Additive, four star or nothing?

Post by **kennatt** » Mon Apr 20, 2009 7:27 am

katie.Honestly don't bother with any additives I have had my split screen for 25 years, (About 90thous mile) and when leaded was removed just used unleaded since that time. I've had to adjust the tappet clearences two of three times . Last year I had the engine out to have a look at the bearings and put a new oil pump in also did a valve regrind there was NO significant burning of the valve seats,no more that any other regrind i've done when leaded was available.Mind It very rarely gets used on hard long motorway driving,which is where the problem starts,Same thing with my MGB and Scimitar gtc,As Bm says and others all you need to do is retard the ignition slightly to stop the engine making a pinking sound under load.Only go down the unleaded head route when and if,and it's a big if,your valve seats get too badly burnt,Might be never if you drive steadily.Cheers

Post by **katiekat** » Mon Apr 20, 2009 7:54 am

Thanks very much. There seems to be some differences of opinion on this issue. I think maybe Ill just leave it then or see how much the four star is.

Would the unleaded conversion cost much then if it's got to be done?

Post by **bmcecosse** » Mon Apr 20, 2009 10:49 am

£100/£150 - only worthwhile if planning on doing more than 10,000 miles per year! I don't use any additives in my 1098 engine - and although it doesn't do too many miles - when it is running, it's flat out!

Post by **katiekat** » Mon Apr 20, 2009 5:37 pm

Well I don't think I'll use anything.

Post by **rayofleamington** » Mon Apr 20, 2009 7:27 pm

There are plenty of options and many people who don't use udditive have had no problems however many people HAVE had problems.
The Castrol additive is proven to work on tests at MIRA using A-series engines. therefore that gets my vote every time - and is cheaper than a head conversion unless you plan to do more than 50,000 miles.

linearaudio · Post by **linearaudio** » Mon Apr 20, 2009 8:46 pm

katiekat wrote:.......I think maybe Ill just leave it then or see how much the four star is.

On the leaded website, they are trumpeting about having negotiated new supplies of 4 star at "up to 65p reduction" per litre, so I think you may be in for a shock.
When I picked up "Molly" last May she ran out of petrol before I got home (due to a badly choked air filter) and the only petrol station within walking distance ONLY had 4 star!! At that time they were charging £1.85 a litre, while unleaded was around £1.12 a litre.

But if you are determined, take the advice on the website- if your local outlet does not sell 4 star, ask them to start!! Must try that at Sainsburys next time I fill up

PS: I've done 8,000 miles since then on unleaded and she is still a happy bunny!

Post by **katiekat** » Mon Apr 20, 2009 9:12 pm

I feel confused again now!

linearaudio · Post by **linearaudio** » Mon Apr 20, 2009 9:21 pm

katiekat wrote:I feel confused again now!

Now its really quite simple..... use unleaded unless you are rich and have a 4 star outlet near you!

Stop Worrying about it!!

Post by **damian1978** » Tue Apr 21, 2009 1:28 am

Hi Kate - you're right about differences of opinion on this issue! I have a SII Splitscreen (1955) and although I am able to get leaded 4 star reasonably locally, I find it simply too expensive.

Personally, I use regular unleaded with Castrol Valvemaster Plus which is the lead replacement additive with the octane booster. It doesn't add much at all onto the cost of motoring and takes 30 seconds to put in before filling up.

Perhaps other members are right, my engine might be fine on nothing but regular unleaded - but maybe it won't. For me, the additive is peace of mind. I can't afford an engine conversion OR the cost of repair from valve seat recession. For a small extra cost per tank, I'd rather know my engine is protected. After all, I'm still saving with the free road tax and cheap insurance, so paying for additive seems worthwhile to me.

It's your choice, but I know what I'd do.... Unleaded with the valvemaster plus. Peace of mind!

Damian

Post by **bmcecosse** » Tue Apr 21, 2009 6:13 am

The 'engine conversion' for a 948 is very inexpensive - just source a later head from a 998 Mini engine (sometimes these engines are free ! and certainly very cheap on ebay) and bolt it on. Same head can be fitted to a 1098 with a slight loss of performance, which would not be important on a car used less than sportingly!

Post by **katiekat** » Tue Apr 21, 2009 8:00 am

Thanks for that advice.

After thinking about it I think I'll use valvemaster plus. It's not expensive and I can't afford to pay for repairs at the moment.

I just paid £160 for the MOT yesterday and had to pay for my moggy to get delivered so I need to be careful!

Thanks again!

Post by **hannahandflossie** » Tue Apr 21, 2009 8:34 am

Hi Katie,

Just to reassure you - i have deliberated over the same issue myself. The guy i bought my current minor from has never used additive - some people say yay the others nay as you can see.

For piece of mind i tend to squirt in a bit of additive (have used valvemaster and redex lead replacement) when i fill her up.

Happy motoring

Post by **damian1978** » Tue Apr 21, 2009 10:23 am

Nice one Kate! Like I said, it's cheap peace of mind.

Hope you get many years of fun motoring from your moggy.

Damian

Post by **katiekat** » Tue Apr 21, 2009 6:05 pm

Yes I just need to get my tax sorted now!

Post by **damian1978** » Tue Apr 21, 2009 7:02 pm

Oh, now that's the best bit! A free tax disc. Better still - order it online through the DVLA website and then they have to post it to you which means it costs them to give us a free tax disc!!!! a bit petty i know, but a nice feeling after years of being robbed!

Post by **rayofleamington** » Tue Apr 21, 2009 7:15 pm

Oh, now that's the best bit! A free tax disc. Better still - order it online through the DVLA website and then they have to post it to you which means it costs them to give us a free tax disc!!!! a bit petty i know, but a nice feeling after years of being robbed!

And you don't even need to wait for it to run out!! If for example your MOT was about to lapse you could just get another 12 months tax on a whim...

Post by **simona1** » Tue Apr 21, 2009 11:06 pm

I bought tetra boost from wilkinsons £4.69

Post by **Kevin** » Tue Apr 21, 2009 11:14 pm

Just remember which ever one you use stick with it as they dont mix and match so to speak.

Post by **bmcecosse** » Tue Apr 21, 2009 11:36 pm

That's a very good deal on Tetra Boost. Unfortunately no 'Wilkinsons' in Scotland, or I woud be tempted to use it!

Post by **katiekat** » Wed Apr 22, 2009 4:24 pm

Well that's very cheap for Tetraboost, I think I'll have a look to see if they have it in Sunderland.