boost mad

iTrader: (8)

what are the average port sizes of a 4x4 saph cossie head ?

there is BBR stage 2 stamped into the front and i am trying to figure out what has been done....

I have contacted BBR and they were no help at all !



thanx in advance !

tabetha

Exhaust port is 48mm X 24.5mm.
Inlet 49.5mm X 25mm.
tabetha

boost mad

iTrader: (8)

thanking you muchly

tabetha

No probs, they respond EXCEPTIONALLY well to a simple de-shroud job about £300.
tabetha

boost mad

iTrader: (8)

De-shroud ?

tabetha

The valve area at the end of the throat is very shrouded, a simple "port" job around this area is VERY effective, it really makes the boost hang on a LOT longer instead of tailing off, and boost MUCH harder MUCH earlier.
I use Darren at Damico 01953 717784, around £275.
It does NOT deliver more power at maximum bhp but power spread is awsome!!
tabetha

boost mad

iTrader: (8)

Karl

"Exhaust port is 48mm X 24.5mm.
Inlet 49.5mm X 25mm.
tabetha"

What load of nonsense is the above info? (I especially have no idea what the 48 and 49.5 figures relate to????)

Standard port diameter on all cosworth heads are 23mm for both inlet and exhaust.

tabetha

How can a port be the same size all the way through when it changes from one oval shape to two round shapes ?
Try engaging your brain next time, I qouted what I understood the person to mean and that is the OVAL size opening at the extremity of the head.
tabetha

Karl

Tabetha,

Try engaging my brain??? ROFLOL I do love your comments, often you give wrong advice, or if not you try slagging a tuner off for correcting you!!

The inlet and exhaust ports on a cosworth head are indeed uniform in diameter. This diameter is 23mm for both inlet and exhaust. Referencing the actual flange outlet size gives no meaningfull idea as to what has been done as I do for example do a 500bhp head that has std size flange faces.

Obviously the ports siamese together but that is irrelevant as it is the diameter of each seperate port that is quoted in any modified head. (i.e. 23mm being standard)

For example the traditional touring car head was 26.5mm/26.5mm (inlet/exhaust). This relates to the diameter of each singular port.

tabetha

I don't slag anyone off unless I think they deserve it.
In case you have not noticed, not everyone thinks you are a god.
I gave this answer to what I thougt was being asked, and the asker seemed happy as he did not say anything else, so I assumed this is what he was after.
No one not even YOU give correct advice all the time.
Another thing you don't seemed to have realised is this is a PUBLIC FORUM, where views expressed are opinions, NOT GOSPEL, if you care to take the time to read the stickies it points this out.
As such you can usually expect to find the "public" on here, just trying to do thier bit.
As you consider yourself a superior knowledge, and from your own admission see myself giving incorrect advice, WHY DON'T YOU HAVE THE DECENCY TO CORRECT THIS ?
I never ever claim to be 100% perfect, and it is up to people to make thier own mind up, about any advice given, this again is in the stickies.
Do you think that no one will argue with you as you have some percieved idea about being god like in the cossie world, there were far better persons before you and I, and there certainly will be afterwards, that is a FACT, but NOT one that is in the stickies.
Incidentally if you don't like my posts/replies you know where the OFF switch is.
tabetha

Blackbid_Leys_1991

Quote:

the traditional touring car head was 26.5mm/26.5mm (inlet/exhaust). This relates to the diameter of each singular port

When you say the traditional touring car head, am i right in thinking you mean the YBD/YBF RS500 heads? ..also, is 26.5mm the maximum size that each singular port can be opened out to or are their any gains to be had, by enlarging them any further? ...if that's possible?

Thanks,
Dean