Getting back on the road

Next update. Lucas sports coil is in (Its the correct 3 ohms needed for a non ballasted system). Starts up now. Misfire is still showing up under load. Idle is smooth,

Things I've done or tested so far:

[1] I replaced the fuel filter to be safe with a new clear one.
[2] The pump is barely filling the filter at idle so I wonder if fuel starvation is an issue too. So, rebuild kit for fuel pump is on its way with E10 proof valves and diaphragm.
[3] Spark seems strong,
[4] Compression is high and even on all cylinders.
[5] I whipped off the valve cover to check I hadn't got a broken spring causing spring bounce at higher revs (Assuming one of the dual springs on each valve had cracked) and all looked good.
[6] Fitted new O-rings between carbs and intake manifold. (a spray with carb cleaner was showing a small vacuum leak but I've fixed that now by adjusting the carb suspension spring preload.

So, I guess Beryl didn't enjoy the track as much as I though. Waiting on the following:

[1] Fuel pump rebuild kit
[2] Spare Lumenition Magnetronic ignition module (in case Pertronix coil damaged the old one when it died)
[3] New Lucas coil. The one fitted is 40 years old and will probably outlive us all - but a spare will save a flatbed ride.

Hoping the fuel pump will do its thing, if I find dirt in there (its before the filter) I'll try and relocate the filter to before the pump to protect both pump and carbs going forward.

For those that read all that - if you have an idea what's up please let me know.
 
Now that you mentioned it, i also had a coil that died when driving / reving hard. At that time i put it down to conicidence as i could not offer any other explanation, but perhaps i am missing something.

Regarding your misfire i agree that the next logical step is to rebuilt the fuel pump and see if this works.
 
I once was asked to look at a 3500S1 with a misfire. No 1 was bad. Pulled the head, and after a bit of poking around found the piston crown centre dimple was burned through. Replaced the piston, new shells, reassembled....one intermediate bolt hole had a short bolt in it, partial thread stripped. Got the longest possible bolt (ie close to bottoming, but not), tightened it very gingerly. Fired up - still misfiring - tracking in the dizzy cap - sorted by a new cap.
 
Before you take apart the fuel system and rebuild the pump try running the car to fill the float bowls, disconnecting the fuel pipe at the carb, directing into a bottle and starting the car, time how long it takes to get pint of fuel in the bottle, hopefully before the carbs run out.
Convert your findings into GPH (GALLONS PER HOUR )
You can then see if the current set up is giving enough flow. If flow is down it may not be the pump, could be the pick up in the tank, or something else. At least it will take some of the guess work out of it.
 
cobraboy said:
Before you take apart the fuel system and rebuild the pump try running the car to fill the float bowls, disconnecting the fuel pipe at the carb, directing into a bottle and starting the car, time how long it takes to get pint of fuel in the bottle, hopefully before the carbs run out.
Convert your findings into GPH (GALLONS PER HOUR )
You can then see if the current set up is giving enough flow. If flow is down it may not be the pump, could be the pick up in the tank, or something else. At least it will take some of the guess work out of it.
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That’s a good thought. The pump has alway been sufficient in the past, but maybe I have a partial blockage in the line downstream of the pump near the tank. I can sometimes feel a slight misfire if I rev it manually, so using the bottle should eliminate flow from my suspects.
 
jp928 said:
I once was asked to look at a 3500S1 with a misfire. No 1 was bad. Pulled the head, and after a bit of poking around found the piston crown centre dimple was burned through. Replaced the piston, new shells, reassembled....one intermediate bolt hole had a short bolt in it, partial thread stripped. Got the longest possible bolt (ie close to bottoming, but not), tightened it very gingerly. Fired up - still misfiring - tracking in the dizzy cap - sorted by a new cap.
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Blimey, that’s a mess of problems. I did try a new cap as I had one on the shelf. Old one had some serious tracking on the posts. No change though. New rotor arm arriving today hopefully, although that seemed fine.
 
sdibbers said:
Well, the rings looked fine. I did replace the oil control rings with spares I had just to be safe.

All back together now, while I had things apart is was able to sort out the misalignment in the alternator bracket. Turned out it was just a spacer on the wrong side of adjuster strap pivot put that in the right place and all was square again.

Anyways, the engine is back together, carbs are balanced and mixture retuned. Car feels about as good as before she started missing a little. I guess I’ll have to wait a few hundred miles to check for oil on no. 2 spark plug, but I reckon she’ll be fine now.

The realignment of the alternator strap seems to have helped, no more squeak when you blip the throttle. Result!
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Steve, I'm throwing out a lot of smoke, which I thought was just the exhaust, but the guys down there said I might need to do the rings and the valve stem seals. Were you very smokey before changing rings and seals? Would you suggest I have a go meself?
 
There was a small puff of smoke on startup of sitting (classic stem seal smoke). Other than that it was fine. The rings I used when I went to 2200 pistons years ago. The only time I had to change a set of rings was when one set lost compression a few years ago. There was wasn’t noticeable smoke, but crank case pressure was present and oil would leak everywhere! In that case I think it was the compression rings that failed and not the oil control rings.

have you noticed a drop in brake fluid on your car? Smoke tends to come from a bad brake servo letting brake fluid into the engine. You can test this by removing the vacuum line to the intake manifold and blanking the port on the intake. Bear in mind you’ll not have servo assistance on the brakes, but if the smoke goes away - there’s your culprit.
 
sdibbers said:
There was a small puff of smoke on startup of sitting (classic stem seal smoke). Other than that it was fine. The rings I used when I went to 2200 pistons years ago. The only time I had to change a set of rings was when one set lost compression a few years ago. There was wasn’t noticeable smoke, but crank case pressure was present and oil would leak everywhere! In that case I think it was the compression rings that failed and not the oil control rings.

have you noticed a drop in brake fluid on your car? Smoke tends to come from a bad brake servo letting brake fluid into the engine. You can test this by removing the vacuum line to the intake manifold and blanking the port on the intake. Bear in mind you’ll not have servo assistance on the brakes, but if the smoke goes away - there’s your culprit.
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Thanks Steve, Ah that's a new one on me. I'll give that a try this evening.
 
Excellent news! When it comes to tuning the carbs I like to start by setting the jets 1.8mm below the bridge (I use the depth gauge on the bottom of my digital calipers to measure). Make sure both are at the same point.

Then adjust idle screws to balance intake speed with the Unisyn. don’t worry about setting the final idle speed yet.

Now set the throttle bar fingers so you have no lost motion. When you just start to open the throttle both butterflies should open simultaneously.

Now adjust your mixture screws (turn both screws the same amount when you do) keep leaning off until the idle rises then drops. Back off until fastest idle and richer by about 1/4 of a turn on each mixture screw.

Now you can adjust your final idle speed.


One thing to be aware of: carbs are last on the list of adjustments you should make. Ensure that you have the valve clearances set correctly (a true PITA to set if change is needed - but well worth effort). That valve timing is correct, that the ignition timing is close to correct. Most importantly - people buy rebuild kits for carbs. That just replaces the needles, jets and gaskets. The real wear items on SU carbs are the spindles and bushes. If those have excessive wear you will never get it to hold a tune. You can do an easy test of spindle wear by having the car idle, and spray some starting fluid around where the spindles enter the carb body. If you see a difference in idle speed (up or down) you know they’re worn.

Sorry for the wall of words. I hope they make sense?
 
sdibbers said:
Excellent news! When it comes to tuning the carbs I like to start by setting the jets 1.8mm below the bridge (I use the depth gauge on the bottom of my digital calipers to measure). Make sure both are at the same point.

Then adjust idle screws to balance intake speed with the Unisyn. don’t worry about setting the final idle speed yet.

Now set the throttle bar fingers so you have no lost motion. When you just start to open the throttle both butterflies should open simultaneously.

Now adjust your mixture screws (turn both screws the same amount when you do) keep leaning off until the idle rises then drops. Back off until fastest idle and richer by about 1/4 of a turn on each mixture screw.

Now you can adjust your final idle speed.


One thing to be aware of: carbs are last on the list of adjustments you should make. Ensure that you have the valve clearances set correctly (a true PITA to set if change is needed - but well worth effort). That valve timing is correct, that the ignition timing is close to correct. Most importantly - people buy rebuild kits for carbs. That just replaces the needles, jets and gaskets. The real wear items on SU carbs are the spindles and bushes. If those have excessive wear you will never get it to hold a tune. You can do an easy test of spindle wear by having the car idle, and spray some starting fluid around where the spindles enter the carb body. If you see a difference in idle speed (up or down) you know they’re worn.

Sorry for the wall of words. I hope they make sense?
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Not at all, I'm with you.

The ignition was set by Strobe, it should be Ok. Valves I'm not sure about yet, they will have to be done at some stage.
Both Carbs rebuilt, the only things I didn't change were the needle, float and butterfly. I need new idle screws, looks like they were adjusted with a Stilson previously. I did send off but Burlen sent me the wrong Sundries kit.
 
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Found the misfire! Turns out the securing screw for my ignition module had backed off from my high rev jinx. That in turn allowed the wiring to move and rub against the bottom of the magnetic trigger wheel. I think I was down to a single copper wire strand.

I fitted a new Magnetronic module (the unit would have been fine if I’d not abused it). Zip tying the new wires away from the Wheel this time. I also used a dab of loctite on the screw when mounting it. Car is back to her glorious self. Can’t wait to drive her to work on Monday.
 

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Little update. Drove the car to work twice this week, adding about 200 miles to the odometer. Car feels great now, a small tweak to ensure both carbs give equal fueling have smoothed out power delivery and maybe added a couple of ft/lbs of torque to higher speed running. I’m going to try a slightly hotter spec of plugs as I notice she runs better a little rich, but the idle gets very slightly rougher in traffic. Pretty sure a hotter spark plug will fix that. Otherwise, a very happy bunny with the results.
 
Little jobs are sometimes the most satisfying.

The instrument lights were very dim on Beryl. Also, the ribbon would bounce around when you lift off the accelerator pedal at speed.

So this morning I pulled the dash top rail and the instrument panel. Both of the original bulbs were almost a solid silver from age. I replaced them with new incandescent bulbs (I just don’t like the look of the LED bulbs).

On the speedo cable, I removed the angle drive from the speedo head and partially dismantled it so I could spray it with penetrating oil. That seemed to free it up quite a bit. It’s pouring with rain today so I’ll take the car out tomorrow to evaluate how the speedo performs. If it’s still playing up I guess I’ll have to pull the whole cable and try and lubricate it fully.

A photo below of the warm glow of success (and my very untidy garage!).
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Little update. I took the car out yesterday for run. Speedo actually moves smoothly now, none of the vast oscillations when lifting off the throttle. So I'm calling that a result!
 
A little video footage of my commute. The best bit is this from the Bear Mountain Bridge over the Hudson River and along the 'goat path' to Peekskill. It shows how little roll the car now has. Unfortunately the last part this morning was slowed by a large artic with a sticking brake (The smell was terrible!).
 
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