we don't do here anymore.

G

Thanks for the answers.
The theme for the five-cylinder Fiat engine would be very useful.
Pity that no longer exists!
Greetings from Bulgaria.

Few days ago i finished my head prep, it took me almost 6-7 summary days to complete.....it's real pain doing 20VT head.....

Open to any critics.....:)

If the material on these Fiat 20 valve heads is anywhere near as hard as that on the Audi 20 valve heads I've done (several) then you most definitely have my sympathies indeed!
Looks quite similar apart from the inclined exhaust valves and the slightly different chamber shape.

My porting experience is with few Alfa 156 TS heads, 2 156's 2.5 V6, and one Fiat20VT, and really have no idea how hard other heads is......
But the problem with 20VT is that port length is way too much for normal carbide burr and its difficult to remove even parts of the port.....

The compact flexi shaft for the Metabo die grinder I use permits me to work in even the most restrictive and long ports, but you can buy 'long series' burrs which have a much longer shank.

Those diamond cut burrs are hopeless for aluminium - the rake is wrong on the tooth form and they're always getting material stuck to the teeth - though if you wet the metal with spray oil frequently they work ok.

G

Guy Croft wrote: they're always getting material stuck to the teeth - though if you wet the metal with spray oil frequently they work ok.
G

True - but few drops WD40 every 5-8 min's works fine for now......and getting 'long series' burrs is next on my list.....

I have seen people rave about a bee wax candle they dip their burr in to lubricate it. I have yet to try it, haven't done any aluminium since I got the suggestion on some forum.

Doing an article for the respected Fiat Coupe Forum on this, see: '20v head prep' by GCRE at:


http://www.fccuk.org/forum/ubbthreads.p ... =17&page=1

G

Thanks for the topic, Mr. Croft.
Many people will be happy!

Very interesting reading indeed. I take it a lot of this will apply to the Alfa 16V TS heads as well? The engines are generally designed the same and share a lot of parts.

in practice - not a million miles removed probably though I have not worked on one of those Ricardo designed heads

G