distrubutor Mallory

[Masot]

Thank you all for all the information.

I working with distributor

[Ronnieroadster]

Originally Posted by Masot

Thank you all for all the information.

I working with distributor

If you need to have the distributer set with the correct advance send me a personal message. Since I have set up many of the type you have.
Ronnieroadster

[hotrodcbx]

I have the same distributor as you, a chev Mallory converted to flathead. Remember, that unit comes with a stepped adjustment tool, that allows you to adjust the number of degrees you get when the flyweights are fully extended. You can then get the curve you want with the springs. I have 8d advance total (16d engine) with 10d initial.. I have this all in by 2000rpm.

[Bored&Stroked]

If you know somebody who has a distributor machine - that sure helps as you can see exactly how much advance you have at various RPMs. As noted by Ronnie and others, your total advance (depending on compression, gas quality, gearing, etc) - will usually be around 22 - 26 degrees (total). I usually run most of mine at about 24 or so.

Carbs: Strombergs do not have any real adjustment for load, other than when the throttle plates are almost fully open and the mechanical power-valve is open at the bottom of the accel pump well. Given this, it is quite hard to achieve optimal AFRs at both cruise and under heavy throttle or load. So, what you'll usually find is that you'll need to jet them such that it doesn't detonate under heavy load . . . the net result is that you'll usually find it will have a richer AFR than you'd like under cruise or partial load. That is just the way it goes.

On AFRs - you have to put the O2 sensor about 2 feet back or more from the exhaust ports. This isn't possible with most of the typical 'Sandy Belond Style' headers (most of which use a "slip fit" exhaust extension). If you put them in the header, they are too close to the block. If you're installing EGT bungs, then put those as close to the block as possible - in the exhaust for the rear cylinders (always run the hottest).

If you put the O2 sensors past a leaky exhaust joint (like a slip-fit), then your AFR readings will NOT be correct - you must have a leak-free system upstream of the O2 bungs. You don't want to tune the engine with an O2 in the wrong place or with leaky exhaust - you'll have incorrect readings.

I always weld in 2 bolt header flanges and use gaskets in my exhaust systems - so that there are no leaks and also so I can easily take the dang thing apart. This is VERY important if you're tuning with any AFR meter.

My O2 bungs are about 1 foot back in the exhaust pipes that bolt to the header flanges. Make sure you weld your O2 bungs into the exhaust pipe at the right angle (never facing down - usually at about 10 or 2 o'clock).

Jets and Power Valves: I'd start with "out of the box" jets and power-valves, then go from there. Also, on the power valves the numbers are BACKWARDS from what we're used too with normal jets -- the bigger the number, the smaller the power-valve (leaner under full throttle).

Good luck!
B&S

2017-04-23 17.18.13.jpg

2017-04-23 14.42.21 copy.jpg

[Ol' Ron]

Max advance 26/28 degrees is only necessary when running a lean mixture in cruise. I try to get 15.5 Af, but this is usuall a waste of time with the 94s/97s. But possable with the Edelbrock 500 4bl. This is one of the reasons I started putzing with the EFI. At present i spend what time I have left with the roadster and the New intake ports. I'd also like to trade am Edelbrock super dual for the late Offy super dual.
Gramps

[Masot]

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Originally Posted by Ronnieroadster

If you need to have the distributer set with the correct advance send me a personal message. Since I have set up many of the type you have.
Ronnieroadster

Thanks Ronnie, I live in Spain (Europe) it would be a problem to send

[Masot]

Originally Posted by hotrodcbx

I have the same distributor as you, a chev Mallory converted to flathead. Remember, that unit comes with a stepped adjustment tool, that allows you to adjust the number of degrees you get when the flyweights are fully extended. You can then get the curve you want with the springs. I have 8d advance total (16d engine) with 10d initial.. I have this all in by 2000rpm.

I do not have a stepped adjustment tool, I have regulation with strobe light and with a lathe

[Masot]

Originally Posted by Bored&Stroked

If you know somebody who has a distributor machine - that sure helps as you can see exactly how much advance you have at various RPMs. As noted by Ronnie and others, your total advance (depending on compression, gas quality, gearing, etc) - will usually be around 22 - 26 degrees (total). I usually run most of mine at about 24 or so.

Carbs: Strombergs do not have any real adjustment for load, other than when the throttle plates are almost fully open and the mechanical power-valve is open at the bottom of the accel pump well. Given this, it is quite hard to achieve optimal AFRs at both cruise and under heavy throttle or load. So, what you'll usually find is that you'll need to jet them such that it doesn't detonate under heavy load . . . the net result is that you'll usually find it will have a richer AFR than you'd like under cruise or partial load. That is just the way it goes.

On AFRs - you have to put the O2 sensor about 2 feet back or more from the exhaust ports. This isn't possible with most of the typical 'Sandy Belond Style' headers (most of which use a "slip fit" exhaust extension). If you put them in the header, they are too close to the block. If you're installing EGT bungs, then put those as close to the block as possible - in the exhaust for the rear cylinders (always run the hottest).

If you put the O2 sensors past a leaky exhaust joint (like a slip-fit), then your AFR readings will NOT be correct - you must have a leak-free system upstream of the O2 bungs. You don't want to tune the engine with an O2 in the wrong place or with leaky exhaust - you'll have incorrect readings.

I always weld in 2 bolt header flanges and use gaskets in my exhaust systems - so that there are no leaks and also so I can easily take the dang thing apart. This is VERY important if you're tuning with any AFR meter.

My O2 bungs are about 1 foot back in the exhaust pipes that bolt to the header flanges. Make sure you weld your O2 bungs into the exhaust pipe at the right angle (never facing down - usually at about 10 or 2 o'clock).

Jets and Power Valves: I'd start with "out of the box" jets and power-valves, then go from there. Also, on the power valves the numbers are BACKWARDS from what we're used too with normal jets -- the bigger the number, the smaller the power-valve (leaner under full throttle).

Good luck!
B&S

Attachment 483217

Attachment 483218

Good information, I do as you indicate.

in photo see where to install nuts, more than 2 feet and 10 o`clock

[Masot]

Originally Posted by Ol' Ron

Max advance 26/28 degrees is only necessary when running a lean mixture in cruise. I try to get 15.5 Af, but this is usuall a waste of time with the 94s/97s. But possable with the Edelbrock 500 4bl. This is one of the reasons I started putzing with the EFI. At present i spend what time I have left with the roadster and the New intake ports. I'd also like to trade am Edelbrock super dual for the late Offy super dual.
Gramps

First test to do with 10/12 idle and 22/24 max. how to indicate Ronnie
with AF finish adjusting