My 1995 Caterham S3 X-Flow Emotional Support Vehicle "Beater" refresh and other journeys down the rabbit hole

[IamScotticus]

Looking for a machinists flat bar for checking flatness and warpage of things like head faces, port faces, block tops, flywheel and pulley runout.  And feeler gauges.... 

All that cool engine stuff better left to a professional...

[fastg]

Just get a steel rule that is long enough to span the head or ports. It will give you enough information.

 

Graham

[IamScotticus]

What say the gallery?

Car sitting for ten years.

Standard Cat Triumph Girling T14 fronts and Ital drum axle.

Im running out of energy and brain cells.

Shall I rebuild everything or replace everything?

Im not opposed to upgrading the fronts. never could lock them before. 

The MC is 50/50 so Im looking for a bias device,  not a variable valve but a proportioning device. 

[MV8]

I'd replace all the hoses with braided if they are not already. If the pistons and bores are in good condition, I'd just replace the seals. Ditto on the wheel cylinders. If the master reservoir is plastic and brittle, I'd get a new master that includes it. I'd definitely fit an adjustable prop, which is much better than no prop despite being 50/50.  

Variables are prop valves but with an adjustable preload on the internal spring. Install it where the driver or passenger is not likely to turn it out of curiosity. Once satisfied with the adjustment, mark the position down the side and leave it be.

Oem valves are typically combination valves with a fixed prop valve setting and a metering valve to apply the rear before the front to overcome the spring tension holding the shoes away from the drums, similar to residual pressure valves.

If you ever suspect brake issues, a test kit is about $50 and includes adapters to fit various bleeder threads.

[IamScotticus]

Thanks Steve.

I need to get the rebuild parts and send them to someone to do the work.  Maybe the carbs too.

Or should I just wait on the carbs to see if I they need it.  IIRC, l was pretty good at using fuel stabilizer.  I have yet to crack one open to see any varnish..

I do have rebuild kits I ordered for DCOE 40s but what I got says on the pack its for 45s.

Can I get a confirmation they are interchangeable?  The package doesn't specify. 

 

 

Edited June 26, 2022 by IamScotticus

[MV8]

What info is on the package? The main gaskets should interchange. Some kits cover both.

 

 

[IamScotticus]

Here's a rabbit hole..

 

Im wanting to do the downdraft carb conversion.

Of course there will be some loss in performance,  but I think there is much to gain in drivability, livability, reliability and ease of setup.  Really...DCOEs "floating"?  A 38/38 DGxx doesn't need to float.  You lock it down and done.  The family wagon that hauled you kids all over in the 70s and 80s, that was probably on a 2 barrel carb.

 

I think the downdraft is probably very neglected by the 7 crowd; perhaps for obvious reasons.  I suspect many have just forgotten how easy they were to live with.  Perhaps,  once the DCOEs and the new bonnet were put on,  they never looked back,  just happily dealing with the syncing and thackary washers as needed, while enjoying the HP gains.

 

Are the downdrafts under appreciated?

Of course,  it wouldn't be a question for racing,  But that's what DCOEs are for.  Downdrafts are still used in racing, where required, like Formula Ford, etc.  But Im thinking downdrafts are more practical for street and road.

 

Lotus and Caterham sold many 7s equipped with the base Cortina & Escort lump.  Why not go back to it, if all Im going to do is be a weekend street driver?  With a dry sump and A2 cam.

 

One question for the gurus is, is there any problem in fitting a Weber 38/38 DGxx to a Ford manifold and running on an A2 cam?  Aldon Dizzy.  Some opening of the manifold flange to clear the 38 plates possibly.

Edited September 2, 2022 by IamScotticus

[fastg]

You are right, you will probably end up with a better running car. I would guarantee that most DCOE setups are poorly jetted and tuned even worse. So I think you will be happy with the results. 

 

Graham 

[MV8]

I agree. Improved drive ability for the same cam spec. Less ooh and ahh though, from those who won't be driving it.

[panamericano]

Two throats get a bad rub all around.  I ran a competition V8 and to slow the class, they ruled we had to use 2 barrels.  We went from a Holley 750 double pumper (4 throat) to a comp blue printed 2 bbl., maybe 600-650 cfm.  NO lose of power and improved mpg, with maybe better mid-throttle response.

[IamScotticus]

I edited my downdraught rant to omit the progressive 32/36 to include the 38/38.  It seems to be golden egg for under 2 liters.  Even better if modified to a progressive primary and secondary opening articulation.  Just cannibalize the linkage off a 32/36, trurn down a shaft,  & plug the secondary accelerator pump circuit (being delayed, you don't want a fuel dump on top of it.)

Now, Im not going to say that DCOEs can't be dialed in well.  They can run just about anything.  The most common mistakes on those is not matching the choke to the drive style.  For our cars, you want to be on 32-37 chokes for general blatting around.  And then theres the famous "dead spot".  That could probably be adjusted for, or compensated for as well.  But its one thing the downdraughts don't have much issue with. 

From what I am reading,  the 38/38, if I can make it fit, will give all the flow I need.  It certainly isn't any slouch on larger cars.

Edited April 9, 2023 by IamScotticus

[MV8]

They both have a diaphragm pump (versus a spring pushing a piston on a 28/32) but the 38 probably has a lot more volume. The shot will be higher volume than 1/2 a 38. Just something to consider. You may be completely satisfied with a 28/36 or a 32/36.

[IamScotticus]

The ubiquitous 32/36 DGAV is certainly out there.  No shortage of YouTube tuning experts and service guides.  It may be the most supported carb around.  I think FF is stuck with it as well.  But, the I have not read the praises for the 32/36 like I have for the 38/38 outlaw.  I am reading that for a engine tuned beyond stock, 38 is the carb.  It may be what my A2 cam needs to feed it.  Not that its anything to brag about, its just the tallest cam Cat could build up a 1600 with, without having to replace pistons.

So yes, the 38 may be larger than my little car needs, a 28/36 may be very sweet for a weekend driver. 

I have a 32DFM(Manual choke) coming my way that was a Cortina carb, and the carb the crossies had that Lotus dropped in the S3s and S4s.  

I will rebuild it and try it out for fun. I have a feeling I may want more, eventually.

I need to see why Lotus used a DF as opposed to a DG before buying any more carbs.

Edited September 4, 2022 by IamScotticus

[IamScotticus]

At home recovering from Sinuplasty and turbinate reduction.   Believe me, any surgery to the nose sucks.  but the roto-rooting was successful and it will all be good.

During thd lucid moments, breaks in the pain fog, I managed to start tearing down the carb.

So, I have a question to put to the gallery....

How far should I tear this down?  Shall I leave the throttle and choke plates on the shafts?  I ask because I could clean around them and I wouldn't have to worry about the screws coming out later.

I believe this carb is untouched.

Special thanks to Carburetor Shop for an excellent parts diagram. 

 

[ashyers]

Depends on if the shafts are worn and what kind of bushings they run, if any, and how you're cleaning the carb.

 

If I can avoid it I don't pull the butterflies. I don't know if that carb runs any shaft bushings, but some carb cleaners are not kind to them. If the shaft for the throttles is not wobbly and seals well I'd leave them be. Did you have a consistent idle and normally functioning idle mixture screw before you took the carb apart? If so the shaft is probably OK.

[MV8]

Also, an ultrasonic cleaner is nice to for that parts that will fit in it. The screws for the butterflies are probably staked so if trying to reuse the screws, you'd need a new way to lock them that is fuel resistant.

[IamScotticus]

2 hours ago, MV8 said:

The screws for the butterflies are probably staked

Exactly why i don't want to muck with them unless I have to.

[IamScotticus]

4 hours ago, ashyers said:

Did you have a consistent idle and normally functioning idle mixture screw before you took the carb apart?

The carb was purchased on Fleabay.  All the screw heads are perfect.  I don't see any signs of previous work.

 

I don't see any visual evidence of shaft bearings or bushings.  There aren't any on the diagram. 

This 32/32 is a late 60s carb that lasted until the introduction of the 32/36 progressive which has shaft retaining bushes on both throttle shafts that bush the shafts in the housing.  I think they are plastic.

Edited September 18, 2022 by IamScotticus

[IamScotticus]

If you read Jake Lamont's book, How To Build And Maintain (yet legal) Formula Ford Ford 1600 Engines, [available from Pegasus Racing] 

Jake's first advice on the preparation of these carbs as found on page 75:

"The first order of business is to remove all of the choke plates and actuating mechanism and toss them in the trash."

I realize this advice is for race car prep, but could it apply to me as well?

Hmmmm🤔

Edited September 22, 2022 by IamScotticus

[ashyers]

You can try to gauge the amount of wear of the throttle shafts by feel or attempting to see the amount of leakage with some carb cleaner or gentle compressed air.

 

As far as dumping the choke mechanism, be careful. some carbs flow worse without it and it screws up the jetting.