Maestro Turbo questions

[John S]

1.) Where do I top up the dashpot oil and what is the best oil to use?

2.) There is a loss of power when changing up to second gear i.e. it splutters a bit before progressing, is this because the idle speed is set too low?

Thanks in advance,

John

[G Force]

hi.

1) Undo the metal locking clamp around the damper rod then remove damper and top up with 10W40 engine oil.

2) See how it drives once damper is topped up, as that may sort it. :)

[MGTurbo]

As above. It's amazing how often people dont ever check the dashpot. My extensive testing has shown a thicker oil is better for acceleration, a lighter oil still causes the piston to flutter and cause the mixture to go weak initially, Not that most people would notice ;)

Gareth

[John S]

Cheers for that, my questions rather show up my lack of familiarity with petrol engines. I'm used to diesels where all you do is check the essentials i.e. oil and water, and that's about it for 1,000s of miles! I have recently found the brakes to be binding ever so slightly so I'll also check that out. I just warm the car up every couple of weeks then get the turbo working by accelerating up my farm track. I've not been over 60mph yet though. I recently changed the oil with Mobil 1 15w 50 and dented sump (pig of a job), the old oil was truly disgusting.

John

[G Force]

[QUOTE=MGTurbo] My extensive testing has shown a thicker oil is better for acceleration, [QUOTE]

I totally agree with that I find 20W50 gives better acceleration throttle responce particulary on 2.0 litre versions (Monty) and Turbo I think they got the damper spec wrong in development, Like you say not that most people notice. If you stick your neck out and quote something other than the manual though you usually get a few posts telling you how wrong you are. :laugh:

Cheers gary :)

[John S]

Just topped up the dashpot with Esso 10w 40 and the car is noticeably smoother and goes like a rocket. :D

Cheers guys.

[MaestroMatt]

My extensive testing has shown a thicker oil is better for acceleration, a lighter oil still causes the piston to flutter and cause the mixture to go weak initially, Not that most people would notice ;)

Gareth

Gareth, do you think that is true for all engines? I have always thought I was meant to be using the thinnest oil i could find...

[Austin-Rover]

My extensive testing has shown a thicker oil is better for acceleration.

I have recently been told that normal engine oil is too thick to work effectively in the dash pot and that i am beter off using something like 'Three In One' oil or something similar. I dont know how right that is though, and i have always and still do use normal 10-40 oil in mine.

[John S]

I've heard that anything will do, even cooking oil would be OK! However, upon reading the manual for 1.6 Maestros it recommends 10w 40 so I took the advice given here being as it was the same.

[MGTurbo]

10w 40 oil was recommended for various reasons on standard car's, mainly because it makes sense its the same as the actual engine oil!

I've tried many different oils for SU carbed car's over the years and found ones that work and other's not so good...

Thinner oil is fine for the NASP car's and anything thats standard. It can sometimes feel sharper to the throttle and can also give better economy.
ATF is best because its viscosity stays stable when hot.

Downside is, when the damper is worn, the oil gets sucked into the engine very quickly.

When the engine is modded however you need to change the fuelling requirements. You can do this in a number of ways.

1. Increase the idle mixture - This will mean a higher CO % but economy isnt usually affected and it can still be under the legal limit. Easy way.

2. File carb needle - Keep idle the same, increases fuelling underload. The proper way.

3. Increase oil viscosity - Piston sits lower in the carb, more fuel is pulled out of the jet , weak mixture less likely upon initial acceleration.

4 . Replace the spring inside the carb for a higher tension item.

I use a combination of 1-3. Although of course i run higher boost, ported head bigger exhaust etc. No.4 is one i havent tried yet but i know it does work.

My idle mixure is around 3% CO, hydrocarbons 220ppm (bloody good for a carb car!) The carb needle has been modified from approx halfway down its length. The last 8mm of the needle doesnt really do much but this is also thinned out to keep a good shape. Finally, 20w 50 engine oil.

I have a AFR meter which tells me what i could feel on the road, but just confirms it. No longer does the mixture go weak upon accleration or coming on boost. Peak torque is higher because the clutch will start to slip, even with a 15w 40 oil it doesnt do this.

So all in all, try a thicker oil. For a worn dashpot assembly its ideal, and it does work. The smaller engines do seem to prefer a lighter weight oil and seem to pick up sharper with ATF/3-1. With standard engines its down to what you feel best. It is a black art and there is definatly differences with lower/higher viscosity oils.

Gareth

[Aussie Montego]

I agree with Gareth about using the right oil and not just any oil for the job. Every car is different and you may even find you need to change the oil between summer and winter. I have just changed the oil in my Morris 1100's carbs from 15w/40 to ATF because winter has hit here in Australia and the Morris was running a bit rough when cold. When it starts mucking up again I will change back.

Michael.

[e692wtt]

I use a 50-50 mix of 20w/50 engine oil and ATF, after much experimentation a couple of years ago, in both my Monty and Maestro (1.6 engines, R-series in the Maestro).


I'd also recommend taking the dashpot apart and cleaning it thoroughly every couple of years, that makes a big difference especially if it's not been done recently. The dashpot on my Maestro seemed to be coated internally with a mix of waxoyl and sugar - that's how sticky and stubborn it was :horror: - I used an aerosol can of brake cleaner to sort that one out :laugh: .

But don't use anything even remotely abrasive in the dashpot innards, or it won't work properly afterwards because it's all extremely finely engineered... ;)

[John S]

Having done these jobs I'm now interested in changing the rubber 'O ring' in order to ensure boost pressure is not lost. Could anyone provide a diagram of where it goes or what should be undone to fit it? It's a genuine old stock item but I'd rather it went on the car than just sitting pretty. :idea:

thanks again.

[MGTurbo]

Having done these jobs I'm now interested in changing the rubber 'O ring' in order to ensure boost pressure is not lost. Could anyone provide a diagram of where it goes or what should be undone to fit it? It's a genuine old stock item but I'd rather it went on the car than just sitting pretty. :idea:

thanks again.


Simple easy peasy. Undo the top boost pipes, then the 8mm bolt holding the outlet onto the compressor housing. It then pulls off. My seal had flattened out with age, and i noticed no difference in boost when i put the new seal on.

Gareth