Right!

That's what I will do then 

I can quickly make a new set of soft jaws to fit inside the bearing (exactly)
and machine the maximum under size thrust faces to suit the case, snug as a bug in a rug!, an exact fit 

Thank you

Peter

Hi Peter, Jon is right for a performance engine, which is stripped down a lot!. But on a slightly tuned engine it is not worth the hassle. All the main bearing manufacturers and stockist have cut down a lot on what size bearings they do. So the sizes you get are in line with every recondition you do. It is hard to get bearings to fit new or first regrind crankshafts if your case has had a couple of line bores or thrust cuts. So you might be buying more than one set of main bearings to do what you might be thinking of. I now have to work out what size bearings I will need and then check if I can get them before I get the parts reconditioned, I often have to use another crankshaft to get the results I need. the other thing to think about is that the cases do not last indefinitely, they corrode and go brittle and crack.

The best thing to do is strip your engine first and see what size machining has been done already, it might be that you only have one machining left on it anyway, you say it has clocked up a lot of miles since it's last recon.

Rob

I have been having thoughts on the Weber jetting and would like to try something jet wise, as I have always
thought, though my bug runs well, that the primary and secondary jets are far too close in size, after a bit
more research its definitely VERY important to get heat into the manifold/carb, if its not warm enough fuel will
not emulsify properly and there will be a trade off even though the engine is running well, if I can successfully
get more heat in there I hope to be able to have primary main jet in the 125 range and the secondary in the 170 range,
the warmth inside will mean the fuel vaporises far better so the jet size drop will be accommodated due to less fuel being wasted,
I will have a better fuel consumption as a result. With the 2 barrel progressive, heat, lots of it really is the ultimate key.

Nice to see you are still trying to get the best set up on the Weber, I am using Eurocarb's 2012 jetting at present and the Doon runs well on it.

http://www.chris-jordan.org.uk/_media/vw-weber-settings.pdf

I did try the settings from aircooled.net in the US but could not get them to work, possibly due to lack of heat.

Chris

Hi Rob,

I completely missed your post, Yes, the first step will be to strip it out
and measure everything to get the sizes of things, then I shall have a good idea of which way I will be going.

As far as the thrust side of things goes, once I have measured it all and if I can, I shall make sure the thrust is
within limits and will machine a maximum under size bearing to suit my case. To be honest I am suprised
that approach isnt done more often as its way cheaper.
I had a rethink and all that's needed is a mandrel in the lathe and then just pop the bearing on, driving off the centre and
a pad in the tail stock I can easily clean each side of the bearing to whatever size I want making allowances for position and
to, plus or minus nothing 

Will keep this thread posted as it goes along... 

Peter

FYI I fitted the new SVDA yesterday that I referenced above (similar to the Aircooled.net ones but UK sourced (although I suspect Far East manufactured)), made a huge difference so will be interesting to see how it holds up with some miles on it.

Cheers,

Paul.

Chris,

Yes, after some research, listening, and trying to understand things, I really do think that the progressive
benefits from a huge amount of heat...

These carbs were used world wide by manufacturers and quite honestly are quite brilliant. We throw bits
away though in how we do things, the air boxes Ford used and the fact that front engined cars had
a nice cosy engine bay with a bonnet were very important parts of the carb system.

I have asked Beelzedub if it would be possible to make me another heat take off for my Sidewinder system,
it will be sited on the other side of the engine and halfway up the corrugated tube will be an air inlet, it will merge
with the heat rising and enter the air box above the throttle linkage, it will be
a curved leg that just enters the tube from the underside... Heat rises, so the inrush of air should keep it there
and mix with the heat in the process.

The air box will be sealed and I am getting a heat proof plastic box with a lid, it will be the right height to fit
the available space and wont melt.

I can then experiment with boxes and shall make two flanges to attach to the sides of the air box, the corrugated tubing, one tube each side,
will slip over these.

Am hoping that I will be able to get the environment in there quite hot as a result, the fuel will emulsify far better and jetting can be mucked about with.... If my mind is working, the primary jet will be far smaller than the secondary and when the two chokes start to open together the
fuel mix will be more even..... 

Maybe.............. 

Peter 

Peter

I am also looking at enclosing my K&N filter to get more heat into the system from the original VW hot air feed on my engine, I came across this no nonsense web page written by the guy's at Aircooled.net in the US which supports your comments that to run a Weber 32/36 progressive carb the more heat the better.

http://www.chris-jordan.org.uk/_media/making-the-weber-progressive-32-36-dfev-work-on-the-aircooled-vw-engine.pdf

Enjoy

Chris

Its interesting isn't it  Thanks for that link, In have often wondered about all this and some things are starting
to make sense now.

Its amazing that the carb ever worked at all really, as modern day stuff with engine management
delivering precise fuel mix on the fly and ensuring the engines get the prefect mixture whatever the weather!...

The problem with the single carb in our VW's is the total lack of attention to heat and what  it actually does.

Stell has always had a hint of a fuel smell even though she runs perfectly well, and its the
over size jets that are doing it, they need to be larger so they can deliver a mixture that will
be used, the extra fuel isnt emulsified (vapourised) and just drains down the walls of the manifold.

Getting some serious heat in there will mean that a dramatic drop in jet size can be used, as no
fuel is draining away down cold inlet walls, the heat will encourage a much higher percentage of the metered fuel
to emulsify into a useable cloud and the smaller size jet will reflect what should have been in there in the first place.

There is a VERY BIG difference between running rich in a perfect setup and wasting neat liquid fuel due to the environment being COLD.....

Peter

a strange design by vw as engines run better on cold dense air but the flat 4 means you need a long hot manifold to keep it going even on a warmish day.
if they had moved the dynamo and fan to the side you could dispense with the tall manifold tube which gets cold and causes the problems.
interestingly enough the type 3 1500N single port, single carb motor had heater pipes but the carb was offset well to the right(not central) and bolted to a very short flanged neck so the icing problem did not occur ( I guess a carb a few inches above the crankcase may have also helped)

 

the flat 4 means you need a long hot manifold to keep it going even on a warmish day

Yes, I should think so, it was very warm today and I put my hand on the manifold in several places, even with
heat risers and a manifold that has a cavity in its main body, the manifold was cold.

I am really thinking now that most of this can be eliminated (and keeping all these other heat sources) by just getting
really warm air into the carb, even on a 30 degree day to stem the temperature plunge specially when the engine is ticking over.

Iv'e been thinking about how I could control the outside air flowing into the air box and will make a tube about 100mm
long with 5mm or 6mm wide slots along its side covering 90 degrees around.

It seems that this would be an easy way to regulate the inrush of air... As sliding the VW perforated pipes inwards
or outwards along the tube may give me the opportunity to 'tune it...

Not sure, but its a start I guess, makes sense, I think, and will have to see what happens...

I was reading an old article today and it stated VW had measurements for how far the tail pipes were pushed into the silencer depending on the engine, this was to get the correct back pressure for the inlet heater system to work correctly and here we are fitting all types of exhausts expecting it to be perfect.
to make it worse we remove all the body work and seals around the engine compartment so all the background heat is dissipated. Inducting pre heated air should help as it cools going through the carb and manifold.

Hi Peter, I gave up on my Weber progressive carb after about 3 months because I couldn't get it running right. I thought for years that you were happy with your carb because you had got it running well. I know you are a cleaver chap and very good at making parts but I do wonder why you want to go to all this trouble when you could get a nice pair of 34 ICT's and have a great running buggy. Or is it that you just like a challenge? just cause you can, doesn't mean you have to 

Rob

Hi Rob,

Mmm, I like the single carb and the Weber is a very good one, all it takes is to
look a little deeper and try to find the issues and how they could be solved. Mine does run well and always has
but there are little issues that I have never really looked at. Something I have to do everyday during the course
of my work, so I guess its a challenge.

Twin carb's would take a pounding in my bug, I use it everyday on the worst
roads its possible to imagine, and when the weather's bad they would get the full force
of unimaginable sh..e and crap thrown at them, the single is nicely tucked away and
that really helps.

The/My VW Beetle engine bay is cold..... the vents beneath the rear window let heat escape
at will and the rain pours in, the Solex never did get the attention it deserved and was
just modified to overcome the problems, I think it should have had a complete redesign.

My Weber runs well but I have not attended to the real niggly little background issues, its running
rich to compensate for the over cool environment in which its working, 'inside the manifold,
there are several now who have taken the 'plunge and fitted one, they have rejetted and
found out just how nice a carb it is, but after looking into some of the issues it has with
the cold recently I have found out quite a lot more.

Chris Jordan really has made a huge effort and has documented the things he has done, all it takes is
to be bothered to read things with the want inside to actually try to understand, just buying
a set of twin carbs because its the easy option isnt on my agenda, am very happy with
the way mine is, as once you get to have a running engine its seamless, instant starting, and no hesitation
with a nice smooth response throughout the entire rev range. I am now looking at whats involved in
getting the carb to run the way it was intended, lots of main stream car makers cant all be wrong, can they!

My engine is wearing now and I expect the compression isn't what it was so I must sort
those things out first, meanwhile we go to work everyday and still running ok... Ie, no backfiring,
instant starting and a smooth response at all levels, I will make two flanges that will connect to VW
corrugated tube one either side of the air box, one will duct nothing but heat and the other will mix
air with heat and have an adjustable air flow rate, not rocket science, just a simple set of slots in the wall
of a tube, and their outlook can be lessened or made larger.

I also have my own heavier weight heat pipes at the ready, they will get hotter, flow the exhaust 'to and through'
the manifold body and I have made the exhaust flow rate through it, adjustable, exiting to air on one side...

I am a Mechanical Engineer at heart so buying something else off the shelf because its the easy option
just wont cut it, there's absolutely nothing wrong with a progressive Weber, it's unbelievably forgiving
and could work even better once all the things it REALLY needs are sorted out.

Peter

Hi Peter, I see you have set your mind on ironing out the problems with your carb and I'm sure you will  I got mine running a treat on the first choke but never got the second choke jetted right; it just made more noise and drunk the fuel like mad. The carb itself is good but like you say, it needs heat with the long vw manifolds. When it is fitted to other engines, it comes with it's own water jacket to keep it warm and they feed warm air through it when needed with thermostat valves, It might not look the best like that but it is hidden under bonnets and it does a good job. Personally I think they did the vw kit for the warm US market, rather than our cool wet climate.

Good luck with your project, I will watch your results with interest 

Rob

Many years ago I had a Fiesta 1300S that had been built by Ford for the Fiesta Challenge race series which was fitted with a progressive Weber and the air filter had a manual inlet flap on it with a summer and winter position on it. One damp autumn night I came to a halt on the M11 due to the carb icing up because I had left the flap in the summer setting. Once the ice had melted and I put the flap in the winter position so it was sucking all its air in from the collector bolted to the exhaust manifold it started and ran perfectly.

Its all about getting the right conditions, the Fiesta had a water heated inlet manifold running at full engine temperature and a fully heated air intake.

Like Peter I went for the simple option of the single Weber as I drive the buggy all year round and didn't want to have to clean the carbs and filters after driving on wet roads.

You are right Rob a lot of VW buggy parts are made for the warm and dry US market.

Chris