Buying a MGB. Should i use a fuel additive or not bother?

Buying a MGB. Should i use a fuel additive or not bother?

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Discussion

elephantstone

Original Poster:

2,176 posts

157 months

Tuesday 15th April 2014
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The Mrs had finished uni and there isn't a need for me to have a long distance cruiser.

Pretty much sorted on a MGB GT 1980 model and been looking at the whole discussion about fuel additives..

What should i do?

1. Run on normal unleaded and use additive?
2. Run on normal unleaded and not add anything?
3. Run on super unleaded and not add anything?

MarshPhantom

9,658 posts

137 months

Tuesday 15th April 2014
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Will the additive make it able to crack the fabled 55mph?

shambollic

70 posts

136 months

Tuesday 15th April 2014
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Regular unleaded and Millers VSP

Riley Blue

20,949 posts

226 months

Tuesday 15th April 2014
quotequote all
Forget additives and run it when you can on Tesco Momentum 99RON. It works a treat in the B Series engine in my Riley 1.5. If you don't have a convenient Tesco, use 97RON Super Unleaded.

elephantstone

Original Poster:

2,176 posts

157 months

Tuesday 15th April 2014
quotequote all
MarshPhantom said:
Will the additive make it able to crack the fabled 55mph?
Haha i went faster than 55mph today during the test drive.

elephantstone

Original Poster:

2,176 posts

157 months

Tuesday 15th April 2014
quotequote all
Riley Blue said:
Forget additives and run it when you can on Tesco Momentum 99RON. It works a treat in the B Series engine in my Riley 1.5. If you don't have a convenient Tesco, use 97RON Super Unleaded.
This is the option i am leaning towards, i have a tesco a couple miles away.

Dbest92

300 posts

133 months

Tuesday 15th April 2014
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I use shell v power and millers vsp and don't have any issues

One big problem that is looming is ethanol content in fuels which don't do old cars any favours. How much addatives help this remains to be seen but I use it anyway as I also don't have hardened valve seats.

Being honest though I think you'd be ok whatever, ethanol is more a problem when the fuel has been sitting for a while so use lots of fuel regularly and all will be fine biggrin

RichB

51,520 posts

284 months

Tuesday 15th April 2014
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Surely the question here is more about running on unleaded and if the head has got hardened valve seats. Rather than the octane rating of the fuel?

SV8Predator

2,102 posts

165 months

Tuesday 15th April 2014
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Of course it is, God knows what all this super premium fuel (bo||ocks advice) stuff is about, an MGB certainly does not need a high octane fuel.

The valve seats have had (literally) decades of getting lead hammered into them, so you may be able to get another decade out of the engine just running on ordinary unleaded fuel.

Then, a good while from now, if you do get valve seat recession, you can remove the head and fitted hardened valve seats.

Are you planning to keep it that long?


RichB

51,520 posts

284 months

Tuesday 15th April 2014
quotequote all
SV8Predator said:
Are you planning to keep it that long?
That would be my only question.

elephantstone

Original Poster:

2,176 posts

157 months

Tuesday 15th April 2014
quotequote all
RichB said:
hat would be my only question.
How longs a piece of string...

I'd like to think id be keeping it for a year atleast.

RichB

51,520 posts

284 months

Tuesday 15th April 2014
quotequote all
elephantstone said:
I'd like to think id be keeping it for a year atleast.
It'll be fine for a year.

Slidingpillar

761 posts

136 months

Tuesday 15th April 2014
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And if... <snigger> you don't exceed 55, valve seat recession is less likely anyway.

Riley Blue

20,949 posts

226 months

Wednesday 16th April 2014
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SV8Predator said:
Of course it is, God knows what all this super premium fuel (bo||ocks advice) stuff is about, an MGB certainly does not need a high octane fuel.
It's advice based on my experience with a Series B engine, it runs noticeably better on 99RON. You can call my advice whatever you wish but I'll continue to use it.

ETA: My view on valve seat recession is that it's far less of a risk than manufacturers and sellers of additives would have you believe; so much so that I'd forget about it and simply use unleaded - super or normal depending on your car - and enjoy driving it.


Edited by Riley Blue on Wednesday 16th April 10:01

benters

1,459 posts

134 months

Wednesday 16th April 2014
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has there ever been any tests on this subject ? I ve almost finshed on my MG Midget rebuild and had the head done to run Unleaded, just curious, and yes it goes faster than 55 mph. . .well according to the speedo which looks a little optimistic smile

Faust66

2,035 posts

165 months

Wednesday 16th April 2014
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IMO older engines prefer super unleaded to the normal stuff.... if you think about it, cars of this age were designed to use 4 star fuel which had an octane rating of 98 (I think!). So running 95 octane fuel is never going to get the best out of your engine.

I run my Amazon on Shell Optimax (or whatever it’s called these days) and use Castrol Valvemaster plus – my engine seems noticeably happier than when I use the ‘normal’ unleaded and the idle always seems better.

Over the years I’ve run a selection of Capri’s on the same combination and have found that they always seemed ‘happier’ on the better fuels.

I would always use an additive: lead memory effect is a valid point, but you have to remember that as leaded fuel was phased out 14 odd years ago, that memory may well have begun to fade... I may well be paranoid here, but as I keep my cars for a long time I like to treat them as well as possible.

benters

1,459 posts

134 months

Wednesday 16th April 2014
quotequote all
Faust66 said:
IMO older engines prefer super unleaded to the normal stuff.... if you think about it, cars of this age were designed to use 4 star fuel which had an octane rating of 98 (I think!). So running 95 octane fuel is never going to get the best out of your engine.

I run my Amazon on Shell Optimax (or whatever it’s called these days) and use Castrol Valvemaster plus – my engine seems noticeably happier than when I use the ‘normal’ unleaded and the idle always seems better.

Over the years I’ve run a selection of Capri’s on the same combination and have found that they always seemed ‘happier’ on the better fuels.

I would always use an additive: lead memory effect is a valid point, but you have to remember that as leaded fuel was phased out 14 odd years ago, that memory may well have begun to fade... I may well be paranoid here, but as I keep my cars for a long time I like to treat them as well as possible.
wise words I reckon

ARH

1,222 posts

239 months

Wednesday 16th April 2014
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I have run classics since the unleaded fuel took over and never used an additive. I would save the money you spend on additive and put it towards a head rebuild if you need to. Valve recession will happen slowly slow it will be easy to spot. once hardened valves are fitted the problem is solved. Our morris minor has now covered 40k miles on hardened valves. My vitesse has covered 10k miles in my ownership on 95 ron unleaded and when last check there were no valve problems. And they regularly exceed 55 mph, although the minor may only exceed this by a few mph.

Riley Blue

20,949 posts

226 months

Wednesday 16th April 2014
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My thoughts exactly.

grumpy52

5,572 posts

166 months

Wednesday 16th April 2014
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If doing constant long journeys at higher speeds, like motorway commuting , get the head sorted or run high octane and additives , if not just run the high octane fuel .