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Installing a spare distributor in an emergency
- Thread starter bigjones
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OP
bigjones
Jedi Warrior
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Bill,
That is a nice gesture and a super price. I might take you up on it.
I do have a spare distributor (don't know if it is any good or not) - this is what started the thread - I was wondering how to drop it and get it running in the least possible time and effort (as in a real world breakdown).. My questions have been answered but before I could practice the procedure, the bloody car broke down in the middle of town and I had to get it towed.
Still not running but I plan on working on it as soon as can get out of my lazy boy chair.
Cheers
That is a nice gesture and a super price. I might take you up on it.
I do have a spare distributor (don't know if it is any good or not) - this is what started the thread - I was wondering how to drop it and get it running in the least possible time and effort (as in a real world breakdown).. My questions have been answered but before I could practice the procedure, the bloody car broke down in the middle of town and I had to get it towed.
Still not running but I plan on working on it as soon as can get out of my lazy boy chair.
Cheers
OP
bigjones
Jedi Warrior
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OK gang, you are not going to believe this but I found the problem.
If you had sharp eyes you could actually see it and it would take 1 second to fix.
I'll explain tomorrow but anyone guessing the answer will receive a bottle of Old Speckled Hen in the mail, unless folks want me to spill the beans now.
Cheers
(rearranging the garage for a major leak-down fest)
Bayless thanks for the comment - I'll go back to believing the pointer - thanks!
If you had sharp eyes you could actually see it and it would take 1 second to fix.
I'll explain tomorrow but anyone guessing the answer will receive a bottle of Old Speckled Hen in the mail, unless folks want me to spill the beans now.
Cheers
(rearranging the garage for a major leak-down fest)
Bayless thanks for the comment - I'll go back to believing the pointer - thanks!
dklawson
Yoda
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The only picture for us to look at was the car going on the roll-back so I assume your statement "If you had sharp eyes you could actually see it..." is rhetorical.
Your posts made it sound like the breakdown was sudden and you tested the fuel pump so it should be ignition. You said the plug wires sort of fell apart on you so I am thinking the carbon brush broke in the distributor cap or the rotor shorted out to the dizzy shaft.
Beyond that I won't make any guesses and I DO want to know what you found, Speckled Hen or not! Regardless, I hope it wasn't too humid for you yesterday and you were able to spend time getting the car back on the road.
Your posts made it sound like the breakdown was sudden and you tested the fuel pump so it should be ignition. You said the plug wires sort of fell apart on you so I am thinking the carbon brush broke in the distributor cap or the rotor shorted out to the dizzy shaft.
Beyond that I won't make any guesses and I DO want to know what you found, Speckled Hen or not! Regardless, I hope it wasn't too humid for you yesterday and you were able to spend time getting the car back on the road.
OP
bigjones
Jedi Warrior
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Thanks for the reply Doug.
The carburetor jet was fully extended. So it was getting fuel, but too much. So it conked out and wouldn't start again.
I was driving from the gas station back home and it started "missing". So I thought it may be fuel starvation so to test this I pulled out the choke. Didn't help any so I pushed the choke knob back home and didn't think any more of it. As I got to the stop sign it conked out.
Not sure why the jet did not go back but when I saw it I just pressed lightly with a finger and it shot back home.
Obviously I need to investigate further but it is going to be in the comfort of the garage with the window AC full bore. First I need to move stuff (big woodworking eqpt) around - I'm about half done.
Cheers!
The carburetor jet was fully extended. So it was getting fuel, but too much. So it conked out and wouldn't start again.
I was driving from the gas station back home and it started "missing". So I thought it may be fuel starvation so to test this I pulled out the choke. Didn't help any so I pushed the choke knob back home and didn't think any more of it. As I got to the stop sign it conked out.
Not sure why the jet did not go back but when I saw it I just pressed lightly with a finger and it shot back home.
Obviously I need to investigate further but it is going to be in the comfort of the garage with the window AC full bore. First I need to move stuff (big woodworking eqpt) around - I'm about half done.
Cheers!
dklawson
Yoda
Offline
I'm glad you found the problem. It was a great day to be working on a car in our area so I hope you were able to get the car out and about for some test driving!
On some U.K. cars there was a version of the HS series carb that had what was called a WaxStat jet. The WaxStat was supposed to change the mixture a bit in response to temperatures in the engine bay for emissions purposes. Most people I know who have them have converted those jets to be "solid" by removing the wax cartridge and replacing it with 2 or 3 pennies. The nice thing about a WaxStat carb is it has a really nice and smooth choke linkage with a ball and socket type arrangement. It is much smoother acting than the stamped sheet metal choke linkage of the "solid jet" HS carb. I have had binding choke linkages on the Mini's SU carbs before. However, our 1500 Spitfire has a converted WaxStat HS4 carb on it and it has never shown any tendency to bind.
On some U.K. cars there was a version of the HS series carb that had what was called a WaxStat jet. The WaxStat was supposed to change the mixture a bit in response to temperatures in the engine bay for emissions purposes. Most people I know who have them have converted those jets to be "solid" by removing the wax cartridge and replacing it with 2 or 3 pennies. The nice thing about a WaxStat carb is it has a really nice and smooth choke linkage with a ball and socket type arrangement. It is much smoother acting than the stamped sheet metal choke linkage of the "solid jet" HS carb. I have had binding choke linkages on the Mini's SU carbs before. However, our 1500 Spitfire has a converted WaxStat HS4 carb on it and it has never shown any tendency to bind.
OP
bigjones
Jedi Warrior
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Yes, it's getting very pleasant now we are into the middle of September.
Thanks for that info on the choke linkages - very interesting.
I have a theory that I thought of at 2 am this morning. When I was cruising the needle would be high up. Pulling out the choke would lower the jet. Maybe they got separated and when I pushed in the choke the needle didn't go back in the jet but got wedged on the jet circumference - so the jet couldn't return.
Cheers!
Thanks for that info on the choke linkages - very interesting.
I have a theory that I thought of at 2 am this morning. When I was cruising the needle would be high up. Pulling out the choke would lower the jet. Maybe they got separated and when I pushed in the choke the needle didn't go back in the jet but got wedged on the jet circumference - so the jet couldn't return.
Cheers!
Morris
Yoda
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Back to your leak down results... It sounds like you are leaking through your valves. Here is a trick I learned that may help—While blowing air into the cylinder, tap the rocker arm with a hammer. If you are lucky, the carbon built up on your valve seats will break free and be blown clear by the air pressure. It's worked for me in the past.
OP
bigjones
Jedi Warrior
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Well, this is pitiful news.
I didn't get a steady reading on any of the cylinders - they all went down pretty quickly.
Just to get actual numbers, I timed each one for 20 sec and then took a reading (starting at 100 psi). For #1, 2, 3, 4, I got 35,43,49,50 psi.
(I would guesstimate any error of -/+ 5 for these numbers.)
From what I heard, the air is leaking from the push rod tubes.
PS Looking at those numbers there appears to be progression. However, the order was # 4, 1 3, 2 with the corresponding reading of 50, 35, 49, 43 psi.
This was on a warm engine.
The car starts first time and runs smooth - just when you are driving it the "missing" is noticeable.
Also, don't forget I got compression readings of approx 115 psi on all cylinders - not to sure of what is going on here.
PS. The plan for this morning is to try a lower input pressure (50 psi). The compressor is a small push-around unit that has trouble maintaining 100 psi. Maybe I'll get some better results :welcoming:
I didn't get a steady reading on any of the cylinders - they all went down pretty quickly.
Just to get actual numbers, I timed each one for 20 sec and then took a reading (starting at 100 psi). For #1, 2, 3, 4, I got 35,43,49,50 psi.
(I would guesstimate any error of -/+ 5 for these numbers.)
From what I heard, the air is leaking from the push rod tubes.
PS Looking at those numbers there appears to be progression. However, the order was # 4, 1 3, 2 with the corresponding reading of 50, 35, 49, 43 psi.
This was on a warm engine.
The car starts first time and runs smooth - just when you are driving it the "missing" is noticeable.
Also, don't forget I got compression readings of approx 115 psi on all cylinders - not to sure of what is going on here.
PS. The plan for this morning is to try a lower input pressure (50 psi). The compressor is a small push-around unit that has trouble maintaining 100 psi. Maybe I'll get some better results :welcoming:
Last edited:
dklawson
Yoda
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Are you saying you disconnected the air supply and watched the decay rate of the air pressure? If so... yeah, it is going to drop. I have never heard of doing it that way. I was taught that you supply 100 PSI out of the regulator, pass it through the 0.040" (1mm) orifice, then plumb it into the cylinder with a second pressure gauge after the orifice. You read the pressure on both sides of the orifice and determine a percentage drop. While not ideal, I have been advised that up to 20% leakage is not uncommon or a problem on a street engine.
EDIT: All done at TDC on the firing stroke as Morris said above to insure the valves are fully closed.
Leakage heard out of the pushrod tubes is typically blow-by.
EDIT: All done at TDC on the firing stroke as Morris said above to insure the valves are fully closed.
Leakage heard out of the pushrod tubes is typically blow-by.
Last edited:
OP
bigjones
Jedi Warrior
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Thanks Morris and Doug,
Here's how I managed to get the crankshaft not to move. I hot-glued on a sharpened piece of coat hanger to a spare rotor. Then I zeroed on the exact spot and made a mark with a fine yellow paint pen. If the first attempt moves the dizzie shaft counter clockwise (normal engine rotation) I know I have to move the next guess clockwise from the paint mark. If the second attempt moves the shaft clockwise, then I have it bracketed and I just keep trying until the shaft doesn't move.
It's a DIY leak-down tester (I'll try and find the link) but it has only one gauge and no provision for a 1 mm orifice - is that important?
I just hook up the compressor, dial in 100 psi on the tester and then hook the tester up to the spark plug adapter. I leave the compressor hooked up.
I'll be trying lower initial pressures later today.
OK, I went back to the shop and made a 1/16" orifice (close enough I'm thinking) as per Doug's comment:
This slowed the fall of the pressure reading (when taking a test). It got to about 40 or so psi and then the compressor kicked in. The reading started to climb! When the compressor shut off, the reading was up to 60 psi. I'm thinking this is the correct reading. It's up to the max of the compressor (say 120 psi) but it is throttled down to 100 psi and holding that 100 psi for quite a few seconds, during which the reading was steady at 60 psi. Pretty bad reading , I know, but this was on, now, a pretty cold, well, lukewarm, engine. Tomorrow I'll warm it 'til the cast iron is about to melt and take the 4 readings.
Here's how I managed to get the crankshaft not to move. I hot-glued on a sharpened piece of coat hanger to a spare rotor. Then I zeroed on the exact spot and made a mark with a fine yellow paint pen. If the first attempt moves the dizzie shaft counter clockwise (normal engine rotation) I know I have to move the next guess clockwise from the paint mark. If the second attempt moves the shaft clockwise, then I have it bracketed and I just keep trying until the shaft doesn't move.
It's a DIY leak-down tester (I'll try and find the link) but it has only one gauge and no provision for a 1 mm orifice - is that important?
I just hook up the compressor, dial in 100 psi on the tester and then hook the tester up to the spark plug adapter. I leave the compressor hooked up.
I'll be trying lower initial pressures later today.
OK, I went back to the shop and made a 1/16" orifice (close enough I'm thinking) as per Doug's comment:
This slowed the fall of the pressure reading (when taking a test). It got to about 40 or so psi and then the compressor kicked in. The reading started to climb! When the compressor shut off, the reading was up to 60 psi. I'm thinking this is the correct reading. It's up to the max of the compressor (say 120 psi) but it is throttled down to 100 psi and holding that 100 psi for quite a few seconds, during which the reading was steady at 60 psi. Pretty bad reading , I know, but this was on, now, a pretty cold, well, lukewarm, engine. Tomorrow I'll warm it 'til the cast iron is about to melt and take the 4 readings.
Last edited:
dklawson
Yoda
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I am confused by how you are doing this Adrian. I am posting some links below for DIY leak-down testers and of course... a Wikipedia article.
https://vmaxoutlaw.com/tech/leakdown_tester.htm
https://www.jalopyjournal.com/forum/threads/tools-guestion-homemade-leak-down-tester.758578/
and
https://en.wikipedia.org/wiki/Leak-down_tester
Yes, you need an orifice between the regulator and the spark plug adapter. The orifice is made by plugging a pipe nipple with something (epoxy, plastic dowel, etc). Then you drill a 0.040" hole through the plug. Thread a 100 PSI gauge into one of the regulator's gauge ports. Thread the orifice/nipple into the output port of the regulator. Attach a T fitting to the other side of the orifice/nipple. A second pressure gauge goes in the T and in the remaining T port you install a quick connect air line coupler. You use a hose with spark plug adapter to go between the quick coupler and the engine.
Set the compressor to deliver its max pressure. Connect the leak-down regulator to the air supply. With the spark plug adapter hose NOT installed, adjust the regulator so it is delivering 100 PSI as shown by the gauge on the the regulator. The other gauge should also show 100 PSI if it doesn't, write down what it does say.
Bring the cylinder you want to test to TDC on its firing stroke and put the car in gear so it won't move.
Screw the spark plug adapter hose into the engine and then plug it into the quick coupler on the leak-down tester. The gauge on the regulator should still show 100 PSI or VERY close to it. The gauge screwed into the T should now be reading lower. Note how much lower the T gauge reads now compared to what it said before connecting the spark plug adapter hose. The drop on the second gauge is your leak down figure. It should be steady. The reading should not drop or climb as long as your air compressor can keep up with the leakage.
https://vmaxoutlaw.com/tech/leakdown_tester.htm
https://www.jalopyjournal.com/forum/threads/tools-guestion-homemade-leak-down-tester.758578/
and
https://en.wikipedia.org/wiki/Leak-down_tester
Yes, you need an orifice between the regulator and the spark plug adapter. The orifice is made by plugging a pipe nipple with something (epoxy, plastic dowel, etc). Then you drill a 0.040" hole through the plug. Thread a 100 PSI gauge into one of the regulator's gauge ports. Thread the orifice/nipple into the output port of the regulator. Attach a T fitting to the other side of the orifice/nipple. A second pressure gauge goes in the T and in the remaining T port you install a quick connect air line coupler. You use a hose with spark plug adapter to go between the quick coupler and the engine.
Set the compressor to deliver its max pressure. Connect the leak-down regulator to the air supply. With the spark plug adapter hose NOT installed, adjust the regulator so it is delivering 100 PSI as shown by the gauge on the the regulator. The other gauge should also show 100 PSI if it doesn't, write down what it does say.
Bring the cylinder you want to test to TDC on its firing stroke and put the car in gear so it won't move.
Screw the spark plug adapter hose into the engine and then plug it into the quick coupler on the leak-down tester. The gauge on the regulator should still show 100 PSI or VERY close to it. The gauge screwed into the T should now be reading lower. Note how much lower the T gauge reads now compared to what it said before connecting the spark plug adapter hose. The drop on the second gauge is your leak down figure. It should be steady. The reading should not drop or climb as long as your air compressor can keep up with the leakage.
OP
bigjones
Jedi Warrior
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Doug, I'm using a single gauge tester, as described in your first link.
When I built it, several years ago, from a plans off the internet, it didn't include a restrictive orifice. But I've included that now. (Although the smallest drill bit I have is 1/16" (ie 62.5 thou instead of 40 thou)). So now it looks exactly like the picture in the first link.
I think the confusion arises because most store bought testers have 2 gauges.
Your wiki link says the single gauge units work fine so long as the leakage is small (which isn't true in my case, maybe that is the problem)
Cheers!
When I built it, several years ago, from a plans off the internet, it didn't include a restrictive orifice. But I've included that now. (Although the smallest drill bit I have is 1/16" (ie 62.5 thou instead of 40 thou)). So now it looks exactly like the picture in the first link.
I think the confusion arises because most store bought testers have 2 gauges.
Your wiki link says the single gauge units work fine so long as the leakage is small (which isn't true in my case, maybe that is the problem)
Cheers!
dklawson
Yoda
Offline
As the Wikipedia article says there is no "official" standard size for the orifice. However, most sites talk about using the 1mm through hole so that the numbers people measure on the second gauge can be compared between different testers. I don't know how your measurements with a 0.063" orifice will compare to the ones I might collect with my leak-down tester and its 0.040" orifice. It just means we cannot compare readings... that's all.
The single gauge leak-down tester can still work the same as the dual gauge. However, looking at the pictures of your tester, the gauge is located in the regulator body which will be monitoring the output pressure of the regulator NOT the downstream (low pressure) side of the orifice... which is what you are trying to measure. If you have a single gauge, it has to be located on the engine side of the orifice, not the regulator side. With a single gauge you can loose confidence in the measurement because you don't know what is happening with the supply pressure on the "high side" of the orifice. Consider what you were seeing as your compressor cycled on and off.
For a single gauge setup, make sure the gauge is installed in a T fitting on the engine side of the orifice (the flow path is: Air into regulator, out of regulator at 100 PSI, through nipple with orifice, into a T (with the gauge), out a quick disconnect for attaching spark plug adapter hose). Disconnect the spark plug adapter hose so no air can flow. Adjust the regulator until the gauge shows 100 PSI. When you connect the spark plug adapter hose you won't know how the supply pressure to the high side of the orifice is changing but you will see the reduced pressure on the low side of the orifice reflecting the leakage.
If you can get a quick measurement as soon as you connect the spark plug adapter hose (before the compressor drops much) that value should indicate what is going on. If it dropped from 100 to 60 PSI that is a serious issue regardless of orifice size. Again, the measurement has to be taken quickly before the supply pressure from the compressor drops much. Pundits will say a race engine leaks 2% or less (I think that really depends a lot on the type of rings used and can be much higher with Dykes rings). Those same pundits often say that a healthy street engine will have around 5% leakage and anything more represents a problem. I don't think that is an accurate statement but since I am not an engine builder... who am I to question them. However, I have seen higher leakage (as high as 15%) on healthy engines. If your measurements are consistently around 60 PSI and you are confident that at least briefly you have 100 PSI coming out of the regulator... the 60 PSI readings are cause for concern. When you consider those leakage readings, the compression values around 110-115 (that I think you measured earlier), and your observation that the air was coming out of the pushrod holes, that suggests tired or worn rings.
The single gauge leak-down tester can still work the same as the dual gauge. However, looking at the pictures of your tester, the gauge is located in the regulator body which will be monitoring the output pressure of the regulator NOT the downstream (low pressure) side of the orifice... which is what you are trying to measure. If you have a single gauge, it has to be located on the engine side of the orifice, not the regulator side. With a single gauge you can loose confidence in the measurement because you don't know what is happening with the supply pressure on the "high side" of the orifice. Consider what you were seeing as your compressor cycled on and off.
For a single gauge setup, make sure the gauge is installed in a T fitting on the engine side of the orifice (the flow path is: Air into regulator, out of regulator at 100 PSI, through nipple with orifice, into a T (with the gauge), out a quick disconnect for attaching spark plug adapter hose). Disconnect the spark plug adapter hose so no air can flow. Adjust the regulator until the gauge shows 100 PSI. When you connect the spark plug adapter hose you won't know how the supply pressure to the high side of the orifice is changing but you will see the reduced pressure on the low side of the orifice reflecting the leakage.
If you can get a quick measurement as soon as you connect the spark plug adapter hose (before the compressor drops much) that value should indicate what is going on. If it dropped from 100 to 60 PSI that is a serious issue regardless of orifice size. Again, the measurement has to be taken quickly before the supply pressure from the compressor drops much. Pundits will say a race engine leaks 2% or less (I think that really depends a lot on the type of rings used and can be much higher with Dykes rings). Those same pundits often say that a healthy street engine will have around 5% leakage and anything more represents a problem. I don't think that is an accurate statement but since I am not an engine builder... who am I to question them. However, I have seen higher leakage (as high as 15%) on healthy engines. If your measurements are consistently around 60 PSI and you are confident that at least briefly you have 100 PSI coming out of the regulator... the 60 PSI readings are cause for concern. When you consider those leakage readings, the compression values around 110-115 (that I think you measured earlier), and your observation that the air was coming out of the pushrod holes, that suggests tired or worn rings.
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Since you can buy a leak down tester for so little (think Harbor Freight) is it really reasonable to try making one at home. I know it will not be a precision instrument but still adequate for home use and probably more so than one you can make from bits and pieces. And if there is any chance that the compressor won't keep up then the whole operation is questionable. Also trying to get a reading before the compressor loses pressure defeats one of the most important aspects of the leak down test anyway. You won't have much time to find out where it is leaking. JMHO, of course.
OP
bigjones
Jedi Warrior
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Morris,
Good thinking about using a needle. I was wondering how people went about it. A 1/16" drill bit is pretty dang thin so I can't imagine a 1 mm rill bit.
Doug,
Thanks for the explanation of the tester. Looks like I have to redesign it.
Before I got your message I went ahead with the method as in my last post. I got the same 60 psi on #4. Things got even worse: Here's the number for #1,2,3,4 - 46,45,50,60. These were steady numbers.
While I was at it, I ran some "wet" compression readings: all about 160 +/- 5 psi.
Looks like I need to see what is involved with a ring job.
Cheers!
Good thinking about using a needle. I was wondering how people went about it. A 1/16" drill bit is pretty dang thin so I can't imagine a 1 mm rill bit.
Doug,
Thanks for the explanation of the tester. Looks like I have to redesign it.
Before I got your message I went ahead with the method as in my last post. I got the same 60 psi on #4. Things got even worse: Here's the number for #1,2,3,4 - 46,45,50,60. These were steady numbers.
While I was at it, I ran some "wet" compression readings: all about 160 +/- 5 psi.
Looks like I need to see what is involved with a ring job.
Cheers!