Starting 'er up

[Sandyman]

Vince, we are all waiting to hear how your start up is going. Any updates and pictures?

[Fotog]

So, Sandyman, I've kept you waiting for over a month.  Sorry about that!
And no, I haven't been hit by a bus.  But I have a number of other irons in the fire, so limited time I can spend on this.

All who cautioned against barreling ahead too quickly needn't have been concerned.  I can really spend some time looking stuff over and contemplating my next move.  I like to know that things are right, or at least what the status is, before I act.   So this isn't one of those exciting, fast-paced restoration threads. 

Thanks for all the suggestions though.  I've pretty much done everything suggested.  But I haven't started it yet.   But soon!  Maybe today or tomorrow.  I finally put a battery in it yesterday and cranked it over with the plugs out, and I got oil pressure.  Hot diggity!

I did flush the cooling system.  Separately the hot-side cooling transfer pipe, the radiator, and then the engine and cool-side transfer pipe, backflushed from the thermostat outlet as Brian suggested.  Not the easiest to access everything but once I did it was successful.  Actually very little sediment and rust came out.  Happy about that.

I rebuilt the two Stromberg carbs, and couldn't resist cleaning them up in the process.
Carburetor question:  Is the 'bypass valve' needed on the forward carburetor?  The diaphragm is shot and I haven't gotten a rebuild kit (interesting that it's always a separate kit from the normal carb kit).  I understand that it's involved with preventing backfiring during deceleration of the engine.  Is that much of a problem and important?  It's only on the one carburetor.  I could used a gasket to block it off for the present.

I rebuilt the original glass-bowl fuel pump.  It seems to be working right.  I had some difficulty connecting the actuating rod to the lever, but I got it.
Fuel pump Question: Does anyone know where to source the actuating rod oil seal?  This is the seal between the bottom section of the pump with the rocker-arm lever and the middle section with the underside of the diaphragm.

Lastly:  Can someone explain what this connection does in the ignition circuit?   Is this the 'starting' connection to the coil providing a higher voltage during starting?  If so, is there a ballast resistor in the other line to the coil?  I don't see it in the wiring diagram.  The diagram shows a 'cold start coil', but the coil that's there is just an ordinary single coil.  I don't know what a 'cold start coil' is.  I guess pictures don't show up in the preview mode?   Hard to know what I'm going to get.....   Vince  P.S. I will post some pix.

[jbcollier]

The bypass valves are to reduce excess HC on deceleration.  As you have already decided, simply replace the valve to carb gaskets with ones without holes for the vacuum passages.

Fuel pump oil seal... nope.  It's just to prevent a potential oil leak out the pump base vent hole.  Probably be fine without it.

Yes, it's a ballast resistor bypass for better spark when cranking.  It is only useful if you have a coil with a separate ballast resistor.  Otherwise, leave it disconnected at both ends.

[Fotog]

Boy, That's speedy. Thanks, JB!
-V

[4129R]

The ballast resistor is a white rectangular thing attached to just above the chassis rail below the carbs.

It has spade connections at each end.

You only need to wire the ignition to the coil via the ballast resistor if the coil is a 9v coil.

With the 9v coil, the wire from the starter direct to the coil gives 12v only while cranking the starter motor over.

The hard part of this is working out whether you have a 12v or 9v coil. They are not in the easiest place to take out, and even once you have taken them out and cleaned them up, there may be no 9v or 12v markings on them. 

[jbcollier]

Measure the coil’s primary resistance (between the two small connections).  3+ ohms does not need a ballast resistor.

[Fotog]

I'll check into the ballast resistor question.  I'm an electrical engineer (by training) but not particularly well versed WRT automotive ignition ckts, so appreciate the info.  I don't think there's a ballast resistor there (haven't seen one) but I'm understanding better how that would work.  Why were some coils made to work on less than the full 12V though?

I didn't start it today.  Had some other things to do.  But I went to re-mount the carbs and initially put them in place with 'Thackray washers' between the manifold and adapter flanges (or whatever those are).  I got those spring washers from Ray at R. D. when I bought the carb rebuild kits.  (They were not there when I disassembled things)  Well, the manual says that the spacing between the two flanges should be .070 in. when the nuts are tightened, but those washers are ~.130 fully compressed.  At first I thought I would just live with that, but then I decided that I would be risking a poor seal at the O-Ring, so I took them off and substituted some plain washers that gave me a spacing of about .070.  I know that the Thackray washers are supposed to provide some resistance to heat flow to the carburetors, but I'm sure that it's not much if any better than my plain washers when they are fully compressed.

If I wanted to start this while watching at the engine bay, I just turn the key to '2' and apply power to the white/red wire going to the starter in the diagram that I posted above, right? 

Thanks....Vince

[jbcollier]

An external ballast resistor has some advantages.  Minor one being less heat in the coil, not a big deal.  The main advantage is with cold starting in cold weather.  When cranking a cold engine, increased internal friction causes the starter to draw more amps.  Cold batteries also have fewer amps available.  Battery voltages during cold cranking can drop to 10 volts, or even lower.  Having an external ballast resistor allows you to bypass it during cranking and have more voltage at the coil than there would be with a coil with a "built-in" ballast resistor.

You are mis-reading the manual.  The gap is NOT between the carb and the manifold, it is between individual coils of the thackeray washer:

http://www.lotus-europa.com/manuals/tcwork/l/index.htm#8

This is extremely important.  There has to be some flexibility in the carb mount to prevent fuel frothing at high rpm  -- just ask MGA Twin Cam owners what happens if there isn't!

You are right about the white/red wire energizing the starter solenoid; however, starting an engine for the first time is a bit fraught with peril.  One bad backfire through the carb and the whole car could burn up, seriously.

- make sure you can shut off the ignition where you are standing.  At least a clear shot at the coil's white wire so you can pull it off if needed.

- same with the battery.  Starter solenoids can stick and the starter keep turning, and turning, and turning.

- also have a fire extinguisher TO HAND -- and not a little 2 lb one!

Not trying to scare the &$#t out of you... well, maybe I am, but, it's an unknown engine, you need to be prepared.

[4129R]

Measure the coil’s primary resistance (between the two small connections).  3+ ohms does not need a ballast resistor.

So 3+ oms = a 12v coil?

What is the resistance on a 9v coil? Presumably noticeably less than 9v, needing the external extra white resistance bar.

[jbcollier]

Yes, 3+ ohms is a 12v coil.  Typical 12V coils in the day were in the low 4 ohm range with "performance" coils at 3 ohms.  Coils meant to be used with an external ballast resistor are usually in the 1 to 2 ohm range.  The lower the primary resistance, the higher the primary current flow.  This gives a hotter spark but is harder on the points and a greater load on the charging system.  If you are running points, stick with a coil in low 4 ohm range, much easier on points.  If you have converted to electronic, follow the kit's recommendations. For example, pertronics wants a minimum of 3 ohms, any lower may damage the system.

All this is for 4 cylinder engines.  Higher cylinder counts may use coils with lower primary resistance.

[Fotog]

I woke up this morning thinking I wasn't satisfied about mounting the carbs without the Thackeray washers.  My impression is that with the O-ring in place and no nuts clamping, the gap between the mounting flange and manifold is only about .10 or so.  I'll have to see.  The car is not at my house.

About that manual, it says: "When assembling the adaptor flange/carburetter to the adaptor blocks, the 'O' rings should be located carefully and the nuts should be adjusted to give an even gap of .070 in.(1.78 mm) between these parts. "

The part about "...adaptor flange / carburetter to the adaptor blocks,..." makes it sound as though that's what they're referring to when they finish the sentence with "...between these parts."  But I find it confusing since I don't know what they mean when they mention "adaptor blocks".  There is an adapter flange bolted to the carburetor with an appropriate gasket.  It has a machined lip that engages with a recess in the intake manifold to retain the O-ring, so I don't think it's missing anything.  What's the Adaptor Block?  I'm now thinking that as long as the o-ring is slightly compressed and the spring washers aren't clamped tight it will be ok. 

I'll follow your precautions about starting when I get to it.

V

[4129R]

Yes, 3+ ohms is a 12v coil.  Typical 12V coils in the day were in the low 4 ohm range with "performance" coils at 3 ohms.  Coils meant to be used with an external ballast resistor are usually in the 1 to 2 ohm range.  The lower the primary resistance, the higher the primary current flow.  This gives a hotter spark but is harder on the points and a greater load on the charging system.  If you are running points, stick with a coil in low 4 ohm range, much easier on points.  If you have converted to electronic, follow the kit's recommendations. For example, pertronics wants a minimum of 3 ohms, any lower may damage the system.

All this is for 4 cylinder engines.  Higher cylinder counts may use coils with lower primary resistance.

Checked my coil. 9 ohms. Does that mean 12v or buy a new coil?

[jbcollier]

What brand of meter are you using?  Cheap and cheerful? Does it have a proper low-ohms setting?

Re: mounting to Strombergs.  Probably your o-rings do not match the original sizes.  No big deal.  Set them up so each thackeray washer is tightened the same and is not fully compressed.  0.050 gap is what you should shoot for.

[4129R]

What brand of meter are you using?  Cheap and cheerful? Does it have a proper low-ohms setting?

A decent digital multi-meter.

0-200 ohms scale gives the rear-out of around 9.

[4129R]

and using the same multi-meter, the resistance of the Lotus ballast resistor which goes in series with the 9v coil, measured at 4.5 ohms.