vhm heads

[Neal]

You can close up the squish a bit and keep the volumes you have measured on your original heads . You must clarify if you are including the spark plug hole volume or not when you order .
I will do a measurement later for reference .

[EEKNOWS]

My one head has pit marks from a piston braking up
Vhm is the easiest replacement  heads to get TZ head vol are also much smaller ...
I will run it as a road bike on 95 unleaded

That's 10min work to fix that.

[Yuri]

You can close up the squish a bit and keep the volumes you have measured on your original heads . You must clarify if you are including the spark plug hole volume or not when you order .
I will do a measurement later for reference .

I found this pdf it has all the head vol info


I just think long term it is the best only $30 for a incert  so if bigends go or any thing $30 fixes it
And thy are nice and shiny gold !

[Paul]

That's what really sells more of those heads in the Rand. The gold coating. Haha

[Neal]

Well I am only buying them cos they are gold

[eyrey1]

these any good to you ?
not mine .
4dp heads 90 quid the pair

http://www.ebay.co.uk/itm/Yamaha-TZ250-Cylinder-Heads-4dp-3yl-TZ-250-Race-Bike-250cc-/201079237760?pt=UK_Motorcycle_Parts_13&hash=item2ed141ac80

[Yuri]

these any good to you ?
not mine .
4dp heads 90 quid the pair

http://www.ebay.co.uk/itm/Yamaha-TZ250-Cylinder-Heads-4dp-3yl-TZ-250-Race-Bike-250cc-/201079237760?pt=UK_Motorcycle_Parts_13&hash=item2ed141ac80

Thanks for the link
The problem is that true TZ head volumes are much smaller than 3xv sp head volumes

[Need4speed]

you can always easily change to larger volumes in a lathe. 
to make it smaller is more complicated 

[Yuri]

you can always easily change to larger volumes in a lathe. 
to make it smaller is more complicated 

I am a electrician so that is difficult for me and after seeing what the turners at work call precise work ....

[jools]

Yuri

I use TZ heads on my race SP, but run a tad more squish around 0.9 - 0.95mm They are 9.8cc heads.

[Paul]

Put 2 base gaskets with TZ heads (unleaded 4TW, they have higher vol and you'll be happy to know a gold insert) that'll give you raised porting by 1/2mm and higher squish clearance. You win all round.

[Yuri]

Put 2 base gaskets with TZ heads (unleaded 4TW, they have higher vol and you'll be happy to know a gold insert) that'll give you raised porting by 1/2mm and higher squish clearance. You win all round.

I will have a look for them