Valves for 1920's v twin

[winchboy]

In the process of rebuilding a 1920's Blackburne v-twin side valve engine.

Valve guides are worn, valves themselves seem ok.

Option 1 was to make new valve guides and use original valves.

Option 2 use original guides, buy new valves with oversized stems and ream guides to suit these.

The engine is in a cycle car so any added performance would be greatly appreciated.

Out of interest one of the valves I have is tulip shaped, this weighs 2/3 of the other normal shaped valve. This got me thinking perhaps I should look for valves with the lowest possible weight to try and gain some performance? Is it worth reducing the valve guide length slightly to reduce friction?

Dimensions are 39mm valve face, 8mm stem and 116mm long. So far BMW S14 valves seem the closest fit.

If anyone has any experience, any tips would be appreciated.

Cheers

 

[OJCar]

Is this a fixed head engine?
There is a technique of inserting sleeves in the valve guide and honing to size.
I had this done to a head a number of years ago and it was very successful.
The trade name of the process was K-Line guide lining system.
It was done by Les Patterson's Cylinder Head Shop when it was in London.

 

[OJCar]

A DuckDuckGo search later;

Cylinder Head Shop
now in Lincolnshire, think he went to Ireland for a bit? (who cares!)

Article on K-Line Guide Liners

 

[minimutly]

In the process of rebuilding a 1920's Blackburne v-twin side valve engine.

Valve guides are worn, valves themselves seem ok.

Option 1 was to make new valve guides and use original valves.

Option 2 use original guides, buy new valves with oversized stems and ream guides to suit these.

The engine is in a cycle car so any added performance would be greatly appreciated.

Out of interest one of the valves I have is tulip shaped, this weighs 2/3 of the other normal shaped valve. This got me thinking perhaps I should look for valves with the lowest possible weight to try and gain some performance? Is it worth reducing the valve guide length slightly to reduce friction?

Dimensions are 39mm valve face, 8mm stem and 116mm long. So far BMW S14 valves seem the closest fit.

If anyone has any experience, any tips would be appreciated.

Cheers

Unless you plan to increase the rpm limit of your "boneshaker" there is nothing to be gained from reduced weight. Get some silicon bronze or cast iron and make new guides - you have a lathe?

 

[Blobber]

A DuckDuckGo search later;

Cylinder Head Shop
now in Lincolnshire, think he went to Ireland for a bit? (who cares!)

Article on K-Line Guide Liners

In the next village to us of all things

 

[dave h 2]

That looks a lovely thing, it'd be a pity to spoil it.
Those valve guides look really short already, surely you have have a more worthwhile issue with unleaded fuel?

 

[Morris]

Unless you plan to increase the rpm limit of your "boneshaker" there is nothing to be gained from reduced weight. Get some silicon bronze or cast iron and make new guides - you have a lathe?

If you don't have a lathe, buy one, it's the rules.

 

[tigdlo]

If you go the replacement guides route, there are universal guides listed here, https://www.serdi.co.uk/webstore/category/bronze-valve-guides