craig1410
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| posted on 3/3/03 at 10:43 PM |
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Rover V8 with Unleaded Fuel? Possible?
Hi,
I'm hoping to use an SD1 carb. engine in Locost project but it just occurred to me that the V8 couldn't use unleaded fuel when it first came out.
Does anyone know the situation with this now? Would I have to get new valve seats fitted to my heads or what? Does it depend on the compression ration
of the engine in question?
There's always a catch...
Cheers,
Craig.
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Simon
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| posted on 4/3/03 at 01:54 PM |
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Craig,
Have you seen my comments in the Donor thread.
I've said I'll do 3000 miles a year at v.approx 25 mpg, with an additional cost of LRP over UL at say 20p/gallon will cost £24/year.
I wouldn't get too excited about that:-)
ATB
Simon
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craig1410
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| posted on 4/3/03 at 08:10 PM |
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Hi Simon,
Yes I saw your other response in the donor section. I think I replied to it when I was at work (will check in a mo').
Yes, I hadn't thought of it in terms of extra cost. Hopefully in the Locost I would expect to get around 30MPG due to the light weight and even if I
did 10000 miles per year then it would only be £67 per year!
Thanks for pointing out the reality of my concerns... Doh!
I noticed at my Local BP petrol station tonight that UL is 79.9/litre and LRP and Diesel are both 80.9/litre so that makes the extra cost onlyabout
5p/gallon and hence about £16/year...
Cheers,
Craig.
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craig1410
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| posted on 4/3/03 at 08:12 PM |
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Sorry, I forgot one question I meant to ask last time.
Does LRP actually work?
I remember when it first came out there were many sceptics who said it was just a placebo replacement for 4 star. Has anyone out there been running a
leaded car on LRP for any decent length of time? Any problems?
I think you still have to retard the ignition a bit don't you? The octane is still 95 RON isn't it?
Cheers,
Craig.
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Viper
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| posted on 4/3/03 at 08:26 PM |
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We use an additive made by milers in our classic race engines and it works a treat cost about £5 for every twenty ltrs of unleaded, or you could look
at using later model heads perhaps from a range rover..
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Jon Ison
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| posted on 4/3/03 at 08:31 PM |
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if its a nice old well used engine there will be enough lead around to last for ages anyway.............1000's of miles B4 you start to do any
damage.......and even then it will be pretty slow to come on.
the RV8 is a well understress'd engine anyway, and in a locost it will be even less so, 6-700 kgs is a fair bit less than a range rover to pull
about.....
its your call, but i would just drop some addative or LRP in around every 5th tank full or so and forget about it.
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craig1410
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| posted on 5/3/03 at 12:31 AM |
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Thanks Jon and Viper,
£5 every 20 litres sounds a bit steep IMHO, I'm hoping to do a decent mileage in my Locost when I get it built (assuming the DVLA haven't taken my
license away for old age by then...)
Jon, you may well have a point. It's the valve seats that burn isn't it? What's the worst that can happen assuming I've retarded the ignition to
prevent detonation? The valves may start to leak due to burning and I get poor compression? Solution - Recondition the heads and fit unleaded seats
and guides and new valves or get later heads as you suggest. Hmmm!
Maybe I'll just spend an extra penny per litre and get LRP but it's nice to know that I probably won't kill the engine if I use the wrong pump once
in a while, assuming I don't stick diesel in it of course 
Thanks for the feedback, looks like you've taken away another excuse for not using the V8!
Cheers,
Craig.
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Rorty
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| posted on 5/3/03 at 01:43 AM |
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I totally agree with all the advice offered so far. But, to answer your question technically, and also 'cause I like playing the Devil's advocate,
you should replace the valve seats with unleaded items. There's also the alternative that Viper mentioned: if you were to pick up some heads off a
range Rover or Discovery, they will already have the unleaded seats.
While your at it, you could also swipe the EFI, which would make your little locost sit back and take notice!
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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craig1410
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| posted on 5/3/03 at 08:52 AM |
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Hi Rorty,
Do you think I'd be cheaper getting my existing heads fitted with new seats or sourcing a set of later heads?
Would new seats REQUIRE new valves?
Cheers,
Craig.
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Jon Ison
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| posted on 5/3/03 at 03:06 PM |
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i realy would,nt worry about it, i had a range rover for many years and at 15mpg it had more unleaded than i care to remember, at some later stage if
you want to "up" the performance then fit later heads and have them "worked" at the same time.............but in the mean time, forget
it.......
all IMO of course...........
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Jon Ison
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| posted on 5/3/03 at 03:11 PM |
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i may be wrong but, in simple terms as i understand it, it don't burn the seats, the led lubricates the seats, unleaded ones are harder, after a
"very" long period of time the valves will start to wear the valve seats if there is no lead around, hence a odd fill now n again would be enough,
you will get years of locost motoring on unleaded B4 you have problems..........
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david walker
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| posted on 5/3/03 at 07:07 PM |
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Discovery & RR heads are u/leaded from new. SD1 Heads are supposed not to be. I've always found this suprising as SD1's were made alongside Range
Rovers.
If you've ever machined seats out of an SD1 head or recut them, you'll know they are not cast iron. They may not be technically hard enough but they
are hard. In my experience you are OK to run with unleaded in an SD1 engine. The only worry you'll have is if you are going to run on LPG. They are
not hard enough for that - but then that is the case with many engines!
Dave Walker, Race Engine Services - 07957 454659 or 01636 671277
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craig1410
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| posted on 5/3/03 at 07:57 PM |
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Thanks Jon and David!
As I said the other day, LRP is only 1 p per litre more than unleaded at my local pump so even using LRP all the time should not be a problem. It's
nice though to know that this is probably not vital.
I don't think anyone answered my question about whether LRP is the same octane as Unleaded. Are they both 95 RON?
Cheers,
Craig.
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david walker
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| posted on 5/3/03 at 08:55 PM |
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There is a general concensus, certainly amongst competition and high performance engine users, that LRP is bad news. I'm not a chemist but it is
something to do with the chemical that replaces the lead not being a very good lubricant for anything other than the valves. No doubt someone on here
can explain.
I think that LRP is 95 RON, the same as Std unleaded.
If I were you I would be using unleaded.
Dave Walker, Race Engine Services - 07957 454659 or 01636 671277
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craig1410
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| posted on 5/3/03 at 10:01 PM |
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Thanks David,
The plot thickens!
I seem to recall that no one believed that LRP was as "good" as 4-star but I didn't realise that it could in fact be more harmful to the engine
that unleaded.
Has anyone else heard of this or can anyone expand upon David's explanation?
Perhaps unleaded would be best coupled with a dose of third-party additive ever few tankfuls? Any takers on that suggestion and which additives would
you recommend? Someone (Rorty maybe) already recommended a fairly expensive additive (£5 every 20 litres or something)
Cheers,
Craig.
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craig1410
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| posted on 5/3/03 at 10:02 PM |
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Sorry it was Viper not Rorty that recommended the Milers additive. I hate it when the thread gets too long to be viewed on the post page and I'm too
lazy to open another window 
Cheers,
Craig.
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Rorty
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| posted on 6/3/03 at 01:35 AM |
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I wasn't going to reply to your query, as i feel it has been well and truly addressed. However, as it was directed at me, I thought I would,
hence:
craig1410:
quote:
Do you think I'd be cheaper getting my existing heads fitted with new seats or sourcing a set of later heads?
As the Rover lump is such a "soft" engine, they last a suprisingly long time, as long as the oil has been changed regularly. If you really want
"leaded" heads, I would look for a good second hand pair.
Cheers, Rorty.
"Faster than a speeding Pullet".
PLEASE DON'T U2U ME IF YOU WANT A QUICK RESPONSE. TRY EMAILING ME INSTEAD!
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