haynes bhp/early/late query?

bak2burbles · Post by **bak2burbles** » Sat Aug 11, 2007 1:58 pm

v8 virgin asking a daft question probably..Haynes manual lists early R/rvr, 74/79, 8.25.1 cr as having 130 bhp. & late 79 onwards 8.13.1 as having 156 bhp? ..All i can fathom out are slightly bigger valves on the later engine.. So what gives it the increase in bhp?
Thanks again for any info & much apologies if its a doughnut question!

Alley Kat · Post by **Alley Kat** » Sat Aug 11, 2007 2:32 pm

Usual stuff really, heads, cams, fuelling & induction, exhaust. Different setups for different porpoises, torque vs power etc etc. So in a transplant any or all are likely to be changed, so the stock figures don't mean a whole lot, except for a starting point.
The Des Hammill book gives a pretty good view of all the bits & bobs over the years.

bak2burbles · Post by **bak2burbles** » Sat Aug 11, 2007 3:19 pm

thanks m8...knew it was a doughnut question...

Alley Kat · Post by **Alley Kat** » Sat Aug 11, 2007 4:19 pm

Yes and no really mate, all depends what you've got or what you want to do. Chevy V8s have huge differences, from 175 (and probably lower) to claimed 300+ as stock. It's well worth knowing what makes the difference so you can pick parts to suit. I see people say (not here) "I have a 350 Chevy, so my car must to 5 secs to 60". Well my old Victor with 3.9 Rover was creaming a few SBC cars last weekend, in the hands of its new owner.

mgbv8 · Post by **mgbv8** » Sun Aug 12, 2007 8:31 pm

My factory original MGB V8 came off the shelf with 134bhp at the flywheel. I went +20 on the bores, fitted a Weber 500 and offy 360 manifold, Typhoon cam, had the spinning bits balanced, home brew free flow exhaust and she put out 187 at the fly on the dyno after the build.