The V8 Owners Forum -

There's a 4.6 on ebay with a starting bid price of £350, it says it has a sd1 timing cover and p6 pump..is this right? i thought they had a serpentine belt? i have a 3.5 sd1 motor in my car on a lt77, would this engine bolt straight in place of the old 3.5? could i fit it with my 360 inlet/390 holley? can you get much power from the 4.6?

The 4.6 litre engine that you speak of is not standard in that it does not have a RR timing cover fitted. You can indeed fit an SD1 timing cover and P6 pump....water I assume?

The type of heads that are fitted along with the sump on the 4.6 will determine whether or not the engine will fit straight into your existing engine bay.

Size wise the engine itself will fit straight in.

You can fit your 360 manifold and 390 carburettor but you will need to change the carburettor mixture settings else it will be far too lean.
I cannot say if the holley 390 will prove to be inadequate given a standard 4.6 will flow in excess of 420cfm.

The difference between a 3.5 and a 4.6 is like night and day,....there is no comparison. The 4.6 delivers at the very least 50% more torque than your 3.5 so if you plant your foot hard you may well break your lt77 not to mention other bits and pieces in your drivetrain.

Ron.

Apart from casting improvements there is barely any difference between heads, and all inlet manifolds should fit all heads and all engines?! Your Holley 390 might be ok if re-jetted but a weber/edelbrock performer 500cfm would be better.

The only differences between the very first RV8 blocks and the last are a few casting changes in the webbing between valleys, later ones have cross bolted mains and of course bore size. Thus basically all ancilleries are completely interchangeable- you could fit a thor front cover on a P5 block or a P5 front cover on a thor block (of course you have to fiddle with cam, crank & sump etc but its all done regularly.

I'll just rule out any ambiguity with regards to my post above re the cylinder heads. It is the number of bolt holes in the end of each head and their relative sizes which may mean modifications may be necessary to your existing brackets, ancillaries etc.

Ron.

There may be differences there I agree- what I meant is that all parts can be made to fit- its not like trying to put a crossflow head on a zetec block

thanks for this advice guys, you've answered my questions, i think i will try and bid for this engine as it wiill be a cheaper power upgrade than boosting my 3.5