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MG MGB GT V8 Factory Originals Technical - 3.5 out 3.9 in

Hello out there Rover v8ers.
I found another Rover, this is a 3.9 from a 1990 Rangie,160K miles ready for a rebuild to replace my 3.5 SD1, I need a good recipe to make this baby cook, rather mildly. increase displacement? to what size?
what cam? what pistons?. etc.
Hope to hear from you guys soon.
Romney.
Romney

There's a pretty standard stroker build using the Rover 3.9L block: Buick 300 crank with mains turned down to fit block, ARP main studs, Buick 300 heads, Ford 255 V8 pistons, Rover connecting rods (pin bores opened to fit Ford pistons), Edelbrock Performer Rover intake manifold, Crower 50232 cam, big bore headers, custom flywheel (available from several sources in lightened steel or even lighter aluminum, can also be made from a Chevy Monza flywheel if you have a good ROver/Buick ring gear). Larger valves and porting as desired. Displacement is in the 4.9L range (292+ cubes or so, depending upon the overbore). Horsepower should be near 300 HP with good headers. A local guy built one with extensive porting to the heads and intake and got over 350 HP on the dyno. For the displacement, the cam is mild and can be daily driven with no problems.

There's a similar build detailed in the MGBV8 newsletter by Dan LaGrou of D&D using the Rover 4.0L/4.6L. The main difference is the Rover 4.0L/4.6L
block has mains that match the Buick 300 crank. Apparently, Rover doesn't sell undersize main bearings so it is recommended that the block be align bored to fit the Buick 300 bearings.

Dan Jones
Daniel Jones

I have an engine similar to the one that Dan describes. Mine has an overbore of .010...and the displacement is approximately 289...per Dan Lagrau of D&D, who did the engine for me. I started with a Rover 3.9 litre. Dan guestimated my bhp at 300 or so...I have RV8 headers./

rick
rick ingram

Thankyuo all for your sugestions, i really dont want to stroke this motor, because, all the machining involved, besides, i dont trust those 2 piece neoprene rear main seal that i have to use if stroked, they never worked for me in my older buicks and i dont want to go back to huge oil leaks in my garage.
Any other ideas to increase stock power without stroking the motor?

Romney.
Romney

Sure, get a crank from a 4.2 and put that in there.
Jack

"without stroking": sure, use mild road cam from RealSteel, have the heads flowed and take care in achieving good compression. So not 9.35:1, but more like 9.75 or more.

Frank
Frank de Groot

This thread was discussed between 16/01/2004 and 25/01/2004

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