Triumph Bronze Head

[runesika]

Bronze head fitted to 1939 T100

[Martin_UK]

If you've also fitted bronze valve guides, ensure the rocker oiling supply works and you get oil lubricating the valve stems, otherwise the valves stick............

[runesika]

Hello Martin , After asking a few different people i went with the cast iron guides rather than the bronze ones , time will tell if that was the right  thing to do but three out of the four i asked told me to go with the iron guides . 

[Martin_UK]

Yeah, I toyed with the idea of iron guides which would have been "self lubricating" but opted for bronze so I didn't get differentials in the expansion and contraction properties of the two materials. Had to upgrade my oiling system though as a result.

[runesika]

The expansion rate of cast iron is faster than bronze so at least they will stay tight in the head , also i think you could buy the bronze head from Triumph with cast iron guides ready fitted for £7.4s in 1939 .
My bike had covered over 78,000 miles in it's long life and although it was well worn out this was done with the standard oiling system to the top end so with the low thousand miles i have planed for it i am sure it will be fine ,  fingers crossed !

[esometisse]

The expansion rate of cast iron is faster than bronze ...

I doubt that....

Cheers
Andy

[Bomber]

Cast Iron     5.8 microinch/Deg F

Phosphor Bronze     9.9 microinch/Deg F

As per http://www.engineeringtoolbox.com/thermal-expansion-metals-d_859.html

[runesika]

Sorry esometisse and bomber i got that arse about face and got that so wrong . I will have to take it for a spin and listen out for the guides going up and down with the valves !
Hopefully they will be tight enough to stay tight but now i am worried 

[runesika]

Picture from "front on" now it's up and running sweetly

[runesika]

 1939 Triumph Tiger 100 fitted with bronze head  ( title of a short youtube clip now posted online if it is of interest to any readers )

[runesika]

Bronze cylinder head for a 1939 Tiger 100 on ebay  now .

[Martin_UK]

It's a very rare Bronze head too as it was made in 1946 , one of a special small batch made by Birco in Birmingham for Triumph as spares for pre war T100 privateer racing bikes, hence why it has the post war part no cast into the head E2258 albeit on the other side to the iron heads being made at the time.

Well worth a punt at it's current price....be interesting to see what it finally goes for.

[runesika]

It's a very rare Bronze head too as it was made in 1946 , one of a special small batch made by Birco in Birmingham for Triumph as spares for pre war T100 privateer racing bikes, hence why it has the post war part no cast into the head E2258 albeit on the other side to the iron heads being made at the time.

Well worth a punt at it's current price....be interesting to see what it finally goes for.

Wow ! never knew anything about post war bronze heads ! My bronze head has E 1454 B cast into it , the same number that is cast into the iron heads .
All the bronze heads i have seen have this number ,that is until i spotted this one on ebay .

Thank you for the info Martin

[Martin_UK]

No worries.

The only reason I know this is one of the bronze heads I have is a Post War one and I had the details confirmed by Hughie Hancox when he was alive. So now someone has posted the question of its rarity on ebay for all to see...I'm interested to see how much it goes for 

[runesika]

I saw that on ebay's latest posting about the head and thought you had posted that up .
I have a picture of a restored 39 Tiger 100 that came out of H H workshops with Speed twin exhausts on it , he stated that " they were not fitted with the removable end caps until 1940 "  so he was not always  100% correct but this info about the head rings true .