Special 313 engines? - 407 and 408 MK1

[Kevin H]

Originally Posted by Connoisseur

It's for the BODA magazine.

Will your article be published in a publicly accessible part of the BODA web site?

Or will you publish it here as well?

[Connoisseur]

Hello Kevin - It's in the paper edition of the magazine. It's not actually directly about the Bristol myths, but I will be covering that topic within the article.
It's in four parts. Part one is due to be printed, part two is at the research stage. Once it's published I try and make it publicly accessible one way or another.

[Geoff Kingston]

Guy Drummond wrote a very interesting article in the Boc bulletin number 37 headed "How special are our Chryslers? (or Plymouths?), the bracketed question related to the fact that in Canada and the US the smaller engines tended to be reserved for the Dodge and Plymouth lines rather than Chrysler despite the fact that the companies were all part of the same family. Guy was a Q.C. who if I remember correctly lived in Canada and at the time owned a 410 and before that a 408. The following extract may be of some help.



" The trouble is that the word 'special' admits of too many shades of meaning and allows too many misconceptions to be inferred. I say this because it's my contention that there is absolutely nothing special or unique to Bristol about the version of the 313/318 used by them -- nothing whatever !

The 'standard' engine had a 2 bbl carburettor and a 9:1 compression ratio giving 240 hp. SAE (note , not 250 ). Through the model years 1960-1962 (possibly before probably not afterwards) certain Plymouths and Dodges were available from the factory fitted with a 'Power Pack' engine.

The only changes were (1) a 4 bbl carburettor and appropriate inlet manifold (2) slight changes in the ignition advance curve (3) a camshaft giving a little longer opening period, a little more overlap and 20 thou more lift. Incidentally, I've compared the valve timing figures given by Chrysler for this Power Pack engine with those given by Bristol --- they are identical. This Power Pack engine is exactly what we have in the Types 407--410 with no alteration that in any way affects its output or adjustment.
Someone may point out that the Bristol version is really special --on my own admission-- because it wasn't offered by the factory after the 1962 model year. But all this only goes to illustrate how confusing that word can be!
One further notion seems to be that Bristol had the engine specially fitted with mechanical instead of hydraulic tappets. The fact is that the Canadian engine standard or Power Pack -- was never available with hydraulic tappets until about 1967, when the engine was completely re-designed and the polyspherical head scrapped"



Certainly some years ago when I had a major engine rebuild undertaken on the 313 in my 408 nearly all the parts for the rebuild were obtained off the shelf from Competition Cars of Hainault, only exception was a new crank and shells bought directly from Bristol Cars. There was no indication at all at that time that the engine had in any way been modified by Bristol's the only issue was that compared to the 318 the 313 was a rare engine over here but thankfully the parts were mainly interchangeable except for the crankshaft.



Geoff.

[Connoisseur]

Thank you Geoff, that's very helpful.

[Roger Morrall]

I haven’t researched this but it seems likely that at that time Commonwealth preferences meant that it was significantly cheaper to buy from Canada than from the US of A, hence the use of the Canadian engine which then got talked up by that consummate marketeer Tony Crook.

As far as I know nobody has yet come up with confirmation that Bristols modified the engines in any respect.

[Kevin H]

Originally Posted by Geoff Kingston

Guy Drummond wrote a very interesting article in the Boc bulletin number 37 ...

From memory Mr Crook wasn't very happy about that article.

Ironically it was this very subject (whether or not Bristol modified Chrysler's engines) that started a row between Mr Crook, BOC and your's truly and led to the formation of the BEEF mail list (Bristol Enthusiasts Email Forum), then this forum website.

[Nick Challacombe]

When I came to rebuild my 407 , 313 engine because, I think, very poor quality Irish petrol on a tour in Southern Ireland had caused one piston to loose its rings and scour the block.
When investigating the supply of 30th oversized liners in turned out to be far cheaper to use 40th pistons which were std on the 318. Every other dimension was the same.
I therefore think my engine is a 318 in effect. Not that relevant but I though interesting given the subject.

[Connoisseur]

Originally Posted by Nick Challacombe

When I came to rebuild my 407 , 313 engine because, I think, very poor quality Irish petrol on a tour in Southern Ireland had caused one piston to loose its rings and scour the block.
When investigating the supply of 30th oversized liners in turned out to be far cheaper to use 40th pistons which were std on the 318. Every other dimension was the same.
I therefore think my engine is a 318 in effect. Not that relevant but I though interesting given the subject.

That is interesting about the piston size...
Also that must be the worst petrol ever supplied if you need an engine rebuild when you use it. Do you mind if I hope you don't mind I use it in my article?

[Geoff Kingston]

This link on the Canadian engines I think throws up a lot of interesting information which supports the points Guy put forward, somewhere I have and at the moment can't find a lot of information on the parts and specifications of the 313 and 318 units which I came across when trying to help someone find parts for a 313. I found out some years after my 313 was rebuilt that the heads would have fitted a 318 block which would have been a cheaper option. The 313 after the rebuild ran beautifully and cemented my admiration for these V8's
especially after managing 17000 miles running mostly on seven cylinders because straight out of college I couldn't afford the engine rebuild. Like Nicks engine when mine had been re bored and fitted with a set of high quality pistons it too was probably approaching 318 cu ins.
Geoff.

https://www.allpar.com/threads/canadian-engines.229915/

[Connoisseur]

Originally Posted by Nick Challacombe

When I came to rebuild my 407 , 313 engine because, I think, very poor quality Irish petrol on a tour in Southern Ireland had caused one piston to loose its rings and scour the block.
When investigating the supply of 30th oversized liners in turned out to be far cheaper to use 40th pistons which were std on the 318. Every other dimension was the same.
I therefore think my engine is a 318 in effect. Not that relevant but I though interesting given the subject.

Apparently there is a number possibly under the cylinder head that tell you the displacement of the block it would be interesting to know if it says 313 or 318 there would also be a letter/number code next to it such as 4W or M. You don't by any chance have any record of that? A bit of a long shot.

[Nick Challacombe]

I may have misled you, when we came to re-bore we required 30th pistons but before we started we were looking at prices and noticed that 40th pistons were under half the price of 30th because they were std on the 318 engine. the only difference we could find between a 313 and 318 was the bore, the stroke was the same.
Therefore what I meant to say was that in effect I now have a 318 engine.
Apologies for the bad phrasing.


The fuel in Southern Ireland was c--p , the time before when we visited the BOC on a Herdiman tour decent petrol was available.
We could not even find additive. I saw a Shell sign passing through a village and pulled over to fill up at the single pump, I asked the operator why there were no other Shell stations around, he said they were not a Shell station, the boss bought the cheapest stuff he could find and he had bought the sign at an auction!!!

[Connoisseur]

Originally Posted by Kevin H

From memory Mr Crook wasn't very happy about that article.

Ironically it was this very subject (whether or not Bristol modified Chrysler's engines) that started a row between Mr Crook, BOC and your's truly and led to the formation of the BEEF mail list (Bristol Enthusiasts Email Forum), then this forum website.

I'd better be diplomatic in my article. Even if Bristol didn't do some of the things suggested there is probably more to this than first meets the eye.
Still quite hard to fathom out myth from fact here.

[Kevin H]

Originally Posted by Connoisseur

I'd better be diplomatic in my article. Even if Bristol didn't do some of the things suggested there is probably more to this than first meets the eye.
Still quite hard to fathom out myth from fact here.

I wouldn't worry about it. Tell it as you see fit, however getting to the truth is not easy. One of the problems is myths can be perpetuated by successive authors. I'd be wanting to talk to someone who has personally dismantled an original 313 from a Bristol.