Cosworth YB Machining

Call us for expert advice and a quotation for your engine machining requirements.

Ford Cosworth “YB” Engine Machining Services

H T Howard offer several special machining services designed specifically for uprating cylinder blocks and heads from the Cosworth “YB” engine found in high performance versions of the Ford Sierra and Ford Escort.


Cylinder Block Re-sleeving

When working on the Ford Cosworth “YB” engine, H T Howard utilise all the same techniques and procedures used when fitting cylinder liners to conventional blocks however we use special liners made from ductile iron which we have manufactured for us to our own design.

Ductile iron is more durable than the conventional material used for cylinder liners and is more suited to high performance applications especially when engines are up-rated for extra performance.

The design of our cylinder liners for the Cosworth “YB” engine includes a top flange for extra security in service.

Long Stud Conversions

H T Howard can machine the cylinder blocks for the Coswoth “YB” engine to accept either 6 stud or 10 stud conversions.  Long stud conversions are especially suitable for up-rated and high performance applications and have the added advantage of eliminating the stresses induced by the original head bolts which can cause cracking in the upper deck face and distortion in the cylinder bores.  Uprated head stud kits are available from a range of suppliers and at H T Howard we have a range of tooling specifically designed to machine your cylinder block to accept these uprated components.

Oil Gallery Modification

Cylinder Head Machining

The cylinder heads from the Cosworth “YB” engine range suffer from a series of known problems which we at H T Howard are well placed to deal with as we have a wealth of experience in this work.

The most problematic areas with this engine centre around valve guide wear through general use and valve recession into the combustion chamber which frequently results from these engines having been machined several time during their life.

As well as all of our usual cylinder head machining services which include re-surfacing, multi-angle valve seat cutting, pressure testing, and valve guide replacement we can also offer over-size valve conversions.  Machining the cylinder head to accept larger valves can have a twofold advantage in terms of gas flow as it allows us to reshape and enlarge the valve throat area and also prevents masking of the valve which occurs when they sink below the chamber roof.

H T Howard also offer a machining service to modify the Cosworth “YB” cylinder head to allow access to the enlarged cylinder head nuts used in conjunction with some long stud conversion kits.

Call us for expert advice and a quotation for your engine machining requirements.