Pinking, Pinging, Detonation - '79 B - And then Mumbling

[Switch]

My '79 B has started pinging recently.

It only does it when it's hot (ie in traffic) and only when putting a quite a bit of load on the engine, ie accelerating from low revs in say 2nd.

Get some open roads and it's fine again after the temp drops a little.
The internet (groan) seems to imply that a tiny little tweak of timing retardation would help it bugger off (or running higher octane, I normally run standard petrol).
How ever I can't honestly work out how to do that.
I don't want do the whole timing job.
I would assume that loosening the dizzy retainer and give it a little twist (oh so tiny) would do the job?

Advice or criticism welcomed.

[wildoliver]

I'm confused by the term "whole timing job" and yet you seem to grasp the timing is adjusted simply by moving the distributor?

Timing is too advanced for the crap fuel available today. Either adjust the dizzy retarding it slightly and accept the loss of performance or put super in.

But you already knew that?

[na]

Oli, (1)
as Oli (2) will tell you, set tappets, points, plugs and then mixture in that order

as I'd say do full and proper regular servicing and maintenance (Driver's Handbooks are available with above info) and drive regularly

theory, set timing for whichever octane and everything is done, in practice you don't know perhaps what's happened to the head or engine in past and some cars like some petrols more than others

but sounds like you been running too thin and got overheated (subject to above adjustments being set correctly and all parts and components are working correctly)

you're not dealing with a sophitcated Jap engine, the B is something from the 50s and your is at least from the days of 4* if not 5* petrol (99/100)

set the controls for the heart of the sun for running on 95 and treat yourself to 97/98/99 for a (placebo?) blast every now and then

I don't know if you kept with the 3,000/3 months on the Cap but the MGB overall will need the same level of attention - grease every 3 months, oil & filter and air filters at least once a year, set the car to run year round and don't tinker with it for the seasons just drive and enjoy

concertrate your mind and efforts on brakes, tyres, steering, suspension, lights, windows not engines and carbs

Edited by na on Saturday 23 June 09:54

[Switch]

wildoliver said:

I'm confused by the term "whole timing job" and yet you seem to grasp the timing is adjusted simply by moving the distributor?

Timing is too advanced for the crap fuel available today. Either adjust the dizzy retarding it slightly and accept the loss of performance or put super in.

But you already knew that?

I just didn't want to take the timing cover off and start from nothing again.
Tappets are new to me...
I'll try some super and see if that helps
If not to the lift with it and a full service. And then a retune....

I kept the cappy running like a nut...
Shortly that engine will reemerge in something else....

[na]

not sure which 'timing cover' you mean

have a good look and read of that Drivers' Handbook and you'll see why I keep banging on about it

and have a look at a lot of the John Twist videos and you'll see it all from another angle - you can go all the way back to no. 1 video and still get great info or I can stack up some relevant vids from my list

http://www.youtube.com/user/Universitymotorsltd#g/...

[Switch]

na said:

not sure which 'timing cover' you mean

have a good look and read of that Drivers' Handbook and you'll see why I keep banging on about it

and have a look at a lot of the John Twist videos and you'll see it all from another angle - you can go all the way back to no. 1 video and still get great info or I can stack up some relevant vids from my list

http://www.youtube.com/user/Universitymotorsltd#g/...

I've already watched most of Mr Twists Video's.
Let's see how the MOT next week goes...

[na]

Switch said:

I've already watched most of Mr Twists Video's.

you'll have seen setting tappets and carbs at least then, plus this and the other servicing details are in the Driver's Handbook

Switch said:

Let's see how the MOT next week goes...

MoT doesn't mean the car is running well or is even near its full potential - it's a minimum standard reached to the opinion of one person at one point of time only, better than nothing but it doesn't mean your car is running well

just a thought, you could sell the B and get a reasonable MX-5 with the funds and have less to do and worry about

[Switch]

na said:

Switch said:

I've already watched most of Mr Twists Video's.

you'll have seen setting tappets and carbs at least then, plus this and the other servicing details are in the Driver's Handbook

Switch said:

Let's see how the MOT next week goes...

MoT doesn't mean the car is running well or is even near its full potential - it's a minimum standard reached to the opinion of one person at one point of time only, better than nothing but it doesn't mean your car is running well

just a thought, you could sell the B and get a reasonable MX-5 with the funds and have less to do and worry about

I like the B. And I really don't want an MX-5 :P

And of course I know there's lot's the MOT doesn't check....I think the car is fine and solid, but I'd rather have someone else's opinion to back mine up.
She runs fine. Speedy and smooth (though obviously I don't know what others are like). Bar the odd bit of pinking. I am sure it could do with a full strip down and re-build of the carbs, probably the head could do with a service.
And then a tune up by someone who actually knows what they're doing (which isn't me, but is my mechanic who will teach me as he goes)

[na]

Switch said:

I like the B. And I really don't want an MX-5

just keep reminding yourself of that

Switch said:

And of course I know there's lot's the MOT doesn't check

not so much the things that aren't checked as they don't matter to the MoT and how well the car actually runs

Switch said:

....I think the car is fine and solid, but I'd rather have someone else's opinion to back mine up.

I'm not getting at you because I'm a bad culprit and should know much better but that's the type of thing you check before buying

Switch said:

She runs fine. Speedy and smooth (though obviously I don't know what others are like).

you make a good point there many classic owners think their car are going well when possibly a simple thing could improve them no end like full and proper servicing and things like change the tyres that have loads of tread but are old

I always revommend potential buyers test drive a good condition example out of their budget to see how well they should go and if they need to increase their budget

for you see if you can get a ride (drive if you can) in a good condition standard example as a comparision to how yours should/could easily be

Switch said:

Bar the odd bit of pinking. I am sure it could do with a full strip down and re-build of the carbs,

whilst that's possible it doesn't have to be so clean, set up, lubricate, leave alone

Switch said:

probably the head could do with a service.

no if it's ok it's ok

Switch said:

And then a tune up by someone who actually knows what they're doing (which isn't me, but is my mechanic who will teach me as he goes)

you could probably do most of it if not all of it first time

the first part of any tune up is full servicing

get the tappets/points/plugs/timing/mixture sorted and the engine will run better especially if it's also been recently serviced

you're also concentrating on the wrong priorities to get the whole car going well it's brakes, tyres, steering, suspension, lights windows - then engine and carbs followed by transmission, as you've already found the car will keep running with the engine, carbs and loads of other parts not fully working at their best

if you intend keeping the car any length of time then getting things sorted sooner than later wil cause you less hassle and expense most things you don't have to be a mechanic to do that's the beauty of these cars, I'm very unmechanical (and unwilling) but even I can easily carry out the basics

I don't know technical stuff but have help a BGT owner before and have the notes to help again

you'll get the car running reasonably well with little effort but a bit more effort and you could be enjoying more of its potential and sooner

keep driving the car regularly as that will improve the car and you

[Switch]

It's worth pointing out that I paid a pittance for the car.
I also bought it sight unseen (because I'm an impulsive idiot) who saw something shiny cheaply.
The fact that it starts, runs, doesn't explode or die at the drop of a hat is frankly startling.
And I drive it to work every day. (it also got 44mpg on a run from London to Hereford at motorway speeds)

There's an ever expanding list of things I'd like to do, But none of them are pressing and are getting worked through bit by bit.
So far, I've dismantled the carbs, tweaked the float level because it wan't quite closing in the rear one and slightly over flowing sometimes. That's gone away now.
New Plugs (accuspark triple ground), leads(accuspark 8mm), cap and rotor. (it's got electronic ignition so the points are gone)
Oil change.
Topped up the box.
Greased.
Wired in a temp new OD switch as the one in the gear knob is bust (waiting on a new switch)
Cleaned out toms knob.
Lost passenger side side lights (found a dodgy spade connector on the fuse box sorted that)

Tappets, air/fuel mixture tune, timing setting.
It needs a new clutch plate as I'm reasonably sure it's slipping at high speeds when hot.
It could do with a mechanical cut and polish (but that's cosmetic).
Clunk from the rear diff on change of load (means the thrust washers need replacing in the diff apparently).
Occasionally 2-3 second after turning off the engine (run on). Internet suggests a Diode between the alternator and dash lamp to prevent current feedback due to a slightly hokey relay possibly feeding current round to the coil after shut off to give a few more sparks.
OD has got stuck in once or twice until you slow down again (I think it needs a new set of seals).
Rear drivers side slightly lower than passenger side so probably needs a new set of leaf springs to even it out.
And who knows what else....

I'm only young and learning. My drive currently has an average age of 1975.5! But soon the 1994 Jap engine will be back (though not in what it was) for my reliable kick!

[na]

Switch said:

The fact that it starts, runs, doesn't explode or die at the drop of a hat is frankly startling.

not that starling that's how old cars like MGBs can be

Switch said:

And I drive it to work every day. (it also got 44mpg on a run from London to Hereford at motorway speeds)

all good stuff

Switch said:

There's an ever expanding list of things I'd like to do, But none of them are pressing and are getting worked through bit by bit.
So far, I've dismantled the carbs, tweaked the float level because it wan't quite closing in the rear one and slightly over flowing sometimes. That's gone away now.
New Plugs (accuspark triple ground), leads(accuspark 8mm), cap and rotor.
Oil change.
Topped up the box.
Greased.
Wired in a temp new OD switch as the one in the gear knob is bust (waiting on a new switch)
Cleaned out toms knob.
Lost passenger side side lights (found a dodgy spade connector on the fuse box sorted that)

all good stuff, consult full 36k service/check list in Driver's Handbook
check brakes (and fluid), tyres, steering, suspension
did you lube and oil dissy, check points

battery(ies) and connection leads and earths
coolant (not just anti-freeze element of it ) and all coolant system components and parts summer is soon
(including heater system)

Switch said:

Tappets, air/fuel mixture tune, timing setting.

mixture last

Switch said:

It needs a new clutch plate as I'm reasonably sure it's slipping at high speeds when hot.

have a Search on here, there are tests you can do to check for clutch slipage, when you topped up the g/box did you check to see what the oil was like in there, also slight chance it could be O/D, John Twist vids for cleaning filter and more on O/D

Switch said:

It could do with a mechanical cut and polish (but that's cosmetic).

just about the last thing that might get done if you're luck to reach the end of the list

Switch said:

Clunk from the rear diff on change of load (means the thrust washers need replacing in the diff apparently).

also check UJ and fixing and rear spring U-bolts and any bolts and fixings are tight

Switch said:

Occasionally 2-3 second after turning off the engine (run on). Internet suggests a Diode between the alternator and dash lamp to prevent current feedback due to a slightly hokey relay possibly feeding current round to the coil after shut off to give a few more sparks.

or it's not unknown on that model especially if the timing, ignition or mixture are out

Switch said:

OD has got stuck in once or twice until you slow down again (I think it needs a new set of seals).

again cleaning the filter, checking solonoid and electrical connections, also as it's so easy and cheap changing the g/box oil might help, get the oil as hot as possible and level to drain as long as possible, same for engine and r/axle

plus when engaging and dissengaging the o/D keep a bit of throttle on, when the O/D is working well it should be almost instant

Switch said:

Rear drivers side slightly lower than passenger side so probably needs a new set of leaf springs to even it out.

not necessarily it could be from something else or a combination or if slight nothing to worry about - these cars are not Jap precision made even with everything renewed you could see 20mm out

Switch said:

And who knows what else....

you will if you go through the check list, better to know and prevent or be prepared than be toatlly caught out

Switch said:

I'm only young and learning. My drive currently has an average age of 1975.5! But soon the 1994 Jap engine will be back (though not in what it was) for my reliable kick!

no reason why the BGT should be very reliable (it already is) and drive and go well without a big cost

you don't stop learning as you get older (although a lot of it is remembering again and not for the first time)

there's a couple of good knowledgeable people (not me) on here that can help you so put up posts with each problems

it's also great that you are doing research but the internet is not the only (or always the best) place for information

might not always seem like it but I also try to help, I've not got much knowledge but I've got lots and lots of experience a lot of it bad and very expensive so you can learn from it without the cost

that Driver's Handbook (I can't, and wont, remember if you've got one) Ref:0053 - http://www.mgocshop.co.uk/catalog/Online_Catalogue... will really help you

and if you can get a copy of this at a sensible price this will help you further and is a good companion to the DH - http://www.amazon.co.uk/MGB-Step-step-Service-Guid...

good luck, keep driving it

Edited by na on Saturday 23 June 15:42

[Switch]

na said:

there's a couple of good knowledgeable people (not me) on here that can help you so put up post with your problems, it's great that you are doing research but the internet is not the only (or always the best) place for information

Helpfully dreamshack is my mechanic man.
He ran a few 'B's back in his younger days so knows them well.
My purchase has encouraged him buy a rolling shell to restore and shoe horn something silly in for racing.

[na]

Switch said:

Helpfully dreamshack is my mechanic man.

yeap know of him from PhN

he should be the type to tell you what to do and supervise you doing it

you always have to do the basics before you can move on with learning and keep a car going well

cheers

[Shoestringracer]

Ignoring pinking can have dramatic results. Like pistons with holes in thier tops.

[Switch]

I intend on not ignoring it... hence the question .

Just tweaked the dizzy a few degrees CCW.
Took it for a spin... good lord.
Entirely different beast... Much more revvy.. loads more power...
I think this needs more investigation...
Pinking still present on hard acc from low revs...

ETA: The bottom bracket of the bonnet stay broke off. Fortunately it happened when I was opening the bonnet not UNDER IT!
It looks like it's normally tack welded in 2 places to the inside of the engine bay... who's idea was that?!

[na]

Switch said:

She runs fine. Speedy and smooth (though obviously I don't know what others are like).

Switch said:

Entirely different beast... Much more revvy.. loads more power...

now you’ve got more of an idea what others might be like

if it’s running well and continues to run well through different cycles of use you may just need to do the mixture (if you’ve already done the rest of the servicing)

are you sure your car is pinking and not misfiring

now you’ve learnt big improvements can be made simply at little or no cost you might be converted to invest £8

[Switch]

na said:

Switch said:

She runs fine. Speedy and smooth (though obviously I don't know what others are like).

Switch said:

Entirely different beast... Much more revvy.. loads more power...

now you’ve got more of an idea what others might be like

if it’s running well and continues to run well through different cycles of use you may just need to do the mixture (if you’ve already done the rest of the servicing)

are you sure your car is pinking and not misfiring

now you’ve learnt big improvements can be made simply at little or no cost you might be converted to invest £8

My mechanic suggests a de-coking... Apparently he's got a trick... And what does £8 buy me?

[na]

Switch said:

My mechanic suggests a de-coking... Apparently he's got a trick...

decoke it, what you running it on, coal
decoke it, clean plugs, drive hard and fast for a good distance

Switch said:

And what does £8 buy me?

if you don't know I give up

. . . and you can even find it on the web

. . . or a shop

[Switch]

na said:

Switch said:

My mechanic suggests a de-coking... Apparently he's got a trick...

decoke it, what you running it on, coal
decoke it, clean plugs, drive hard and fast for a good distance

Switch said:

And what does £8 buy me?

if you don't know I give up

. . . and you can even find it on the web

. . . or a shop

Like that is it!?
I'm taking it to the workshop to do the carbon removal tomorrow and then give it a hiding on the way home...

[alfa pint]

Mine pinks if I run it on normal unleaded. Works fine on super unleaded. Didn't want to retard the ignition, as this engine is a bog standard B, pushing out about 93bhp on the rolling road last year. I'm holding out to the next big paycheck over the winter and I'll look at dropping a K series in it.