P6 V8 manifolds and loss of power

Personally I wouldn't restrict return when the float bowl is full the floats restrict fuel amount and excess returns to tank.
If you've got fuel returning to tank..I put clear pipe on mine so I could see.. then I would strip and clean carbs as a first step and check for any filters po fitted in the line as on tickover engine gets enough fuel to run but under throttle emptys carbs..guess how I know!

Yea there's an old cheapie disposable filter still in line, didn't think to mention it as already ordered a replacement. Not found any others - don't think there's one pre-pump in any case! Looking at a 150micron one pre-pump, and a 40micron one between the pump and carbs.
I like the idea of clear pipe, but worry about rubbing and whatnot. Maybe a small length... worth a think anyway, thanks for the idea!

I'd change filter before replacing anything and see if you get it running properly again ...blocked filter is classic case of fuel starvation which is what you've got by the sounds of it.

Replaced filter ...running back to normal let us know dude..

All the V8 manifolds are the same where they bolt to the heads, but only Range Rover Classic manifolds will fit Series 2/3 V8 conversions as they tuck tight to the block.

Thanks RR - will probably end up getting a custom S/S tubular exhaust system - looks like the RRC manifolds cost almost as much anyway so kinda thinking why bother! But if that doesn't end up being feasible, I've bookmarked those
Shippers, will definitely update when I've sorted that bit - I'm really hoping you're right and it's that easy! Weather's been horrendous (I have no garage or carport so it's all got to be done on the roadside...) so have been refurbing the heater box (on the Ninety) in the warmth of the kitchen this weekend instead! (I hate those threads where you never find out whether any of the suggestions sorted the problem!)

Feel for you mate seen weather on tv I'm working outside on 101 getting ready to refit head when gaskets arrive next week but it's t-shirt weather here in the Algarve.
Why are you changing the manifolds anyway?

Rest of the exhaust system already been patched together a good few times, manifolds themselves mostly rust now (although appreciate they're not 1mm 'steel' like the rest of the cheap crap normal exhausts are made from, so have a much longer lifespan) so just getting prepared

The pic you posted of them looks like they just could do with a good wire brush they're cast iron so not smooth to start with,if not cracked they will do,tubular manifolds cost and will make a difference in a kit car with a custom exhaust in terms of power but no difference in a landy due to gearing.
I'm restoring a 68 2000tc p6 as well and there's a facebook site for parts\for sale thats good for engine bits.

Hi Nick,

I have a Facet pump that was going to use on my V8, didn't use in the end, it MUST be gravity fed - I live in Shepton Mallet, looks like you might be close, you are welcome to have a go with it - if that works, will save you the fuss of a return pipe.

I'd rather it was on a Landy than sitting in my garage!

RobV8Defender said:

Hi Nick,

I have a Facet pump that was going to use on my V8, didn't use in the end, it MUST be gravity fed - I live in Shepton Mallet, looks like you might be close, you are welcome to have a go with it - if that works, will save you the fuss of a return pipe.

I'd rather it was on a Landy than sitting in my garage!

Click to expand...

Still think it's the in-line filter he hasn't changed yet imho.

Thanks Rob that's really very kind! I am looking at the Facet Posi-Flow ones, or possibly the Holley Mighty Mite - they too need to be below the tank. But as Shippers suggests, need to swap out the filter first - might be the pump's just fine!

I spent a day swapping fuel pump,fittings and lines only to find a block in the supply pipe in the tank due to it sitting for 10yrs without a sender unit in,it was leaves dust and metal fillings that on tick over allowed enough fuel but under power not enough drove me mad for weeks...I've got 2 spare pumps here in the Algarve as a result lol if anyone needs one

That's a good shout too - I've emptied the tank and it all looks beautifully clear, but it's an easy task to pull the supply pipe out too, which I hadn't thought of trying after finding no rubbish in the tank. I'll be dead chuffed if it's that easy to fix...

Fingers x it's the filter...once sorted you can do what I'm doing replacing old with new while it's running!!
Where is the pump fitted at the mo is it gravity fed?

It's right up at the front by the distributor. It's some random black thing with no ID on it. One reason why I've not been hurrying to fit a new pump as most of the ones I've been looking at are gravity fed and so I'll need to mess about with the pipework - don't mind the hoses, but it's all solid pipe from the tank right up to there, with about 6" of hose fitted at the end. [Yea, I've done about 5 miles in it in the last 2 months as don't dare get stuck in some of the traffic-light one-way systems we have all over the place here - would love to have it just running OK!]

I had been looking at the Facet Interrupters, which would simplify my hose / pipe work quite a lot... can't remember why I talked myself out of them exactly now. The Silver Road version looks like it'd be just the right pressure too. 18gph sounded really low compared to the other ones, but when I do a back-of-the-fag-packet calculation I can't see how I could use 18gph in this thing anyway. If I'm getting 10mpg and managing 80mph (haha) that to me says 8gph is about the most I could expect to use in an ideal world. Obvs at 80 my gearbox would be throwing bits through the floorboards, but you get the idea! Have I missed something?

Wow that got me didn't expect that installation...

Hope you don't mind me saying but I think you're over thinking\engineering you're fuelling...tank..filter...pump...carbs all connected with rubber fuel pipe....return to tank clear fuel pipe...you can also fit a non-return and a glass seperator along with a cartridge filter between pump and carbs I would ditch the solid pipes.

Well fuel hose finally showed up, hadn't spotted it was on backorder when I paid for it all ... so will hopefully swap out the slightly tired fuel hose and the filter tomorrow morning if the weather's OK. I like the idea of just going super-simple, Shippers, works for me! Will take a few pics as I go on...