V8 into Series 3 - bulkhead Q

The bulkhead in my 109 is fairly comprehensively shot, and with an eye to the future I was wondering whether it'd be better to fit a 6 cylinder bulkhead if I can find one - I understand that these have a deeper inset to allow for the longer engine which *may* suit a Rangie V8 conversion better?

Just considering this as I don't want to spend potentially £1k on a galvy bulkhead only to have to chop it in a year or so to drop a V8 in.

I know about the Stage One bulkhead, but that had a different gearbox and thus floor where as I believe the 2.6 6cyl jobbie used the same transmission as the 4 cyl engines, so there should be no need to mod these panels?

Thanks as always

Good luck if you can find one. Even more difficult to get a 2.6 engine. Not sure if a std gearbox can take the power from a V8.

As John says, good luck finding a straight 6 bulkhead, I've recently done some fairly extensive repair work on mine due to the difficulty of finding a replacement!

PS - No you can't have mine.

ajb403 said:

As John says, good luck finding a straight 6 bulkhead, I've recently done some fairly extensive repair work on mine due to the difficulty of finding a replacement!

PS - No you can't have mine.

Click to expand...

The force is strong with you, young ajb403 :fighting2:

As you say, they're likely to be rocking horse poo-poo, but I understand that Ashtree or similar may be able to restore a 4 cyl bulkhead to 6 cyl spec, hence my interest and question.

Is the only difference with the sixpot the centre panel?
As that portion usually does not rust and could be transferred to another standard bulkhead.

Thats my understanding Blackburn. If they can fit a 6cyl panel as part of the resto then I should be sorted - IF its true that it gives enough clearance for a V8...

I think the edge of the passenger footwell where it attaches to the transmission tunnel is a bit different too, the generic replacement footwell I bought and fitted on the near side needed a little pushing around to fit in place.

I presume you'll also be looking out for a Stage One bulkhead too?

Is there an easy way to tell between the two bulkheads (4 and 6cyl) as I have an immaculate one in my shed with a seeking suspicion I removed it from a 6cyl around 14-15 years ago.

For V8 conversions, length is not the issue, it's width, so I don't believe a 6 cylinder bulkhead will help. I had to chop the footwells around to get my 3.9 in.

I'll try and remember to take some measurements/pictures of the transmission tunnel on mine so you can see if it matches up with yours. It won't be tonight as I have plans but I'll try and get it done tomorrow. Alternatively you're welcome to come have a look yourself, I'm in Radstock so not far from you.

Many years ago I fitted a V8 into my old 109 ex 6 cyl.

The greabox sits 3" further back in the 6cyl chassis, this meant that a LOT more cutting out of the n/s footwell amd a tiny modification to the d/s was required to fit the V8 in.

In reality the differences I recall were more in the gearbox tunnel, bellhousing cover and floor sections rather than anything to do with the actual bulkhead differing from a 4cyl. This was compared with my brothers S2 88"

However I assume you will keep the 4cyl gearbox location as you would otherwise have to change prop shafts and gearbox mount cross member!!

So to recap, a 6cyl bulkhead on a 4cyl chassis wont give you any real benefit that I can see.

Fitting a v8 to a pre-existing 6cyl vehicle gave you an important extra 3" of room allowing you to keep the radiator in the existing location and with a shorter (3") oil filter you didnt need a remote filter adaption.

Either way you need to cut a chunk out of the passenger footwell to make room for the n/s exhaust manifolds to snuggle in.

+1 for just chopping a 4cyl footwell. Not too hard. Footwells will get hot so consider heat proofing in summer!

Thanks for that very useful reply KillaJoules - I did try to thank you yesterday but my PC crashed during the 'send' and my reply was lost in the ether... bloody computers lol

Anyway, thats really good info - I didn't realise that the 6cyl gearbox was mounted further back for instance - you learn something every day!

Looks like I'll be doing some extensive welding then...

Thanks everyone else too BTW, knew I'd get a decent response here

Yes I had no idea 25 years ago either when I bought the vehicle as it had a Perkins d4.203 up front.

The 6cyl bell bousing was different too as it was the same as the S1 2L IOE with the studs in the wrong position.

With a 4cyl layout it is simply a matter of chopping a small corner out of the n/s footwell and plating over it to allow the exhaust manifold room.

How you handle the exhaust is the next great problem, I managed to get an entire installation from another 6 cyl although the actual V8 was truly stuffed with 2 split pistons so I then had source another V8 and replace it. The installation had the O/S downpipe running round the front of the sump and joining the N/S pipe almost below that manifold. Not good for balancing, but it worked as there is little opportunity to get the exhaust aorund the engine xmember on the drivers side. That then ran into a Volvo 240 back box and out just in front of the rear n/s wheel gave an awsome burble.

Again with the 4cyl vehicle I believe you can use the existing chassis/engine mounts, in the 6 we had to fabricate new mounts.

I am going back 20+ years here when I did my 6cyl and then helped a pal do his 4cyl LWB.

The despondency I felt when I finally put the whole vehicle back together only to find that the first V8 was royally stuffed and I had no money, only to have to find another V8 in an SD1 and pray that it was a good one.

Fortunately it was and was amazing

Ahh bitter sweet memories

I have done a few V8 conversions on Series motors. The best way is to drill out the spot welds of the two inner panels in the foot wells and weld them back in further out, then make a new flat panel to go in between. Looks factory when done.
As stated above a 6cyl bulkhead dosen't help

Thanks everyone, I'm going to ask Mosside LandRover for a price - a bit too much welding for a novice like me