BSA Unit A50 A65 - Engines

SRM Engineering offer a Quality and Professional Engine and re-conditioning service.

  • Needle roller bearing conversion
  • Crankshaft grinding
  • Dynamic crankshaft balancing
  • Rebores
  • Helicoils & thread repairs
  • Lead free valve seats
  • Colisbro valve guides
  • Gas Flowing
  • Fin repairs
  • Alloy polishing
  • Stove enamel for cylinders

 

NEEDLE ROLLER MAIN BEARING CONVERSION
BSA were aware of the shortcomings of the crankshaft bush and developed their own crankshaft oil feed system for use with their racing engines. Our Needle roller and oil end feed conversion completely eliminates the problems associated with the timing side bush. The bush is replaced by a combined ball and needle roller bearing which withstands substantial radial and axial load, the combined bearing eliminates end float, it locks the crankshaft to the timing side so no more shimming of the crankshaft. The oil ways are altered and re-routed so the oil is fed directly from the oil pump to the big ends (via an oil seal housed in the timing casings) and through an end feed quill situated in the end of the crankshaft. Oil pressure and delivery to the big ends is up rated by at least 40 %

CRANKSHAFT
Sludge tap thoroughly cleaned.
Regrinding accurately to  size and specified radii.
Best quality big end shells.
Dynamic balancing to smooth out the vibrations.

CONRODS
Checked and polished but we would recommend NEW billet conrods.
Failure of an old conrod will destroy the engine.

CYLINDER HEAD
Colsibro valve guide fitted and sized.
Hardened valve seats fitted to run on Unleaded fuel.
Fin and thread repairs.
Blasting and cleaning to restore the Original finish.
Gas Flowing and tuning.

CYLINDER BARREL
Bored to within 0.002” (thou) then honed to an exact size, within two tenths of a thou (0.0002”) tolerance,
Bore size is matched to piston dimensions for correct clearance.
Bores are straight and parallel.
Barrels are shot blasted and a high quality stove enamel paint before machining.

BUSHES, BEARINGS & OIL SEALS
High quality bushes are always used and can be made to size to accommodate worn shafts or casings. 
New quality bearings and oil seals are always fitted.

ENGINE REBUILD
All our engines are carefully assembled by fully trained engineers in a purpose built dust free room with no machine tools present, this ensures the engine components and the partly assembled engines do not get contaminated.

OUR GUARANTEE

We rebuild engines to be used, be reliable and give thousands of trouble free miles.
We guarantee the engine for a full 12 Months unlimited mileage.

 

HOW MUCH DOES IT COST?

Before we commence the rebuild on your engine, it is inspected for wear and damage. An estimate is then compiled listing all new parts, engineering work and repairs required include a list of options such as exterior cosmetics and other useful modifications & options such as Needle Roller maim bearing conversion, dynamic balancing, lead free conversion and tuning options.