what do you guys think to this idea?

UncleThunderpants · Post by **UncleThunderpants** » Mon May 04, 2009 7:14 pm

I have a 9.75 cr sd1 v8 that is completely standard other than a 390 holley fitted with a 360 manifold, and a set of mgb block huggers which i know are restrictive but i had no space for anything else. My car was rolling roaded and featured in this months ppc at 145 bhp (grey escort). What sort of power gain would i get from fitting a cam such as real steel mild hurricane, a set of p6 pistons, and a set of range rover injection heads with the vitesse style valves? i would also be grinding the heads for better flow.

kiwicar · Post by **kiwicar** » Mon May 04, 2009 8:00 pm

Hi
That lot would get you 180 real bhp with a moderate cam, set of decent headers would probably get you to 195 if you could route them through the inner wing, or forward to the front of the engine and down there (tvr style). I think until you sort out the exhaust situation you will be stuck at 180 ish putting in more and more radical cams will just make the engine more peaky.
Clean up the head castings (don't polish them, leave the surface rough) and open them out at the valve seat bullet the guides but don't open the gasket face (people match the ports to the gasket and it makes this section far too big for anything but out and out race heads where the push rod pinch hase been ground out and sleeved) leave the short turn radius alone apart from blending any machining. that lot would get you another 10 to 15 BHP.
The P6 pistons (I presume you mean the 10.5 :1 ones) are not the strongest and are only 10.5 :1 with tin gaskets, knock off 0.7:1 for composite gaskets, though with the SD1 heads you should be on tins.
Mike

Darkspeed · Post by **Darkspeed** » Mon May 04, 2009 8:11 pm

Hi Lee,

If you have a 9.75 CR engine - then that's a Vitesse lump and should already have the better heads with wasted stems etc.
A new cam of any sort will be a help in an old Rover.
The right sort of head mods will certainly give a few extra BHP
It should be possible with what you are considering to get the power approaching 200BHP.

Cheers

Andrew

mgbv8 · Post by **mgbv8** » Mon May 04, 2009 9:10 pm

Lee!
My old pre sd1 3500 made 187 at the fly on the dyno.
This was my original Factory MGB V8 engine.

I had the engine bored +20. I had the heads skimmed 10thou. I fitted a Real Steel Typhoon cam. Fitted Rhoades lifters. Had the whole thing balanced by Real Steel. I fitted SD1 heads which I ported myself. I swapped the old inlet manifold for an edelbrock 360 and fitted a Weber 500 carb.
I also fitted Real Steel valve springs and caps to match the cam.
I also ditched the blockhuggers and fitted RV8 style exhaust manifolds.

I think thats about it.

I ran 187bhp at the fly (and this is with a chevy 3 speed auto box and 2800rpm stall converter which show tranny losses of around 40hp) on the first run.

I then added a 50hp shot of nitrous and ran 257bhp at the fly.

Not bad for a stock engine that came out of the factory with only 134bhp at the flywheel!!
50bhp increase for £800 at Real Steel
Then another 77bhp for £500 on Ebay

I dont know what that engine ran in the end as I didnt dyno it. But it went on to run a 150hp of gas and ran mid 12's on the 1/4 mile.

One thing I noticed at the track with the blockhugger setup was, if I disconnected the exhaust from the Y piece she would rev more quickly. She became very responsive. I suggest you increase the size of the exhaust from the Y piece to at 2 1/2" to reduce back pressure.