Leaded / Un-Leaded Help

if you have a 110 then its most likely you have a low compression v8 fitted which will run all day long on unleaded .

i ran an ex 110 v8 in a range rover with an SD1 camshaft and SD1 electronic ignition fitted and all ran great on unleaded .

it all depends on what kind of distributor you have on the engine, ie if its just a vacuum advance or if its a vacuum advance and retard type . the timing will need setting according to type of dizzy you have .

basically youll be looking at either 6degs advanced, top dead centre, or 6 degs after top dead centre for static ignition timing but best way to see which suit best is to check general performance and also idle performance at one of these settings .

if ignition distributor is fitted with vacuum retard as well youll need to set idle revs and advance together .

on some engines if you find revs dont drop at idle then timing needs to be retarded more .

i had great fun sussing out my timing because there are at least 4 different variations of engine >ignition types i found details on and the settings can make a lot of difference to performance .

vacuum retard types will have 2 hoses from dizzy advance unit, the rear [retard] one will go to the inlet manifold centre front under carbs if i remember correctly .

i think in end i ran 6 degs advanced at 850rpm idle speed and that ran as smooth as anything and would pull in top gear from very low speeds , in fact would still pull at 500rpm , would run on unleaded all day and could hammer engine flat out uphill and down and no pinking whatsoever ...

hope this helps

Except for some early Sd1 V8's the V8 has always had hardened valve seats suitable for unleaded, so you'll have no problems going unleaded. The timing will need adjusting a bit, but V8's being V8's its a question trial and error to get it right for your particular engine (or find a mechanic with a magic ear who can do it).

Richard

Does that mean that if I wanted another P5B I'd be in trouble? Would I have to source later heads and would they fit? I miss my old 3l P5 Coupe. Wonder if a P5B would tow my 2000kg trailer short distances...

I'm sure if did a Google groups search you would find a group that can give you the exact engine numbers - certainly a lot of the car engines are suitable for unleaded, but which ones I couldn't say.

Richard

On or around Wed, 15 Jun 2005 15:16:53 +0000 (UTC), beamendsltd enlightened us thusly:

fair bet that the P5B isn't though. Although running a 10.5:1 "old" (pre SD1) V8 on LPG didn't result in valve problems.

Fair 'nuff... But would it tow my trailer - it's got to weigh about the same ;)

On or around Wed, 15 Jun 2005 21:33:42 +0100, Danny enlightened us thusly:

don't see why not. I doubt, though, that a P5B is really a practical proposition as an everyday workhorse now - lovely cars, though. ISTR they used the Borg-Warner 35 auto gearbox, which is not a bad piece of kit but not in the same league as the ZF 4HP22.

I spose, with a bit of effort, you could substitute a 3.9 RR + auto box; which would give you about the same power output as the high-compression 3.5 did in the old days on 5* petrol.

dunno what axle the P5B ran.

I had a lovely 3.0 (Westlake head) P5 coupe (1963) that I bought from an auction 15 years ago and drove for 4 years. I loved it. At the time there were still people making parts for them and it was my daily driver. I only do 50 miles a week towing the trailer and have a bike (Honda Blackbird) for personal transport...

I'm sure it's a pipe dream - I don't know if a P5B can be kept in rust-free condition or if it can tow 2 tons for a few miles on the level each day. The 110V8 was happy with the trailer.

I'm sure the engine will cope - it's the rest of the car than might be a problem. What is the max train weight for a P5B? That will give you your answer.

Richard

Thanks for this, exactly the information i needed. Bryan