75 HP Bristol engine.

[Lewis]

I own the HRG 2 Litre. The one and only. An experimental chassis built by HRG in about 1948/9 for a Bristol engine. Having got as far as a rolling chassis with an engine borrowed from Bristol Cars, the penny dropped when HRG realised everyone else was using this engine for racing. The engine was, very reluctantly, returned and the chassis ended up with a cousin on a New South Wales sheep station.

To complete the car I found an early 400 engine near Melbourne. It is engine number 1065, stamped 400/75 on that brass plate on the offside rocker cover.
Now the Oz Bristol gurus don't acknowledge the existence of a 75 HP engine outside early Filton development cars, so what have I got?

I wrote to Tony Crook a few years ago but did not receive a reply. A pity because long ago when I married in London he lent me a 403 for a weekend.

Does anyone out there know whether 75 HP engined cars were sold by Bristol and if so how many and to whom?

Lewis.

[johnelfixit]

Well, my 400 instruction manual suggests that the "touring engine"
produced 75 bhp at 4500rpm and was equipped with a single dual port solex
carburetter, whilst the sports engine (with special camshaft) produced 85
bhp and had three downdraught SU`s. This sports engine is usually referred
to as the 85A. The engine and was then fitted with three Solex carbs,
became the 85C and was used in the 401. The single Solex was fitted to a
special manifold connected to the water circulation system.

John P

[brianjgkidd]

> I had an early Bristol 400 - still in existence, but not with me, unfortunately.

The Bristol Parts list (I still have it) which came with the car shows a SINGLE
Solex twin choke carburettor with a separate induction manifold. It also shows
three SU carburettors, attached directly to the head, to make it an 85A engine,
but with a catalogued power of 80 bhp.

My engine was subsequently fitted with three Solex carburettors to turn it into a
85AC engine, with a catalogued power of 85 bhp.

I'm sure an engine fitted with a single Solex would have given less than 80 bhp,
and Setwright's book refers to early 400 car engines giving 75 bhp. But how many
of these were sold, I don't know.


Best wishes,

Brian Kidd> > > > >

[Geoff Dowdle]

Lewis and others,
It is interesting that this engine is marked 400/75

The 400- 403 Workshop Manual states "Type 85 engine is 75BHP at 4200rpm
fitted with single Solex30 AAPI

85A is 80BHP at 4200 three SU - D2

85C is 85BHP at 4500 three 32 BI

You all would have known this , but there is no mention of a type 75 engine
( it could have been a special engine producing less than 75 BHP )

Of the First series 400's delivered to Australia the BOCA has record of
eight 85 series engines , most have been converted by fitting 3 SU's or 3
Solex
Lewis your 75 series engine is the only one of it's type that I have heard
off . I can only assume it produced lower bhp by lower compression or change
of
camshaft although there is no mention of those parts in the 400 Parts Book .

If you look at Ashley's website www.jel450.com there is a Register I
compiled of all known 400's .
Engine 400/75 #1065 was originally fitted to a first series chassis # 530
which is Car# 266 ( one can assume the 166th type 400 of approx 420
produced ) ,
although the engine I assume was the 65th produced & unlikely to be a
development engine.
Chassis 530 is currently owned by Nick Wood in Perth , W.Australia it would
be interesting to find out what was stamped on the bulkhead ID plate.
BAC did not assemble type 400's , chassis # , engine # or Car # in any
order , its a real jumble , unlike later models .
I believe that the standard Filton bodied 400's were produced in Car#
sequence and Chassis and Engines were just selected from a stock at random.

The Blocks of the early engines were different to later 400 engines . At the
rear of the block there is a screw in welsh plug rather than a bolt on alloy
plate ,
Lewis does you engine have this feature ?
What engine number is stamped on the block near the starter motor mounting
? Does it have a prefix ?

We can all have our theories , but as time passes facts & knowledge pass
with men that produced the cars.
All the inaccuracies printed in the past by so called experts are reprinted
and eventually become fact.

Regards
Geoff Dowdle

[Geoff Dowdle]

John,
The sports engine you refer to is a 85B having Sports Cam & 3 SU Carbs
producing 85 bhp

85 , 85A & 85C (or 85AC) all had the same touring cam but different carbs ,
Geoff D

[johnelfixit]

Geoff,
You could well be right, however my workshop manual for the 85A engine and
gearbox clearly shows an engine with three SU`s and quotes 80 BHP at 4200
rpm. The instruction manual (the book supplied with the car) quotes power
output figures at 4500 rpm which are 5 BHP higher. Early marketing speak??

John P