603S Engine

[will7262]

Greg
Thanks for the E bay isting ......I wonder what sort of HP and Torque this puts out? I will enquire.

[will7262]

Kevin
Good to know about the original manifold.
If I did to a set of headers i would get them ceramic coated to avoid head build up...might even do the same with the cast iron ones anyway.

[GREG]

A UK engine builder / tuner

American Engine Parts from Pauls Place UK

[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

[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

[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...

[GREG]

Lot's of Torqueflite upgrades available from companies like this one, for different applications.

Torqueflite Conversion KIT: Hemi 426, 440-6, Six-Pack | eBay UK

Some explanation of different Torque converters available for 360 to 440 engines

http://cgi.ebay.co.uk/Torqueflite-72...item3355013bbd

[will7262]

Well a lot to absorb in that lot from that conversation. Guess I need to find out what gearbox I have as a starting point and go from there. Trust me I will not be drag racing or sitting with foot on throttle and brake just want enough power to keep up a little respect for Bristol.
Surly others out there have taken this route with a 603 and it's variants
and all these questions have been answered before if nothing else than by trial and error.
Looks like only a small band of enthusiast use the Forum ......pity.
Still onwards and upwards.

[Kevin H]

Originally Posted by will7262

Looks like only a small band of enthusiast use the Forum ......pity.

Will, I think you need a bit of perspective.

Bristol have made less than 9000 cars in 55 years. There are probably about 2000 still in on the road. Over 500 "enthusiasts" (most of whom are owners) are a member of this forum. Some of them own more than one Bristol (some own several).

As time went by Bristol made fewer and fewer cars, and the 603 was not one of the more popular models.

How people on this forum have put a 400 HP engine a 603? probably none.

[Kevin H]

I'll just throw this into the mix and let others form their own opinions.

The legendary torqueflite automatic transmission
TorqueFlite - Wikipedia, the free encyclopedia

As for Will, I suggest you install your 400HP crate engine and if any part of the drive train breaks, upgrade it!

Or, you can save time and worry now

[will7262]

Kevin
An interesting perspective on the lack of feedback on the 603.....guess that puts that matter at rest then.
I think I will upgrade to turbo car drive line and assume that will do.
Good stuff on the gearbox. Thanks
Will

[GREG]

I agree with Kevin :-)

Try it and see -- no big deal if you need to upgrade.

My 600 HP 603 runs fine ...........