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MG Midget and Sprite Technical - 79 Midget 1500 Dashpot Oil

Hi Guys

My car is stored in a garage at the moment, but I go on a regular basis to start and warm her up. What I've noticed is that the carb dashpots need topping up every time I go to start her, probably every two weeks as a minimum (I use engine oil 20W/50).

Does anyone have any experience of this happening?, I don't see that oil is leaking externally, but it must be going somewhere, right?

Any pearls of wisdom would be greatly appreciated.

Many thanks

Dave
D Williamson

Dave, are you overfilling?
The dashpot is a rod with a tube drilled into the end over which another tube fits which is part of the outer body of the carb (the top cover if you like). This is to allow one to slide up and down the other as you accelerate and slow down. The damper is pushed into the rod tube for damping it. If you overfill then any oil over the end of the rod tube will probably leak into the carb and just be ingested with the petrol into the engine and burnt.
No real sweat but as yours is not used much could build up in layers if the above is happening and impair the vacuum chamber moving I would hazard a guess.
Dave Squire (1500)

Hi Dave

Thanks for the advice, i think I must be overfilling as I top up the oil so it surrounds the tube and to a few millimetres above it. I must be an idiot!, could this account for the rough idle and unwillingness to accelerate over 3,000 rpm? If so, you might have just solved another issue to boot!

I must try and understand carbs a little better!!!

Cheers

Dave
D Williamson

I think it says somewhere in the drivers manual roughly how much to put in. (rough level guide) All I know is that it does say somewhere not to overfill which makes sense when you have one in bits like I did today.
If the overfilled oil is gumming up the inner tube which slides up inside the body then probably. The harder you rev the more the tube needs to rise to open the needle to let in more fuel. If there is a lot of resistance to it rising then yes. It relies on vacuum to rise you cannot force it to open by flooring the pedal.
Maybe needs taking apart and a clean inside the vacuum chamber now to allow the sliding up higher for higher revs.
Dave Squire (1500)

Thanks Dave, I will certainly take it apart and clean up, could probably do with a proper service at the same time, seen the kits from Turner Carbs on Ebay for 50 quid or might even go for the rebuild kit with the fixed jet conversion at 75 quid!!

Someone also told me I will need richer needles and red carb springs, as i have fitted K&N filters.

Dave
D Williamson

Dave,
there's a downloadable SU booklet somewhere on net

as long as there's some oil and a suction type resistance when you pull the damper rod up by the lid there's enough oil - try not adding any oil at all for a good while and see if they find their own level and stick with it

I wouldn't bother starting the engine unless I was going for a 15-20 mile drive, the drive will help not just the engine but the brakes, tyres, suspension, clutch, electrics, etc. and of course help you with driving the car and enjoying it, sitting in garage barely helps the engine and could even be detrimental to the running

these John twist videos are excellent at giving information, some may not be exactly for the model of carbs in your car but the basic principles apply and all full of useful information - plus there are many more useful videos about the cars

44 Secrets of the SU Carburettor Part 1 of 2 - http://www.youtube.com/watch?v=7GRAcqDySog&feature=plcp

43 Secrets of the SU Part 2 of 2 - http://www.youtube.com/watch?v=60Bj_2cZQnc&feature=plcp

29 SU H-Type Carburetters - http://www.youtube.com/watch?v=GHNlT5yHDxk&feature=plcp

41 Matching SU Air Pistons - http://www.youtube.com/watch?v=IfU47Oqq9wA

123 MG Carburetors & Doors (first part needles and seats, springs and carb oil) –
http://www.youtube.com/watch?v=v9QI3NlvwiY&feature=plcp

147 MG Carburetter Tuning - http://www.youtube.com/watch?v=4nvGLgO6pj0&feature=plcp

35 Tuning HIF Carburetters - http://www.youtube.com/watch?v=ASeMfXfjNpw&feature=plcp

ETA: John Twist recommends "90 weight gear oil" it's not as thick as you think, I'm using it and it's jolly good but that's what I'd expect from one of his recommendations
Nigel Atkins

Dave, send over your e-mail I have something useful for you.

Don't rush out and buy the kit etc. Do a looksee and maybe a clean as that may be all it needs. Its not as daunting as you may think. I now do mine although I freaked a lot on this site before I got the courage. Can't see what all the 'carburettor fuss' is about now. As far as I can see the original parts and set up were all just fine so unless you are looking for more horses I would suggest just getting the carbs back to where they were.

Be methodical so you can put everything back as it was and its a piece of cake. Just uses some time.
Dave Squire (1500)

Gday D W
Go with Dave S, I personally find that 25-30ml of 20w sewing machine oil works OK. Not sure what the theory is with 90w it probably takes longer to disappear through evaporation or whatever. The damper stops the piston from dropping too quickly and leaning the mixture off suddenly. To check (motor not running), take off the air cleaner, lift the piston up with your finger and let it drop, if it clunks down rather than sliding gracefully down, then you need oil. 90w will increase the drop time thereby lengthening the rich mixture period when you button off.
Cheers
Rod
R W Bowers

Rod,
when I was researching the oils that owners use in their dash pots I found that sewing machine oil was a very loose wide term and that there are just so many oils that come under that description with different 'weights'/rates


I've put up a thread on this subject so if you want to see it it's in the Archives

I've used clean engine oil, SU SAE20 and a combination of the two when I was low on SU 20SAE but because John Twist said 90 weight gear oil I've tried that and I'll stick with it

the number for oils are not straight forward links to explanations are in that thread all in that thread

damper oil isn't a matter of life and death death so, what ever floats ya boat
Nigel Atkins

I always used 20w/50 and that seemed fine. I once did have a misfire caused by a sticking dash pot which could be felt by lifting it from within with the air filters removed. I simply removed the dashpot cover screws and lifted off carefully not to damage the springs and cleaned with carb cleaner. Worked a treat. As for level I used to unscrew from the top and if the plunger felt plenty of resistance I would leave alone.
Paul.
Paul1970

Hi Nigel Thanks for that advice, I'll try 90W Gearbox/diff oil and see if it retards the rate of loss from the damper.
Cheers
Rod
R W Bowers

Hi Rod,
it wont retard the rate of loss down to the level the dash pots want to work at, the excess will still be spread on the underside of the bonnet but once they've thrown out what they don't want they should keep that level, hold your nerve and just leave them there as Paul has put as long as you feel resistance as you lift the damper rod lid up
Nigel Atkins

Nigel I was thinking more about allowing the carbs to stay open slightly as you button off to downshift rather than heel and toe to blip the throttle.
I found that about 30ml is perfect from empty and 3-4 drops per week to top up, haven't had any hitting the bonnet.
Cheers
R W Bowers

Rod,
if it doesn't go to the underside of the bonnet then where do you think it might go, try 25ml and not topping up - hold your nerve

if you find that the oil drops so much that there's no suction when lifting the damper out then things need investigating

as for asking the carbs to do other than they're designed for then you could mess with damper springs, which will mean weaker or richer mixture, return springs, cable, etc. but all stuff you might regret, the driving technique might be safer

note, I'm referring to road use, if you're doing track stuff then all warranties and guarantees are off :)
Nigel Atkins

Nigel
Tahnks for all that no she doesn't lose that much I'm probably just losing one drop per month but i do enjoy just fiddling occasionally. Only road use and quite sedate especially if the missus is on board.
The carbs have new red damper springs.
So you reckon that thicker oil will not change the return rate on the pistons?
cheers
Rod
R W Bowers

Rod,
just don't worry about that drop per month, as for fiddling I'm dead against it, get the whole car full and properly serviced then set up correctly then leave the carbs and everything else alone, check at services only, instead of fiddling with them drive the car - that's me

I'm no expert on anything mechanical (or anything whatsoever) but because I drive my car frequently I do notice any sudden changes and I *felt* (not measured, gauged or recorded so totally unscientific) that things *seemed* smoother and even my wife commented on it

now whether it was a coincidence, other items or actions being the real cause, placebo, wanting it to be better, or whatever, I'm happy enough to stick with it

when emptying out the previous oil and before reassembly I did also wipe clean and very lightly oil the dashpot and piston although they weren't dirty or bone dry but perhaps that helped or is the true cause of the benefit

I do on occasion drive sedately but mostly I drive in a spirited or very spirited way with or without the wife, as an example we'll be on a run this weekend with quick and fast cars some even super and hyper cars but come the twisty bits we'll surprise many
Nigel Atkins

Actually, the damper isn't meant to retard the drop of the piston... it slows its RISE during acceleration, thus increasing air velocity and therefore vacuum (depression) at the venturi, which then draws more fuel to enrich the mixture. If you look at the little valve at the end of the damper rod, you'll see that it's free to slide up and down slightly. When you accelerate, the valve slides downwards on the rod, sealing against a washer and restricting the passage of oil. When the piston drops, the valve moves upward and opens to allow a free fall. For a demonstration, reach inside the mouth of a carb and lift the piston... you should feel a healthy resistance to upwards movement, but it should then drop freely when released. This is roughly equivalent to the "accelerator pump" in conventional carburetors, feeding more fuel when needed, leveling off to the proper mixture during cruise (i.e., reaching equilibrium), and then basically shutting during deceleration.

These are "variable venturi" carbs, referred to as "Constant Depression" due to the fact that regardless of engine speed, the vacuum in the venturi stays the same because the venturi enlarges or restricts with rise and fall of the piston. Thusly, fuel is metered not by the level of vacuum, but by the tapered metering needle. When you prevent the rise of the piston... the duty of the damper valve... you increase the vacuum, and therefore the fuel drawn, enriching the mixture as mentioned above.

Cheers,

-:G:-
Gryf Ketcherside

thanks for that Gryf I totally forgot about the up and down aspect and question as I got distracted by the red spring (and if it was correct on the 1500 - it is but not on my 1275 as originally fitted by PO on my car which is what got me thinking about the spring colour)

I'd have had to direct Rod to the previous JT vid links I'd posted as I'd never be able to put what you have or anywhere near as well
Nigel Atkins

Nigel,

If I understood correctly, you are oiling the large inside diameter of the dash pot and the large outside diameter of the piston. Check your books and see if I am right, but I think these are supposed to be run dry.

I believe the machining is supposed to be such that these parts are very close but do not touch. Since they do not touch they need no oil. In fact, the oil is likely to attract dirt, which then causes them to touch and wear.

The point that I believe does need light lube is the small tube (outside of the tube where you put the oil) and /or the inside of the small diameter upper portion of the dash pot. This is the guide that keeps the piston from touching the inside of the dash pot. If the small diameter tube is run dry, wear may occur that allows the piston to drag on the inside of the dash pot.

Another reason for not overfilling the oil reservoir is that the extra oil may find its way to the piston and dash pot, which like I believe is supposed to be dry.

Charley
C R Huff

Charley,
thank you,

at first I did wonder where you got that idea from then saw my usual tumble of words, no I -
wipe(d) clean the dashpot and piston and very lightly oil(ed) the piston (top rod part only) although they weren't dirty or bone dry

although tbh your are also right the piston wasn't bone dry from my previous overfilling

I should have just linked to the JT vid but I only changed to 90 weight oil recently and it was fresh in my head but as you can tell I need more than 5 minutes edit time to see my typos, I must have as I sometimes do cut and paste alterations to speed up edits and then miss that the sentence (or paragraph or whole post) doesn't make sense (such as I missed putting those words just now)

I haven't got books on carbs just JT vids links
Nigel Atkins

Ah, yes Nigel. Simply a case of ambiguous wording. I didn’t really think you would be oiling that part, but thought I should check to be sure.

Charley
C R Huff

From the SU website:

"Oil dampers

After the carburetters have been correctly set it is necessary to check that the oil damper reservoir in the piston rod has sufficient oil. This operation should, in any case, be carried out periodically at about every three months, and it is usual to use an oil of grade SAE 20 (it should be no thicker than SAE 30). The operation is not a critical one; simply unscrew the damper unit and pour oil into the hollow piston rod until it is within t in. from the top of the rod."

Note the top up frequency.

I think the most important point is to ensure both carbs [assuming twins] are filled to a similar level.

See the diagram attached

HTH



Doug Plumb

Rod,
sorry about my cock-up typos but it has brought me back to another thing I forgot 25-30ml sounds a lot even if shared between both carbs, I've not measured how much I put in but it was from in a three-quarters full 125ml bottle and I can't see I've used any whereas 25ml out of say 95ml in the bottle would show

Charley,
the wording was totally messed up and the silly thing is I altered it to that way trying to avoid be ambiguous !

the main thing in my mind was to convey that I'd cleaned the inside not outside of the dashpot and that didn't and didn't need to be mentioned - rushing and trying to do two things at once and I know I can do neither

Doug,
I used to follow that regime but then Fletcher reminded me that with my first car with a SU over 30 years ago I never topped it up and was happy as long as when I lifted the cap I could feel some suction, I'd forgotten this with my current midget and most of what I topped up ended on the underside of the bonnet
Nigel Atkins

Hi all in order:
Thanks Doug, looking at the diagram really highlights the remarkable simplicity of these devices.

No offence taken Nigel

I'm sure that the problem is simple evaporation of the light weight oil hence the 90w option and my fiddling seems to fit in with the book service period i.e. 3 months. 27 ml (my quantity) is to fill from empty. A cap from a plastic disposable water bottle seems to be about right.

Please excuse the long periods between posts sometimes I'm not able to check this site everyday.
Cheers
All
R W Bowers

Hi Rod,
by fiddling I didn't mean checking or as part of service work I meant adjusting the carbs unnecessarily outside of these times

I think you should try keeping the oil level lower than you perhaps have it now, I used to try to keep it at a book level (and the level varies depending on which book you look at including those from SU) and this meant I was always topping up because I was filling above what was required so the excess was always being thrown out

below I've highlighted the diagram Doug provided showing the oil level shown, my oil level is around that level - when the oil level is below the top of the piston rod it is difficult to see, also bear in mind the illustration shows the damper in the piston rod so if the damper was fully extracted the oil level would be lower still

yesterday I was out on a 85 mile run with various cars, about half were Porsche, and some others that are faster and quicker than Porsche, so I was using most of the rev range and driving in a spirited way and I didn't find the carbs holding me back or uneven

on the last run I got stuck behind the Ferrari Enzo and McLaren (which didn't run this year) for a short time as these very wide super and hyper cars have to slow down or pull over if a car comes from the other way on some of the country roads, I had the same happen years ago on a one day tour and I got stuck behind a Fezza on a narrow road and I was in the Spridget sized Suzuki Cappuccino

Nigel Atkins

Oops...

I was re-reading my post above RE: operation of the damper valve, and noticed that I had the valve operation backwards. When the air piston rises during acceleration, the valve rises as well until it contacts the washer above and stops, restricting oil passage and retarding upward movement of the piston. When the piston falls, the valve falls also to the open position, allowing free passage of oil.

Cheers,

-:G:-
Gryf Ketcherside

So, as regards the amount of damper oil - the piston must be immersed at all times. From those drawings, it looks to me that if the piston were to drop all the way down to the venturi bridge, then the piston would no longer be fully immersed. I know it is a manufacturer's drawing, but I think that oil level as shown is insufficient.
Guy W

I've no idea, I was just using the drawing Doug put up as an illustration of what I meant as I have no other illustration to use

when the engine isn't running and carbs operating, so static(?) then the level at which oil seems to settle in my 3 years old carbs is roughly as the simpler illustration now in this post

if I wanted to keep it higher I would have to top it up after each spirited run - perhaps there's a fault with my carbs but as I put before 30 years ago I can't remember topping the carb oil level other than perhaps at a service

also in the original drawing Doug's put up wouldn't the oil be below the damper when the piston was at rest at the bottom of it's travel

I hope this illustration better conveys what I'm trying to get at

Nigel Atkins

Yes I agree. It was actually Doug's SU drawing that I was referring to. But they are the same. And if you measure the oil level above the piston in the drawings, and compare it to the amount the piston would drop to the bridge, then you will see that the oil level wouldn't cover the piston.

Like you, Nigel, I don't fill mine right up to the very top, but the oil surely has to cover the piston at rest. I think the drawing is just indicative, to show how it works, rather than intending to show exactly how much oil there should be.
Guy W

I was just using the drawing as the oil level was about where I meant

I was too stuck on how to use MS Paint to colour in the oil to show what I was on about, none of the MS programs on this Windows 7 seem as easy to use and even a bit of a fight with user aids hidden away compared to the previous programs on Windows 2000
Nigel Atkins

Hi All
FWIW, I found the correct? amount of oil, 27ml, by trial and error. having to pull the tops off the carbs quite a few times during the sorting process I measured the oil that was left and found it to be 27ml.
Nigel you'll love 2010 you can customise your toolbar e.g. "Quick access"
Cheers
Rod
R W Bowers

How can such a simple thing get so complicated? As gryf described earlier, the oil damps the rise of the piston, and prevents a massive flat spot on acceleration. Leave out the oil and go for a drive. Put some in and notice the difference.

Just pour in the oil, and if you put too much in, don't worry. As the piston rises, a little will seep down the sides, and some will be expelled through the small hole in the dashpot cap. It will find it's own level, and over time you will lose a little oil, so you top it up again. It's likely that the level is only "correct" for a short period of time, unless you check it everytime to drive it. In which case, logic suggests that the level isn't that critical. which is precisely what Doug Plumb posted from the SU website.

I've used 3-in-one, 20/50 and straight 30. I've even used, "used oil" from the end of my dipstick. to be honest I haven't noticed much difference, except when driving in hot temps, such as greece/spain in the mid summer. Then the oil is definitely too thin when using less than a 20/50, as evidenced by flat spots when accelerating.

Lawrence Slater

Agree, its no big deal. It needs topping up every now and again. That's it!
"It's likely that the level is only "correct" for a short period of time"

Disagree. Correct is between pretty wide limits: enough to cover the piston but not overflowing.
Guy W

When I said "correct", it was in the context of supposedly having to be a set level from the top of the oil well. I agree, the correct level is pretty wide. As you said earlier, as long as the piston remains covered, it works.
Lawrence Slater

Yep!
Guy W

Hi Rod,
I'd love it if one MS product worked with another !
I can't download the MS tool to show me the differences between 2000 and 7 because MS thinks I need a program that's already on my computer, so I tried downloading it again hoping to see I've already got it or it overwritten but no that didn't work so I remove the program MS said I'd needed but already got and downloaded it, Ms said I needed the program that I'd just successfully downloaded !

MS is perhaps the proof that the Devil does exist

anyway ...

just as an experiment today I topped up my dashpots to roughly the level in illustration on this post so see how long it stays there, note the level is before the damper is submerged into the oil so the level will raise after it is

Guy,
also note please that the illustration is not to scale, the level is approximate as is the illustration and does not represent a technical scaled drawing to engineer standards - I'm not sure it would even have made it on to the 'Vision On' wall with Tony Hart ;)

and it still took me a good few minutes to do with this 7 package, I'm lost if a right-click doesn't find what I want


Nigel Atkins

Ok to summarise then:
1 - pretty much any amount of oil will do as long as it covers the moving bits
2 - anything above 20w and below grease will do
3 - there is no point 3
4 - fiddling with carbs is OK as long as the carb consents
5 - refer to point 3
6 - I still don't know where the oil goes
7 - there is no need to post any more on this topic
8 - in the immortal words of the great antipodean pugilist Jeff Fenech - I LUV YOUSE ALL (even prop)
R W Bowers

Rod,
point 7) - is probably correct but as I've started my experiment (if/when I remember) I'll report back

btw 3-IN-ONE Multi-Purpose Oil is SAE 17 (at least in the UK) I know because I asked the producer (WD40 Company)

and to show other opinions see this video, chap claims to be running without the damper - http://www.youtube.com/watch?v=Wa589N8g7IQ

and viscosity chart below to show 20w (and other numbers) is a range rather than fixed point, note 90 gear against 20-50 crankcase

Nigel Atkins

Running without the damping, is because,

"The fiddling with spring tensions made this work - that's already been done ;)".

What does this prove then Nigel?



Lawrence Slater

I have learnt something, SU carbs are very forgiving. I shall try heavier oil
Cheers all
Rod
R W Bowers

I think it was mentioned above that John Twist, in one of his video tutorials, recommends 85-90 gear lube in carb dampers. His reasoning is that after many years of service, the dampers wear a bit and tolerances aren't as tight as they were when new... hence he compensates with a heavier damper oil. Based on that reasoning, I've been using 85-90 myself in my 1500's ZS, and it seems to work fine. But then, it would probably work fine with engine oil too, so who knows...

Cheers,

-:G:-
Gryf Ketcherside

Gryf,
I've not heard that reasoning and it wouldn't apply so much to my carbs as they were brand new 2 years ago (I wish I'd went with my instincts and bought brand new carbs when I first got the car instead of various repairs as advised by some, not on here)

90 weight gear oil recommended on this vid see at 1:50 (min) - 123 MG Carburetors & Doors –
http://www.youtube.com/watch?v=v9QI3NlvwiY&feature=plcp

Nigel Atkins

Hi All, Nigel I have changed to 80-90w gearbox oil and the result is, (drum roll) an improvement in throttle response i.e. no flat spots, smooth as silk now. My apologies to all who I may have doubted.
There is a but, I fancy that the mixture nay now be slightly too rich as the revs rise i.e. the piston may not be rising fast enough but this may be my imagination.
R W Bowers

well Rod, all your troubles are because you deviated, went your own way

90 I put but you choose to use 80-90 !





just pulling your leg, that'll do

I keep meaning to check the level in my dashpots as we went for a quick run Wednesday night

you'd have to ask a tuner if the oil would make a difference, what about the spring weight too(?)

I'm more interested in whether things will be different in UK winter but as my car is going so well as it is I'm not worry about something that doesn't seem broken

if I find any different I'll let you know

John Twist was very definite in that video about the oil and it would be silly just to dismiss advice from such a source, I had to get some 90 gear oil back off a mate that I gave him because I don't use it now as I have other ideas about what goes into the gearbox and diff

as for driving, I tend to lift off and let road and engine speed dissipate rather than more frequent or harder braking and quick changes up or down are not really possible on my g/box
Nigel Atkins

Rod,
I remembered to check the oil level today and . . .




if anything it's higher than before, could it be the warm weather, my poor eyesight, lack of accurate measure?

I'll report back when I notice a drop in level

oooowh, the tension (or not, as the case may be)
Nigel Atkins

Nigel Warm? above freezing? I don't know how lucky I am. FWIW the rear carby had lost half of it's oil, the front was only slightly down, dunno. I think the flat spot was a combination of very low oil in one carb and using too light an oil anyway.

R W Bowers

Rod,
low oil - not checked, oh no, I've got to lie down in a darkened room

it's spring here and sunny and warm (well today and yesterday anyway)

yesterday's stats from local weather station:

Maximum Air Temperature: 18.6C
Minimum Air Temperature: 5.0C
Total Rainfall: 0 mm
Maximum wind gust:16 mph
Total Sunshine Yesterday: 10.8 hrs

a pleasant temperature and weather

Nigel Atkins

Glad to hear it
todays stats here in Melbourne late autumn
Max air temp 16 c
Min air temp 6 c
no rain so far
suns out as I type

what we class as a bit chilly
Yes I do know how lucky I am, no salt on the roads to rot out the chassis etc. Even contemplated removing the heater box to fit in a brake booster.
Cheers
R W Bowers

those sound like good temperatures, just wrap up more

but there again I thought you Aussie chaps were all macho, wrap up and the need for a brake servo !

an often debated subject, brake servo not wrapping up

personally if you don't find your brakes good enough now I'd look at if the rear brakes are adjusted (helps handbrake too)

then at tyres, regardless of tread depth left if they are old, see halfway down this page - http://www.carbibles.com/tyre_bible.html

next I'd look at the brake fluid and when it was last changed

perhaps a change of pads might help I run Mintex 1144 and with newer tyres they can lock the wheels up easily

... and of course uneven dashpot oil levels will reduce braking efficiency
Nigel Atkins

Nigel I'm half english and half german hell of a combination. I'm not worried so much about my ability to stop, it's the appalling driving habits of most us here, no one will leave you a braking distance, if you back off to create one some fool will dive into it. We have to drive our priceless toys on the freeway to get to an interesting twisty bit, no exceptions. I want to do the great Ocean road here but there's 100 km of freeway first.
Anyway the dashpot question is for me closed, thanks all bye.
R W Bowers

Hi Rod,
we get the same problems here, don't forget the importance of good tyres (not old but loads of tread or little used) on braking

a servo wont really stop you quicker but it might lock you up quicker which means the car is out of your control

having the rear brakes adjusted, fresh or good condition brake fluid, flexihoses (and solid pipes) in good condition, not crumbling from the inside, good pads and discs and those good tyres should be enough

I have standard brakes except s/s flexihoses and Mintex pads and have no trouble with my brakes and lock up the wheels if I press too hard

as for he dashpot oil I've yet to check again and report how long or quick the level drops, no run today but we will tomorrow so we'll see (if I remember)
Nigel Atkins

Gday Nigel Im sorry but this is turning into a brakes post. I'm running EBC greens, new calipers, new drilled/slotted rotors, rebuilt M/C, new rubber hoses, new drums, shoes, slave cylinders even the brake lines are new. No way I can lock the wheels in the dry (don't drive in the wet). brakes are bedded in and rears are adjusted perfectly, I can lock the rears with the handbrake. Your 1275 runs a different M/C?? may be the answer. Or the Mintex 1144's are the answer, shall purchase some and see what happens.
Cheers
R W Bowers

Hi Rod,
sorry after all this I don't know if you have a Frogeye, 948, 1098, or even 1500

don't drive in the wet, you should be able to stop your car just by holding your hat out of the window !

EBCs, drilled and slotted, for road use, what engine have you got - or are we talking track machine

EBC is a very local company to me, still privately owned so I should be loyal but I had a mate that worked for Pagid Performance Brakes about 10 years ago and he'd swear ever time a magazine done a test of his brakes against green-stuff on a track for road use cars

Guy, Bill and I, that I can remember, certain about me, can lock our front wheels (not that you want to) with more or less standard brakes

I personally think that you have to fairly regularly use your car to keep your tyres and brakes in good order

you've not mention your tyres age and use, that makes a big difference, or even to an extent tyre pressures
Nigel Atkins

Hi Nigel and others in order:
79 1500, normal road use.
I got all the bits as part of a job lot from a mate who started doing up his 1500 then decided to scrap it (too much rust - philistine)
Tyres are sh*te and will be replaced as soon as I can source some Michelins.
I'm going to repost this as "1500 MC question" as I have some questions, I think the MC may be plumbed up backwards i.e. front lines connected to rear port and vice versa. This happened during the rebuild, I followed the very rudimentary diagrams I could find but found two diametrically opposed views. I followed the English version, but who knows??. Other pundits (OZ) have assured me it makes no difference, but the fronts are definitely not cutting it. Yesterdays road test (after a bleed and rear adjustment) resulted in fairly easy locking of the rears, but the tyres are as hard as a MIL's attitude.
Anyway going to repost.
Cheers all
R W Bowers

Rod,
don't under estimate the poor effects of sh*te tyres on braking (and steering, road holding, ride, comfort and noise)

but even allowing for them sounds like you have something else wrong

I'm not sure why you're holding out for Michelin tyres but if you have a look at the many threads on tyre recommendation you'll see other good tyres to consider (subject to availability to you)

unless there's something wrong with the road surfaces where you are can I suggest as well as possible MC or other brake system problems that if your mate had the green-stuff pads a very long time they might (I don't know just speculating) have gone hard now and/or are an earlier compound that needed more warming up to be at their best

any numbers on them and EBC should be able to tell you all about them
Nigel Atkins

Gday Nigel
Only tyres I can find not made in the east which come in the correct profile, however I'll probably go with 165x75's which allows a far greater choice.
I think it's the pads mate, see my post on the 1500 MC ports, I would value your opinion
Cheers
R W Bowers

This thread was discussed between 04/05/2013 and 03/06/2013

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