Raph406
New member
does anyone have a pbs head for sale? i don't think they make them anymore. I might be wrong.
Did they only inlarge the intakes?
Did they only inlarge the intakes?
General PBS big valve head
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General PBS big valve head
fiatfactory
New member
Or you could do it yourself... for a tiny fraction of the cost gc would charge.
Oversize valves are available from later fiat models of the sohc, so it's a relatively staright forward job, you will need a good machinist to install the oversize seats for you though.
PBS did use nissan valves with the collet groove recut, overall the valve is shorter, so it required the use of lash caps or a machined cambox.
If you want some decent information about different sohc heads and which ones are best to use and why check out a thread I've written on turbo124.com/forum in the "X19 discussions" forum.
SteveC
Oversize valves are available from later fiat models of the sohc, so it's a relatively staright forward job, you will need a good machinist to install the oversize seats for you though.
PBS did use nissan valves with the collet groove recut, overall the valve is shorter, so it required the use of lash caps or a machined cambox.
If you want some decent information about different sohc heads and which ones are best to use and why check out a thread I've written on turbo124.com/forum in the "X19 discussions" forum.
SteveC
jimbro1000
Established member
The exhaust flow side of the SOHC head is very good as standard and generally doesn't need any particular modification beyond flowing of the port and matching the head ports against the manifold.
The inlet side is where the most gains can be found hence the larger inlet valves - I've even seen the exhaust valve size reduce in order to make more clearance for even bigger inlet valves.
The effectiveness of the valves is then limited by induction gas flow and camshaft profile (and of course displacement and compression ratio but we are talking about just the head).
If you are going to all the trouble of using or recreating a PBS BVH then you have to get an appropriate camshaft in there and decide on your induction components. A standard DMTR/DATR is not going to let the head do much so you really need to look at either a bigger progressive twin choke carburettor or look at a twin carb setup (or even throttle bodies). If you aren't prepared to go down this route then there really is very little point in the BVH by itself - it just isn't going to do much and may even make the car slower in some situations.
Incidentally the Guy Croft head mentioned previously is a big bargain at that price - it may not feel it but Guy's work is highly prized and for a newly prepared head that is excellent.
The inlet side is where the most gains can be found hence the larger inlet valves - I've even seen the exhaust valve size reduce in order to make more clearance for even bigger inlet valves.
The effectiveness of the valves is then limited by induction gas flow and camshaft profile (and of course displacement and compression ratio but we are talking about just the head).
If you are going to all the trouble of using or recreating a PBS BVH then you have to get an appropriate camshaft in there and decide on your induction components. A standard DMTR/DATR is not going to let the head do much so you really need to look at either a bigger progressive twin choke carburettor or look at a twin carb setup (or even throttle bodies). If you aren't prepared to go down this route then there really is very little point in the BVH by itself - it just isn't going to do much and may even make the car slower in some situations.
Incidentally the Guy Croft head mentioned previously is a big bargain at that price - it may not feel it but Guy's work is highly prized and for a newly prepared head that is excellent.
http://simefiatpower.tripod.com/
http://www.project-x19.de/forum/viewtopic.php?t=9978
If you not find head -prepared look on that site ....he have all SOHC racing parts
http://www.project-x19.de/forum/viewtopic.php?t=9978
If you not find head -prepared look on that site ....he have all SOHC racing parts