Valve suppliers

[jono]

There seems to be a large variation in price for valves and inserts among the usual suspects.

I know that QED supply REC which are excellent but I'm not building a race engine - does anyone have any experience of the valves and inserts supplied by SJ Sportcars which are significantly cheaper?

Cheers

Jon

[steveh]

Hi Jon ,
Although we spoke about this recently i thought i would post a picture of a G & S REC valve v's a cheaper version.
These are not twincam but Jaguar inlets , but it does show how the quality can vary and what a difference to the port flow could be.
Cheers Steve

[jono]

Thanks for this Steve, it's good to be able to see the difference!

[tonyabacus]

Steve's pictures are worth a thousand words, but that still leaves us with the question of where best to get good quality valves and for that matter other parts.Perhaps one of the regular engine builders visiting the site may wish to contribute as no doubt they have come across the problem more often than the member who might only ever build one engine.

What is interesting from the picture is the width of the valve seat itself, given that some valves have more than one angle cut on the seat
Tony

[vstibbard]

For what my opinions worth, I don’t skimp on the valve train, apart from flow benefit, the effect of a failure of a valve, spring, mismatched retainer is expensive!
Buy matched set from QED or Tony Ingram or DBE. No affiliation.
With age of reciprocating parts of most Twincams I now change cranks rods pistons. Vaughan

[2cams70]

Those valves may be great for a race engine but for a road engine that very narrow seat width may pose a problem for longevity

[rgh0]

For race engines typical valve seats width are 1 mm for inlets and 1.5 mm for exhaust and both set to the very outer edge of the valve. Also reduced stem thickness and more curved shape on the back on the inlets also normal. With the ports modified to match all this is aimed at maximising gas flow

Original valves typically had around 2.5 mm seat width and a lip from the valve seat outer edge to the edge of the valve.

These modifications are not really needed for road engines but also given the limited miles most road Elans do these day would not be a problem i believe.

Suppliers like Burtons and QED change who they buy valves from routinely so what you got yesterday from them may not be absolutely the same as what they supply tomorrow. I have been buying valves from Tony Ingram in the last couple of years and he also has changed and improved the valve design he supplies somewhat

cheers
Rohan