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3.9 V8 exhaust manifolds


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Just got a 3.9 for my 110 and was planning on using 3.9 exhaust manifolds, 'cos they're better. Does anyone know whether these are the same shape (length and fittings) as the 3.5 ones, so that they will match up to the downpipes and rest of my exhaust. If not, anyone know the solution. Thanks.

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Just had a 3.9 fitted into my 110 to replace my 3.5.... Same Janspeed manifolds / exhaust pipes, radiator, main loom etc. used and great result....

Nothing moved, all fits & loads more smiles !

Edit: Sorry, mis-read the original post ! :) Hope my information helped......

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Beg to differ - 3.5 EFI and 3.9 (which were all EFI) are the same fitting (two pipes on a 3-bolt flange) but the 3.9's are slightly larger bore, hardly noticeable to the naked eye though and TBH almost certainly not worth the hassle of retro-fitting. In your case you probably won't lose anything by leaving them on but your downpipes will be slightly smaller than the diameter of the manifold outlet, again this is so little difference that it's unlikely to be worth worrying about - remember it's a 2-ton aluminium wardrobe not an F1 car :rolleyes:

3.5 carbed have the single pipe I think, Nige is obviously more of a luddite and knows about these clockwork things :lol:

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Thanks guys. My 110 currently has the standard 3.5 carb exhaust, so it seems from what you are saying I will need manifolds, downpipes and Y piece. Time for some shopping...

It was lovely getting the new lump out on the drive in the rain last Sunday. I must say that once we were completely cold and soaked, the labelling of where things attached wasn't quite as diligent as I had intended... So expect a few questions :rolleyes:

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Beg to differ - 3.5 EFI and 3.9 (which were all EFI) are the same fitting (two pipes on a 3-bolt flange) but the 3.9's are slightly larger bore, hardly noticeable to the naked eye though and TBH almost certainly not worth the hassle of retro-fitting. In your case you probably won't lose anything by leaving them on but your downpipes will be slightly smaller than the diameter of the manifold outlet, again this is so little difference that it's unlikely to be worth worrying about - remember it's a 2-ton aluminium wardrobe not an F1 car :rolleyes:

3.5 carbed have the single pipe I think, Nige is obviously more of a luddite and knows about these clockwork things :lol:

One is of course quite right :blink:

My excuse me lud was I supposed that a 110 had in it a V8 on carbs, and the defendant was placing a 3.9 EFI in its place, as such I advised that 3.5 Carbtootee manifold was single and 3.9EFI PODM (Price of Darkness Model Manifold was twin)

Additionally my fingers when typing seemd to be disconnected from my brain

Be gentle with me...........

Nige

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Unfortunately only moving one step up the evolutionary scale from carbs. The 3.9 has the flapper injection with Prinz sequential LPG - hence a few questions coming up, especially as 1) it was running v. rich on fuel before switching, 2) I have some plans Baldrick and 3) as implied in my earlier submission, it looks v. complicated and not sure my labeling is up to it!!!

Now, where's the Add Reply lever.

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I suspect that I may have identified why the vehicle was running rich. While the engine loom is out, I have had a little investigation. 18 years of engine bay heat has taken its tole and although several insulation cracks there were two obvious shorts, both on the clip on connectors (similar to the injectors) by no.1 cylinder (front n/s). One is a Burgundy colour and one is white.

Any flapper fans know what these connect to and whether their shorting would cause it to run rich?

Good news is that Autosparks do new looms for about £60 which is a fraction of what it would cost to buy all the connectors, the time to fix. Plus, I would still end up with an old loom with brittle insulation.

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I suspect that I may have identified why the vehicle was running rich. While the engine loom is out, I have had a little investigation. 18 years of engine bay heat has taken its tole and although several insulation cracks there were two obvious shorts, both on the clip on connectors (similar to the injectors) by no.1 cylinder (front n/s). One is a Burgundy colour and one is white.

Any flapper fans know what these connect to and whether their shorting would cause it to run rich?

Good news is that Autosparks do new looms for about £60 which is a fraction of what it would cost to buy all the connectors, the time to fix. Plus, I would still end up with an old loom with brittle insulation.

White is Coolant Temp Sensor

Brown is Thermotine sensor

Nige

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