I need to replace valves in my race engine. Currently has Stainless 40mm Inlet and 33mm Exhaust. Stems are 8mm but are 'wasted' down to about 6mm where they pass through the ports.

One of the Inlet valve heads broke up so I want to replace them all.

I bought the engine already built up but was told the valves were VW.

Am keen to hear all suggestions for replacements or what others have used?

GW

i have L16 vaulves in my head.... cant tell you wat they are like yet tho because still awaiting that fire up ! haha
wasnt to much work to fit them either, im not sure. just a sugestion maybe
cheers
Dan

yep i'm running L16 inlet (i think) valves too. same size (from memory) so would suit your application.

I'm running L series valves too
Cut down length
Regrooved for collets
And hardened lash caps on top

yeah thats it, not to difficult at all!
i did both inlet and exhaust tho.
i figured bigger was better and if i was gonna do inlets may aswell do the exhaust too.

I run toyota 2R inlets [40mm] and L16 exhaust. both have been cut down and re grooved.

Thanks - keep the ideas coming.

I ran shortened L16 valves in my previous engine and they were fine.

Ideally am after S/S valves along the lines of what this engine has been running. ie S/S, 40mm head, 8mm stem, waisted stems.

u can only go so big b4 they more or less hit each other, after that look into hi-tech valve grind angles for what u want, it can open up a lot of different gains.

If they are stainless and all that other jazz won't they just be custom valves?

If you are chasing "Hi Performance" valves, try these guys pep-pro race valves I have heard good things, but I have not personally used their product.

some technical data:

Material Specifications
Both intake and exhaust valves are manufactured from 21-4N stainless steel, which is recognised as a quality material for both performance and race applications. 21-4N materials is able to withstand the high engine temperatures and extreme heat created by turbo and supercharged engines.

21-4N stainless specification is the right choice for performance valves at an affordable price. The high cost and restricted life of Inconel and Titanium valves is not the market position we choose to service.

Valve Construction
All valves are manufactured from single bar stock.
The bar is heated and the head is formed by a drop forged process.

One Piece Forged Construction
Original equipment manufacturing are usually a two-piece valve with fusion welded head to stem. The single piece construction makes for a stronger and lighter valve.

Oversize Valve Head
Every Pep-Pro valve has a larger head than the original valve. The larger intake valve allows for increased intake air/fuel volume to the engine to improve power. The oversize exhaust valve increases the escape of exhaust gas from the engine. Both of these features improves engine performance.

Hard Chrome Stems
All valve stems are hard chrome plated. This process extends the life of the valve. Chrome also has micro holes which carry micro drops of oil to the valve stem and valve guide to reduce friction and heat.

Swirl Polished – Under Valve Head
The surface under the valve head on the intake has been swirl polished to direct the intake fuel/air mix. The concept of swirl polishing is to create a mini-vortex into the chamber of the cylinder head. The same applies to exhaust gas flow. It’s all about producing maximum benefits from valve operations.

Stellite Tipped
Again, this is another positive step to enhance valve operation and engine performance. All valves are fitted with a stellite tip during manufacture.

Imagine the number of times the valve tip makes contact with the rocker arm during the life of an engine and then relate this to a performance application where the engine rev range is way beyond a stock engine. The stellite tip reduces wear on both the valve and rocker arm. This small add-on feature to the Pep-Pro valve improves the overall performance and durability of all valve components.

Nitrited Finish
Some engine builders prefer a nitrited finish on the valve stem as it improves the lubrication of the valve stem and guide on dry start-up. This finish is available only on custom valves if requested.