The V8 Owners Forum -

I'm thinking seriously about putting bike carbs on my 3.9 and am wondering if theres a (cheap) resource for profiles of the head where the inlet bolts on?

This is before I think of whittling my own out or adapting the bottom half of the injection inlet.

Theres plenty of these to suit ford zetecs engines but wonder if theres a clever dude with access to a cnc water jet machine about?

Steve

A valley gasket will give you the rough shape you need to make a plate.

Thanks, just realised that, found some parts on ebay but a bit expensive.

I'm thinking of adapting the upper inlet to take the carbs.

Once I've decided which way to go I'll post some pics.

Hi
Have you talked to Bogg brothers http://www.boggbros.co.uk/ they do a lot of this sort of thing, they are not the cheapest if you need custom fabrication but they also are not the most expensive. They may have this sort of thing on the shelf ready to go and this could work out well for you.
Best regards
Mike

coozer wrote:I'm thinking seriously about putting bike carbs on my 3.9 and am wondering if theres a (cheap) resource for profiles of the head where the inlet bolts on?

This is before I think of whittling my own out or adapting the bottom half of the injection inlet.

Theres plenty of these to suit ford zetecs engines but wonder if theres a clever dude with access to a cnc water jet machine about?

Steve

Give Ralph85 a shout. He can do all the waterjet stuff. He has a RV8 in his car, so who knows might even have a CAD drawing already

www.componentengineering.co.uk

I made my own years ago and I still have them if you want to make me an offer on them. They arent the best in the world, but ran on my TVR500.

They are flat, so need wedges under the bolts, I also have a remote thermostat somewhere, I will dig them out.

If your interested give me an email and I will send you some pics:
phil @ extraefi.co.uk
thanks
Phil

Thanks Phil, at the moment I'm not sure whether to use the carbs or run the MS2 I got off you a while ago for my ST170 kit car.

I will be using the MS to run the ignition but really like the idea (and cheapness) of the carbs.

Depending on what you want, the cheapest option for bike carbs is to use the throttle bodies from an injected bike and use the MS to control them,
Phil

There's a DIY bike carb manifold kit on eBay at the moment - can't access the auction from work, but using the right keywords will get you there. 138 pounds though (as far as I remember).

Is there any real benefit in using four throttle bodies on any RV8? If so, why didn't Lotus go down this route for racing rather then the TP? FWIW, I'm even less convinced about boxer SUs - rather than 2 large enough ones.

Hi
The boxer set up works once the carbs are corrrectly matched, you also need enough compression ratio for it to work well. The use of 4X 1.75" SUs is really a bit much for the flow level a rover heads can sustain. However once set up they give good fuel economy, good part throttle and will sustain pretty high horspower even if they probably only gain you an extra 4 to 6 HP when all sorted on a 190 bhp engine against 2 SUs and a bit of work on the manifold.
Again is it worth the effort of individual throttle bodies on a road tune rover? I would say no as you can get good results with the SU manifold and carbs but they look pretty and they "feel" as they should be producing a lot more power even if they are acounting for an extra 7 or 10.
Best regards
Mike