410 exhaust manifold

[Bryn Tirion]

Forgive me dear Mod, but I think you are not entirely accurate. I have made something of a study of this over the last 15 years, and have (I believe) every Chrysler, Dodge and Plymouth, including Canadian editions, of the workshop manuals for all car (not truck or motor home or combine harvester though) variants that took the specific wide body poly engines featured in the 407 to 410 models. At the bottom I attach a page from the excellent Bristol 408 parts book, which reproduces Plymouth manual pages in its engine and transmission sections, not surprisingly. The centre-outlet exhaust manifold pictured there was from the 1960 Plymouth (Canadian market) 313 c.i. engine. No changes. Bristol used this specific engine in the 407 and 408 cars, then an identical (I believe) 318 poly for the 409, but by the 410 had to use a different engine. This may well be what Bob has in his 410, and I have often speculated that this must be the Dodge Dart variant. This did have an exhaust manifold with the outlet at the rear (in the Dart.... nothing to do with Bristol!) which is why I'd like to see a picture of Bob's, but one must be cautious because the later LA engine also had a rear outlet, and that is an entirely different engine, although it would have been a very easy retrofit into a Bristol.
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On a related topic, I believe that all models from 407 to 410 used the Carter AFB 3131S carburettor, and I would be very interested to hear if there are other apparently original carburettors in these cars. In North America, the 3131S was only fitted to one series of cars, namely the 1960 to 1962 Dodge Dart with US built 318 V8. It has been claimed many times in the past that the Bristol engine had a Plymouth Power Pak option (note the quirky spelling), but this appears to be not strictly true, since that option (which for 1960 was called Super Pak) came with a series of other AFB carburettors, closely related, but with quite different jetting. If you look at the performance specs given for the 313 by Bristol, they are effectively identical to a stock 1960 Plymouth Belvedere sedan with the AFB carburettor option, although a quite different carburettor was used. Frankly I think Bristol just copied all the numbers out of the Plymouth manual.

At the bottom I have added pictures of the 1960 Plymouth Torqueflite buttons: note that they are round and without a Park button. These buttons changed completely every model year, and were unique to the particular range of cars they occurred in. If you own a 407 or 408 Mk.1 you will find that picture very familiar. They are specifically Plymouth and one year, 1960. I have also attached an extract from a 1960 Plymouth brochure discussing some of the engine options. As you will see, there is a Super-Pak option which closely matches 407 and 408 performance figures. And these were family sedans..... no nod, nod, wink wink, Bristol did some clever things to make those American engines perform better, as Mr. Crook was telling the motoring correspondents back in 1963 or so. Just standard American engineering.

[Bryn Tirion]

313 Canadian market vs. 318 US market: In the 1960s Canada still had a road taxation system based on the egregious RAC horsepower system. This caused a rise in road taxes to come with an increase in bore, rather than stroke. To fit the Canadian variant of the 318 poly engine into a slightly cheaper taxation class, bore was reduced. Nothing to do with making poor old Canadians think they had an inferior car!

[Kevin H]

Originally Posted by Bryn Tirion

313 Canadian market vs. 318 US market: In the 1960s Canada still had a road taxation system based on the egregious RAC horsepower system. This caused a rise in road taxes to come with an increase in bore, rather than stroke. To fit the Canadian variant of the 318 poly engine into a slightly cheaper taxation class, bore was reduced. Nothing to do with making poor old Canadians think they had an inferior car!

That's interesting Bryn. Was it based on the sum of the bore of all cylinders in the engine? (surely not the bore of one cylinder?)

Nevertheless, there does appear to have been some favouritism shown to the US market. Some of Chrysler's cars available in the US were never offered in Canada and Canadian cars were still given the older poly engines after the US market had moved on to the B series engines. Not a bad thing for earlier V8 Bristol owners looking for parts!

As for the "Crook bunch", I don't think we should be too harsh on them. After all they had a private car company to run which needed to be profitable. Maybe their use of cheaper engines was one of the reasons why they outlasted all other prestige marques that bought in a Chrysler power train, and many other companies who developed their own. In fact if it wasn't for the cost of developing the Fighter, Bristol still might never had gone bust.

Of course we now know the "Bristolisation" of Chrysler engines was BS, but in those days, in the UK market at least, most car manufacturers marketing departments were full of it

[Bryn Tirion]

Originally Posted by Kevin H

That's interesting Bryn. Was it based on the sum of the bore of all cylinders in the engine? (surely not the bore of one cylinder?)

Nevertheless, there does appear to have been some favouritism shown to the US market. Some of Chrysler's cars available in the US were never offered in Canada and Canadian cars were still given the older poly engines after the US market had moved on to the B series engines. Not a bad thing for earlier V8 Bristol owners looking for parts!

As for the "Crook bunch", I don't think we should be too harsh on them. After all they had a private car company to run which needed to be profitable. Maybe their use of cheaper engines was one of the reasons why they outlasted all other prestige marques that bought in a Chrysler power train, and many other companies who developed their own. In fact if it wasn't for the cost of developing the Fighter, Bristol still might never had gone bust.

Of course we now know the "Bristolisation" of Chrysler engines was BS, but in those days, in the UK market at least, most car manufacturers marketing departments were full of it

You are quite right of course. Bristol survived amazingly well where others like Allards and Alvis had to fold, and the salvation was largely due to finding the right American engine and packaging it very well (because of course Allard and Alvis and other UK luxury manufacturers had been using American V8's for quite a while too). I do however find the Crook & Co. variety of BS very condescending and arrogant when read. Bristol did however do many things very well, and certainly any V8 Bristol would outhandle any of the Chrysler Corporation products using the same power train. Other things like the owner's handbook and parts books were exceptionally well done for such a small manufacturer, and must have cost a fortune relative to production numbers, and for me the 408 to early 411 cars were lovely beasts indeed.

There were big differences in the US and Canadian market. Primarily because Canada was poorer and more agricultural than the US, and so Canadian models tended to be more spartan, although just as large. Canadians tend to be very large, after all! Quite a few manufacturers would not offer V8 engines in Canadian models, but only a couple of straight six models. This was probably true until the mid Sixties, when Canadian prosperity increased greatly to be close to par with the US.


Taxable Horsepower:
This was pretty common and found in most European countries in one form or another dating from the 1920s up to the post WW2 period. Most systems were based on bore and stroke and number of cylinders, but the British system was largely unique in being based entirely on bore (expressed as piston surface area) and number of cylinders, to the exclusion of stroke, probably since the ratio between bore and stroke was fairly uniform in early cars. The British system was the RAC system, but it was also employed throughout the British Empire and Commonwealth. I don't know when it was phased out, but you Australians would have had it too. The Canadian Plymouths and Dodges (in Canada frequently just badge engineered, unlike the US) were exported in large numbers to the Commonwealth, and so the story is that the 318 was reduced in bore to 313 not just for Canada, but to satisfy export requirements from other CW countries. If you can find when these RAC rating-based taxes were phased out in Australia it would be very interesting. In UK, 1948 saw their demise, since their inevitable consequence had been to lengthen stroke dramatically, but one presumes the Commonwealth kept them on for another decade or so.

Note:
RAC horsepower was calculated by taking the piston diameter in inches and squaring it, then multiplying by the number of cylinders and dividing the product by 2.5. Quite arbitrary eventually, but in 1925 or so not very far off for a BHP estimate.

[Kevin H]

Originally Posted by Bryn Tirion

Forgive me dear Mod, but I think you are not entirely accurate.

I stand corrected. I should have first taken a look at the parts list in the resources section on this site Resources - Bristol Cars - Owners and Enthusiasts Forum

Bit embarrassing really given it was I who scanned and uploaded the parts manual!

[Bryn Tirion]

Originally Posted by Kevin H

I stand corrected. I should have first taken a look at the parts list in the resources section on this site Resources - Bristol Cars - Owners and Enthusiasts Forum

Bit embarrassing really given it was I who scanned and uploaded the parts manual!

The virtue is in having scanned and uploaded them..... I don't think you were expected to memorise 'em too!

Do you have an exploded head diagram for the 410 by any chance? I would very much like to see that manifold.

[Bryn Tirion]

I have found my 409/410 parts book (I had forgotten I owned one!) and I see that it uses the same illustration of a log-style exhaust manifold with medially located outlet. I am suspicious that you may have a non-standard engine, Bob.