Which is best head 2V or Crossflow

[Anonymous]

Execute.

Do you know (or does anyone know) how much better if any the Crossflow head is compaired to the 2V head. And what happens to the comparison when a change is made to a performance manifold for the crossflow. Was the Iron crossflow the same design and structure as the Alloy crossflow.
If a 250 2V would be about a 94 kw emission control engine which is very close if not identical to the carbed crossflow, then it seems that all the expertease by Honda in designing it doesnt seem to have paid off at least not in performance possibly in efficiency.
Im not sure but I think the valve layout in a 2V (two exhausts next to each other instead of staggered by inlet valve) can make them more prone to cracking due to hot spots. In addition the crossflow does look like a stronger head.
I dont know if youve heard this or not but the machine shop told me that a 2V head is stronger than the log head. I cut a log head head in half to get a cross section and it looks just as strong to me. (no I wont cut the 2V in half to compare)
I know crossflows rocker ratio gives more valve lift than a 2V.

 

[aussie7mains]

Ok heres what I know from personal experience of those two heads.
250-2v with 1.78 inlet valve,flows about same as alloy or iron crossflow on inlet side with stock valve.
Crossflow exhaust ports are vastly superior to 250-2v heads in any form.
Crossflow alloy and iron share many common parts, but not manifolds.
Iron crossflow is no good for unleaded or LPG, unless stellite inserts are fitted to exhausts seats.
Alloy head is MUCH lighter than iron head.
Alloy head from late XF or EFI engines have largest valves and best airflow.
Iron heads are considerably less common than alloys.
Alloy crossflows are cheaper than 250-2vs, there is more availability of aftermarket parts for the crossflow.
Its really a matter of want you want from your car, if its an XY and you want to keep it original go the 250-2v, if your not concerned with this the get a alloy crossflow, junk the inlet manifold and get a Ultraflow Limited sprint, with with a Holley two barrel will go just about as good a a 5litre V8.
Hope this helps you make up your mind.
A7M

 

[Anonymous]

Thanks
I like the 2V for its novelty but I think Ill go for the crossflow next time. Ill have to change my signature.

 

[xctasy]

See how much simpler it is to get advice from an expert? He's only been gas flowing heads and working on engines for years, after all :rolflmao:

A summary of the ohv Falcon heads in less than 500 words. Good on ya A7M.

And that Taz avatar is sh** hot, Tim!

 

[Inline6-66]

So who has a 250-2v head they would like to supply a fellow Australasian petrol head?

 

[Inline6-66]

Ok heres what I know from personal experience of those two heads.
250-2v with 1.78 inlet valve,flows about same as alloy or iron crossflow on inlet side with stock valve.
Crossflow exhaust ports are vastly superior to 250-2v heads in any form.
Crossflow alloy and iron share many common parts, but not manifolds.
Iron crossflow is no good for unleaded or LPG, unless stellite inserts are fitted to exhausts seats.
Alloy head is MUCH lighter than iron head.
Alloy head from late XF or EFI engines have largest valves and best airflow.
Iron heads are considerably less common than alloys.
Alloy crossflows are cheaper than 250-2vs, there is more availability of aftermarket parts for the crossflow.
Its really a matter of want you want from your car, if its an XY and you want to keep it original go the 250-2v, if your not concerned with this the get a alloy crossflow, junk the inlet manifold and get a Ultraflow Limited sprint, with with a Holley two barrel will go just about as good a a 5litre V8.
Hope this helps you make up your mind.
A7M

Hey mate how ya doing?

Hey so I have found an Ali 250 2v head (Needs a good make over) but the seller is unsure what it came off.. sigh
Do you know the size of the valves on the late XF and EFI so I can have them measure them before I purchase and have it sent over to New Zealand.

 

[gb500]

As an aside . The Australian 2v cast iron heads are regularly going for $2000-2600 Australian dollars at the moment.
Crazy money.....

If only the vintage inlines alloy head was easily available .