MED 9/32" STEM COMPETITION VALVES

Name: MED 9/32" STEM COMPETITION VALVES
Brand: MED Engineering
SKU: MED-2229-SS
Price: 27.0 GBP
Availability: InStock

Part No: MED-2229-SS

£27.00 £22.50 EXC VAT

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Product variants

Availability: In Stock

Description

Our 9/32-inch stem race valves are manufactured from 21NS stainless steel forgings and plasma nitrided after manufacture for extra strength and wear characteristics. 9/32-inch is the standard stem diameter.

Available in various sizes and collet arrangements as below.

Valves are priced individually.

Inlet valve choice:

35.7mm triple - three-angle seat, waisted stem, triple collet groove, for standard top caps

35.7mm single - three-angle seat, waisted stem, single collet groove, for MED steel top caps

37mm single - three-angle seat, waisted stem, single collet groove, for MED steel top caps

Exhaust valve choice:

29.5mm single - three-angle seat, standard stem, single collet groove, for MED steel top caps

29.5mm triple - three-angle seat, standard stem, triple collet groove, for standard top caps

31mm single - three-angle seat, standard stem, single collet groove, for MED steel top caps

Frequently Asked Questions

Do I need a specific valve guide for these valves?

Yes we would recommend to only use bronze guides. Please see part number MED-2300-VG for a compatible valve guide set. You will need to ream the guides once fitted to give suitable clearance.

Is there a recommended valve-to-guide clearance?

We would always suggest that you leave this to the machinist in charge of the valve guide fitment, as different engine builders have their own preference. However, for a general recommendation, we aim for 0.0015-0.002" on the exhaust valves and 0.001-0.0015" on the inlets.

What is the difference between triple and single-groove valves?

These suit different collet designs. The 1275 A-Series came with either single or triple groove valves and matching collets from the factory. Generally we recommend single-groove valves for competition engines and triple for fast road applications. You must ensure to use the correct top caps to suit the collets.

Do these suit all A-Series cylinder heads?

No, only the 1275 five-port cylinder head, 12G940 castings and also the later SPi/MPi heads. These do not suit small-bore A-Series cylinder heads or Cooper S type AEG163 castings, which have shorter valve stems. They will not suit Arden 8-port heads.

Can I run a combination of single and triple-groove valves?

You could do, but we would not recommend this, as it can give a different fitted length between the valve spring platform and stem tip. As a result you may end up with varying valve spring seat pressure and valve lift. To get the most performance from an A-Series, aim to optimise every dimension.

Do I need to run separate lash caps on the valve stems?

No, there is no need to run separate lash caps with these valves. This was something we used to produce for the 6mm slim-stem race valves, when combined with firm race valve springs, a race cam and 1.5:1 rockers. It's not necessary on these larger diameter 9/32" stem valves.

Is there a recommended combination of valves for set applications?

For fast road and trackday cylinder heads, we typically run 35.7mm x 29.5mm triple-groove combination. When likely to see sustained high RPM, swap these for single-groove valves, steel caps and collets. For full-race use, increase the exhaust valve size to 31mm. For larger-capacity engines, our largest valve combination would be 37mm x 31mm, but you will need to offset the exhaust valve guide to achieve this.