A
Anonymous
Guest
Got my 250 2V head back on the other day with extensive porting and polising of exhaust ports. with the addition of the new 500 holley (instead of 350 holley).
I went against conventional wisdom and enlarged the hole in the inlet manifold where the carb sits and removed the ventury slope off the base plate so it goes almost straight down all the way from the carb
Took it for a test drive and noticed BIG inprovement in overall performance.
The shame about all this is that my extractors (actually a lot bigger than another pair I had) are too small for the newly enlarged ports. I had to use a power file and bevel back the head plate openings to 45 degress and about 7mm in some places.
Does anyone know for sure if 2V extractors are different from the standard integral head. Some of the worst problems I encountered were on the two centre siamese ports. These two centre exhaust ports seem to be in a different possition compared to the standard head which also has a grated section on top that the 2V doesnt have. Its also interesting that some exhaust gaskets made for the standard head will not fit a 2V without shrouding problems on these centre ports.
I dont really want to go to the expence of getting some custom made. Does anyone know of extrators that are 2V specific. Im not sure just how much this will effect the perfomance, but I imagine it would be significant and perhaps others with 2Vs may be unaware that a similar problem exists even without enlarged ports (was in my case before porting).
Ive read literature that says when porting in most cases you are very unlikely to encounter this sort of problem (ie,smaller on extractors). Ha.
An original article on the 2V I have says that the exhaust ports on a 2V were cleaned up at factory? I wonder what they mean by "cleaned up".
I went against conventional wisdom and enlarged the hole in the inlet manifold where the carb sits and removed the ventury slope off the base plate so it goes almost straight down all the way from the carb
Took it for a test drive and noticed BIG inprovement in overall performance.
The shame about all this is that my extractors (actually a lot bigger than another pair I had) are too small for the newly enlarged ports. I had to use a power file and bevel back the head plate openings to 45 degress and about 7mm in some places.
Does anyone know for sure if 2V extractors are different from the standard integral head. Some of the worst problems I encountered were on the two centre siamese ports. These two centre exhaust ports seem to be in a different possition compared to the standard head which also has a grated section on top that the 2V doesnt have. Its also interesting that some exhaust gaskets made for the standard head will not fit a 2V without shrouding problems on these centre ports.
I dont really want to go to the expence of getting some custom made. Does anyone know of extrators that are 2V specific. Im not sure just how much this will effect the perfomance, but I imagine it would be significant and perhaps others with 2Vs may be unaware that a similar problem exists even without enlarged ports (was in my case before porting).
Ive read literature that says when porting in most cases you are very unlikely to encounter this sort of problem (ie,smaller on extractors). Ha.
An original article on the 2V I have says that the exhaust ports on a 2V were cleaned up at factory? I wonder what they mean by "cleaned up".
Do your cusomers get such a good hairtrigger reaction such as the one you've just provided. If so, I'm telling every NZ'er to come to your place when there overseas!
