Vauxhall Owners Forum banner

Coscast Heads

1K views 24 replies 13 participants last post by  Tefal 
#1 ·
Right just a quick question, to sort out an arguement. My mate is saying the engine I have in the GTE 16v isnt a coscast and im saying it is.
If it says coscast in a little oval on the head it is an original cosworth made head isnt it
 
#3 ·
right, so i was right, i have the engine in the car (its a 1990 G) and have had the head off and it says coscast, my m8 was saying they are only on 1988 cars, i also have a coscast engine from another 1990 G
 
#8 ·
Ideal, that means the XE lump I`m putting in my 94 Cav (engine came from a late 90 GSi) is a CosCast :D
 
#9 ·
Just to confuse things further the first heads were cast by Vauxhall and finished at Cosworth in Wellingbourgh. Cosworth then took to casting the heads under contract and finishing them, again the finishing was done at Wellingborough.

HOWEVER! When the contract soured, Cosworth held onto a load of unfinished heads, when Vauxhall paid them for what they had done they then came to an agreement and sold the last of the heads un-finished to Vauxhall. These heads often crop up on later engines. He told me how to tell the difference between the types too, the Cosworth finished ones are done "On Centre" and will have alignment marks that look like a countersink hole drilled on the back of the head in the middle of the head towards the top. Vauxhall, when they did them, simply clamped them in a machine as for them close enough is good enough!

Now the guy who told me this works for Cosworth and is an engineer, not a production operative, so I doubt he was lying to me. He also told me that several hundred heads were supplied un-finished to the racing division in Northampton where they were finished by hand. He has no idea where they went after that!
 
#11 ·
16vastra said:
the 1st heads never made it to road cars
the cosworth cast heads did
the late 'bastard' ones are probably dumped on the LETs :p

anyway, whats this about a countersunk centered mark?
heres mine, whatchootalkinbout
well they guy at Cosworth said they did a few thousand of the GM castings, so god knows where they all went then!

And if I got what he ment by the drill marking bit then it is on the little square bit above 2 & 3 inlet ports. I could be wrong though, will look out for him when I am at work next week and ask him to clarify for me.
 
#24 ·
My 93 cavy sri doner has a coscast head the easiest
way to check for the actual coscast marking is to stick a
small mirror behind the exhaust manifold at no2 cyl
(when the engine is cold saves a trip to the burns unit)
here's mine




It has a lot of work been done recently water pump
cam belt tensioner and fg25 roller's so I would recon
that the head's been replaced too posibly because of a porous
one.

:cool:
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top