Flathead distributor "service"
- Thread starter BUBBAS IGNITION
- Start date
BUBBAS IGNITION
Well-known member
No resistor is needed with the bosch blue coil....
Attachments
BUBBAS IGNITION
Well-known member
Looks like the coil number is 0-221-119-027 we get them from a off road VW dealer here in town for $40-$50 each........
HotRodmicky
Senior Member
Bosch says the blue coil is for 4 and 6 cylinder engines.
Red coil for 8cyl.
Red one needs a resistor
I always use the blue one......
My 276ci sees 5K rpm not often but, the blue coil still fires the spark plug ok,
no problem there.
Maybe Bubba can explain when you need which coil, but
i think blue is all you need
A 6cly engine at 8K rpm
and a 8cyl. at 6K rpm
have the same cycles per minute
an who revs his Flathead to 6K ????
Red coil for 8cyl.
Red one needs a resistor
I always use the blue one......
My 276ci sees 5K rpm not often but, the blue coil still fires the spark plug ok,
no problem there.
Maybe Bubba can explain when you need which coil, but
i think blue is all you need
A 6cly engine at 8K rpm
and a 8cyl. at 6K rpm
have the same cycles per minute
an who revs his Flathead to 6K ????
BUBBAS IGNITION
Well-known member
As mentioned above the Bosch Blue coil was made for 4 and 6cylinder engines based on ramp ( coil build up time) and overall rpm ranges etc. However with the flatheads rpm band the bosch blue works very well.
The key is having the correct primary ignition resistance. Coils have got pretty bad in quality over the last few years with many companys buying off shore stuff that doesnt seem to hold up well with the heat, but in their defense its usually a misapplication that causes the problems.
Most of the time when someone walks into the shop with a fryed coil its the wrong coil for the application purchased at a swap meet or a buddys garage.
The 12 volt ignition system needs approx 3-4 ohms of primary resistance to maintain a current flow of 3-4 amps to keep everything working for many happy miles . A electronic system usually is higher amps and lower resistance.
We have a coil made for us ( USA made) in Layafette Indiana thats oil filled and is a very good quality. Costs a little more but very seldom do we have a return.
Another tip is that spark plug gap goes with the engine and combustion chamber NOT the ignition system. A wide gap and hotter spark is seldom needed in a flathead application...
The key is having the correct primary ignition resistance. Coils have got pretty bad in quality over the last few years with many companys buying off shore stuff that doesnt seem to hold up well with the heat, but in their defense its usually a misapplication that causes the problems.
Most of the time when someone walks into the shop with a fryed coil its the wrong coil for the application purchased at a swap meet or a buddys garage.
The 12 volt ignition system needs approx 3-4 ohms of primary resistance to maintain a current flow of 3-4 amps to keep everything working for many happy miles . A electronic system usually is higher amps and lower resistance.
We have a coil made for us ( USA made) in Layafette Indiana thats oil filled and is a very good quality. Costs a little more but very seldom do we have a return.
Another tip is that spark plug gap goes with the engine and combustion chamber NOT the ignition system. A wide gap and hotter spark is seldom needed in a flathead application...
BUBBAS IGNITION
Well-known member
Butch11443
Senior Member
Bubba, I'm running a light brown Bosch coil I got off a 72 Fiat years ago. It's marked 12volt, so I hooked it up with no resistor. I'm running a Mallory dual point converted to electronic. It works great so far. Can I do the same with one of your Chevy's converted to electronic?
Butch
Butch
BUBBAS IGNITION
Well-known member
I would think so..
BUBBAS IGNITION
Well-known member
Richard in Florida
Well-known member
[BUBBA]... the design and the compression ratio of the flathead doesnt really need the features a MSD box can bring.[/QUOTE]
I was running an HEI ignition when I found a very clean MSD 6A for $60. I didn't expect to feel any difference at all, but I couldn't resist.
I was wrong!
More low-end torque was immediately apparent. Fifth gear (OD) now felt like fourth gear. I was effortlessly turning corners in fourth gear that used to call for third.
It makes a difference.
I was running an HEI ignition when I found a very clean MSD 6A for $60. I didn't expect to feel any difference at all, but I couldn't resist.
I was wrong!
More low-end torque was immediately apparent. Fifth gear (OD) now felt like fourth gear. I was effortlessly turning corners in fourth gear that used to call for third.
It makes a difference.
56shoebox
Junior Member
"The blue bosch ( vw beetle) coil is a 3-4 ohm internally resisted ignition coil and one of the best out there . Good choice for a coil..."
"As mentioned above the Bosch Blue coil was made for 4 and 6cylinder engines based on ramp ( coil build up time) and overall rpm ranges etc. However with the flatheads rpm band the bosch blue works very well. The key is having the correct primary ignition resistance. The 12 volt ignition system needs approx 3-4 ohms of primary resistance to maintain a current flow of 3-4 amps to keep everything working for many happy miles . A electronic system usually is higher amps and lower resistance."
I am confused as to what Bubba is saying. Please clear me up. Above he says to use a 1.5 ohm primary resistance coil then later in the post he recommends the Bosch 3.4 ohm primary resistance coil (part 0-221-119-027).
Another thing confusing me is where he is talking about the primary ignition resistance and not needing an external resister with the blue Bosch coil. Is he talking about the ballast resister? Is it a 1.5 ballast resisiter he ships with his GM conversion points distributor?
Thanks ahead of time for any clarification help provided. Bubba if you answer this yourself I am referring to you in a third party in case you don't see this post.
BUBBAS IGNITION
Well-known member
We typically want approx 3 ohms resistance in the primary of a 12 volt point type of ignition.
One way to get that ressitance is to use a 1.5 ohm coil and a 1.5 ohm resisitor for a total of 3.0 ohms or 4 amps in the circuit. ( We ship this resistor with our units as many have had trouble getting them )
Another way to get this is to use the Bosch blue coil at 3 ohms as well.
The actual rpm band of the flathead works very well either way....
Ralph Moore
Well-known member
Just read this post, and now I'm going to get yelled at.
I'm putting all cloth wiring in my car, from RI wiring, and in the process of doing so I took out the dist primary wire and out a cloth covered 14 ga wire.
I did not know that was so critical. Now I have to see if I can find the one I took out, or I can grovel and see if I can get Bubba to send another.
I'm putting all cloth wiring in my car, from RI wiring, and in the process of doing so I took out the dist primary wire and out a cloth covered 14 ga wire.
I did not know that was so critical. Now I have to see if I can find the one I took out, or I can grovel and see if I can get Bubba to send another.
pineapple
Member
I have never cared for the coil mount on the 8ba cylinder head, I feel it's clunky and crowded. I just finished building a new engine for my f1, (maiden voyage was sunday actually). Anyhow, I fabricated a new coil mount that attaches to the inner fender, to clean up the cylinder head area. I have one of your distributors in my engine, the lead was not long enough to reach my new coil mounting position. Since I did not know any better until I saw this, I cut and spliced the lead and covered it with asphalt wire cover. I'm happy to get a new bosch blue coil, but my question is, do I need to replace the lead with a longer one of the same type, or different gage as the length is different? Also if I use the bosch blue, do I need to remove anything from the distributor?(resistor?)
Thanks.
Matt.
Thanks.
Matt.
Roger/Sacramento
Senior Member
Amazon has three for sale:light blue is $70, dark blue is $50, and another for $27 made in Brazil. No specs available. Which one is correct to buy ?
BUBBAS IGNITION
Well-known member
Leave the lead in place as final resistor and extend if needed . Shouldnt need a resistor with the Bosch blue...