360 heads on a 318 of any benefit?

rumblefish360 said
While this is true, the 318 gobbles down air and fuel at a much lower rate. The potentail flow of the 360 head is not fully realized on a 318 until much much later in the rpm band. Until you get to the area where the engine can make use of the air flow ability of the larger port, the air moves slowly in the intake and head track. This drops fuel out of suspension and creates big droplets of fuel that will not burn so well once in the combustion chanber.

While it is true that the air will move slower for any given RPM, accelerating the car, and thus the rise in engine RPM, requires as easy a flow as possible. Realistically, the valve seat is the most restrictive part of the runner. Swapping the 360 heads onto the motor will allow faster cylinder fill due to larger valves. The real issue won't be airspeed in the runner as much as it will be the vacuum signal to the carb. I have done this swap, and never had a problem with it while I was running it.

rumblefish360 said
This is simply not true of the heads. This is a mistake. It should read 360 instead of 318. I'm going to assume this is a typo. The smaller 318 head port will keep velocity up instead of droping it. Velocity is the key to makeing HP in any engine. The 318 suffers greatly from a lack of it.
Between the smaller bore and shorter stroke, the engine needs a smaller port so it can draw on the air and fuel well and really, the small port is an ideal set up.

I'm sorry to disagree, but I must. Anytime a mismatch of port sizes occurs, there will be "reversion", which causes huge amounts of turbulance where the ports meet. It doesn't really matter if its a 318 head and 360 intake, or a 360 head and a 318 manifold. The mismatch will cause turbulance and the engine will not be making the best of the two parts.

rumblefish360 said
On the cheap, a 360 head , intake and a T-Q are the best hop up parts for a 318.
However, if you want to do better and take some time and money spent well and not just spent......

Add a 1.60 valve to the 318 head, port the stock 318 head and back cut the valves. Add the Edel. Performer intake. The head and intake's ports should match. Carb of your choice. I like the T-Q for a dual performance carb, but add what ever carb you like.

Certainly the heads should match the intake, and if I did not suggest that, I should have. Given the 360 valve size of 1.88", I disagree with the valves being too big for the 318. In fact, if the exhaust valve can be enlarged to a 1.65, or 1.70" that would be very effective. But thats just my experience, YMMV.