Fuel filter

C

carlssonaero

New Member
At the last service in June by now retired P6 expert I was told he could not get hold of a petrol filter. Does anyone know ehere I might get one as its now about time I changed it.

Also on another topic does anyone know whether sdi heads would make much difference in performance if I could get hold of them and what I would also need to do (apart from make sure they were in good condition). My p6 is a 1974 lower compression model.

Thanks
Julian
 
Julian,
I too struggled to find one last year and ended up fitting a filter for a carb equipped SD1. It's not a perfect fit, the inlet and outlet being slightly longer than the original AC item, which raises the pipe to the carb slightly, but it does the job. I bought it from rimmers, and the olives and nuts are included. However, it may be possible to find another source on here.
Regards,
Dave
 
SD1 heads are definitely preferable, they have larger valves, so restore performance back to the level of the 10.5:1 engine.

Chris
 
Hi Chris,

Are they a straight swap? I've read a few bits by Ron and yourself referring to bigger engines in the P6, and wondered what changes need to be made for different things. I guess I need a rover v8 101 lesson!

Rich.
 
Hello Rich,

The heads on your P6B came from the factory during their time of manufacture fitted with double valve springs. From the SD1 on until the final Rover V8 engine that was fitted by Land Rover into a Discovery in 2004, the heads all came with single valve springs. The valves as Chris mentioned are larger and this will allow your engine to breathe more efficiently. The valve lift for the P6B and SD1 heads are both the same. You can remove your existing heads and fit the SD1 heads without problems. Inlet and exhaust ports for both types of head are essentially the same,...the only change you will need to make are that the SD1 heads require long reach spark plugs as opposed to the short reach of the P6B.

You may also need to swap your carburettor needles for slightly richer ones should your current ones prove to be too lean, the tell tale signs will be hesitation when you accelerate or an unwillingness by the engine to pull as well as it should on a long fast uphill stretch.

Ron.
 
That's interesting stuff then. What about head gaskets etc - i've read of composite gaskets for instance - are these important?

I wonder if the (somewhat poor condition) heads on my current car are actually SD1 heads - I say this as the needles appear to be richer than than they should be in the carb i dismantled on sunday. I'm swapping the engine for a runner for now and i'll take the current engine out and strip it to see what i have and if it's worth repairing/salvaging things off it. (It's very noisy - i altered the timing to remove the pinking and it sounds more like clashing valves than a camshaft...)

Reading the Rpi website i read that the standard 3.9 cam is good for putting on a 3.5 engine...?

THanks for answering my newbie questions :O)

Rich
 
Hello Rich,

Composite gaskets appeared circa 1994 for using with the then new 10 bolt cylinder heads which featured smaller combustion chambers...28cc compared with 36cc) They offer a significant improvement in sealing between the head and block, however if you fit them beneath 14 bolt cylinder heads you will alter the lifter preload and this will need to addressed if you wish the engine to run as reliably as it might in the long run.

You can of course have the SD1 heads skimmed so that the combustion chambers are of the same capacity as the later 10 bolt heads, fit the composite gaskets and you will have no problem at all.

Ron.
 
thanks thats great. good to understand these things - especially as the previous owner said it might have sd1 heads...

rich.
 
Rockdemon - At risk of teaching grandma to suck eggs... Are you sure the engine noise isn't "pinking" or pre-detonation? Can sound very alarming - basically the fuel charge in the cylinder goes off on its own before it should, often before the piston gets to the top of the stroke. Cause is usually poor quality petrol in a high compression engine - 10.5:1 engines should definitely need an octane booster - or something awry in the engine. Most likely timing way out, very weak mixture, carbon build up in the combustion chambers. A distinct possibility with your engine might be incorrect cam timing caused by a knackered timing chain and gears slipping a cog...

Chris
 
mmmmm... eggs :O)

It had occured to me that something of this nature was wrong - the only thing that makes me think that it's something wrong is that the noise comes from one particular cylinder ( number 3 ) and is a hard metal on metal sound that resonates. It doesnt sound cammy (although i can see the follower on number 3 is not moving) - it's much harsher than that. like hitting a frying pan with a wooden spoon....

I think it's possibly a combination of things - when i moved that dizzy to stop the pinking noise (well what i'd call pinking from experience with 4 cylinder engines) it got much worse sounding - making me wonder if the dizzy had been spun round a bit to stop the noise being so bad.

I think just changing the engine over and investigating when i have it out is going to be best as i have a variety of things that could be wrong and i'm having trouble picking between them. We have:

1. worn cam/followers ( probably the case whether thats causing the noise or not)
2. stuck valve
3. timing chain maybe ( but the timing seems pretty solid - doesnt wander)

Oddities to go with this are Rich running - exhaust is black and feels slightly damp.
Slight misfire that comes and goes.(stuck valve related maybe)?
Very heavy breathing fromt he crankcase - like a constant sludge of oil ends up pouring through the air filters. I've emptied some oil out because it was overfull - it's still up near the top though so thinking i should take a little more out.

I'll try and geta video of it runnig tonight and post it up and see if anyone can comment from that maybe?

Rich.
 
Hello Rich,

If your engine is pumping oil into the air box and filters, then either the flame traps / connecting pipes and hoses are blocked or.......the rings are totally shot.

Your thoughts on removing the engine and stripping it down to reveal the horrors within sounds like a good plan. Most likely it wil be "all out all change please"

Ron.
 
Well i've done the pipes and flame traps ( new ones) so that sounds most likely!

Long easter weekend coming up so hopefully i can get it soted then :eek:)
 
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