hey guys
Im doing a rebuild on an A14 and i have a oval port head and a round port head and i was just wondering whats the defference is one better then that other.
cheets matt

oval port gets more fuel into it and more power not too sure on the more revs and stuff like that but i have been told and i have use the oval port on an a12 it flies really good fun compared to the standard round port. it is a little harder to find the manifolds for oval port heads(intake manifolds that is)

oval port has bigger port, bigger valves, yes?


meaning the powerband is shifted upward :)



i use a a12a stock bottom with a oval port head (H89) and stock a14 carbs on my b310. the result is superb :)

power from 3k rpm till 6k.

What are you using the car/engine for. If it's a daily driver, I'd use the smaller port head, but if it's just a weekend driver, you should use the oval port engine. In a daily driver, I find instant throttle response is a good thing, being able to close any gaps ahead with just a squeeze of the throttle pedal is good, having to wait for the engine to clear, or change back a gear gets to be a pain & somebody usually jumps into the gap just as you get moving. If you're just using it for a sporty runaround, that isn't as important. I've had a stock A14 with GX carbs in a 1200 wagon & it was great for keeping up with traffic. I've also had a 120Y coupe with an A15 with a mild cam & a 32/36 weber & it was a pain in traffic, by the time the engine responded, somebody had definitely filled the gap. I'e just stopped using a 120y with a stock A12 & it was great in traffic, instant response, & have just started using a Sunny coupe with an A12, it must have some sort of cam & it looks like it's going to be a pain in traffic. I plan to drop a stock A15 with a rejetted stock carby in it & it should be a good daily driver. So, my advice would be round port for a daily driver, oval port for an occasional use car.

cheers for the advice guys ill see what i plan on doing with the car and choos what i want to do i got an oval port manifold so thats sweet
cheers matt

A popular site of a datto 1200 coupe had a dude with fuel injected stock roundport
with home made stainless manifold going over to the dissie side for inlet and it makes
100hp at the wheels with a small turbo.
Im sure that thing is very tractable and perhaps goes better than an oval port for low
to midrange.