Unleaded or not?

[PHart]

Owning the car a little over a week now, and being told that (and assuming from its age, 1986 350) it was run on 4 star, I have been using unleaded super and a castrol lead additive. However I see in Steve Heaths book that all the V8's were fitted with hardened valve seats and its fine to run unleaded, allbeit with a timing adjustment. What do you guys all do?
I also get a load of burbling back fire when using engine braking, sounds great but is this normal, or incorrect timing/ overfueling?
All suggestions much appreciated!

[number 7]

PHart said:

Owning the car a little over a week now, and being told that (and assuming from its age, 1986 350) it was run on 4 star, I have been using unleaded super and a castrol lead additive. However I see in Steve Heaths book that all the V8's were fitted with hardened valve seats and its fine to run unleaded, allbeit with a timing adjustment. What do you guys all do? I also get a load of burbling back fire when using engine braking, sounds great but is this normal, or incorrect timing/ overfueling? All suggestions much appreciated!

You can run on unleaded no probs.- as you say, hardened seats. If you want ultimate power stick to super, ordinary unleaded may cause pinking, so you might need to adjust the timing a bit. I've always run super on my wedges. A certain amount of poping is normal, but if it's got a standard exhaust, loud banging like a shotgun may indicate an air leak somewhere.

7.

[dickymint]

PHart said:

I also get a load of burbling back fire when using engine braking, sounds great but is this normal, or incorrect timing/ overfueling? All suggestions much appreciated!

Perfectly normal.............bloody great innit

[D1 MAD]

Greetings PHart, I've had my 87 350i for nearly seven years, at first I ran mine on LRP or super, both 97 ron. Did this for about two years. Then.....when on holiday in southern Ireland I had to put 95 ron unleaded in the tank as that was all that was available that week. Expecting a bad case of pinking / poor running (not what you want at the start of a motoring holiday) imagine my surprise when it ran better than it ever had before! Certainly no detectable difference in the power, but the tick over was more even and temperature more stable.

Thinking it may be the after effects of that glorious black beer over in Ireland I went back to 97 ron when back in England but only for one tank full as my beast definitely prefers 95 ron.

[wedg1e]

I always run my car on 95 RON: it's my mision in life to make it just as fast as anything else using the cheapest petrol

Pops and bangs on over-run are one of the main reasons to own a Wedge, did nobody tell you?

[cdt]

May be of help:

www.pistonheads.com/gassing/topic.asp?h=0&t=233591

[PHart]

Thanks for all your help, i'm now going to go try a few different fuels and see which one my beast prefers, ditch my additives, probably dig the timing strobe out when I get a minute too. I'm glad I can keep the noises, great when you want to show cruising chavs up!

[Hoover.]

I can't see why 4 Star (not LRP) will cause pinking as it is the same RON as the supers, infact it has a higher RON rating then some of the supers....

Problem is finding somewhere that stocks genuine 4 Star.... my nearset place is .5 mile away

another problem is how long the fuel has been standing, many tests done recently and the conclusion they have come up with is down to fuel qualilty which deteriates with time...... so best use a fuel station with a good fuel turn round.

[wedg1e]

PHart said:

Thanks for all your help, i'm now going to go try a few different fuels and see which one my beast prefers, ditch my additives, probably dig the timing strobe out when I get a minute too. I'm glad I can keep the noises, great when you want to show cruising chavs up!

I have an expression for small hatches with big pipes:

"So much noise, yet so little progress"

[Selmer]

dickymint said:

PHart said: I also get a load of burbling back fire when using engine braking, sounds great but is this normal, or incorrect timing/ overfueling? All suggestions much appreciated! Perfectly normal.............bloody great innit

Haha...an acquaintance of mine commented just yesterday, "errr...Tony, is your exhaust alright? I heard a big bang as you pulled up the other day....."
Yeah, you would!