Police Spec' P6... What made it so?!

grifterkid said:
Were the Police cars auctioned off after use or were they broken/scrapped...?!

Auctioned off. Then they were broken up..... (As most of them had hard frontal damage....)
 
This thread has answered a question I have been hoping to have answered for 25 years, while posing others.
In 1961 I bought a V8 engine for a kit car I was building. The seller said it was out of a police pursuit car but I put that down to sellers hype. I later checked the Rimmer manufacture numbers:

( 48100001A P6 3500S manual 10.5:1: cr 1967-1976
48500001A P6 3500S manual 10.5:1:cr 967-1976 )

and found it part of a batch built for P6 manuals and thought no more about it until last year when I had the engine rebuilt by a very clever man in Willenhall. After nearly two years the engine re-appeared and I checked the number, as you do, and found oddities I had not noticed before. Firstly the casting markings seem to show the block as being manufactured in October 1974, which was pretty much as expected, but what stumped me was that the Compression Ratio was not at all as expected, being 9.25:1 while the Rimmer numbers for engines of this period and use are shown as all being 10:5:1 (3500S). My engine number, within the Rimmer range for this period, has a D suffix. The only other CR shown at this period was 8.5:1 for P6 Auto boxes. Digging around led to this thread and to the BL leaflet showing standard Police P6 offered with a CR of 9.25:1., which seems to be a unique CR on the V8. (Thanks to grifterkid )

Why?? What clever bit of engineering led BL and, presumably, some, if not all, buyers of Police P6 manuals to order a vehicle with a unique CR that was not seen again, although some RRs came out with a similar CR of 9.35:1 from 1970 on. What does the D suffix on the block number signify ?

Being a simple minded chap I thought it was easy - low CR = slower but less fuel used and high CR giving more power and faster. This is probably wrong!

All illuminations gratefully received. Answers on a post card please.

PS I assume the car this engine came from is long gone, but hope that the previous drivers would approve of the engine now powering a very fast road car ( GD mark 3 )

 
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In NZ thats the standard compression ratio for all the later V8's `1974 onwards

Graeme
 
All is explained (Perhaps). Wadhams spares site refers to a reduced CR on Rover 3.5 P6 UK police cars so they could run on poorer fuel due to the loss of 5 star fuel. I then found this in Hansard, speaking of the Opec oil crisis of 1973:

Five-star Petrol
HC Deb 05 November 1973 vol 863 cc608-9 608
§ 21. Mr. Rost
asked the Secretary of State for Trade and Industry if he will hold discussions with the oil companies on the subject of phasing out five-star premium petrol in order to conserve aromatics and so ease the shortage of styrene, polystyrene and phenol.


§ The Under-Secretary of State for Trade and Industry (Mr. Peter Emery)
As from the beginning of next year, British motor manufacturers have agreed to phase out production of vehicles requiring five-star petrol, thereby releasing additional amounts of aromatics for the chemical industry.


§ Mr. Rost
I thank my hon. Friend for that reply. Is he aware that in considerable areas of British industry there is already a shortage of raw materials derived from oil, such as polystyrene and styrene? Can anything be done to ensure that industry and exports will not be seriously affected until this restriction on five-star petrol, which is a luxury we can no longer afford, is applied?


§ Mr. Emery
I accept that there are shortages, but the elimination of five-star petrol would permit a marginal increase in the overall petrol production and would release about 300,000 to 400,000 tons of extra aromatics. I must point out that there will be a requirement for 100-octane fuel even though the motor
609 manufacturers will have taken this particular step.


§ Mr. Maclennan
If that will release only a small amount, what do the Government intend to do to make more available?


§ Mr. Emery
I am not certain what the hon. Gentleman means by "more available". If he means more aromatics, that, as I am sure he will know, is a matter of refinery policy depending on the split of the barrel, and that depends on the type of crude and the amount of crude available.


§ Mr. Marten
What contact is the Department having with American industry, which is producing additives which not only reduce pollution but extend the mileage obtained from a gallon of fuel?


§ Mr. Emery
A certain amount of contact is made on all the factors concerning economy in fuel. The only point one must be careful of is that massive claims are often made for additives, which do not always meet the advertised claims.

So, my 1974 block looks like one of those supplied to the police with reduced CR to allow better running on poorer fuel once 5* disappeared. I suspect that the reference to American industry refers to Ethyl addition, something we are now about to see an increased use of here. The last sentence of the quote is, perhaps, still true! ( The civilian P6 V8 retained a CR of 10.5:1, perhaps a reflection that posh folks should be upset not to be offered a reduced power item, with consequent impact on the well heeled market for the P6?).
 
Our department manager at BL Longbridge had a Rover 2000TC as a company car which needed 5 Star . He was also provided with free fuel from the company pumps inside the factory. The problem was Longbridge had no 5 star petrol only 4 star. As he refused to buy fuel, he had his workshop replace the pistons to the lower compression ones used on some export version. I am sure it was never converted back before onward sale & often wondered if the new owner ever noticed, or has someone got it now & complaining its got the wrong pistons.
 
Blue flashing lights and sirens :)
well to really give a nit picking reply, this is the accurate answer, MET P6s had one blue light and that was it (blue lightS came in during 1978 at the same time as the arrival of the SD1) none of the Met vehicles had sirens prior to 1978, most had a bell but the P6s had two tone horns and a bell ;)

the choice of sounding the bell OR the two tones was usually up to the driver
 

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From the P6 to the SD1 its hard to imagine from the P6 to the Sd1.
The SD1 being a rover production car to me just look so different like they have 20 years between them the P6 with such stylish lines rear wings that look like fins and the SD1 looking so modem for its time compared to the P6 even though it was the next of kin to the P6 its like the P6 designers jumped forward 50 years from the P6 to the SD1 such a vast difference.
But apparently they did the same thing with the P6 it was something amazing and advanced for the year, if only they could have kept up the advanced thinking the later days was a disaster.
 
I was never really a fan of the SD1 and often thought, "SD" stood for slightly disappointing, and was a poor copy of the Ferrari Daytona.

I have seen a few recently though, at various shows and I must admit they are growing on me.
 
I am P6 all the way but I do also like an SD1 but cant they RUST :oops:
and leak water, but the sound of the SD1 twin plenum is something else
 
They used to have a valve radio set in the boot that weighed a ton I don't think it would be an area car maybe special duty's
like embassy's ect but please correct me if I am wrong I am not sure if area cars was blue ?
 
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