Fuel Pump in earlier V8s
 

Can anybody tell me where the fuel pump is located on a (V8 (410 in particular)? I suspect that the car has picked up some rubbish into the fuel system and sustained running at higher speeds has the engine misfiring and showing signs of fuel starvation. I want to check the fuel pump and replace the filter. Thanks, John Keighley

Fuel Pump in earlier V8s
 

Hello John, my fuel (in a 408) pump is in the right front wing near the battery - I guess this is the normal position in a V8 Bristol. Best Hans

Fuel Pump in earlier V8s
 

Hi John,

Unless your car has been altered to an electric fuel pump, many have.
The mechanical fuel pump is located on the LH side of the engine block,
looking
from the front.
It is a Carter M2504 S on my 407

Hand book say no maintenance is normally required ( it is mechanical).
The pump can be removed from the engine and dismantled and cleaned
the following parts will need to be renewed at re-assembly,
M.203-89S Diaphragm Assembly
M.203-46 Outlet Airdome Diaphragm
M.121-124 Flange gasket.

The Fuel filter. Moper 2084 258 should be changed every 10,000 miles.

Hope this helps, I have converted my 407 to an electric fuel pump located
under the offside wing on the
wheel arch. The filter is an in line particulate transparent filter located
under the bonnet between the
new fuel pump and the carburettor.

Nick Challacombe

My 410 has an SU electric pump, located high up in the boot on the right hand side. I think some other cars also have had them fitted in the boot. The diaphragms (it's a double pump) do not last forever and I had to rebuild mine a few years ago after it failed without warning on the motorway. If it's not original, I would guess it was fitted when the car was restored circa 1990.

Fuel Pump in earlier V8s
 

John
My fuel pump in my 410 is in the boot as described in Sam's reply. On my 411 which was a mechanical pump but not working properly due to slight wear on the rod and cam we conveted to an electrical pump.
The first attempt with a Holly pump was a disaster, mounted on the boot bulkhead it made more noise than the engine on tick over and low speeds, this was replaced with a Facet pump also bulkhead mounted and much better, just the priming sound before start up. I am told this pump would also work mounted up front near the battery but have not tried that so can't be sure.On my 410 I had the pump rebuilt with an electronic update to do away with the points and I must say it works very well.
Geoff

Fuel Pump in earlier V8s
 

Thank you all for replying, I should have known where to look but as the car was going in to my local mechanic,didn't have time to search. It is on the right hand side of the boot floor. As it happened, the pump turned out not to be the culprit but we discovered this afternoon, the filter was almost fully blocked due to having sat around for an extended period of time. At this point, a new filter has restored normal operation. Since emerging from restoration the car has covered about 3500Ml, so I'll have to keep a lookout for crud in the fuel system.
John Keighley.

Fuel Pump in earlier V8s
 

Hello,

reading this thread made me wonder if I knew anything about the fuel pump
installed on my 409, and the answer was negative. I was quite sure that I
didn't see any mechanical pump in the engine bay so I asked to the guys at
the body shop (where my 409 sits now for some minor work) to check into the
boot. In fact the pump is there, exactly as described by Sam on his 410, and
looks like a double pump. This is a picture of my pump:

http://www.stefanopasini.it/Bristol_...uel_Pump_1.htm

I cannot see any numbers on it because it is installed in a position where
is not very easy to check; I would like to ask if anybody has any idea of
what model this pump might be and what could be the correct replacement for
this pump. Maybe an 'electronic' pump might be better? I have checked Burlen
site:

http://www.sucarb.co.uk/ProductCateg...px?ParentId=16

to find several types of double pumps, but I couldn't decide what would the
right choice be for my 409. high or low pressure? Points or electronic?

Thanks, as usual, for your help,

Stefano

Mine was a double pump like yours, part number AUF406, equivalent to the AZX1404, which is in turn identical apart from the fittings it is supplied with to the AZX1405, sold by Burlen. I would presume that the AZX1405EN is simply an electronic version of the same pump. I'm no expert, but I suspect an electronic pump would give similar advantages and drawbacks to electronic over points ignition

This is what I put on the BOC Wiki about it at the time (July 2007):

"The fuel pump on my 410 recently gave up the ghost, and so I was obliged to investigate current replacement options. Burlen Fuel Systems were very helpful; my car had an SU twin pump, model AUF406, fitted as described above, in the boot. The AUF406 is now known as an AZX1404. The AZX1405 is apparently the same but comes with different fittings for the fuel lines, although if you are replacing a pump you would already have the correct fittings so it should be trivial to swap them over. Burlens offer a restoration service, but that (at time of writing) has an 8-week turn around, and costs only a few pounds less than buying a new pump. However, they also sell overhaul kits, which contain new diaphragms, gaskets, points, and all the consumables apart from the main coil. These were fairly straighforward to fit, and have the part number EPK300. You need two kits for the twin pump obviously. Mine initially still didn't work, but once I'd taken it apart, checked all the setup, and put it back together a second time it seemed fine. If the coil itself has failed (which according to Burlens is extremely unusual) the unit will need complete restoration or replacement and the overhaul kits will be of no use."

Fuel Pump in earlier V8s
 

Hello Sam,


thank you for your message. My pump looks very similar to the AUF406/AZX1404
that you mention, so I think that I could just order one and be safe with
that. I'm wondering if it is better to buy the electronic version AZX1405EN
or the classic 'points' type, though. Maybe some of you with a real
understanding of these pumps has a definite opinion on the possible choice?
It would be a great help.

Thanks

Stefano

I can understand having standard service items as spares,although none are rare on a V8, but I do not understand the logic of keeping items like fuel pumps.

However, what do I know !

Hello,

I decided to stop worrying about my old fuel pump, that works fine but looks quite 'tired', so to speak, and I asked Burlen what pump would they recommend. They said that AZX1405EN is the right electronic pump to substitute my doubloe SU. I bought one and when it arrives I shall install it, keeping the old one as spare. I'll let you know what happens when I have installed the new one.

Thanks

Stefano

Mechanical Pump
 

Both my 408s had mechanical ones and according to the Bristol parts book (p. 19 item 16) the part numbers are:

1843400 Fuel Pump up to Chassis No. 7350
and
909-1-33012 Fuel Pump Chassis No. 7351 on & 410

George

I didn't realise that the fitting of electric fuel pumps to V8 Bristols was so common. I suppose I shouldn't be so surprised given that you can buy a Mopar branded blanking plate for the spot where the mechanical pump goes (for B/RB engines at least). That suggests it is very common practice. It certainly makes starting the 400 CID engines much easier from cold.

I don't think it really matters what pump you have so long as it can supply an adequate flow rate and the pressure isn't too high. You wouldn't want any more than 5 psi, but you can use a fuel pressure regulator if necessary, I have one on my 411.

The EFI system for my 411 (which is in boxes in my garage at the moment) has two fuel pumps, just in case one fails!

Fuel Pump in earlier V8s
 

1969 383 - 411 (S1)
Some years ago I fitted the Edelbrock carburettor, fuel pump (model 1723)
and inline filter.
All work like a dream.
From the Edelbrock item description:
"Performer RPM Street Fuel Pumps
Designed for use with all Edelbrock carburettors used in Performer or
Performer RPM applications. The unique valve design improves flow quantity
and quality, and will support engines up to 600 hp. High-volume, 3/8" NPT
inlet and outlet surpasses the capacity of conventional models. Produces 6
psi and does not require a regulator. For gasoline only. Clockable lower
housing can be rotated for best inlet/outlet alignment."
JEVS

Glad it works well John, but unless one has increased the performance of the engine, does it ever experience fuel starvation? Not necessarily your usage, but many electric pumps fitted by people as after-market bolt-ons do what it says on the box, but then the inlet valves to the carburretor prevent one from wasting all that precious fuel!

George

Fuel Pump in earlier V8s
 

> Hi Sam,
>

just a question: did you have to fit a fuel pressure regulator after the
1404/1405 pump? If you did install one, what did you use? Thank you!

Stefano

>
>
>
>
>
>

The SU pump was already fitted when I bought the car. I don't think there is a regulator fitted, but I am not certain what it would look like or be located so if anyone can tell me I shall check.

Fuel Pump in earlier V8s
 

Geo
Thanks for your contribution, but I am not sure what you are trying to say!
Some twenty years ago I started to 'update' my 383 engine (from 12 miles per
gallon).
I replaced a lot of items and today I am getting 20 (+ or - 2) miles per
gallon depending on the traffic and my temperment.
Remember - the Canadian '383' was manufactured for use in California which
then had very tight emission controls + lead free fuel.
This engine was fitted with a Carter Four Barrel carburettor which met those
emission controls by restricting the airflow through it.
The Four Barrel Weber carburettor allows some 40% more air (cubic feet per
minute).
I have a 360 degree unrestricted air filter + new intake manifold fitted.
No modification to the bonnet is/was required.
The Edelbrock fuel pump was only part of that updating process.
I have three 1950's Carter mechanical fuel pumps which broke down - the
Edelbrock pump uses a different method of pumping and is self regulated at 6
psi as required by the Weber and is much quieter.
Some years ago, the 'leaded' fuel disappeared from the market.
To date, I have not re-tuned for that loss.
My email is jevs@iol.ie if you would like more detailed info.
JEVS

Fuel Pump in earlier V8s
 

My 313 Canadian Plymouth/Dodge engine had no emission controls and was
designed to run on leaded fuel.
It has always had a Carter 4 barrel carburettor and a large circular air
intake to the carburettor.
No modification has been made to the fuel side of the engine at all apart
from changing, for convenience, from
the std Carter mechanical fuel pump, to a Facet electric fuel pump situated
by the servo under the offside front wing.
The Facet comes with an adjustable regulator attached. I also put in a dual
point distributor and an inline fuel filter.
I have now done 30,000 miles with this set up in the last 11 years with
19mpg on runs, no sign of any valve seat wear,
the older the engine gets the better it gets.
The 407 was renowned for overheating but since I rebuilt the radiator 10
years ago and kept the right amount of anti-freeze
in summer and winter, no problems.
Keep it simple I think is the answer.

Nick

John, are you sure about this?
Where was your 383 made? (what's your engine number?)

I thought Chrysler only started making changes for the emission standards late in 1971, when they started to restrict air flow in the cylinder heads.

383's manufactured from 68-70 (and possibly into 1971) would have had the heads with a casting number 2843906. These were a relatively high performance head with very good air flow, so I can't imagine why Chrysler (or Bristol) would put a restrictive carb on a 383 engine with these heads.

As for air flow and carbs, I'm no expert but I did a bit of research on the topic a few years back and wrote this on the old BEEF mail list;

----

There must be many a V8 Bristol out there with a tired or non original carburetor, so for those who are thinking about fitting a new carburetor I thought I might share a few facts I which learned recently about carburetor selection, and possibly explode a few myths in the process. This is a fairly simplistic view but it should at least point people in the right direction!

Carburetors are rated according to the airflow capacity, that is the volume of air which they can supply or 'flow' in one minute, this is measured in Cubic Feet per Minute or 'CFM'. The air of course combines with a measured quantity of fuel on the way through, which ideally will be vaporized by the time it gets into your engine's cylinders.

There is a 'rule of thumb' formula which can be used to match carburetor size or capacity to engine size;

engine capacity (CID), multiplied by maximum engine speed (RPM), divided by 3456 = Carburetor CFM

CID x RPM
__________ = max CFM
3456

For example for a Bristol 411 series 4 or 5 the formula would be (400 x 5500) / 3456 = 636 CFM

However this formula assumes 100% volumetric efficiency (VE), which means the 400 CID engine actually consumes 400 cubic inches of air/fuel mixture for every two revolutions. Which in the case of a normal 400 CID Chrysler engine produced in the 1970's, it doesn't. In fact of the Chrysler V8's used by Bristol, the 400 CID engine, fitted to the 411 S4 & S5 and 412 S1, probably has the lowest VE because of the anti pollution, or 'smog' measures in force in the USA at that time. It is effectively 'de tuned' and probably has a maximum VE of about 70%. All other V8's used by Bristol probably have a maximum VE in the region of 80% to 85%.

An engine's VE varies with engine speed and is highest when peak torque is produced. So taking into account the VE of the 400 CID engine fitted to Bristols, it really only NEEDS a carburetor which flows about 445 CFM.
CFM ratings are only a guide and it is possible for a four barrel carburetor to flow at least 20% more air than it is rated.

At the other end of the scale they can of course flow a lot less, in fact the secondary throttles on some four barrel carburetors are activated by manifold vacuum controlled air valves (commonly known as 'Air Valve Secondaries'). If these are working properly the carburetor will only flow the amount of air required by the engine (Manifold vacuum varies with engine speed and load).

However, most carburetors are fitted with jets, metering rods, etc, which provide a fuel supply in keeping with their air flow rating. So the greater the CFM rating the bigger the standard jets will be and vice versa, (to allow the correct maximum air/fuel mixture). Jets are of course changeable (as are often metering rods ) so there's nothing stopping you from re-jetting a carb that is slightly too small or too large for your engine to make it more suitable. There are however, other specifications which may need to be modified to achieve optimum performance from a wrong sized carb. Including but not limited to; metering rods, air valve adjustment, inlet 'needle and seat' size, air bleed, float level, float drop, accelerator pump adjustment, enrichment circuit timing. Most of these modifications should not be attempted by anyone other than an experienced specialist.

When a carburetor is significantly larger or smaller than the engine requires, these issues are exacerbated because the manifold vacuum becomes too high or too low. Larger carbs, for example, have larger throttle bores and venturi area, which means the manifold vacuum will not reach anywhere near that which the carb is rated at WOT wide open throttle (1.5-inch/Hg), unless the engine is highly tuned to a greater volumetric efficiency and probably higher maximum engine speed. Generally speaking any significant variance in manifold vacuum from the standard at which a carb is rated will make carburetor tuning very difficult.

Many people have been, and probably still are, led astray by the carburetors fitted as standard by American muscle car manufacturers in the 1960's. According to the formula given above, it would seem they fitted oversize carburetors to some particular production model Corvettes, Camaros and Mustangs. Well they did! But that's because these cars were frequently entered in sanctioned competition events where the standard equipment carburetor had to be retained. So when competing they tuned the engine 'up to' the capacity of the carb.

The moral of this story is, if you need a new carburetor for your Bristol, unless the engine has been seriously modified for performance, use the formula above to correctly size your carburetor and it will likely work very well 'straight out of the box' with very little alteration.

NB: Carter, and most other manufacturers of 4 barrel carbs, made different models for different engines (Chevrolet, Pontiac, Ford, Chrysler etc). Make sure you get the correct one for your engine or the throttle linkages won't be correct, the choke actuation will likely be incorrect, and it probably won't fit your intake manifold without an adaptor plate!

Kevin Howard

Fuel Pump in earlier V8s
 

Hello,




I have read Kevin's remarks about the carburettors and I would like to add
that the 'large' Edelbrock 1406 (600cfm) that I tried on my 409 was probably
a bit of an excess for the engine. As my Carter was beyond repair I bought a
1403 (500cfm, similar to the old Carter 3131/3249) and having enlarged the
holes for the secondary throttle valves on the intake manifold (pls see



http://www.stefanopasini.it/Bristol_...nifold_Mod.htm

for details) it now seems to work pretty well. The 1403 is cheap (I bought
it for $200), its linkages are not as different from those of the Carters as
the 1406 are, and has the advantage of an auto electric choke as well.

Cheers


Stefano

What replacement carb for a 411-S1?
 

Reviving an old thread. I am currently in the USA, and may have a few kgs extra allowed on my luggage allowance when I head home in three weeks. My 411 S1 came with a 383 which my rebuilder says blew up at some point and the block was replaced with a 400, but the Bristol 383 heads (which he reported were "high performance" were bolted on to the 400 block.

The barn-find car's carb was corroded, so when I was packing the container to move to NZ 13 years ago, I bought a new replacement, which from memory was a "Carter" by Weber. When the engine came back from rebuilding, it ran awful, but as I had other problems with the work done by the shop, so I just stuck the car in the garage for another day.

That day is now coming, and last time I was in the states I picked up a used 383 with transmission that I popped in the container. The 383 is now down with Bob Schmidt's mechanic in South Island, NZ to be sold or rebuilt and sold. However, I kept the carb off that engine, to add to my choices when I open the hood (bonnet) and try to get the beast running right.

Given the very inexpensive prices from folks like JEGS ($229), however, my best solution may be to buy a bolt-on carb and sell the old ones on NZ's auction site. Thus, my question:

What carb should I buy? What number is a direct bolt on that will have the least problems. I am not looking for performance, but economy is fuel use.

Edelbrock 9906 Edelbrock Performer Factory Remanufactured Carburetors looks interesting and is priced right. It is a rebuilt 1406. Bob Schmidt pointed me to a Chrysler web site that speaks highly of Edelbrock, but before I make the decision, I would appreciate experience or knowledge from others in the Bristol fraternity.

Thanks
Claude

383 in NZ
 

At 08:20 AM 10/10/2010, you wrote:

"That day is now coming, and last time I was in the states I picked up a used 383 with transmission that I popped in the container. The 383 is now down with Bob Schmitt's mechanic in South Island, NZ to be sold or rebuilt and sold. However, I kept the carb off that engine, to add to my choices when I open the hood (bonnet) and try to get the beast running right."

To update Claude's "spare" 383. It is at Leitch Motorsport & Restoration (Leitch Motorsport and Restorations, Ltd.), the shop that completed the restoration of my Frazer Nash Mille Miglia in 2005. Their engine specialist, Greg Hunter, has torn down the 383 and pronounced it "good". He also sent me a list of parts needed to rebuild it to original specs. However, he explained that most buyers in NZ would prefer to buy the engine "as is" and complete it to their own tastes, or by their own shop. We have not yet tried to sell it either as is or completed and I'll confer with Claude soon. He'll set a price and make all decisions but I'll be involved in any rebuild.

So if anyone wants/needs a 383, contact either of us - or Barry Leitch.

Bob (Burbank)

PS I have a high regard for the work by Barry and his staff. I now have two more projects with him: 1977 Ford Ranchero and Vespa Restoration in New Zealand

What replacement carb for a 411-S1?
 

Hello,

I must make some amendments to what I wrote about the Edelbrocks several months ago. The difference in linkage from the standard Carter was not as little as I thought initially and, though the 1403 was quite good, the kick-down never worked well and arrangement was awkward. At the end I found that rebuilding the original Carter 3249 (once again, but this time with a brand-new quality kit) was enough to have a good result. Then the engine blew, and now that I am waiting to get the parts from the US I have also bought a brand-new Carter 3131S (NOS, never installed) and I'll have this one rebuilt too and fitted to the 318. BUt the Edelbrocks were good, well built and worked well.

Cheers

Stefano

411-S1 specs
 

I found a vendor on EBay that offers the Edelbrock carb for $199, and then includes setting it up for the car. He has asked for the following information. If someone can provide me with the ones that I mark with underline, I would appreciate it. Thanks Claude

TYPE OF CAR OR TRUCK........Bristol
WEIGHT.........._____________
CUBIC INCHES: 400
ALTITUDE YOU LIVE AT........ sea level
GEAR RATIO.............. _____________
TYPE OF TRANSMISSION.............727 Chrysler automatic
CAM SIZE............ ____________
HEADER TYPE AND SIZE............ _______________
MAX RPM'S............. factory redline or less which is __________

Why not send these questions to Bristol Cars ?

Just a thought !

Maybe because they have a service department which they would understandably like to stay in business by servicing cars and selling parts, rather than offering free advice to people who want to bypass them and buy their parts on ebay :)

Shouldn't that be 383 or have you changed the engine?

Max RPM is probably 5200 for the 383, but it you do have a 400 I'd say 5000 to be on the safe side.

Gear Ratio probably means the final drive and I believe a couple of different options were available, but most likely 3.07

Weight - 1 ton, 13 cwt (imperial)

Headers will presumably be standard 4 into 1 cast iron but I don't remember whether they are rear exit or centre exit.

Haven't any idea about cam size.