Conversion Engine advice

[jon1630]

Hiya all

I was wondering if any of you know what gets changed for a ford v6 conversion?

My stag has a ford 2.8 v6 lump with a ford 5 speed box in it and is running well, but its not a v8 is it, so i am thinking of putting a rover in it as the triumph engines seems to go for silly money and i want to do this as cheap as i can. so does anyone know what i would need to change it over?
is the prop the same ?
should i use a triumph or a rover gearbox?
whats the best v8 engine to use,  p6?

hopefully someone out there can point me in the right direction.

cheers
jon

[badger]

Can't help re. conversion parts, but I know rover v8 engines very well as part of my business is rebuilding them!
Don't use a P6 block, the block isn't as strong as later (post '83/84) ones, and it has the troublesome rope-type crankshaft oil seals. If you want to stay with a 3.5 size, use a post-'83/84 "stiff-block" and fit the higher compression (10.5:1) pistons from a P6 if you wish, but beware they are of a weaker skirt design than the later rangerover/SD1 (9.35:1) type. Be wary of early landrover engines as some were a lowly 8.13:1 cr, fine for turbo use but not much cop for any real performance otherwise. Fit a set of ARP main bearing studs instead of the std bolts, for vastly superior main bearing cap security and fit composite head gaskets instead of the std tin crap! (Skim the heads by 27 thou to compensate for the thicker gaskets). Fit an MGB oil pressure relief valve spring to up the oil pressure to around a nominal 50psi, this improves the oil flow to the rear main bearing without putting too much extra strain on the drive gears, but don't be tempted to go any higher as drive gear wear will increase.
You could always fit a rangerover/discovery 3.9, with an SD1 timing cover and water pump to drop the fan height down a bit, and either convert to fuel injection (giving 185bhp at the flywheel) or fit the MGB V8 carb setup to avoid the need for any bonnet bulges....? (There's an MGB V8 manifold complete with carbs on ebay at the moment!)

Badger.

[badger]

Forgot to add, don't torque the outer row of 4 bolts on each head to any more than 40lbft as they "tip" the heads and cause gas leakage into the valley area of the engine. Rover themselves did away with these bolts on the later (4.0 and 4.6) engines for this very reason.

Badger.

[wakaday]

Jon.
If you are handy with the spanners then you could probably buy a complete running resto stag with a V8 from martin at justriumph. Grab the engine and box and recoup your money from selling the bits from the stag and your Ford Engine on Ebay. It may sound a bit speculative but believe me, it will work.
The Stag V8 is a great piece of  under rated Engineering and all those ealy horror stories are well behind it now.
The Rover is great as well and a lot cheaper but you will need a few different parts to make it fit well.
Exhaust Manifolds, Alternator bracket, Rad mountings, Short water pump and pulleys, PAS Pipes and pump brackets and possibly a bulge in the bonnet unless you fit a Four Barrel carb are a few of the things you will need.
I have been involved in a few Rover conversions over the years and would never slag them off because it is truly a great conversion when done properly but for the easy route, I would go for the original everytime.

[Richard B]

This leads to a question I've had. Can you fit the Rover V8 onto the Triumph Manual gearbox?

[wakaday]

Yes you can and in my opinion, its a better gearbox.

[Richard B]

Any clues as to what is required? Which clutch, which adapter plate (who can supply)?

Cheers

[wakaday]

Richard.
Martin at justriumph had few stag boxes with the Rover adapter ring fitted. He may well still have them.
The clutch is a Stag item to fit the input shaft and the cover is a Standard SD1.
Try justriumph in a search and you will probably end up at his ebay shop.
Nice bloke. Very helpful and knowledgeable.

[shenderson]

If staying with 3.5 litres I wouldn't go for 10.5:1 CR because that requires 5 star fuel; better stick with 9.35:1 using SD1 heads for increased valve sizes.  If going for a larger engine I always found the 4 litre smoother than the 4.6.  There is little point going for huge torque anyway because the diff won't take it.

Also, don't forget though that the Rover engine is much lighter than the Triumph unit so you will need to replace the front suspension springs.  I have some data on this somewhere if you need it.

Cheers

Steve

[badger]

Assuming you are starting with an SD1 or landrover type engine, fitting these heads with 10.5:1 pistons gives around 9.8:1 with composite gaskets, as the head chambers are larger than the pre-SD1 heads. This combination will run quite happily on regular unleaded, I've done it, even to the extent of fitting weaker advance springs in the dizzy to increase low to midrange advance for more torque. The dizzy also had total advance reduced by 6 degrees and the base setting increased by the same ammount. The rover engine responds particularly well to a lot more advance and certainly mine didn't pink at all in this spec. The important factor is not to increase the total advance.

Badger.