> British Pacific Tech Tips
>

>                 Topic: V8 Engines

>                 Tip: Performance options
>
>                 All V8 engines sold in the US fall into 2 rough categories; carbureted
>                 or injected. The carbureted models (3.5 from 1970 to 1987) were not
>                 built for the US market specifically, and are commonly known as 'grey
>                 market'. The 1987-on models that were built with US emissions and safety
>                 requirements in mind are all fuel injected.
>
>                 Carbureted models have a wide range of performance options available,
>                 but depending on where you live, those modifications may not be legal.
>                 Remember to check all local laws before investing in engine parts you
>                 may not legally use!
>
>                 Before complaining about your V8's power, first determine that it's in
>                 good shape. A high mileage engine (anything over 100,000 miles) will be
>                 down on power due to worn parts in a number of systems. Even though the
>                 engine is smooth and doesn't burn a lot of oil, stretched timing chains,
>                 flat cams, worn distributors, leaky valves, worn rockers, worn throttle
>                 shafts, and carbon build up on intake valves can rob tons of top end
>                 power from an engine. High mileage engines will benefit more from an
>                 overhaul than from speed parts added on.
>
>                 If you are serious about more power out of your V8, start by purchasing
>                 a copy of "Tuning Rover V8's" (available at BP). This book details all
>                 of the variations in engine design, including parts interchangeable with
>                 Buick. It's indispensable for the serious hot rodder.
>
>                 [Image] Tuning Rover V8's 119792AE $34.95
>
>                 For those of you looking for simple increases, replace the twin
>                 Stromberg set up with an Offenhauser intake and Holley 390 4v carb
>                 (available through BP). This simplifies tuning (eliminates carb
>                 balancing), improves breathing, increases both mileage and performance
>                 (dual plane intake manifold), and is a simple, straightforward swap. For
>                 a bit more, fit an electronic ignition and a 3.9 cam (also available
>                 through BP). Also good is a true dual exhaust with low restriction
>                 mufflers. These changes will result in noticeable performance
>                 improvements with a modest outlay, and can be done in stages.
>
>                 Fuel injected engines are much harder to upgrade, because they come in a
>                 well developed state as built. In California, emissions laws prevent
>                 many modifications, and your choices are indeed limited. Start by
>                 evaluating your engine's condition, and determining if repair work is
>                 called for. If you have a 3.5, a 3.9 displacement increase works well.
>                 The 3.9 cam also helps the 3.5. Cat back exhaust modifications, such as
>                 the Borla, help the top end. K&N air filters also improve top end
>                 airflow.
>
>                 Our favorite method for improving performance in V8 powered models is to
>                 lower the axle ratios. The 3.5, 3.9., and 4.0 are small engines by
>                 anyone's standards (3.5 is 215 cid, 4.0 is 244 cid), and small engines
>                 need to rev to make horsepower. The 4:70 axle ratio moves the engine
>                 closer to it's power band at freeway speeds, and performance
>                 dramatically improves. It's especially noticeable climbing long grades
>                 or around town. While mileage may drop a bit (how heavy is your foot?),
>                 the drivability is so much better! The big advantage is that it won't
>                 effect emissions testing. Combine the lower gears with the Borla and
>                 K&N, and your V8 will really perk up! (You will need to change axles
>                 both front and rear, and speedo drive gears. Discovery owners will also
>                 need to convert the driveshaft back to Range Rover style, eliminating
>                 the Rotoflex coupling.) Regearing is the most cost effective way to
>                 dramatically improve V8 performance.
>
>                 For those of you with deep pockets, Rimmer Engineering provides an Eaton
>                 supercharger kit (as used on the Buick/Pontiac 3.8's). As of this
>                 writing it's still pending California emission certification, but should
>                 that pass, the system gives the car a real kick in the pants. It's
>                 especially useful at higher altitudes. It's a well engineered system,
>                 using Bosch controls, and should give years of reliable service. Price
>                 of this writing is $5000, excluding installation.
>
>                 We will update this page as new stuff is developed.
>
>                 Steve
>
>                             This document last updated: 03/27/97 06:14:39 PM
>                             ) 1997 British Pacific Ltd. All rights reserved.