A7 valves/guides in star twin head

[Drew Back]

Is there any difference in standard long stroke valves and star twin valves??I have a standard head that is really bad off but the valves all look great that I wanted to put in a star twin head that is in much better shape/less welding and rust..

[Brian]

I had a search through my literature and I couldnt find any reference to the valve size being different. The only thing I could find is the paragraph in the picture I have attached.

Do you have valves in both heads to compare ?

[Beezageezauk]

Drew Back,

On checking the part numbers of the valves, the Star Twin data shows 67-531 for the inlet and 67-532 for the exhaust.  The A7 longstroke equivalents are 67-29 (inlet) and 67-30 (exhaust) so there is obviously a difference.

The part numbers for the valve guides are the same for both models. 67-31 for the inlet and 67-32 for the exhaust.

Beezageezauk.

[bikerjohndavies]

Hi Drew, I think the valve part numbers that Beezageezauk has given you are for a short stroke A7SS. The long stroke Start Twin had different valves than the standard long stroke A7 with the part numbers 67-189 and 67-190. If you look at the Draganfly web site they list all the different part numbers of valves for the different models. John

www.draganfly.co.uk/index.php/bsa/bsa/a710--b3133--c101112--m202133/category/863-cylinder-head

[Drew Back]

Now why did I not think of checking Draganfly I just placed an order the other day..I just dropped the stock head off at the welder hopefully he can work some magic..Thank you all for your help