Shortening valves

[cardiffrob]

I've been trying to track down a source of valves for my 1950s head. I've found that VW made one that is perfect, apart from being too long. Is it possible to shorten a valve and to cut a new collet groove in it? The keepers are designed for one long 8mm+ square cut groove.

Has anyone done it?

 

[the snooper]

I've been trying to track down a source of valves for my 1950s head. I've found that VW made one that is perfect, apart from being too long. Is it possible to shorten a valve and to cut a new collet groove in it? The keepers are designed for one long 8mm+ square cut groove.

Has anyone done it?

I would imagine it could be done with a lathe

 

[rikrobson]

Are valves not hardened? you could aneal them then turn them and then hardenand temper them

 

[rtbcomp]

Probably too hard to machine, maybe grind them?

I believe some valve stems have sodium in the stems which may get in the way.

 

[the snooper]

Are valves not hardened? you could aneal them then turn them and then hardenand temper them

I imagine they are but was thinking of a grinding wheel in conjunction with a lathe

 

[colnerov]

Probably too hard to machine, maybe grind them?

I believe some valve stems have sodium in the stems which may get in the way.

Hi, I think it's the heads are sodium filled, certainly on the Saab turbo engines, and then friction welded to the stems. So they be easier to machine with appropriate heat treatments.

Colin

 

[optima21]

I've shortened some valve by 2mm by grinding them, its a few years ago but I think I used a v block on a grinder (or belt sander) and rotated the valve by hand until they were the correct length. Im still using them in the engine about 8 years later. there are vw valves (for 1.0 and 1.3 engines from the mid 1980's to the mid 1990's ) and they were used with hydraulic followers.

you may be able to cut new grooves with an air cut off tool mounted on the toolpost of a lathe (as a toolpost grinder).

 

[mike 109444]

Don't see there would be a problem Rob just make sure you match any radius in the corner of the collet groove to avoid stress point as the loading/forces on that part of the valve will be vertical.

 

[Seadog]

Sodium filled valves have hollow stems. Sodium is a very efficient heat conductor so passes the heat to the stems so that the head, and of course the seat, run cooler.

 

[lotus 30]

I have a mate with a model A ford the valves were worn out he bought some that were to long. my mate at the royal mint llantrisant took a whole night shift to shorten them and regrind the collet retaining grooves. The time was spent mostly dressing the grinding stone but it worked and the car is running fine doing the winter trials.

 

[mike 109444]

I have a mate with a model A ford the valves were worn out he bought some that were to long. my mate at the royal mint llantrisant took a whole night shift to shorten them and regrind the collet retaining grooves. The time was spent mostly dressing the grinding stone but it worked and the car is running fine doing the winter trials.

They must have cost a pile of money

 

[lotus 30]

They must have cost a pile of money

They made more dosh the next night LOL

 

[cardiffrob]

Wow. Quick replies.

The valves I'm looking at are to go into a tuned up OHV conversion to a SV Minor engine (Think Ford Pop conversion) so the car isn't very high tech. I doubt they are sodium cooled.

Morris 1098 ones would be perfect but the collet position is wrong. Stems are 7mm and heads are 28mm inlet and 26mm for the exhausts.

 

[Seadog]

Sodium was used in high performance engines such as for planes.

 

[Bladevane]

Which ever method you use for grinding make sure you take tiny amounts of material off and use coolant to avoid softening the stem.

 

[lotus 30]

Might try small ford spares it may be aquaplane manufacture conversion or elva also done one. DID YOU KNOW AQUAPLANE MADE TUNING PARTS FOR BOATS THEY WERE BASED IN ST OLAF ON THE BROADS HENCE THE NAME Just some rubbish i have in my head.

 

[dannyp]

sodium filled valves are found in some of the vw 1.8 16v motors KR code all the KR code engines with 027 head castings i've take apart have had sodium filled valves 051 castings seem to be conventional valves, it's eay to tell them apart as the profile of the valve back is flatter on conventional valves from the valve sizes you mention your after 1.8 16v or 2.0 16v valves

 

[Stueeee]

Valve stems are hard, but aren't so hard that a file will whistle across them without making a mark.

If you have a lathe I think it would be worth having a go at machining the groove in before resorting to grinding. knock up a very narrow parting type tool to minimise the cut width at each end of the "square" groove.

I couldn't get exactly the right size valves for a TVR motor, so reduced the head size on a set of inlet and exhaust valves successfully. Although valve heads are not the same material as the stems, they are still pretty hard;especially the exhausts. I set it up one of my lathes with a dead sharp HSS tool; low speed, lots of coolant and had the valves held in a collet to maximise rigidity

 

[Popcorn]

Shorten the stem by grinding and then either use shims under the springs or grind the spring seat on the head to correct the valve spring length.

 

[Wallace]

Stem tips are often a different material from the stem and hardened for wear resistance. You might be able to shorten them and add lash caps so they don't end up with mushroomed tips.

On the subject of sodium filled valves, these are development items cutaway to show the hollow cavity produced by Omes Faulkner Ltd, Colnbrook. The upright valve is used and from a Vanwall.