[Red Morris]

I’m hoping that the increased popularity of Erics show, and the Fairmont project might have drawn a few more fabricators and modifiers to the site that can help me with my project which is still ongoing 🙁

A quick update: I’ve bought and installed a 3-exit master cylinder for a Mk1 Lotus Elise, which is 19.05mm/ 3/4″ bore. After many attempts, I have a leak-free system. I’ve bled the system as best I can, and there’s something of a pedal, but it doesn’t hit a hard stop, it just gets tougher and tougher. This is the first boosterless system I’ve ever bled so I don’t know if that’s to be expected, or if I need to keep going until I get a pedal.

My other issue is that the last test drive (with leaks) was rather rubbish, but the car has been sat for 2 years now, and brakes always feel glazed until you drive it a bit, so that’s muddying my judgement on whether I’m close to a working solution or not. Is there something I can use on the discs or pads to “de-glaze” them? I’ve heard fine sandpaper on the discs and pads can help.

[Red Morris]

That does make sense. I was only thinking about getting oil up into the top of the engine.

I haven’t tried it again. I was a bit shaken and didn’t want to risk causing more damage before I had some idea what had happened.

[Red Morris]

Well, I’ve done some calculations, and I’m fairly confident in them, but the outcome doesn’t seem quite right. :unsure:

I have 4 pots on the front with 2 38.1mm pistons and 2 41.3mm pistons each.
On the rear I have single pots at 36mm.
I’ve been told to expect 0.25mm of piston travel.

So…
38.1mm x 4 x 0.25mm = 1140.5cmm
41.3mm x 4 x 0.25mm = 1339.7cmm
2.480 ccm for the front
36.0mm x 4 x 0.25mm = 509.2cmm
0.510 ccm for the rear

That’s a total of 2.990 ccm, so let’s call it 3ccm. And let’s assume we will need some slack for pipe swell and that needing the whole pedal travel is not ideal and double it to 6ccm. Or 0.366cu.

The smallest bore master cylinder I have found (Wilwood TM1 5/8″) will displace 6.6ccm or 0.4cu.

Is this correct? It seems odd to me that beefy brakes like that could be stopped by the smallest available bore.

I really hope it is, because 5/8″ would require little force and allow me to do without a servo, and it should have a nice high psi too. But somehow I think I’ve missed something

[Red Morris]

Well, I’ve done some calculations, and I’m fairly confident in them, but the outcome doesn’t seem quite right. :unsure:

I have 4 pots on the front with 2 38.1mm pistons and 2 41.3mm pistons each.
On the rear I have single pots at 36mm.
I’ve been told to expect 0.25mm of piston travel.

So…
38.1mm x 4 x 0.25mm = 1140.5cmm
41.3mm x 4 x 0.25mm = 1339.7cmm
2.480 ccm for the front
36.0mm x 4 x 0.25mm = 509.2cmm
0.510 ccm for the rear

That’s a total of 2.990 ccm, so let’s call it 3ccm. And let’s assume we will need some slack for pipe swell and that needing the whole pedal travel is not ideal and double it to 6ccm. Or 0.366cu.

The smallest bore master cylinder I have found (Wilwood TM1 5/8″) will displace 6.6ccm or 0.4cu.

Is this correct? It seems odd to me that beefy brakes like that could be stopped by the smallest available bore.

I really hope it is, because 5/8″ would require little force and allow me to do without a servo, and it should have a nice high psi too. But somehow I think I’ve missed something

[Red Morris]

I didn’t know these existed actually. 🙂

I’ve looked at it and see a few things that would be a problem though. The car is a Lotus Esprit, so there are some unusual challenges.
The brake pedal would be too wide to fit between the clutch and the accelerator, and the brakes live in the front storage area which is quite small and slopes down.
Any booster would need to sit past the clutch master cylinder, not alongside it, and we start getting close to the booster preventing the bonnet from closing.
What’s to say the master cylinder included would supply the psi and fluid movement required for my pistons?

[Red Morris]

I didn’t know these existed actually. 🙂

I’ve looked at it and see a few things that would be a problem though. The car is a Lotus Esprit, so there are some unusual challenges.
The brake pedal would be too wide to fit between the clutch and the accelerator, and the brakes live in the front storage area which is quite small and slopes down.
Any booster would need to sit past the clutch master cylinder, not alongside it, and we start getting close to the booster preventing the bonnet from closing.
What’s to say the master cylinder included would supply the psi and fluid movement required for my pistons?

[Red Morris]

Yeah, I hadn’t thought about it when I posted, but I guess it would only help the DIYer who doesn’t have scan tools. Nor had I thought that a lot of the cars you see are probably not in a bad shape. Plug wise. If you do start a collection of plugs for a later video I will be sure to see it. I watch them all ☺

[Red Morris]

Yeah, I hadn’t thought about it when I posted, but I guess it would only help the DIYer who doesn’t have scan tools. Nor had I thought that a lot of the cars you see are probably not in a bad shape. Plug wise. If you do start a collection of plugs for a later video I will be sure to see it. I watch them all ☺

[Red Morris]

I thought I’d come back with an update now that I know a bit more.

Last weekend the neighbour went away and I wanted to use the car I keep in the garage. I only have a single driveway so that means the Volvo usually blocks this in. Normally this is when I park the Volvo on the kerb and have the starting issues, so I thought I was being clever and parked it on the neighbours driveway. When I went to start it again 36 hours later it was acting like it had been put on the kerb! 🙁 It’s in exactly the same position it is every day, just 10 feet to the right!! :angry:

As annoying as it was, it helped me diagnose the issue as “lawnmower syndrome”. Some cars suffer from this when you start them and only run them for a minute or two before shutting them off, e.g., to move them out of the way! So at least I can (hopefully) avoid the situation in the future.

For those of you reading this and thinking “That’s great for you, how do I get my car started?” the issue is actually that the tappets don’t close because the oil hasn’t warmed enough to slide out the way when you shut the engine off, so you don’t get any compression, then you flood the cylinders with fuel when you try to start it and wash all the oil off the cylinder walls making the compression worse. To get rid of the fuel you can either pull the spark plugs and let it evaporate, or pull the fuel pump relay and try starting the engine until you can hear it’s not got fuel any more. After this it may well start with a lot of effort, and I would try that because while the next step works, you look like a hillybilly.
If you can’t get it to work, pull the spark plugs and put a teaspoon of oil into each cylinder. This will help with the compression, but after that you are going to be burning that oil and creating SOOO much smoke! lol

[Red Morris]

I thought I’d come back with an update now that I know a bit more.

Last weekend the neighbour went away and I wanted to use the car I keep in the garage. I only have a single driveway so that means the Volvo usually blocks this in. Normally this is when I park the Volvo on the kerb and have the starting issues, so I thought I was being clever and parked it on the neighbours driveway. When I went to start it again 36 hours later it was acting like it had been put on the kerb! 🙁 It’s in exactly the same position it is every day, just 10 feet to the right!! :angry:

As annoying as it was, it helped me diagnose the issue as “lawnmower syndrome”. Some cars suffer from this when you start them and only run them for a minute or two before shutting them off, e.g., to move them out of the way! So at least I can (hopefully) avoid the situation in the future.

For those of you reading this and thinking “That’s great for you, how do I get my car started?” the issue is actually that the tappets don’t close because the oil hasn’t warmed enough to slide out the way when you shut the engine off, so you don’t get any compression, then you flood the cylinders with fuel when you try to start it and wash all the oil off the cylinder walls making the compression worse. To get rid of the fuel you can either pull the spark plugs and let it evaporate, or pull the fuel pump relay and try starting the engine until you can hear it’s not got fuel any more. After this it may well start with a lot of effort, and I would try that because while the next step works, you look like a hillybilly.
If you can’t get it to work, pull the spark plugs and put a teaspoon of oil into each cylinder. This will help with the compression, but after that you are going to be burning that oil and creating SOOO much smoke! lol

[Red Morris]

😆 Indeed I am. Where abouts are you Dreamer

[Red Morris]

😆 Indeed I am. Where abouts are you Dreamer

[Red Morris]

The list is short for a life-long petrol head

1. 1996-2001 = 1985 Peugeot 205 Gti 1.6 – Bought as a learner. I had the fastest car of my friends for years
2. 2001-Now = 1997 Mitsubishi FTO GX – Probably the best car I’ll ever own
3. 2010-Now = 1996 Volvo 850 2.5 CD – Ridiculously cheap and reliable car

[Red Morris]

The list is short for a life-long petrol head

1. 1996-2001 = 1985 Peugeot 205 Gti 1.6 – Bought as a learner. I had the fastest car of my friends for years
2. 2001-Now = 1997 Mitsubishi FTO GX – Probably the best car I’ll ever own
3. 2010-Now = 1996 Volvo 850 2.5 CD – Ridiculously cheap and reliable car

[Red Morris]

I’m not patriotic at all, yet the 3 cars I would go out and buy straight away if I won the lottery are all British.

Lotus Esprit GT3
Lotus Elise S2
TVR Sagaris

[Author]

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