Twin Engine Indentity

[julian]

Hi All
I am new to the forum and would appreciate some help and guidance.

Over 35 years ago I inherited a Jowett twin engine from my Grandfather. I hung on to it and moved it around in storage and from house to house as I moved. Having now retired I finally have some time to give it the attention it deserves. I believe it is an 8hp engine from the late 1930's but would appreciate the opinion of the forum experts. My aim is to purchase a car similar to the one this engine came from, and keep this as a spare (or possibly sell) once fully refurbished. I've been a bit surprised by the prices being asked for cars on eBay and specialist car dealers, so it may be a while before the right on comes along at the right price!

Anyway, I spent today doing a bit of cleaning-up and taking some photos. Details I have are as follows:

Twin engine, mostly complete, but missing distributor & coil
Distributor driven from dynamo
Dynamo: Lucas 12 V, type C418A AJ3 with integral cut-out
Carburettor: Zenith type 30VEH
Petrol pump: SU
Brass engine plate: 76 Z 108, 1927
Crankcase serial number: 232026
I've attached photos. I would like to provide a few more photos, but I understand 3 is the limit - is there another way of providing photos on the forum?
Many thanks
Julian

[Jack]

Hi Julian,

You can post more photos by replying to the thread. I think the photo limit is per post.

Nice port and starboard paint job!

Jack.

[george garside]

Its a 1932 model year . I don't know what the brass plate means??

george

[Tony Fearn]

Hello Julian, and welcome to the forum.

I agree with George. The number 2 at the start of the engine ('crankcase') number gives the year of manufacture.I suppose the serial number is punched into the top of the aluminium casing at the green side, near to the slight recess in the front cover which takes the horn bracket.

Being a 1932 engine, I would suggest that it's a 7hp and not an 8.

There may be one or two initials stamped on the other side of the engine, near to the oil level indicator pipe. If present, this shows who set-up the engine for the first time ever at the Jowett factory.

You might find that the petrol pump with integral sediment bowl is an AC pump, not an SU. I think AC is moulded into the top cover.

Now that you're able to access this forum, I think you'll also be able to log in to the Jowett Gallery where there is a number of publications that may be of interest, especially the pre-war ones.

Best wishes,

Tony.

[ian Howell]

Julian: -

Welcome Aboard!

I don't have much to add at present except my thoughts on the brass plate.

It is POSSIBLE? that the numbers 76 x 106 indicate the bore and stroke, perhaps after a rebore at some time?

The '1926' is a mystery - unless someone was guessing at the age of the engine,or perhaps this engine was at one time installed in a 1926 car and then removed. Who Knows?

The following may be of interest. Tony posted it in October 2008: -

In 1980, whilst at the fantastic National Jowett Rally at Middlesborough, in the North East of England, which my friends Dennis Goode and his late wife Margaret and the North East Section organised, we met a former Jowett employee who had worked on the assembly and bench testing of the pre-war Jowett engines.

I reported this in the 'Jowetteer' Vol. 25 No. 6 August 1980.

I know that there are many newer members with pre-war vehicles that perhaps didn't see that edition of the 'Jowetteer'', so perhaps they will be interested in what Wilf Lester told us at that Rally.

Your engine will probably have some initials stamped on the off-side of the engine casing near to the oil level indicator tube.

The initials belong to the following gents who set-up your engine before it left the Jowett Works.

'L' ..................... Wilfred Lester.

'W' or 'VV'........... Jack Wilkinson

'H'or 'HH'............. Harry Holmes

'A' or 'AH'............ Alf Hutchinson

'LT'..................... Luther Tiswell

Doesn't it bring you closer to the past and the people working at Jowett Cars Limited in the 30's when you know the name of the chap that sorted your engine out for the first time?

[julian]

Many thanks for all the replies. I am truly impressed with your level of knowledge.

The fuel pump is an AC - my mistake.

I found the letters LT so many thanks to Luther Tiswell for setting up the engine . I also found the letters AC within an ellipse nearby. I also thought the brass plate might be the bore and stroke, the letter looks like a cross between an"Z" and an "X" (maybe badly stamped) - it doesn't quite match up with the published figures - I guess I'll have to lift one of the heads to check. BTW the plate was attached to the flat area on the casing which I now know is for the horn bracket.

The challenge now will be getting hold of a distributor! Presumably there was a drive cog on the end of the dynamo.

Further photos attached:

[george garside]

Julian, the club has an excellent spares scheme with new and used parts for pre and post war Jowetts. You need to and would be very welcome to join the Club in order to avail yourself of spares

george

[julian]

Many thanks, George
I'll look at joing the club when I get a bit further with the refurbishing. As I mentioned in the first post I would like to aquire a full car at some point, although if probably isn't going to be a 7hp to match the engine as I would have liked.
Julian

[julian]

Some information following further cleaning and removal of one cylinder head:

The letters "F3" are stamped low down on the crankcase.

The bore and stroke is as per the brass plate i.e. 76mm bore, 108mm stroke. This gives a capacity of 980cc, so I'm not sure what that means in terms of what car this may have come from, but it wouldn't appear to be a 7hp or 8hp.

I've attached photos showing the various numbers stamped on the casing.

[george garside]

the stroke on all Jowett twins from vintage to last Bradford is 101.5, the bore is 7hp 75.4, 8hp 77, post war Bradford 79.4.

capacity 7hp 907cc, 8hp 946cc, Bradford 1005cc.

george

[Tony Fearn]

Presumably there was a drive cog on the end of the dynamo.

Here's the matched pair:

015.jpg

Tony.

[julian]

Thanks for that, Tony. Another useful piece of information.

I have loaded the original size photos on google drive and will keep adding to this as I progress.I've not tried this before but hopefully it should work OK:

https://drive.google.com/folderview?id= ... sp=sharing

I'll also make a few more measurements of engine parts and compare these to the published data to try and solve the mystery of the engine size. It would seem that the bore of 76mm is close to the 7hp (75.4mm)and this could be a 20thou over size piston. The stroke of 108mm is a bit of a mystery and must have been achieved by a change of crank shaft. Anyone any thoughts on this?

Was the basic construction of the 7hp and 8hp the same or were there some distinguishing features other than the bore size?

Thanks for all the help so far.

[Tony Fearn]

Hello again Julian.

I notice in photo 11 of 12, that the breather vanes aren't complete, but also that they are the wrong way round.

The larger 5 bladed vane should cover the breather holes, and the smaller star-shaped 5 pointed vane should be on top of it to give a little strength to the larger vane. Each point of the smaller vane covering one of the vanes on the larger piece. (Jowett Car Spares have made reproductions at reasonable prices - that's if there are any left).

There's also a little hole at the bottom of the breather casting which might just need a wire through it. This allows excess oil to drip back into the engine. If it's blocked, the oil mist will exit through the breather pipe.

The cylinder head gasket seems to be from a Bradford. The oval holes for the waterways are ok, but the original 7hp gaskets had rectangular water holes to correspond to the orifices in the cylinder and cylinder head.

As to the 7 and 8hp cylinders, I've a feeling that the water outlets on the 8 were different to the seven that you have. .............George??? (or anyone else???)

"and this could be a 20thou over size piston" ... Look on the cleaned-up piston head, it should give the piston size stamped on it.
Tony.

[julian]

Hi Tony - thanks for the guidance on the breather - that was the next item I was going to as about - you must be psychic! OK about the drain hole -its now clear.

I've had a close look at the top of the piston and it looks like it's stamped 30 o/s. 30thou = 0.76mm. 75.4 + 0.76 = 76.16mm which is more or less what I measured. Ive looked again at the stroke & realised that I measured the distance from the top of the cylinder face to the piston at it's lowest point which of course is incorrect as the piston doesn't come up level with the top of the cylinder. Now I've repeated the measurement correctly this time, it is indeed 101.5mm. Apologies for the confusion.

Interesting about the gasket & the waterways- it all adds up to this definitely been a 7hp engine.

I've removed the other cylinder head and will add pictures - this has no gasket & hasn't been de-coked.

[julian]

I've uploaded pictures showing the other cylinder - there is a gasket, and presumably this is the correct one as the water hole apertures are square to match those in the casting. I cleaned up the piston and took a close-up photo & the 30 THOUS O/S can clearly be seen, along with other markings.

I'd be interested to know what the rest of the oil level indicator looks like - the photo shows what is fitted at present.

Also is there a cover that fits over the distributor drive gears on the end of the dynamo & if so how is this fixed?

Julian