MG-Cars.net

Welcome to our resource for MG Car Information.

Recommendations

Parts

MG parts spares and accessories are available for MG T Series (TA, MG TB, MG TC, MG TD, MG TF), Magnette, MGA, Twin cam, MGB, MGBGT, MGC, MGC GT, MG Midget, Sprite and other MG models from British car spares company LBCarCo.

MG MGB Technical - Headgasket? or worse?

Last week I was enjoying a steady drive home over the Pennines in my 5-bearing 1950cc engined MGA with only occasional bursts up to 5000 rpm.
We decided to stop for some fuel but the local service station we found only had regular unleaded fuel and not the super-unleaded that I prefer to use. So I only put 3 gallons in so that I could get the better stuff when I got home.

As soon as we drove away the engine began to pink really loudly and the power seemed down.
So I gently drove it the 30 miles home using almost no throttle to keep the pinking down to a minimum.

When I got home I drained the tank and refilled with super-unleaded, swapped the distributor for the spare one, changed leads and plugs.
But this made no difference, the power was still down and the pinking was still there.

Next I did a compression test and found that No 1 and No 2 were both around 90 psi. Weirdly, the No 3 and 4 were at first showed over 200 psi but on checking again later they were then around 180 and 190.

So I reckon that when the head comes off I will probably find that the head-gasket between No 1 and No 2 has blown.

However, the heavy pinking is a puzzle and I cant think of any reason for it now that the fuel has been changed.
The timing hasn't slipped and so I can only think that the electronic distributor has gone faulty.

Any other suggestions?

Colyn

1950cc engine.

Weber 45 DCOE
Newman PH1 Cam
140 bhp




Colyn Firth

if compression test was done cold (or not fully hot) then that may explain variations on 3 & 4.

how much timing are you running all in and what is your CR? 10:1, or more with compressions over 200. sounds like you might have been running right on the edge...

i have a supercharger and on the dyno a few weeks ago, pinking was zero to almost white noise in the space of a couple of degrees.

my sympathy goes out to you....i hope it's a gasket and not holed pistons. but then you say it's still pinking so you must have driven it again and i think you would have had a very rough engine if they were holed. and not sure if you would make compressions of 90.

take a look at plugs - are there shiny metal deposits on them? having said that, when head is of it will become apparent....

what distributor do you have? 123? as most (other) 'electronic' distributors have weights and springs just like a points unit. so a failing unit would give no spark rather than advanced.

as to why it's still pinking...dunno. sure your all in timing is the same on both distributors?

G

Graham Moore

I would imagine that your 'pinking' noise is actually the gases travelling through the hole between the cylinders.
Dave O'Neill 2

I had a similar symptoms experience. The B suddenly started pinking at any throttle opening. This was after a long trip where we did run to 4500+ rpm. Filled up at home then the linking started.

checked the ignition advance,fuel mixture, all OK. Compression test showed just under 100 psi on both 1 and 2 cylinders.
Found the head gasket between 1 and 2 blown. The head was eroded slightly but the block was fine. The head studs were loose hand tight! This motor was according to the p.o. NOT OPENED. I had the head skimmed just enough to remove the erosion new valve seats for unleaded fuel. What a difference more power,smoother .

Would seem a head off look see is in the pipeline.


Cheers. Ray.
Ray Bester

Thanks everyone,
The plugs were fine Graham, a bit sooty but having to drive it so slowly home and with 2 cylinders with low compression I'm not so surprised.
The initial high compression figures on 3 and 4 is a puzzle and likewise why they then showed 185 the next time I checked them.
The ignition timing is set a 30 degrees at 3000 rpm.
The electronic distributor came with the motor but I know it has an advance curve tailored to the motor.
The spare dizzy is supposed to be identical but I know from experience that the engine often has to be re-timed when you fit a new one.

Ray, I'm hoping that the pinking noise is down to the blown gasket, a friend of mine suggested something similar.

Interesting about the head studs,the special studs on my engine come with instructions which state that they should only be installed finger tight.

The head comes off on Thursday and we will find out then for sure.
I will let you know how it turns out.
Thanks
Colyn



Colyn Firth

Colyn
The pinging is caused by the blown headgasket
After you have removed your blown headgasket,make sure you have a real good check and measure up of the top of the block and the cylinder head in the area between nos. 1&2
Having driven it 30 miles you will be a very lucky boy if you get away with not having damaged the top of the block being a big bore unit
Good luck to you man--I've got my fingers crossed for you--
willy
William Revit

I actually had a head gasket go (between cyls 1 and 2) after putting in higher octane fuel. It started clanking almost immediately.

No explanation, but it happened.
R G Everitt

Thanks Willy
I will check the block between the bores very carefully.
My fingers are crossed too, head comes off on thursday, I will take some pictures and post them on here for you.
Cheers
Colyn
Colyn Firth

Unfortunately the head gasket was probably not the cause of the problem, but the symptom. SC engines are sensitive to the fuel octane, timing and fuel mixture. Get one wrong and it with rattle like nails.

The head gasket probably went because the combination of lower octane fuel and your mixture setting and timing was too lean or early and caused some pre-detonation.

Once you start with pre-detonation, it will rapidly find the weak point of the engine - hopefully in your case only the head gasket and not a piston crown or two. When you have the head off, look too for play in the bottom end, and look at the pistons closely.

It may be avoidable in future by permanently retarding the timing a couple of degrees. A temporary fix when faced with only being able to tank with 95 octane is to remove the vac hose to the dizzy (if you have one) to disable any vacuum advance under lower revs or under load, which is where you will get the problem in a supercharged engine that is running too lean or with too much advance for the fuel in use.

I have just fitted a new gadget to control the timing - it has a pressure sensor so plugs into the pressure side of the SC manifold and between the hall-effect ignition - then I can plug an advance curve into the laptop and upload it. I'm still playing around, and it took a fit of studying to figure out the instructions, but I am very confident that it will be a great benefit. If you want the old unit without the pressure sensor for a very fair price, drop me a mail. I can now give all details of how to fit either!

the old unit
http://www.accuspark.co.uk/Blackbox.htm

the new one
http://www.cbperformance.com/product-p/2013.htm
Dominic Clancy

Thanks for the information and advice Dominic.
Your old ignition unit sounds very interesting but my engine is not supercharged, it just has a Weber 45 DCOE. The dizzy has no vacuum advance.

So would the Accuspark blackbox still be suitable for my 1950cc unit?

It has run faultlessly for over a year with no signs of pinking, even when I have accellerated hard from low revs in high gears. ( I do normally accellerate through all the gears)

I will double check the timing and the compression pressure when we look at the motor on Thursday.
I also really should find out the exact advance curve of my distributor too so I can work out if it is actually correct for the engine.

Thanks
Colyn
Colyn Firth

Hi Colyn

A high compression engine like yours also has the same issues as a SC engine.. Getting max performance is about getting mixture and timing correct and the mixture depends also on the octane level of the fuel in use.

The Accuspark unit will be fine for your car, you just need to lock out the mechanical advance or buy a new dizzy from Accuspark where this is already done.
Dominic Clancy

I don't know if this is a stupid question. Why not carry a can of octane booster in case of these emergencies?
Max71

Hi Max
the strange thing is, I actually do carry some octane booster around with me in the car.

Here in the UK many service stations dont carry the super unleaded that I usually get from my local garage.
So I have to use the regular unleaded when I am away from home and for over 12 months, the engine has run fine with this whenever I have used it, no pinking (pinging) or bad running at all.

So I expected the same when I used the regular unleaded this time (I put 3 gallons in to the tank which already had about 1 gallon of super in there).

It may be coincidence that the head gasket blew as soon as I left the forecourt but the fuel was the only factor that had changed.

The service station was not one of the big chains like Shell or Esso etc and so probably the fuel quality was the main cause of the problem.

With hindsight, I should have used the octane booster but I probably have become a little complacent.

In future, I will wait until I see a petrol station with a name on the sign that I trust.

Colyn
Colyn Firth

I tried the octane boosted version of Castrol Valvemaster when we first went unleaded but found it made no difference to the timing I could run, so only use the cooking version. Many years ago I could not get higher octane in the Scottish Highlands and had to retard at the roadside. However I now have a 25D4 and the vernier adjustment on those makes that job a doddle, should it be needed again.

Any high-compression engine will not pink if the timing is set low enough, and by the same token any such engine will pink if it is set too high. However with low compression engines you can set the timing so high it will stall the starter, but still not pink on 95 octane if you got it running some other way.

Usually the method of setting the curve with programmable systems is to advance each rev point for best performance just short of audible pinking at any combination of throttle opening, revs or engine load. That's also the best method with standard ignition systems, although usually that means you only get 'ideal' timing at one rev point and not across the range, unless you are very lucky or spend a long time tuning the curve on a rolling road. Our engines are pretty crude and even within one spec will pink at different points between different engines. The original specs took account of this and set them for a worst case plus a safety factor, and on most engines you can advance beyond the book figure and get the benefit of increased performance and economy without pinking.
paulh4

My Osseli 1950cc fast road blew its head gasket between 2 cylinders a few years ago. I just put a new one in & the problem has never returned. It was just one of those things. I don't think its related to the fuel you put in if it happened right away. Just a coincidence. I always use regular unleaded in mine anyway.
G Britnell

Part of the increase in capacity of those 1950 (and higher), engines is generated by over-boring. This puts a very narrow "land" between cylinders 2 & 3. Hence it is the usual fail point for head gaskets.
Allan Reeling

Just a side question in follow up to Allan's comment. Right now my lump is .030 over and it will eventually need a rebore. Is going to .040 too much? Some say yes, some say no.
Max71

+ 0.040" is generally accepted as the max you should go. My last 1800 re-build was taken to that and broke through and had to be sleeved. Probably the core had moved or part of it had broken away.
Allan Reeling

Back to this headgasket-----
It's simply the nature of the beast--it happens every now and then
I've had it happen after going for a drive and returning home, idles fine, turn the engine off, open the shed door ,start up to garage the car and poof--missing ,headgasket gone for a holiday--it happens
If the surfaces have escaped damage and the head is nice and straight,(I've still got my fingers crossed after your 30klm drive though), my choice would be a Cometic mls headgasket and the problem will be gone---
You can get them to suit your bore size and various thicknesses
willy
William Revit

Thanks for that Willy,
I hadn't heard of Cometic gaskets but their performance claims for its multi-layer stainless steel design does seem to fit the bill.
A vast choice of thicknesses too.

I will give them a call
Cheers
Colyn
Colyn Firth

Colin,
My 1950cc engine 11:1 compression runs at 27deg BTDC @ 5000 rpm with A/F 12.2 set on dyno with knock sensor attached. I did detonation damage with 32 deg advance previously. So far I have never popped a head gasket using Payen AK 660 composite gaskets despite other damage (83.5 mm bore)
Mike
Mike Ellsmore

My Gold Seal is +40, for what that's worth.
paulh4

Well it was the head gasket, a chunk of it was missing between 1 and 2 but it was also beginning to fail between 3 and 4.
It looks like a Cometic laminated gasket and so we have replaced it with a Payen which we hope will work out better.

Willy, we checked the deck and the head with a true straight edge and there is no problem there, so we got away with it.
Like you said, the "pinking" sound must have been caused by the head gasket failure as it has now disappeared and the engine is running well again.


I have attached a picture to show the gasket.
Thanks everyone for your advice.
Cheers
Colyn


Colyn Firth

2nd picture of the gasket as we found it on the engine.


Colyn Firth

Yep
That's blown
You're lucky to get away with no damage there,it looks like it got fairly hot across the blow area--

Nice sized valves you have there---

Looks like it's running fairly lean but I guess you were only cruising along and the blown gasket would come into play there as well--All the same, it might pay to check the mixture now it's going again------------

Very unusual for a Cometic to blow
I blew a few solid metal gaskets on my hillclimber with similar looking results and traced the problem down to the sealer I was using on them-- It was actually insulating the gasket from the head and block and not letting the heat sink out of the gasket
Changed over to a metal based sealer and all went well from then
Cheers
willy

Probably an optical illusion, but in the second pic the headgasket looks to be hanging into the chamber near no1 exh valve and sitting off centre to the bridge between 1-2
Bit hard to tell in the pics-- but looks a bit strange-------not many coolant holes
William Revit

Yeow! Glad you found it and glad I use what you're going to now use: Payen.

Paul: new billet cam, rebuilt dizzy etc only the drive gear is re-used. Maybe its that.
Max71

It does look a little offset there Willy, we have made really certain that the new gasket doesn't overlap into the combustion chambers.

I should have measured the new gaskets thickness but we just put it back together. The valve clearances were a little larger when we checked them which probably means that the new Payen gasket is a little thicker than the old one.

Ah well, it will probably drop the compression a little which should help the gasket to survive a little longer😁.

We are taking the car over to the Alps and the Dolomites in a few weeks and so, after this episode, I think I had better find somewhere to stash the torque wrench!

By the way, the Weber dcoe is set to run a little rich which seems to keep the it running pretty cool, although I only get around 25 mpg.
Cheers
Colyn
Colyn Firth

could it be that the cometic was installed wrong way up. they are not marked and look almost symmetrical (ie will fit either way up) but not quite...

i have a 120 thou cometic and a few other guys use them on supercharged engines to bring CR down.

G
Graham Moore

in fact looking at pic 1, the pointed part looks to be at the front (as you said 1&2 had gone thro) which is correct. there is a slight different profile between front & back. scary
G
Graham Moore

So Graham,
do you think that the gasket was fitted upside down?

I noticed that the new Payen gasket was marked with the words "top" and "front" which kind of idiot-proofs it.
(Not such a bad thing for this idiot who once fitted the front suspension swivel links the wrong way round which produced an astonishing amount of toe-out😁)

I'm next going to double check the timing and maybe retard it a degree or so to see if this helps extend the longevity of the gasket.

The engine is now running as sweetly as ever with no audible signs of pinking, can detonation still be taking place even if I can't hear it?

Maybe it would be appropriate to start to look at fitting some sort of anti-knock sensor?

Colyn
Colyn Firth

"Maybe it would be appropriate to start to look at fitting some sort of anti-knock sensor?"

BT, TT. The MGB engine (or mine at least) is so noisy the sensor I fitted was triggering either all the time or not at all *(even when pinking) depending on how I adjusted the sensitivity.

Some say that inaudible pinking is damaging as well as audible, but if that's the case how far do we back off the timing after pinking has stopped? And Haynes says barely perceptible pinking is the thing to aim for. With the age and mileage of most MGB engines I think occasional gasket failure is to be expected. I had my roadster 26 years and 60k before I had to replace it, and who knows how long it had been on already? Just go for no pinking, and if it happens again then something is probably wrong with block or head.
paulh4

Too much retard can also damage the gasket Colyn as the engine runs hotter. We have only seen one MLS fail due to head lifting under race conditions. I am not sure how often an MLS needs retorquing so I have instructed the race drivers to retorque after every couple of races. We are torquing at 70 lbs ft with ARP studs. 54lbs ft if Payen head gasket and single torque.
Cometic do specific sized MLS gaskets for 1950s.
Make sure you only run the good fuel or + octane booster.
Paul, I think the inaudible knocking is what happens at full power high rpms, we see power drop well before anyone can hear the pinking.

Peter
Peter Burgess Tuning

Thanks Peter
you may remember that you set up my 1950cc engine for me last year on your amazing dyno.

Im the idiot who had fitted a heat shield onto the underside of my Weber DCOE and you discovered that the carb linkage was fouling on it and restricting the throttle opening "just a little!"

On the first dyno run you found 100 flywheel bhp, then when you took the heat shield off you found around 140 bhp.
I remember you saying it was just about the biggest improvement you had ever found from one dyno run to the next!

You set the timing at 31 degrees at 3000 rpm. Should I leave it at that setting?

It does have ARP head studs and they are torqued to 50 lbs-ft on this Payen gasket but I know that it was set at the same torque on the Cometic gasket because I re torqued them after a couple of hundred miles when I first fitted the engine last year.

When I check the head after a couple of hundred miles I will re-torque them to 54 lb-Ft and re set the valve clearances.

I do usually run the engine with Super unleaded but on occasion I have had to use Regular unleaded if I am travelling away from home and I must admit that have never added any octane booster. I have never heard any pinking though.

We are taking the car on a trip over the Austrian Alps soon and so it looks like I will have to stash a load of octane booster bottles around the car.
It will be worth it though if it helps prevent gasket failure.

This is my 1950cc engine on your dyno with you at the wheel.
It is really impressive to stand behind the car whilst you are driving it at 90 mph!

Thanks Peter
you may remember that you set up my 1950cc engine for me last year on your amazing dyno.

Im the idiot who had fitted a heat shield onto the underside of my Weber DCOE and you discovered that the carb linkage was fouling on it and restricting the throttle opening "just a little!"

On the first dyno run you found 100 flywheel bhp, then when you took the heat shield off you found around 140 bhp.
I remember you saying it was just about the biggest improvement you had ever found from one dyno run to the next!

You set the timing at 31 degrees at 3000 rpm. Should I leave it at that setting?

It does have ARP head studs and they are torqued to 50 lbs-ft on this Payen gasket but I know that it was set at the same torque on the Cometic gasket because I re torqued them after a couple of hundred miles when I first fitted the engine last year.

When I check the head after a couple of hundred miles I will re-torque them to 54 lb-Ft and re set the valve clearances.

I do usually run the engine with Super unleaded but on occasion I have had to use Regular unleaded if I am travelling away from home and I must admit that have never added any octane booster. I have never heard any pinking though.

We are taking the car on a trip over the Austrian Alps soon and so it looks like I will have to stash a load of octane booster bottles around the car.
It will be worth it though if it helps prevent gasket failure.

Which octane booster would you recommend?

This is my 1950cc engine on your dyno with you at the wheel.
It is really impressive to stand behind the car whilst you are driving it at 90 mph!

http://www.youtube.com/watch?v=rfQnZd8aWtw

Cheers
Colyn



Colyn Firth

Sorry, some of my last post appears twice for some reason, I was to slow to edit it out, hope it still makes sense.
Colyn Firth

Hi Colyn, yes, I knew it was you. I know nutheeeeng about heat shields Meeeester Fawlty :)
I reckon I would use the Millers CVL Turbo as it is easy to get hold of.
yes to running the 31 again.
What plug grade is it running?

Peter
Peter Burgess Tuning

Thanks Peter,
I will always remember what you said to me after you had fixed the heatshield problem and found me the missing 40 bhp!

You told me to test drive the car round the block and you said that you could predict exactly which two words that I would say when I returned. You were absolutely right!
When I got back from 2 minutes of wheel spinning and big grins, the second word was "Hell!"
(I cant say the first word on here. :-)


I have just had a look and the plugs are NGK BCP 6ES.

Are these ok?

Cheers
Colyn
Colyn Firth

Hi Colyn
Try 7s

Peter
Peter Burgess Tuning

Will do Peter,
plugs are on order and I will let you know how things go,
thanks again,

Colyn
Colyn Firth

Just curious--
You mention regular and super unleaded fuels
What octane rating are they in your part of the world--

We have
91
95 premium - and
98premium
and the same again in E10
With the demise of localy built Ford and GM vehicles which were the major users of 91 there seems to be a push to stop supplies of 91 and we will have 95 and 98 only and also the dreaded E10 in 95 and 98
Cheers
willy
William Revit

Usually,here in the UK, regular unleaded is 95 and super is 98 although I believe I have seen slight variations on this from some of the petrol companies.

Colyn
Colyn Firth

Shell V-Power Nitro and Tesco Momentum claim 99. Europe uses RON classification, there is another method of calculation called MON, and America for example uses RON + MON/2 called PON, or AKI. 95 RON for example would be 85.5 MON or 90.5 PON in America. 99 RON for example would be equivalent to 90.75 MON or 94.9 PON. However according to Wikipedia MON and PON for a given RON can vary significantly according to country.
paulh4

Ahh
So we will be about the same as you guys with 95-98
I knew the US had MON but didn't know about PON--what a balls up - why can't everyone be the same
There again why can't all oil filters be the same
Thanks for the info---

With the E10 rubbish fuel
A mate here has an early injected 911 Porsche that he runs trouble free on 95
He mistakingly filled it with E10-95 with drastic results
He got about 50klm up the road and the muffler started glowing red hot, The car behind him pulled him over to tell him and while he was out looking at it the rear bumper started melting and dripping on the ground--Lucky he got pulled over in time to avoid a fire

Where this question was going was--
Colyn, you don't suppose that when you got your tank full of regular unleaded ,that it may have been E10---possibly enough to make it run hot enough to have caused your gasket failure------maybe--or not--just a thought
Cheers
willy
William Revit

RON, PON, MON. Strewth, they couldn't make it much more complicated could they!
Mike Howlett

Sounds like a Monty Python or a Two Ronnies sketch to me!!!! All they need is a Don, a Gon, a Jon, a Non and a Ton (much too confusing), and they would have a full set!!
Allan Reeling

Update on my Cylinder Head Gasket issue. (Its a long post but a lot has happened! :-)

Well, we got the engine running well again for our trip to cross the Austrian Alps, I had fitted some NGK BPR 7ES sparkplugs which were a little cooler than the 6ES plugs I used before, I had retarded the ignition by 1 degree and also begun to use the octane booster.

There were no problems with the engine on the 200 mile run to Dusseldorf apart from a faint smell of fuel which I assumed was coming from the many bottles of octane booster that I had got stashed everywhere under the bonnet.
The car (and crew) had an easier time from Dusseldorf to Innsbruck as we loaded both on to Motorail sleeper train, which was great fun as we just happened to board with four or five of the Belgian MGA Registers MGs at the start of their journey to tour Croatia.

We planned to drive the high passes of the Austrian Alps, then to the Italian Lakes, then into Verona and then finally back through the Dolomites back to Innsbruck.

The car ran ok at first but when we got to the higher Alpine section I began to notice a very slight misfire at half throttle.
Also the power seemed just a little down but otherwise the engine seemed to be running ok.
So I put this down to a combination of a Weber DCOE and high altitude which was something I had been warned about.

This continued for a few days until we well into Italy when the fuel smell became much much stronger. Then there was a splash of a volatile fluid out from under the bonnet up onto the windscreen and I thought that maybe one of the octane booster bottles had burst under the bonnet.

So we quickly stopped the car in a garage forecourt, lifted the bonnet and checked the bottles, all of them showed signs of an oily covering but I couldnt really make out which one had burst.
Almost as an afterthought I switched on the ignition and immediately the banjo bolt feeding the Weber began to spray fuel everywhere, it was coming out like a Karcher pressure washer!
So we switched it off and retired to a safe distance for a few minutes whilst the fuel dried off. So much fuel had been coming out that it had dissolved the paint off the top of the rear inlet manifold
Then I tightened the banjo nut and this seemed to stop the leak instantly.

The engine did run better after this but it was still seemed a little down on power, also the fuel economy was poor, around 20 mpg!
I had a good look at the carb and noticed that the anti vibration mounting bolts were quite loose, only finger tight and so I tightened them up as best I could on the car.
It ran slightly better but I decided to live with the performance issue and wait til I got the car home before investigating further.

After we returned home I sent for some new carb/manifold o-rings and a new set of rubber anti-vibration washers.

We then went on a mornings run with the local MG group but after filling the 10 gallon tank and having only driven for 167 miles, we were astonished to find that we had run out of fuel! Less than 17 mpg!

I then decided to sort it out, I took the entire carb and manifold assembly off the engine and was surprised to see neat fuel running out of the inlet ports out from the cylinder head down the side of the engine. Also, much of the remaining paint came off the Maniflow inlet manifold onto my hands! (it just shows how much ethanol is in the fuel theredays)

So I assumed that I must have a sunken carburettor float or a loose float chamber cover etc.
I moved the entire carb and maniflow onto the wing still connected to the tank and switched on the ignition to see where the fuel was leaking from.

The carb was surprisingly completely dry, not even a hint of fuel leaking from anywhere?

So I began to remove the carb, fuel lines first, then throttle cable and finally the choke cable connector.

When I loosened the choke cable Im sure I heard a faint click and the Webers choke lever appeared to have flipped from being vertical to its closed position of 45 degrees!

Oops! it seems that for quite some time the choke has been half closed!

On a DCOE the mixture enrichment device is a little like having an extra carb built onto the top which runs more fuel into the venturi when it is operated.

So that means that loads more fuel has been pouring into the carb causing it to be way over rich most of the time and what I thought was a symptom of driving at high altitude was in fact caused by yours truly not checking that the choke cable was connected correctly.

No wonder I havent needed the choke to start the car recently!

So I filled the tank, drove for 40 miles or so and now the fuel consumptiom has gone up to 27 mpg or thereabouts, a vast improvement.

The next job is to change the oil and filter again because heaven knows just how much neat fuel has run into the sump over the last few weeks?

Certainly running a Weber 45 DCOE has been an interesting learning experience. :-)

Colyn

Colyn Firth

Colyn, There is no need to use a choke when running a DCOE. Our rally midget has a 45DCOe and the choke system is blanked off, starting is a few full pushes of the pedal and off she goes. There is a special plate/kit to remove the choke.

David
David k Brenchley

Why store your octane booster bottle in the engine compartment? Much safer anywhere else in the car, surely, although is it even 'volatile'?
paulh4

Paul
I had to smile when I read your post, you should have a look at the MGAs boot space, especially when you have to fit all the wifes clothes (plus a little of mine! :-( into it, enough for a 2 week trip into Europe.
We have to use a couple of soft flat beach bags which we can just squash into it and everything else, shoes etc just have to be squeezed into any available space we can find around the car. The octane boosters go into any cubby holes left under the bonnet because that is the only place left.

You MGB owners dont realise how fortunate you are, it must be great to be able to actually fit a case into your boot.

I must admit that I dont really know just how volatile the octane booster is, but looking back at this thread, it seems I am an expert at making the wrong assumptions when it comes to diagnosing problems with this engine.

Hopefully I will have learnt something from all of this :-)

Colyn
Colyn Firth

Best Colyn! Hopefully its all sorted out.
Max71

Crikey, how many bottles did you take?

OK, it's an MGB, but we've done two-weeks self-catering in France i.e. taking a box of groceries as well as clothes, spares and tools (which weigh as much as a third occupant) all stashed in the boot and the cabin - no boot rack or anything else, and still had space for wine coming back. We did put two cases on the rear shelf but never in the boot as they result in too much wasted space, always soft bags. What the navigator can't see when I'm squashing them in with everything else she can't moan about. But then I inherited my master-packing skills from my father, I moved my son down to London for his first job in one go in the V8.
paulh4

We were going to do between 1500 and 2000 miles and so I had to take enough octane booster to cover this.
At 2 bottles per tank full it worked out that I should really take 20 bottles if I had to use the booster at every fill up.

I settled for 16 bottles in the end hoping that I could get super unleaded some of the time.

As it turned out, I could get 105 octane almost everywhere in Austria, but surprisingly in Italy, the home of the supercar, it was quite difficult to find anything except 95 octane.

I could make life much easier if I fitted a boot rack but on my bumper-less ex-race car, it would look just wrong.

http://www.youtube.com/watch?v=hdIUxtqI9aM&t=1s

I have added a YouTube link of a slideshow I put together for an amazing group of people we met with on the shores of Lake Garda in Italy and spent a brilliant day with.
They were the Italia MGCC MGA Register and they had driven for 2 hours just to meet with us.

My car is the dark blue one with no bumpers

Cheers
Colyn
Colyn Firth

Sorry, that link didnt seem to work
you may have to try cut and pasting this into the YouTube search.

Italy Uk MGCC Marque of Friendship

Or this one
https://www.youtube.com/watch?v=hdIUxtqI9aM

Colyn
Colyn Firth

A single bottle of Castrol Valvemaster will more than last a season of 3k or so for me, although that is for unleaded protection and not octane boosting. However they do an octane boosting version as well and that is dosed at the same rate, as far as I can recall. What brand are you using?

Came across two classic tours in Sicily in June, several MGs as well as many other marques represented, all Italian based from the number plates.


paulh4

enjoyed the utube
Man you were lucky with that banjo fitting
Could have been nasty that
willy
William Revit

What a trip! Makes me want to ship my car to Italy and Europe and do some serious touring.
Max71

Love Lake Garda. Aussie 2015 tour.


Mike Ellsmore

This thread was discussed between 14/05/2017 and 09/08/2017

MG MGB Technical index

This thread is from the archive. The Live MG MGB Technical BBS is active now.