All this talk of engine changes......

[KentishS2]

....has made me consider the question of how difficult it would be to fit the RV8 unit into the S1, S2, S3 models. Probably not with EFi, favouring carbs so that the engine management doesn't present a problem.

Gearbox and clutch compatability are one question, as are angine mounts, chassis space/width, exhaust manifold, cooling and probably many others!

Any ideas, discuss?

[Roy C]

...or save a load of money and buy a V8S!

[KentishS2]

Roy C said:

...or save a load of money and buy a V8S!

Uhhmm, not sure it'd cost about £4k to do this if you could do much of it yourself, would it

[KentishS2]

Also, is the 24v cossie unit suitable for fitting carbs to instead of Efi, I beleive somebody has in an S but I can't recall who. Can anyone remember?

[SotonS2]

KentishS2 said:

Also, is the 24v cossie unit suitable for fitting carbs to instead of Efi, I beleive somebody has in an S but I can't recall who. Can anyone remember?

gbgaffer, on the Isle of Wight IIRC

[SotonS2]

KentishS2 said:

....has made me consider the question of how difficult it would be to fit the RV8 unit into the S1, S2, S3 models. Probably not with EFi, favouring carbs so that the engine management doesn't present a problem. Gearbox and clutch compatability are one question, as are angine mounts, chassis space/width, exhaust manifold, cooling and probably many others! Any ideas, discuss?

Plus all the mods to suspension, extra strengthening of the chassis, brake upgrades etc etc.

And, at the end of the day, it would be a non-standard S1, S2 or S3 which may have a market value less than had it been unmodified.

Would seem a bit pointless to me. Just buy a V8S.

[KentishS2]

SotonS2 said:

KentishS2 said: Also, is the 24v cossie unit suitable for fitting carbs to instead of Efi, I beleive somebody has in an S but I can't recall who. Can anyone remember? gbgaffer, on the Isle of Wight IIRC

Thanks, found the link now too!

www.pistonheads.com/gassing/topic.asp?f=11&h=&t=28120

[KentishS2]

SotonS2 said:

Plus all the mods to suspension, extra strengthening of the chassis, brake upgrades etc etc. And, at the end of the day, it would be a non-standard S1, S2 or S3 which may have a market value less than had it been unmodified. Would seem a bit pointless to me. Just buy a V8S.

I know what you mean but...

My shocks are standard AFAIK and I'll be upgrading them at some point anyway, my brakes have been upgraded already (fast road grooved/drilled discs with greenstuff pads). Chassis I think is not an issue as the size of the engine bottom end is similar so physical fit should be OK but if you mean power handling then I think the extra hp can easily be handled without chassis mods.

Looks like GBGaffer had problems clearing his bonnet with carbs looking back at his posts and also his exhaust was too noisy (is that a problem )

It's probably worth me having a chat with someone who's done the swap at some point to satisfy my curiosity. I'm just considering it as a long term possibility but not sold on the idea or anything yet and thanks for the advice and opinions folks.

[HarryW]

I'd personally just buy a V8S its got to be easier IMHO.
Don't forget Gbgaffer started with a S4 which has the V8S chassis. If you happen to have a S4 then yes worth doing as there are unconfirmed reports that the S4Cossie actually puts more down on the road that most 500's including tweeked ones .
Then again there were only 34 S4C's to begin with, so it could be construed as a crime to convert them all.

Harry

[dern]

A V8s might be easier but converting yours sounds like a lot more fun if you don't mind getting your hands dirty.

If you decide to keep the type 9 (don't know how much power they can handle) then you'll need a bellhousing to convert a rv8 to a type 9 and that's got to be something that's been done loads of times. Or you could go for a rover gearbox or maybe an MT75 gearbox assuming they'll go in the transmission tunnel (both have been fitted to S's so there should be).

Alternatively you could be more unusual and go for a ford small block v8 as was used in the capri conversion in issue 1 of practical performance mag. They aren't as heavy as you imagine and not too expensive to buy, overhaul etc... that would be my choice. The recommendation was to get an old 80s mustang with a 302 engine and use the engine and gearbox from that. One thing I don't know is the height of the engine however but it seemed to fit in a mark 1 capri ok.

Mark

[SotonS2]

KentishS2 said:

Chassis I think is not an issue as the size of the engine bottom end is similar so physical fit should be OK but if you mean power handling then I think the extra hp can easily be handled without chassis mods.

I thought the V8S had an uprated chassis to cope with the extra grunt ??

[WildfireS3]

SotonS2 said:

KentishS2 said: Chassis I think is not an issue as the size of the engine bottom end is similar so physical fit should be OK but if you mean power handling then I think the extra hp can easily be handled without chassis mods. I thought the V8S had an uprated chassis to cope with the extra grunt ??

[dern]

SotonS2 said:

I thought the V8S had an uprated chassis to cope with the extra grunt ??

When you mean "cope" you do mean that the chassis will bend or suffer fatigue or do you mean that the resulting car's power will over-power the ability of the chassis to manage the power in terms of handling?

If it's the former then I can't imagine it would be that difficult to weld in strengthening bits into the chassis to cope as, presumably, tvr did with the v8s. The big advantage of this situation is that you could probably use v8s rear suspension arms if they are a weak point and building stronger wishbones wouldn't be that difficult as you've already got the dimensions worked out in the existing bones.

If it's the latter then uprating the dampers/tyres etc may help but you'll inevitably get to the point where the power will overcome the ability to grip the road at some point and then the buck stops with the skill of the driver and his/her ability to use the throttle as an analogue device rather than a digital one.

I almost wish I'd kept my s3 now as putting a small block in one sounds fun

Mark

[SotonS2]

dern said:

SotonS2 said: I thought the V8S had an uprated chassis to cope with the extra grunt ?? When you mean "cope" you do mean that the chassis will bend or suffer fatigue or do you mean that the resulting car's power will over-power the ability of the chassis to manage the power in terms of handling? If it's the former then I can't imagine it would be that difficult to weld in strengthening bits into the chassis to cope as, presumably, tvr did with the v8s. The big advantage of this situation is that you could probably use v8s rear suspension arms if they are a weak point and building stronger wishbones wouldn't be that difficult as you've already got the dimensions worked out in the existing bones. If it's the latter then uprating the dampers/tyres etc may help but you'll inevitably get to the point where the power will overcome the ability to grip the road at some point and then the buck stops with the skill of the driver and his/her ability to use the throttle as an analogue device rather than a digital one. I almost wish I'd kept my s3 now as putting a small block in one sounds fun Mark

I guess that's a question best directed at the TVR designers responsible for the V8S.

As with everything that is 'engineered', a certain factor of safety has to be built in. It may be that the factor of safety in both your former and latter cases would have been less than specified with the addition of the extra bhp and, more importantly, torque.

[S1.5f]

I seem to recall Mickeypee is fitting a 4.0litre ford V6 to his S and it's pretty much a direct replacement with 200 horses stock

[dern]

SotonS2 said:

I guess that's a question best directed at the TVR designers responsible for the V8S. As with everything that is 'engineered', a certain factor of safety has to be built in. It may be that the factor of safety in both your former and latter cases would have been less than specified with the addition of the extra bhp and, more importantly, torque.

True.

Go for it anyway and we'll soon find out

Mark

[S3Swiss]

"I seem to recall Mickeypee is fitting a 4.0litre ford V6 to his S and it's pretty much a direct replacement with 200 horses stock"

In South Africa, Ford released a Sierra with a US Ford V6 engine (late 80s) - suspect it was about 4.0l. It certainly gave the car some power! I drove a UK import once and it was wheel spinning in the dry in third. If you can find one of these blocks - it is about the same dimensions as the UK V6.

[Psychobert]

I thnk there are a couple of Cossie engined Ss either running or in the pipeline, RT Racing were certainly looking at doing it to an S2 I think a while ago.

JW Developments do various tweaks for the V6, some of which involve larger capacity mods which I guess are quite expensive.

No idea about shoehorning a V8 into a V6, but I think it would be hellishly pricey and you would need to do a few serious mods to keep it in the direction you originally pointed it. On twisty roads at speed, mine can be a little vague at times.

[Roy_S2]

I will be at some point in the future fitting the Cossie in mine. I have read that a 'sorted' one will produce in the region of 330bhp. I really can't see how an earlier S chassis won't take the power. If the engine and transmission rubber mounts can handle it for quite a while then the chassis MUST be more than up for the job. I did read somewhere though that the type 9 box was good for up to about 250bhp, so it may be best to fit either a less 'sorted' cossie or upgrade the gearbox. I'm not sure how much the MT75 box will take and I don't know about the diff either. My philosophy on stuff like that is sort it when/if it breaks.

My theories are based on what info I've managed to read on t'internet. I don't know how accurate the values quoted are but I can't see them being too far from the truth.

Roy.
Roy