The V8 Owners Forum -

i'm gettin ready to put my 3.5 v8 back into the kit car. the engine was rebuilt at pretty much standard spec professionally. it currently has the original su's and after having seen the injection set-up in sales i'm wondering whether this would make a decent upgrade?

what types of power increase could i be looking at by going injection, and what are the potential pitfalls?

thanks

paul

Assuming your carbs are ok and set up properly very little difference really power wise. Possibly smoother running and a bit more torque lower down assuming your engine is close-ish to standard. These older systems don't adapt as well as the newer ones.

The heads are slightly different - EFi heads have a small notch in the roof of the inlet to clear the spray from the injector.

Although some people have ignored this detail and got on just fine....

Chris.

I would think the issue would come down to compression ratio.

The injection set up was on 9.75:1 CR where-as most other late carb V8's were on 9.35:1.

A carb v8 would make about 155 bhp where-as Rover claimed 190 bhp for the single plenum inj version and if some (sales) documents are to be believed, up to 225 bhp for the twin plenum version.

Then again the inj cars had slight different valves with waisted stems.

So the answer to your question is - unfortunately - it all depends.

Or to be more exact somewhere between 155 and 190 bhp.

Anyway - it something to consider.

One thing for sure - if you were able the change the CR to 9.75:1 and fit vitesse heads and a twin plenum induction system, you would definitely notice the (155 to 225 = > 40%) difference when you hit the loud pedal.

Ramon
vintagemodelairplane.com

thanks,

i just wanted to make sure i knew what the difference will be. will still with my su's for now thwn.

thanks