True Speed

[stuffedpike20]

What do you mean by floaty?

I mean the sensation at increasing speed that the steering gets lighter and lighter and the car feels tiny, vulnerable and easily buffeted by lorries etc like it is floating on air. I think that whereas a modern car is designed with spoilers etc to maintain down force that exactly the opposite happens with a Minor at speed. Mine is better with the weight of 2 people in it.

Just realised both Stuffedpike and I used this word.

Stephen

I was using it because you did....but it is a good description!

[stuffedpike20]

I have sometimes wondered if a more hotrod trimmed Minor would feel more grounded and less floaty.
Either a spline lower on the torsion bars, or a longer rear spring shackle to lower the front end to give a ground effect ( like 'gentlemen lift your skirts' ).

[stuffedpike20]

Does knowing how a car works make the driver more cautious, or more confident?

[jiminwatford]

Old thread, I know

My Minor didn't particularly like going over 50 until I had it tuned by AC Dodd last weekend

He said the advance curve way far too weak and it needed a new distributor and the carb was heavily worn

But working with what he had and new service items it runs very smoothly and flows past 50 without noticing. Cruises easily at 60 and accelerates well from there. We slowed down at an indicated 80 because the wheel wobble was a bit distracting 🫨

I think he'll make any SU carbed engine run better and in most cases transform it.

Check out his YouTube https://youtu.be/Z6M2yV0Ajbw?is=evYrr7_GjBqSzu16

[myoldjalopy]

Good result then!

[svenedin]

Somebody on Minors on Tour was telling me they were very pleased with AC Dodd's work. Although I don't have his expertise, I can tune my car quite well in terms of getting the fuel mixture right at idle and the ignition timing. The advance curve is what Distributor Doctor determined for my engine. What I can't do at home is measure the percentage carbon monoxide (CO) at different speeds and loads to determine whether the fuel mixture is right throughout the rev range. That kind of thing really needs a rolling road and somebody with the skill to interpret the results and either choose an off the shelf needle or create a custom profile.

Stephen

[jiminwatford]

Somebody on Minors on Tour was telling me they were very pleased with AC Dodd's work. Although I don't have his expertise, I can tune my car quite well in terms of getting the fuel mixture right at idle and the ignition timing. The advance curve is what Distributor Doctor determined for my engine. What I can't do at home is measure the percentage carbon monoxide (CO) at different speeds and loads to determine whether the fuel mixture is right throughout the rev range. That kind of thing really needs a rolling road and somebody with the skill to interpret the results and either choose an off the shelf needle or create a custom profile.

Stephen

From what i have seen fitting an AFR gauge shows the fuelling under load but if fine tuning the needle is what's needed to optimise things then i would say getting your car to AC is what's needed

The most cost-effective way is to find out about a group tune he is doing where he spends up to an hour on your car for around £150 but can transform how it runs

He doesn't have premises but will come out to you and you pay depending on distance. He's based in Salisbury. He's main method of communication is via Facebook Messenger

[svenedin]

Somebody on Minors on Tour was telling me they were very pleased with AC Dodd's work. Although I don't have his expertise, I can tune my car quite well in terms of getting the fuel mixture right at idle and the ignition timing. The advance curve is what Distributor Doctor determined for my engine. What I can't do at home is measure the percentage carbon monoxide (CO) at different speeds and loads to determine whether the fuel mixture is right throughout the rev range. That kind of thing really needs a rolling road and somebody with the skill to interpret the results and either choose an off the shelf needle or create a custom profile.

Stephen

From what i have seen fitting an AFR gauge shows the fuelling under load but if fine tuning the needle is what's needed to optimise things then i would say getting your car to AC is what's needed

The most cost-effective way is to find out about a group tune he is doing where he spends up to an hour on your car for around £150 but can transform how it runs

He doesn't have premises but will come out to you and you pay depending on distance. He's based in Salisbury. He's main method of communication is via Facebook Messenger

Yes indeed. Actually I had mine tuned on a rolling road a while back and a custom needle was made. Sanspeed of Bexleyheath.

Stephen

[stuffedpike20]

I did post recently about AC Dodd, and his practice of drilling holes in the air filter box.
The replies convinced me to leave well alone.
I think I have maintained all my minors reasonably well over the years, but the one with the pipe from the rocker cover to the carb was exceptional.
No idea why.

[svenedin]

I did post recently about AC Dodd, and his practice of drilling holes in the air filter box.
The replies convinced me to leave well alone.
I think I have maintained all my minors reasonably well over the years, but the one with the pipe from the rocker cover to the carb was exceptional.
No idea why.

The owner of that car, the one with the drilled air filter box was the owner I spoke to. She told me the car goes much better and she is delighted. I said I don't like the idea of a drilled air filter housing and and she said "How often is anybody body going to see it, why don't you get another undrilled cover just for car shows?". Fair point I thought. Nonetheless, nobody is going to drill my air filter housing!

Stephen

[jiminwatford]

AC did drill my airbox. Which was totally my decision. It's essentially free power and he did match the fuelling to meet the extra air flow. It's makes a bit more noise but I like that and when you put your foot down it has a nice growl I believe this is what has given it the extra 'go' at the top end

As full disclosure, AC was quite clear that i needed a new distributor and as such drilling the airbox reduced the low end torque. I asked him about this and he said 'yes it will, you've drilled the airbox' lol. But if i replaced the distributor with a good advance curve i would have 'more torque than ever' so fair enough

I've considered blocking the holes back up to see if it returns some of the torque but it could potentially richen the mixture up to a dangerous extent. Asking AC if I should do this he said 'No, don't do that. That distributor needs a new advance curve'

There are other things i need to do before worrying about this. And in the mean time i can enjoy overtaking things i wouldn't have dared to before

[svenedin]

AC did drill my airbox. Which was totally my decision. It's essentially free power and he did match the fuelling to meet the extra air flow. It's makes a bit more noise but I like that and when you put your foot down it has a nice growl I believe this is what has given it the extra 'go' at the top end

As full disclosure, AC was quite clear that i needed a new distributor and as such drilling the airbox reduced the low end torque. I asked him about this and he said 'yes it will, you've drilled the airbox' lol. But if i replaced the distributor with a good advance curve i would have 'more torque than ever' so fair enough

I've considered blocking the holes back up to see if it returns some of the torque but it could potentially richen the mixture up to a dangerous extent. Asking AC if I should do this he said 'No, don't do that. That distributor needs a new advance curve'

There are other things i need to do before worrying about this. And in the mean time i can enjoy overtaking things i wouldn't have dared to before

That's very informative. I thought there would be more noise with a drilled air box. There certainly is with the pancake type filters. Also interesting to hear the trade off between low-end torque and top end acceleration.

I live in a hilly area.. Low-end torque is very important whereas flat out top speed doesn't matter much to me. Having said this, I was doing 70 mph going uphill on the A3 a few weeks ago. It was 6am on a Sunday. morning having arrived on an overnight ferry into Portsmouth with an empty road. I was rather impressed but I broke down a few miles further on with a failed condenser! The speedo cable also gave up and the gearbox starting leaking oil from the rear seal. Serves me right for pushing my luck.

Stephen

[jiminwatford]

AC did drill my airbox. Which was totally my decision. It's essentially free power and he did match the fuelling to meet the extra air flow. It's makes a bit more noise but I like that and when you put your foot down it has a nice growl I believe this is what has given it the extra 'go' at the top end

As full disclosure, AC was quite clear that i needed a new distributor and as such drilling the airbox reduced the low end torque. I asked him about this and he said 'yes it will, you've drilled the airbox' lol. But if i replaced the distributor with a good advance curve i would have 'more torque than ever' so fair enough

I've considered blocking the holes back up to see if it returns some of the torque but it could potentially richen the mixture up to a dangerous extent. Asking AC if I should do this he said 'No, don't do that. That distributor needs a new advance curve'

There are other things i need to do before worrying about this. And in the mean time i can enjoy overtaking things i wouldn't have dared to before

That's very informative. I thought there would be more noise with a drilled air box. There certainly is with the pancake type filters. Also interesting to hear the trade off between low-end torque and top end acceleration.

I live in a hilly area.. Low-end torque is very important whereas flat out top speed doesn't matter much to me. Having said this, I was doing 70 mph going uphill on the A3 a few weeks ago. It was 6am on a Sunday. morning having arrived on an overnight ferry into Portsmouth with an empty road. I was rather impressed but I broke down a few miles further on with a failed condenser! The speedo cable also gave up and the gearbox starting leaking oil from the rear seal. Serves me right for pushing my luck.

Stephen

I'm not an expert but i believe that if my dizzy was in good condition there wouldn't have been a trade off with the torque. I wouldn't like it to be set in stone that if someone (as skilled as AC) were to tune your car and give the option of drilling the airbox it would result in a loss of torque. Maybe by mentioning it here it gives a heads up to ask the question before going ahead with it. He's not obsessed with drilling holes in things and the more you know before going in the better result you'll get

He's very approachable on Facebook and usually in the comments of his videos

[stuffedpike20]

What is it on the distributor that wears, and why does it make so much difference?

[les]

The main spindle revolves in a brass sleeve bearing which can show signs of wear over time, it’s difficult to replace. I presume it can vary the points gap.

[svenedin]

Various things wear out. The profile of the cam lobes change as they gradually wear away where they contact the heel of the points. Obviously it is the heel of the points that wear much faster. The bush that Les mentions wears as the spindle is subjected to a lateral force as the cam pushes against the points spring. So even if the points gap is properly adjusted, the profile of the cams wearing "flat" (for want of a better way of putting it) changes the duration of points opening (dwell). The wear in the bronze bush makes the spindle tend to wobble which causes the ignition timing to wander (this wandering can be seen with a strobe). The centrifugal advance weights don't wear but they can stick and the advance springs can become weak with age. This changes the advance curve. Finally, the vacuum advance diaphragm tends to lose its flexibility or crack which leads to insufficient vacuum advance or no vacuum advance at all.

Electronic ignition systems using Hall effect or optical triggers don't wear the cams at all and don't exert sideways forces on the bearing but otherwise the same issues can occur as with points. This is why it makes no sense to install electronic ignition in a worn out distributor or to buy a Far East copy that's poorly made and does not have the correct advance curve.

See this diagram: https://mossmotors.com/mgb-085-25d4-dis ... 7lTLJ3Jku1

Stephen

[stuffedpike20]

Thanks les, and Stephen for that very comprehensive explanation.

Are the Powerspark distributors any good, or would you only replace with a Distributor Doctor one?

[svenedin]

Thanks les, and Stephen for that very comprehensive explanation.

Are the Powerspark distributors any good, or would you only replace with a Distributor Doctor one?

In my opinion they are not good. I bought an Accuspark one when my original to the car Lucas 25D4 was away with DD. Out of interest I put the strobe on it and I found the timing wandered around even though it was brand new. The car ran OK to be fair so I'd say a new Accuspark is better than a totally worn out Lucas but nowhere near as good as a professionally rebuilt and calibrated Lucas.



Stephen

[stuffedpike20]

Thanks Stephen.
I am guessing that Powerspark and Accuspark are the same ?

[Bill_qaz]

Thanks Stephen.
I am guessing that Powerspark and Accuspark are the same ?

Well not the same company I believe they are competitors.
My car came fitted with accuspark 5000mls 3 year never touched it or even checked it. Starts first time, runs smooth and I never go above 60mph. SO for me "if it ain't broke don't fix it"