I have read a little about the B distributor and I am using one on my 30 Huckster. What I am not sure of is what initial timing I should set it up on. I have a Nurex Timing timing tab set with the pulley marked on TDC so I can check things with a timing light. Right now I have the initial set at 9.5 degrees but the engine wants to run hotter than it used to. Should I try more initial timing? What is everyone else running who is using the B distributor on their model A?
B Distributor Initial Timing
- Thread starter DBSHELTON
- Start date
J Franklin
Well-known member
I time mine by ear since I still have the A gear cover. I will note your answers for reference.
Synchro909
Well-known member
I would expect that at those speeds without a heavy load like pulling up a steep hill or towing, you would be at maximum advance. (lever all the way down.)
CWPASADENA
Well-known member
Set the initial timing at 17-18 Deg. That will get you in the ball park. The "B" distributor only has about 12-13 Deg. of mechanical advance. The mechanical plus the initial will give you about 30 Deg. total which is where you want to be. This is assuming that your "B" distributor is in good condition.
Chris W.
Chris W.
I was wondering if 17-18 was too much initial, but now you mention it, I am only getting about 12 or so advance. (I actually have 3 Model B distributors that I have refreshed and they all top out at about 12 degrees advance) Sounds like a plan. Thanks.
GRutter
Senior Member
Don't confuse crankshaft degrees with distributor degrees.
The mechanical advance of the B distributor was 8.5 degrees (17 crankshaft degrees)
If you had a Model B timing cover, the initial timing would be 19 deg BTDC.
The mechanical advance of the distributor would add 17 degreees to that, giving you a maximum of 36 degrees advance.
Set your initial timing at 19 degrees.
Other considerations:
The model A distributor initial timing is at 0 deg BTDC, but the manual advance would allow you to move it to 40 deg. That is why it is always recommended to not advance the spark all the way... it is too advanced for an A engine. But it's lower compression was more tolerant of over advancing.
The Model B engine had a higher compression head and a better cam. It's max advance of 36 deg was perfect for that combination.
The mechanical advance of the B distributor was 8.5 degrees (17 crankshaft degrees)
If you had a Model B timing cover, the initial timing would be 19 deg BTDC.
The mechanical advance of the distributor would add 17 degreees to that, giving you a maximum of 36 degrees advance.
Set your initial timing at 19 degrees.
Other considerations:
The model A distributor initial timing is at 0 deg BTDC, but the manual advance would allow you to move it to 40 deg. That is why it is always recommended to not advance the spark all the way... it is too advanced for an A engine. But it's lower compression was more tolerant of over advancing.
The Model B engine had a higher compression head and a better cam. It's max advance of 36 deg was perfect for that combination.
Patrick L.
Well-known member
I would not recommend setting base timing more than 12º. Any more than that and the engine could kick back while starting.
A distributor advance putting out 12º equals 24º at the crank. So 36º total is plenty.
So if you have TDC marked on the pulley just raise the engine speed to a good cruise RPM and then guesstimate the amount of timing advance with the timing light. Or add a timing strip and you'll know for sure.
A distributor advance putting out 12º equals 24º at the crank. So 36º total is plenty.
So if you have TDC marked on the pulley just raise the engine speed to a good cruise RPM and then guesstimate the amount of timing advance with the timing light. Or add a timing strip and you'll know for sure.
Joe K
Well-known member
This description is closest to Vince Falter's description at http://www.fordgarage.com/pages/bdistributoradvance.htm
Joe K
Who is currently going through converting a Model A block for use as a Gordon-Smith compressor using Model B distributor & timing. (Gordon Smith kind of relies on centrifugal variable timing to compensate for the automatic loading/unloading of the engine.)
Jack Shaft
BANNED
Model A or model B engine timing..one degree of advance per thousand rpm is what you are shooting for.
diameter of pulley x3.1416 divided by 360 gives you degree spacing.On a model A stock crankshaft pulley 5 degrees is a bit over 1/4 "..or use your nurex timing grid and TDC mark.hook up timing light and cheapie garage sale tach and dwell meter (40 bucks on Amazon) start engine,at 500 rpm either move the breaker plate or turn the distributor cam (pain,you have to shut off the engine and fiddle with it) to be 5 degrees advanced at 500 rpm,10 degrees at 1000,15 degrees at 1500 and so on check up to 2000 rpm.Basically as rpm goes up you can see the mechanical advance rise,basically 'mapping' the advance,this tell you if your advance is working correctly.the b works well,what get confusing is static timing it,so dont,use a timing light.
diameter of pulley x3.1416 divided by 360 gives you degree spacing.On a model A stock crankshaft pulley 5 degrees is a bit over 1/4 "..or use your nurex timing grid and TDC mark.hook up timing light and cheapie garage sale tach and dwell meter (40 bucks on Amazon) start engine,at 500 rpm either move the breaker plate or turn the distributor cam (pain,you have to shut off the engine and fiddle with it) to be 5 degrees advanced at 500 rpm,10 degrees at 1000,15 degrees at 1500 and so on check up to 2000 rpm.Basically as rpm goes up you can see the mechanical advance rise,basically 'mapping' the advance,this tell you if your advance is working correctly.the b works well,what get confusing is static timing it,so dont,use a timing light.
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Y-Blockhead
Well-known member
Jack Shaft
BANNED
Was playing around with timing. Not hard to start until almost 30 degrees. I now have the initial set on 19 degrees. No problem starting at all, sounds very good but it is raining so a test drive is out.
Jackshaft, One degree of advance per thousand RPM? Surely that is not right.
Jackshaft, One degree of advance per thousand RPM? Surely that is not right.
Jack Shaft
BANNED
One degree per 100 rpm..24 degrees at 2400 becareful,check full advance make sure you don't exceed
CWPASADENA
Well-known member
The Model "B" distributor has only 12 Deg. mechanical advance as measured at the crank shaft, (or 6 deg. Distributor shaft deg.). You could hand crank Model B's with 18-19 deg. initial without a problem at all. Time it the way Henry said to do it and it will be fine.
If you do not have enough initial timing when using a "B" distributor, the engine will be too retarded and will run hot and be down on power.
If you are running a 6.0 high compression head, it is not a good idea to have more than 28-30 deg. total timing at 2000 rpm.
My opinion,
Chris W.
Patrick L.
Well-known member
OK, I was wrong. I should have looked it up. I thought there was a 9.5º difference between the A and B front covers.
Apparently Model B base timing is 19º with minimal distributor advance totaling 36º.
http://www.fordgarage.com/pages/bdistributoradvance.htm
I know in 'more modern' cars I don't want base timing any more than 12º for kick back reasons.
Apparently Model B base timing is 19º with minimal distributor advance totaling 36º.
http://www.fordgarage.com/pages/bdistributoradvance.htm
I know in 'more modern' cars I don't want base timing any more than 12º for kick back reasons.
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