MTI heads
MTI heads just wondering why is it that MTI hand ports all of their heads? Also I would like to know, should the intake ports of heads be polished or not? I was told that the intake side should never be polished so that the fuel will mix properly!
Re: MTI heads Hand porting allows greater attention to detail. CNC porting does a good job of removing primary material, but isn't as good for the tight corners and is limited to the places where the bit cannot be manipulated to reach. You will find very few heads on all-out race vehicles that are not hand-ported.
The intake ports on LS1s can be fully polished, although there is litte, if any, gain from doing so. Its mostly cosmetic, to show the buyer the attention to detail of the finished product. Your statement is valid for carbureted intake setups, where fuel is introduced at the opening of the throttle area and must atomize within the intake ports. On an LS1, the injectors fire right into the cylinders and are already atomized.
Polished surfaces have thicker boundary layers than semi-polished surfaces. Depending on the velocity of the fluid and the shape of the intake path, it is sometimes more efficient to have a non-polished surface. But, as I stated, this is more important on carb'd setups, not EFI.
Tony
The intake ports on LS1s can be fully polished, although there is litte, if any, gain from doing so. Its mostly cosmetic, to show the buyer the attention to detail of the finished product. Your statement is valid for carbureted intake setups, where fuel is introduced at the opening of the throttle area and must atomize within the intake ports. On an LS1, the injectors fire right into the cylinders and are already atomized.
Polished surfaces have thicker boundary layers than semi-polished surfaces. Depending on the velocity of the fluid and the shape of the intake path, it is sometimes more efficient to have a non-polished surface. But, as I stated, this is more important on carb'd setups, not EFI.
Tony
