Weber 500 Filter & starting issue

dmcsweeney

dmcsweeney

Active Member
Hi all,
i need to relace the badly pitted chrome airfilter housing on my weber 500/edelbrock performer equipped 3500S. I'm considering an edelbrock 1207 or 1208, and was woundering what other members have fitted. BTW I do not have a 90deg banjo fitted to the fuel inlet at the moment, a braided hose enters the carb at right angles to the clyinder heads, should this be changed? The current filteris approx 2" high and 12" diameter, make unknown. I'm also having continuing issues with starting the car after a lay up. If left for more than a few days it is impossible to start. I posted this a few months ago and tried the starting procedure suggested but with no luck. I flattened 2 batteries at the weekend cranking, with only a few coughs. The last time i started it i connected 2 batteries and eventually got her to fire after pumping in lots of fuel with the throttle. Does it need a rebuild? Where can i get a kit?
Regards,
Dave
 
I believe these can suffer from fuel evaporation from the carb. I fitted an electric pump to mine to assist but it does still require quite a bit of throttle pumping to get it to start. From my days of driving Yank tanks, I seem to recall that this is fairly normal. They're not like SU's.
 
I never have problems starting my 500 equiped motor from cold but as stated I have an electric fuel pump fitted.
Normally to start I just pull the choke 4/5 of the way out, pump the accelerator about 3 to 4 times then as I apply the starter motor lift my foot off the floor till the engine fires however I don't know if this proceedure will work with the mechanical pump. My only issue has ever been hot restarts where petrol boils in the carb, this issue I have ammeliorated by fitting a heat spacer between the manifold and carb.

Perhaps you have moisture getting into the cylinder heads? I have not provided an engine breather return to the carb choosing instead to vent engine gasses to the road this can reduce moisture entering the carb.

I have sourced all my weber and related bits from the states from those sites listed as resellers off the Edelbrock site.

Cheers Graeme
 
hi all does this weber 500 make any difference then the old su's is it better on fuel and more powerful then the su's i might be thinking going down the line with 1 so more information would be nice
 
Perhaps the best answer is to refer you off to the Rpi engineering website but yes the fuel efficiency is improved and if you beleive what others have said BHP is increased by up to 40 to 50 BHP.

Graeme

PS engine responsivness is greatly improved as the weber has a fuel pump rather than the SU which waits for increased vacuum to supply the omph from the petrol, so no acceleration lag that lets minies and low powered cars drag you off from the lights :)
 
I very much doubt if you can get anything like 40bhp extra from the carb alone.

Gareth, read up on it on the net, and don't forget to read up on the inlet manifold too. The 'Offenhauser dual port' is designed for smaller engines such as the rover V8 as it runs the primaries through smaller ports which gives it better response, stops fuel dropping out of the vapour, and apparently gives better economy. Until the secondaries come in that is. Have a look at this forum for more info - http://www.v8forum.co.uk/forum/index.ph ... 8bbcb5af00

You will get induction roar from the Weber, which some do not like (I do) and can sometimes smell petrol, especially if you do not have that heat resistant gasket fitted.

I changed the normal fitting to the banjo type as I was re-siting the fuel regulator to keep the fuel lines away from my exhaust manifolds.
 
Hi all,
thanks for the replies. I have got an electric pump fitted (facet 4psi at the rear), and a filter king on the bulkhead. I'll try Graemes method and see how i get on, but tbh I've tried nearly every combination at this stage. Any more suggestions?
Regards,
Dave
 
Other than maybe being an incorrect jet and rod combination or perhaps the idles set incorrectly...... possibly another cause, worn cam? headgasket issue, slipped timing, points dodgy battery or faulty ballast resistor.

Graeme
 
dmcsweeney said:
Hi all,
thanks for the replies. I have got an electric pump fitted (facet 4psi at the rear), and a filter king on the bulkhead. I'll try Graemes method and see how i get on, but tbh I've tried nearly every combination at this stage. Any more suggestions?
Regards,
Dave
Click to expand...

If your Facet only gives you 4psi you do not need the regulator. What pressure is the reg set at?

My air filter is a 14" x 3" which appparently causes no restriction to air flow at all - with the K&N filter that is.
100_8118.jpg

I did have to remove the angled spacer to get it to fit under the bonnet however - fitted a 1/2" Mr Gasket 98 heat dissipator at the same time to stop the fuel boiling off. That worked; starts first time every time now.
100_5790.jpg

If you think the non starting is fuel related, try just lifting the top off the carb prior to first start up (when cold) and just see if there is any fuel in the float chambers - don't forget to remove the centre stud first as this can tear the gasket if you don't. What rods and jets are you running?

Richard
 
Thanks Richard,
I got the carb, pump etc as a job lot of parts which included an SD1 engine and box and all attached. At the time I didn't know what pressure the pump operated at so i fitted a filter king. The fuel is set at 3.5psi (I stuck a pressure guage on the line to the carb when i bolted it on). As the carb had been on an SD1 i left the jets etc alone, hence don't know what is fitted. I basically bolted it on, fired it up and drove it. I had no issues at all until I started to store the car, in a dry workshop. It is normally only fired up once a month or so at the moment (I'm working away alot this year). Once she gets running I have no problems in general, apart from one occassion when she got hot after 45minutes in traffic and stalled, starting again perfectly once cool. The engine is standard as far as i'm aware (though even with SUs it was far faster than any S i've ever driven), what rods and jets should I have?
PS: Stunning looking engine!Wish mine looked that good :oops:
Regards
Dave
 
Give it a spray with Easy Start ( I think this is ether in aerosol form ) If it fires up immediately , you'll know it's a fuel issue

I think that leaving a car with SU's and a mechanical pump for a month would result in a lot of cranking to get it going but it doesn't do the engine much good to flatten 2 batteries trying to start it
 
Thanks Dave,
what amazes me is that my 3rd 3500S is currently sat next to it in the workshop, with it's totally original pump and SUs and that fired very quickly having stood for the same length of time, with a battery that had also stood all that time (though I have battery switches fitted to them to stop discharge). I really need to start using them more! Unfortunately I'm working away and usually just use the one I've got at the house (when it works!!). I finally gave in and bought easy start on saturday afternoon but never used it, I hate the stuff and have always been led to believe it damages engines. I think of it as only for use in york engined transits! I did try to limit the cranking time to short periods and watched the oil pressure, but I'm sure it still isn't great. Will give the easy start a try saturday. I asked a friend who used to run rover V8 specials about the problem some time ago and he said it was a common problem with his, and a mustang he used to run. He said is was down to a lack of vacuum when the carb was left to dry out. Does this make any sense?? I've also found that to have any hope at all of starting i need 2 batteries connected to give it a good fast crank. The car has a 12V coil fitted with a few years (hence no ballast resister), but will still start easily from cold if only left a day or two. I also store the cars with very little fuel for safety reasons so it is topped up regularly and should be fresh.
Regards,
Dave
 
here is my filter set up, I will look up my invoices for the rod and needles purchased, the values were recommended to me by Rpi for my engine setup.

enginebay.jpg


Graeme
 
dmcsweeney said:
Thanks Richard,
I got the carb, pump etc as a job lot of parts which included an SD1 engine and box and all attached. At the time I didn't know what pressure the pump operated at so i fitted a filter king. The fuel is set at 3.5psi (I stuck a pressure guage on the line to the carb when i bolted it on). As the carb had been on an SD1 i left the jets etc alone, hence don't know what is fitted. I basically bolted it on, fired it up and drove it. I had no issues at all until I started to store the car, in a dry workshop. It is normally only fired up once a month or so at the moment (I'm working away alot this year). Once she gets running I have no problems in general, apart from one occassion when she got hot after 45minutes in traffic and stalled, starting again perfectly once cool. The engine is standard as far as i'm aware (though even with SUs it was far faster than any S i've ever driven), what rods and jets should I have?
PS: Stunning looking engine!Wish mine looked that good :oops:
Regards
Dave
Click to expand...

The pressure can be up to 5.5psi on the weber 500.

A good starting point on rods 'n' jets would be the 86 jet and 68/57 rod. This is a good deal leaner than the standard set-up but quite a bit richer than the RPI recommended set-up which was far too lean for my car. You can check to see how it is running by removing one of the plugs and seeing what colour they are. When you take the air filter off and hand operate the throttle, do you get a jet of petrol into the primaries? i.e. is the accelerator pump working? If it's ok, leave it alone :?

(My car is a 4L stage one, and the RPI recommended set up for this was far too lean. The RPI recommended for a 3.5L is even leaner)

Thank you for the comments on the engine, but it still needs a lot of work.
 
Lads,
thanks again for your inputs. I'll have a look at the plugs saturday and see how they look. If i can get her to run I can also stick the colour tune on. I removed the air filter last Saturday and confirmed the fuel supply from the accelerator pump , there was a good strong jet of fuel into both primaries. The strange thing is the car runs perfectly once started, and really only presents a problem if left to stand a few days, which led me to believe the mixture was ok. Anymore thoughts would be welcome. Thanks for the rod & jet info Richard!
PS: Graeme, that looks like one of the filters i looked at online, do you have a product number for it by any chance? I assume it is a 14" X 3"?
Regards,
Dave
 
Talk of Easy Start takes me back a bit! I remember one Christmas / New Year, when we had the train service shut down, we got some very cold weather. Most of the engines - Paxman Valenta 7.5" by 7.5" V12's of 2,250Hp and built exactly like a car engine complete with car type starter motor - were very cold but started normally. One stubbornly refused. Eventually we emptied half a case of easy start into each bank's inlet manifold, stood well clear, and pressed the start button. The cylinder heads on these engines are individual to each cylinder, and with a succession of percussive pings each head lifted from the block against the springiness of the head studs. I now had a clear picture in my mind of the firing order of a Paxman V12. I very carefully didn't check the engine's subsequent history of broken head studs!

Chris
 
dmcsweeney said:
Lads,
thanks again for your inputs. I'll have a look at the plugs saturday and see how they look. If i can get her to run I can also stick the colour tune on. I removed the air filter last Saturday and confirmed the fuel supply from the accelerator pump , there was a good strong jet of fuel into both primaries. The strange thing is the car runs perfectly once started, and really only presents a problem if left to stand a few days, which led me to believe the mixture was ok. Anymore thoughts would be welcome. Thanks for the rod & jet info Richard!
PS: Graeme, that looks like one of the filters i looked at online, do you have a product number for it by any chance? I assume it is a 14" X 3"?
Regards,
Dave
Click to expand...

The filter on mine is a 14 inch Edelbrock part number 1221, the jets I used are .080 part no 1421 the rods .062 x .052 part no 1441.
incidentally the heat gasket I used is part no 9266 though it's not an issue with your problem.

Graeme
 
ghce said:
The filter on mine is a 14 inch Edelbrock part number 1221, the jets I used are .080 part no 1421 the rods .062 x .052 part no 1441.
incidentally the heat gasket I used is part no 9266 though it's not an issue with your problem.

Graeme
Click to expand...

That is the set up recommended by RPI. I found their recommendations for the 4L set up to be far too weak and it caused hesitation.
That set up gives you a cruise setting of 19% leaner than stock and a power setting of 21% leaner than stock.

The 86 and 68/57 gives cruise of 12.5% leaner than stock and a power setting of 11.6% leaner than stock.
 
I presume that the Rpi figure will be dependant on the head configuration ie SD1 or P6B heads as the p6B has smaller valves.
I cant say I have noted any particular detriment using their recommended jets and needles as there is far more power and drivability than the SU's that were replaced, unless it has some effect on the hot start issue that seem to randomly occur with mine.
Maybe with a richer mix I may get more thrust when accelerating, it is certainly worth me getting in some different needles and jets to have a play as they are quite cheap.

Graeme
 
Lads,
thanks again for you help on this one, I'll try and establish what is fitted over the weekend. I printed and exploded diagram of the carb to help. Is it safe to remove the top of the carb without a replacement gasket or should I get one first? I assume I have to remove this to access the jets?
Regards,
Dave
 
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