Aluminium cylinder heads for a twin

Tony Fearn · Post by **Tony Fearn** » Tue Sep 16, 2008 12:11 am

I've just unearthed (from the depths of a garage) a couple of aluminium cylinder heads which obviously fit a Jowett flat twin engine - (why should they not do!!). They have 'R' and 'L' cast into the outer surface. As you can see from the photo, the spark plug comes out at right angles to the head. They take a CA/CB type head gasket. The plugs are 14mm type.

Are these from a WP stationary engine, and what about the compression ratio?

Tony.

Post by **Forumadmin** » Tue Sep 16, 2008 11:18 am

Measure the combustion chamber volume using a pipette. Remember chemistry?

Tony Fearn · Post by **Tony Fearn** » Tue Sep 16, 2008 6:16 pm

Much too complicated.

Wi't rack o' th' eye and twist of t' gob, someone will know the answer.

PAUL BEAUMONT · Post by **PAUL BEAUMONT** » Wed Sep 17, 2008 12:50 am

I am almost certain that the 1940 van that belongs to our friend in Sheffield - sorry Tony its too late for the grey cells to recall his name - is fitted with just such heads.

george garside · Post by **george garside** » Mon Sep 22, 2008 10:38 pm

[quote="PAUL BEAUMONT"]I am almost certain that the 1940 van that belongs to our friend in Sheffield - sorry Tony its too late for the grey cells to recall his name - is fitted with just such heads.[/quote]

they were standard on the 1940 model year cars but I think the vans retained normal cast iron heads but not absolutely certain. The late 39 eight tested by autocar in july '39 also had them but not the other 1940 features of vacuum advance, borg & beck clutch & enclosed flywheel. I have never been able to ascertain whether they were fitted to all 1939 model year cars ,whether this was a mid season change or whether Jowett's just stuck them on the autocar road test car.

I tried a pair on a CB Bradford with absolutely no noticeable difference in performance!

george

PAUL BEAUMONT · Post by **PAUL BEAUMONT** » Tue Sep 23, 2008 12:49 pm

Hi both George and Tony!
Firstly, as it is not just past midnight the grey cells remind me that I spoke of John Ellis and what he calls the Idle van. It definitely had such heads last time I saw it, but I am not sure if the engine is original to the car. I also recall him telling me that it had a number of "new" features on it.

Post by **Forumadmin** » Tue Sep 23, 2008 2:30 pm

I cannot imagine a company selling cylinder heads operating from Regent Street today!

k. rogers · Post by **k. rogers** » Wed Sep 24, 2008 9:43 pm

Thought some of you may be interested in the attached article from a 1932 Light Car & Cyclecar.

george garside · Post by **george garside** » Wed Sep 24, 2008 10:11 pm

[quote="k. rogers"]Thought some of you may be interested in the attached article from a 1932 Light Car & Cyclecar.[/quote]

any chance of this article being scanned into oneof the galleries so that the print is legible.
I haave not encountered these accesory heads which are quite different from the official isssue 1940 veriety in having plug at top centre and smaller water jacket capacity.

george

k. rogers · Post by **k. rogers** » Wed Sep 24, 2008 10:17 pm

Sorry George, I didn't realise it would be so illegible, so I've uploaded the same on my Gallery section which I believe you can then save on your computer and zoom in (correct me if I am wrong, Keith!). I wonder if any of these heads still exist?

The Bradford man · Post by **The Bradford man** » Sat Jan 24, 2009 3:14 am

I read in one of the Jowett books that the Godfey Weasels had alloy heads

PAUL BEAUMONT · Post by **PAUL BEAUMONT** » Mon Feb 09, 2009 2:14 pm

: http://www.youtube.com/watch?v=rqN_wXJ7 ... re=related
Hoping that this works! Look at them heads!!

The Bradford man · Post by **The Bradford man** » Mon Feb 09, 2009 2:56 pm

I was looking at that vid a while ago and didnt even notice they had alloy heads.

Question... How long will the alloy heads last for the jowett 7/8etc?
Do they corrode badly? Some heads ive seen off 1970s etc cars have corroded so badly

PAUL BEAUMONT · Post by **PAUL BEAUMONT** » Tue Feb 10, 2009 12:29 am

I do not see any reason why they should corrode more than manifolds do on the twins. I know some pre-war manifolds are now a bit "iffy", but Bradford ones seem to stand up OK and that with a history of little or no antifreeze, I suspect.
Any one else got ideas?

The Bradford man · Post by **The Bradford man** » Tue Feb 10, 2009 12:43 am

dads 1939 8hp manifold got very thin and broke and badly corroded. thats why i was asking about the alluminum heads.

Whats the difference between alloy 8hp/7hp compaired to the normal steel/iron heads? apart from the metal they are made from

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Aluminium cylinder heads for a twin

Aluminium cylinder heads for a twin

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