603S Engine

[will7262]

Greg
That EBay engine you sent me the link to has 420HP and 440ftlbs torque with ancillaries.
Fantastic value for money but perhaps tomuch for the Britol gearbox, drive train chassis and brakes?
My gut feeling is 350HP is enough.

I wonder what sort of HP etc. the Bristol upgraded engines had?

Perhaps you or someone else might enligten me on that one?

Cheers

Will

[GREG]

The company on ebay are engine builders and I am sure they would build it to the HP you need / want, as would the company in Southampton.

I would guess they were 180 to 200 HP when new ?

Why not have it checked first.

[will7262]

Greg

I am going to import a crate engine I have decided....still doing research.

Do you or anyone out there know the rear axle ratio for a 603S? This is relevant to the rebuilding of my gearbox and its stall settings etc.

Will

[Kevin H]

Originally Posted by will7262

Do you or anyone out there know the rear axle ratio for a 603S?

Standard was 3.07:1 (or 3.066:1 to be precise)

However, I believe Bristol offered the option of 2.8:1 on some models.

Kevin

[Kevin H]

Originally Posted by will7262

Greg
That EBay engine you sent me the link to has 420HP and 440ftlbs torque with ancillaries.
Fantastic value for money but perhaps tomuch for the Britol gearbox, drive train chassis and brakes?
My gut feeling is 350HP is enough.

I don't think you need to worry too much about those numbers. The transmission and drive train are heavy duty, but at the end of the day it depends on how you drive it. You don't have to use all the power. A Chrysler V8 at 5000 rpm is a scary thing!

As for brakes, speed and weight are the two important factors, unless you plan on applying the brakes while you have your foot on the accelerator

[will7262]

Kevin
Thanks for the advice. I guess if the drive train could take the turbo engine power and the earlier 383 /400 ci engines torque I guess it's pretty robust. Do you know if they updated any of the drivetrain / brakes for the Turbo cars?
Will

[GREG]

Originally Posted by will7262

Kevin
Thanks for the advice. I guess if the drive train could take the turbo engine power and the earlier 383 /400 ci engines torque I guess it's pretty robust. Do you know if they updated any of the drivetrain / brakes for the Turbo cars?
Will

The turbo cars had the 440 engine prop shaft and torque converter and my BF has better brakes.

[Kevin H]

Originally Posted by GREG

The turbo cars had the 440 engine prop shaft and torque converter ...

Greg, I'm not sure what you mean by "440 engine prop shaft and torque converter". Care to expand?

Kevin

[GREG]

"The additional torque required not only a heavier propeller shaft: the Torqueflite 3 speed automatic gearbox was uprated with the 440 cubic inch engine's torque converter and internal clutches."

Instead of the Chrysler standard 360 propshaft and gearbox.

But I have heard of uprated engines running fine without upgrading. I guess it depends if you are drag racing or not.

I think P. Wilson's drive train was upgraded to BF spec when Bristol did the superb restoration.

[Kevin H]

Originally Posted by GREG

"The additional torque required not only a heavier propeller shaft: the Torqueflite 3 speed automatic gearbox was uprated with the 440 cubic inch engine's torque converter and internal clutches."

I could be wrong, but I don't think the 727 had specific internal clutches or a special torque converter for the 440, or for any other engine for that matter.

Maybe the 603S didn't have a 727 transmission! Maybe it had an 904 or a 998. Now those would need beefing up, but surely you would just use a 727 instead...

[Kevin H]

Originally Posted by will7262

Do you know if they updated any of the drivetrain / brakes for the Turbo cars?
Will

I don't know Will. But it's worth considering that the A727 Torqueflite was used by Aston on the V8 Vantage. Jensen also used it on the Interceptor, including the SP (383 Six Pack) and the J series 440 engined cars. And Chrysler used it pretty much everything including the 426 Hemi engined cars.

It is still used to this day by many much higher performance builds of these engines in drag cars and monster trucks, so I really don't think you need to worry about the tranny.

Later versions of the Torqueflite got a lock up torque converter, but that was just to give better fuel economy at highway speeds.

The Salisbury rear axle was also used by Aston and Jensen and was made by Dana.

I don't know for sure, but I suspect the same transmission and diff were used in the experimental Aston Martin Bulldog which produced well over 600Bhp!

Can't help you with the prop shaft