100/4 Top End

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ALUMINIUM CYLINDER HEADS - 4 CYLINDER

Since 1995 we have been successfully producing our aluminium 100/4 cylinder heads.  In 2003 we took the decision to upgrade our product. We went  back to the drawing board and started with completely new CAD drawings to ensure accuracy and perfect detail in our product. We then further enhanced this ‘design to manufacture’ investment philosophy by including state of the art CAM software. When it comes to machining, we have seen a huge upgrade to our capabilities with the acquisition of a brand new 5 axis CNC machining centre in 2010.

For more information on our new cylinder heads and how we can improve your cars performance please see below or contact our Sales personnel.

TYPES OF CYLINDER HEADS

  • BARE HEAD
    Fully machined bare head (as cast ports) with valve inserts fitted and semi-formed seats. Ready for you to supply and fit valve guides, cut seats, final skim head gasket face and assemble with your components. (Must use 6 cylinder exhaust valves).
  • STANDARD COMPLETE
    Supplied ready assembled by us in our own factory. Bronze valve guides, stainless steel valves, steel valve top caps and heavy duty springs etc. All as listed on page 14. Head gasket face final skimmed giving a combustion chamber of 62cc as original.
  • FAST ROAD COMPLETE
    As ‘Standard’ with the addition of gas flowed ports, all symmetrical and matching. Aluminium valve top caps, competition valve springs and top hat stem seals. 62cc chamber volume.
  • FULL RACE COMPLETE
    As ‘Fast Road’ with larger ports, for increased flow. The significantly larger exhaust ports are best suited to a large bore manifold gasket and big bore exhaust. They also benefit from dowel holes machined in the manifold face to match the inlet manifolds precisely to the ports. 62cc chamber volume. Both inlet and exhausts ports are hand fettled after CNC machining to achieving the desired surface finish and gas flow characteristics.


PLEASE NOTE: If intending to use any of the above with our roller rockers (CENG502K) please specify with order to have push rod holes machined to suit. 

100/4 Top End
Code: CENG495AF
Sku: CENG495AF
Availability: In Stock
CENG495AF
£3,150.00
Qty
Code: CENG495AR
Sku: CENG495AR
Availability: In Stock
CENG495AR
£2,950.00
Qty
Code: CENG495AS
Sku: CENG495AS
Availability: In Stock
CENG495AS
£2,350.00
Qty
Code: CENG495AB
Sku: CENG495AB
Availability: In Stock
CENG495AB
£1,795.00
Qty

Attachments

4 CYLINDER HEAD INFORMATION.pdf 4 CYLINDER HEAD INFORMATION.pdf View Download

COLISBRO-BRONZE VALVE GUIDES

These are essential in all engines with gas flowed ports whether aluminium or iron and engines converted to lead-free fuel.
Precision turned with honed bores these should not require reaming after fitment. Colisbro material being of a copper colour should not be confused with the inferior yellow brass coloured cheaper alternatives.

Now available - Tapered Bronze Value Guide.

100/4 Top End
Code: CENG722
Sku: CENG722
Availability: In Stock
CENG722
£19.95
Qty
Code: CENG722A
Sku: CENG722A
Availability: In Stock
CENG722A
£19.95
Qty
Code: CENG722C
Sku: CENG722C
Availability: In Stock
CENG722C
£0.19
Qty

VALVES

All our valves are made from one-piece forgings in 214N stainless steel with stellite tips and plasma nitrided stems for increased life. Suitable for both leaded and unleaded fuel. These are made to the lightest design using standard size stems and collets.

100/4 Top End
Code: CENG720
Sku: CENG720
Availability: In Stock
CENG720
£29.95
Qty
Code: CENG720S
Sku: CENG720S
Availability: In Stock
CENG720S
£22.95
Qty
Code: CENG721
Sku: CENG721
Availability: In Stock
CENG721
£28.95
Qty
Code: CENG721S
Sku: CENG721S
Availability: In Stock
CENG721S
£22.95
Qty

COMPETITION VALVE SPRING SET

Our Competition Valve Spring Set provides increased seat and nose pressure.

PLEASE NOTE: To fit these springs in the 100 it is necessary to use (CENG731 or ENG731) 3000 Top Caps.

ENG525HD - Double springs to suit standard & 100M cams.
CENG525 - Single springs to suit higher performance cams i.e our DWR 2.

100/4 Top End
Code: ENG525HD
Sku: ENG525HD
Availability: In Stock
ENG525HD
£42.87
Qty
Code: CENG525
Sku: CENG525
Availability: In Stock
CENG525
£150.00
Qty

LIGHTWEIGHT VALVE TOP CAPS

Our Valve Top Caps are manufactured from either top quality aircraft aluminium and are hard anodised red or high grade steel and heat-treated, both are to suit 3000 size springs.

100/4 Top End
Code: CENG731
Sku: CENG731
Availability: In Stock
CENG731
£10.95
Qty
Code: ENG731
Sku: ENG731
Availability: In Stock
ENG731
£5.95
Qty

VALVE COLLETS

We have had these made to the highest tolerances from EN24T steel and heat-treated. These are also a direct replacement for the standard.

100/4 Top End
Code: ENG733
Sku: ENG733
Availability: In Stock
ENG733
£3.95
Qty

VALVE SPRING SHIMS

Our Valve Spring Shims have been specifically made so that the race engines and badly worn road engines can have all the valve springs shimmed to the correct length. We have two sizes of bore diameter available to suit valve guides with or without circlips.

100/4 Top End
Code: CENG725G
Sku: CENG725G
Availability: In Stock
CENG725G
£0.69
Qty
Code: CENG725C
Sku: CENG725C
Availability: In Stock
CENG725C
£0.69
Qty
Code: CENG725B
Sku: CENG725B
Availability: In Stock
CENG725B
£0.69
Qty
Code: CENG725A
Sku: CENG725A
Availability: In Stock
CENG725A
£0.69
Qty

VALVE STEM OIL SEALS

These are top hat type oil seals which fit around the top of the valve guide. We offer Black which feature a rubber case and are suitable for single valve springs or Green which have a metal case and are suitable for single or double valve springs..

100/4 Top End
Code: CENG735
Sku: CENG735
Availability: In Stock
CENG735
£1.09
Qty
Code: CENG735W
Sku: CENG735W
Availability: In Stock
CENG735W
£2.26
Qty

ROCKER OIL FEED PIPE

Our Rocker Oil Feed Pipe is a faithful reproduction of the original.

Made in our own factory.

100/4 Top End
Code: ENG515
Sku: ENG515
Availability: In Stock
ENG515
£32.50
Qty

CYLINDER HEAD STUD SET

Our Cylinder Head Stud Set is manufactured from the highest grade steel and heat-treated in order to have a greater resistance to stretching and with the special nuts that are supplied helps reduce head gasket problems.

100/4 Top End
Code: CENG561
Sku: CENG561
Availability: In Stock
CENG561
£119.50
Qty

A Little About Us...

Company Info

Welcome to the Denis Welch Motorsport website for Performance Parts. We cater for every aspect of work on your classic car be it road, race or rally, using our unrivalled success in many aspects of Motorsport to make your car as successful and reliable as possible.

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Contact Details

Parts Hotline +44(0)1543 472244
Office +44(0)1543 472214
Fax +44(0)1543 472339
E-Mail sales@bighealey.co.uk
 

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