Grey mtoor cylinder head identification

[Harv]

Ladies and gents,                              
                              
As I get more serious about the Normans, I have started getting the FB ready to act as a test-bed for the finished product. The motor has been re-ringed not long ago, but the head was a little sad. I ended up biting the bullet and getting the spare head done up... no rush job, but will be interesting to see how it goes. Head will get ported out, chamber relieved and some red motor valves thrown in. No head shaving, as I don't need any extra squeeeeze once the Norman is in place. There will however be a time when I will run this head in naturally aspirated form (at least until the Norman is ready  ). Given that the chambers are being relieved, I'm starting to wonder what the compression ratio is going to end up at... will be interesting to calculate once the heads are CCd.                               
                              
All this mucking around with cylinder heads made me have a bit more of a think about what I started with. All the engine parts I have are a mad mixture of vintages... the cylinder head could be anything from FX-EJ. When I go through the data from the Workshop Manuals though, it is clear that a number of head changes were made.                              
                              
Model/   Bore (")/   Stroke (")/ CR/   Capacity (ci)/   Cylinder capacity (ci)/   Clearance Volume (ci)
         
FX/      3/   3.125/   6.5/   132.5/   22.09/   4.016            
FJ/    3/   3.125/   6.5/   132.5/   22.09/   4.016            
FE/      3/   3.125/   6.8/   132.5/   22.09/   3.809            
FC/      3/   3.125/   7/   132.5/   22.09/   3.682            
FB/      3.062/   3.125/   7.25/   138.1/   23.01/   3.682            
EK/      3.062/   3.125/   7.25/   138.1/   23.01/   3.682            
EJ/      3.062/   3.125/   7.25/   138.1/   23.01/   3.682            
                              
It looks like FX and FJ had the same cylinder head, whilst the FE had a head with a reduced chamber volume (clearnace volume) to increase comrpession ratio. The same change (smaller chamber again) was made at FC. FC-EJ seem to have the same head - whilst the compression ration went up for FB, this was done by increasing bore size rather than playing with the head. This would infer there are (at least) three distinct grey motor heads: FX-FJ, FE and FC-EJ.                              
                              
My question for today - does anyone know how to positively identify these three cylinder head types (other than pulling them down and CC'ing them)?                              
                              
Cheers,                              
Harv (aprentice cylinder head thinkerer).

[hsv-001]

Harv, I am finding your posts very interesting . I had never really studied these capacity and compression ratio figures before. All I had concentrated on back in the day was women, and getting my old holdens to go faster and as far as I ever got with the old holdens was the usual ,late ,bigger engine, headers or extractors, a small amount of head work to improve flow and multiple carbies. However I did put a electric fan inside a cake tin as a air cleaner on a mates FC when he complained of a dead spot in his carby . The pressure held his throttle butterfly open and he wasn't real impressed. A mate down the street a few years ago showed an idea he had where his supercharger was recessed on his inner guard and he had a carby mounted directly behind it and a length of pipework across the engine to the intake manifold. He was about to start it when I asked whether he understood the basis of how a ramjet works and what would happen if the engine backfired and ignited the fuel in the pipework. I don't believe he ever went ahead with it . Anyway keep at it ,like I said I am watching and reading with interest.  cheers

[customFC]

I have always been of the understanding that the EJ had the extra water outlet towards the rear of the head.
Regards
Alex

[Harv]

G'day Alex,

I am pretty certain that the head change to two holes happened at least as early as FB... and I suspect at FC. The Smiths "installation instructions for fitting model RA200/FB recirculatory heating and demistingto G.M. Holden FB vehicles" refers to:
remove the screw plugs from the nearside rear of the cylinder head  and from the water pump housing
The plugs are listed in the MasterParts catalogue (Plug, square head pipe ½” 103868) for FB onwards.

Cheers,
Harv

[fe350chev]

Just some general notes when not much info at your disposal on any build etc. It says "clearance volume" not "chamber capacity", so this is an important notation to keep in mind because increased cc could be achieved by increasing thickness of the gasket, valves being dished in, or crowned or larger thus reducing cc chamber volume (inserts can have same effect) or piston pin height (compression height) relative to piston crown may change. Always a good idea to look in parts books to see part numbers on any engine (I'm just giving tips for people generally cos internet makes this easily accessible) to ensure parts were the same or different across model ranges. This will allow you to narrow it down to physical head differences or not. Even torque specs can be worth looking at sometimes cos this also affects cc on some engines. Static compression as your talking about here is not your be it, end all measurement for your scenario. Your real "actual" or effective compression will be determined by the cam. So if you are running higher compression as standard fitment, a way around the problem if too high for the supercharger application could be to use a high lift cam when running in stock form at high static compression (ie close to stock) and change the cam and not the head to reduce your actual compression ratio at tdc (known as dynamic compression which at the end of the day is more important in a non efi motor)  by increasing duration at the end cycle of the exhaust valve this will increase scavenging and probably increase torque. Other factors that affect older engines that have been rebuilt numerous times is their deck height and another trick Is to advance or retard that camshaft at fitment. Basically everything needs to be measured properly to know what u got because how would you know what deck height you have unless you know the engines history etc. Ignition curve will also have to change. The numbers on the head will give you what model it is from. The link below will be quite useful to give you a headache. I think harv is right too.

http://www.projectpontiac.com/ppsite15/compression-ratio-calculator