Which v8 for mgb conversion?

Personally, I wouldn't go more than a 3.9, in the interests of insurance sanity, axle life, brake and suspension ability etc. Any rover V8 can be made to fit, the differences being the interchangeable front covers, exhaust manifolds, and induction system. You could, if you wanted, uprate everything and put a 4.6 efi engine complete with management system into it, might need a bonnet bulge though. Post-SD1 engines are better, they have better heads (with slightly larger valves) and a stronger piston design with longer life rings. They all, however, eat camshafts and followers. I'd say go for a known running 3.9 and convert it to carbs, throw a new cam and followers in it at the very least (I'd do the rings and shells as well, then you know it's a good 'un). Whatever you do, don't touch anything with a history of overheating or coolant usage! As for gearboxes, you can't simply convert the landrover LT77 by removing the transfer gearbox, get a V8 LT77 from a rover, tr8, ldv v8, tvr etc etc., or go for a later R380 conversion. There's a 5 speed Getrag box with rover v8 bellhousing on ebay just now...... Badger.

Liam Healy ( snipped-for-privacy@aol.com) gurgled happily, sounding much like they were saying :

Stuffed TVR?

Hi, and thanks,

Do you mean I *can* pick up something like a 3.9 v8 auto, chuck the box, keep the engine, and then use a gearbox from something like a TVR or SD1? Or from any rover v8 for that matter as a straight bolt on?

Yes, exactly that. if using an engine from an auto, you will need to insert a spigot bush into the end of the crank though, easy job. Badger.

I have no idea if the things are still available or the practicality of it, but a Daimler 2.5 V8 would be a very sexy thing to put in it.

You wont belive this but my friend and neighbour bought one a month ago from Oxford - I can see it 80 yards away out of my window! I had a drive the day he got it - an automatic, it was so smooth and light and in very good Nick, he paid 2K for it so no change of pulling it to bits :-) But I'm more familiar with the rover lump, so will probably stick to that.

Hmmmm, I think I need to find a terminally rotten Alfa 6. I reckon an MGB with that lump would be lovely.

SteveH ( snipped-for-privacy@italiancar.co.uk) gurgled happily, sounding much like they were saying :

1. B with a transaxle... Mmm.

"...There's a 5 speed Getrag box with rover v8 bellhousing on ebay just now...... "

So in theory I could (1) mate it to this Item number: 4576514384, and (2) get it to fit into an MGB? or would the BMW box cause a few difficulties ?

Heh, that would be a bit challenging, I reckon. Which is why I plumped for the 6, ISTR that's the only RWD application of the V6 without a transaxle.

[...]

Nope, it would be an MGB with a lovely motor.

A

Well, the mgbV8 only ever had a 4-speed box (throwover from the P6, I think) so any 5-speeder may require some tunnel mods, and that is a very good

5-speed box - better than anything Leyland/rover ever managed to throw together! If it were my project, I'd get that box, mate it to a decent 3.9 with a mild or semi-fast road cam and modify the tunnel as required. After all, it's only carpeted, isn't it? Badger.

Hi I would think this site would be a good place to start:

Then anything V8 wise, the guys on this forum are very good at:

I have an SD1 lump in mine which is an NG with MGB running gear.

Hope this helps. Martin

SteveH ( snipped-for-privacy@italiancar.co.uk) gurgled happily, sounding much like they were saying :

Mmmm. But I suspect that you'd be hard pressed to find either of the Alfa

6s sold here.

Lol. Good point.

I came very close to buying a half decent 90 with 8 months MOT for 200 quid a couple of years ago. Kicking myself I didn't snap it up now.

If you can get one, the SD1 Vitesse or EFI 3.5 engine is by far the sweetest and most powerful of all the variants. The bigger ones might have more grunt - but just ain't so sweet, or have the right characteristics for a sports car. Of course some of the TVR variants are excellent, but difficult to find.

I *think* it used the MG C box.

Yes, but with the 3.5 engines, unless you fit the efi system the power will drop back to around 160/165bhp with the 9.75 comp. ratio, 155/160 with the

9.35 ratio. The vitesse was quoted at 190bhp, in the BL days of exaggerated power output quotations, whereas the 3.9 has a modern quotation of 182/185bhp depending on application. A true dyno average for the vitesse was probably nearer 180, i've witnessed 2 vitesse spec 3.5 engines on the dyno, both at around 175-180 after bedding in. It's also interesting to note that the only figures quoted by landrover for the 3.9 are on installations fitted with catalytic convertors also, so your bhp argument holds no water Dave. Any decent 3.9 will break 200 with no cats fitted. The 3.9 uses the same camshaft as the vitesse/efi SD1 (Different cam in the rangerover 3.5 efi) but retarded 2 degrees to give a little more bottom end torque. A 3.9 with a mild/fast road cam will give more power and torque than the 3.5 but will deliver very similar characteristics. The larger the capacity, the "softer" a given camshaft's delivery characteristics will be. For instance, a 5.0 with a road/rally cam designed for a 3.5, will have power delivery more akin to a mild/fast road 3.5. As you say, some of the TVR variants are a little hard to come by, but they are nothing more than a std engine with a different cam, certainly in 3.9 guise. I don't even think there are any porting mods done on the basic engine. The 4.2 tvr engine has, however, been condiderably "worked over". Badger.

The bloke who put a Nissan 2 litre turbo from a 94-98 200SX in his MGB had the right idea. 205bhp stock, MGB chaissis twisting 300bhp just needs a few bolt on mods. Don't have to run a silly high overdrive to get economy and keep bangs per minute down to something that doesn't sound demented when cruising. Most people don't like running much more than 6000 bangs/min in cruise = 3000 rpm 4 cyl, 2000 rpm 6cyl and

1500 rpm 8 cyl. So for 70mph at 1500rpm V8 winds up geared for well over 240mph in top (but runs out of go way before so top speed is only obtained in 4th or 3rd). Gear ratio is so high that any claim to having "low down power" or "bottom end torque" is negated.