Head Identification

[Derek 328]

Hi
Does anyone have a definitive list to be able to identify a cylinder head?
Thanks

[Geoff Dowdle]

Derek 328 ,
I should be able to identify the type of Bristol head by the number stamped on two raised bosses on the inlet side , close to the bottom face ,towards the front and rear.

Pls advise that number or post a few photos .

I have made a list of most of the 6 cylinder engines produced ,listed by engine number and chassis number of the car it was originally fitted to .

Geoff

[Derek 328]

Hi Geoff Thanks for the quick response.
I don't have a head but I want to get one.
As I understand it the 100 is the one to go to if possible.
I would like to know how to recognise an appropriate head and it might be useful for other members.

During my search I have spotted numbers like

N321941
N322040

3227
2266

and dates like
22 6 54
8 6 53

[Geoff Dowdle]

Derek 328 ,

There are a few different heads

400 with 85A engine N322030
85C engine N322030 with tube inserted into centre throat to
block balance tube , also some fitted to early 401

401 all with 85C engine N322040

The stamped engine number of these 85 engines/heads are between 1001
and 2292

The 100/110 series heads have larger diameter inlet ports & inlet valves

403 with 100A & AB2 engine N322080 with # 3000 - 3300
404 with 100B &C engine N322690 with #3501 - 3634
405 with 100B2 engine N322080 with #3700 - 3838 & 4001 - 4341
406 with 110 engine 110-1-2002 with #5001 - 5204

Pls note there are some variations in the detail above and often there are large gaps in the engine numbering system.
There are also heads fitted to Bristol Sports engines 100D,100D2, FNS & BS

What car / engine will you be fitting one to , ans what type of use will you give it ??
I noticed you have a Frazer Nash BMW 327 , I suggest any 85 series head would be more suited to that engine than the 100 series head. But if you want it for an engine that can rev as high as 6000rpm a 100 series head might be more suitable .

I have had 85 series engines/heads that will go to 6000 rpm with minor porting and slightly larger inlet valves (depending on cam,compression and carburation). The smaller diameter inlet ports increase the air speed and mid range torque.

When inspecting a head check for corrosion around the water transfer holes and the amount of previous machining of the bottom face of the head .
My recommendation is to buy the one in the best condition .

Good luck in your search.

Geoff

[bristolbavaria]

Derek 328,
should you need a head for a 327 I could sell one reproduced according to origial specification (BMW 1938). Valve diameter 33 / 36 mm, inlet ports will fit Solex 30 and 32 mm carbs. That is about the same as Bristol 85A but with a different (BMW) water pump.

Best regards from Bavaria,
Bernhard