4.7 Litre and 550 HP !

[JensenA]

But it's a Speed 6 engine!
There's an article in Sprint magazine this month, reporting that Al Melling Sports Cars are offering rebuilds on the Straight 6's, with 2 options. A 4.5 and 4.7, giving 517Hp, and 550Hp respectively.
The cost? £7500.00 for the 4.5 and £8500 for the 4.7. and accompanied by 2 year parts and labour warranty.
Hmmmmm, interesting

[JensenA]

For those who don't have Sprint. Here's a precis of what was written...

Cylinder head - Re-machined, re-positioned finger followers and camshaft, additional oil galleries, as per the original design.
New Valves, valve stem seals, Colsibro valve guides, New melling finger followers and valve springs.
New Solid Billet camshafts, with new profiles - as per the original design.
New Molybdenum disulphide impregnated Timing chain tensioner and new High spec timing chains.
New Solid Billet Crankshaft - as per the original design.
Re Bored Cylinder Block with Melling High performance Cylinder liners.
New melling Forged Pistons with custom High Spec piston rings and Dows D10 Dry lubricant to skirts.
New Forged H Beam 4340 Stell rods with ARP200 rod bolts. New Main and big end bearings.
New sump baffle and all new seals and gaskets.

All BHP figures are genuine Engine Dyno results obtained ffrom the development engine and are NOT estimated rolling road figures.

2 Year parts and labour warranty underwritten by Al Melling Supercars.

Quite a few references there to "as per the original design."