I know that if I don't put a radial in this Zero I'll not be satisfied. I've learned after 56 years that I have a retentive personality, it must be as close to scale as allowed by market availability. In fact, being a gear head I'm not sure if its the plane or the engine that has my imagination fired up. I kid, but the war in the Pacific influenced me to join the Marine Corps to get to the Pacific region to scout out some wrecks. The best laid plans of mice and men, mingled with the optimism of youth. So this plane will represent a dream once dreamt by a very naïve youngster, finding a Zero and bringing it home. Naïve isn't the word is it.
Getting back on subject, the question of cowling fitment comes to mind. I know the engine needs airflow around it to keep it from over heating. How much clearance is necessary? I don't want to cut holes in the cowling, as I saw someone do to fit a radial. I suppose I should have stated that this plane will be built from a Platt short kit. I read where a person put a Saito 5 cylinder 1.70 in a Platt Zero. But it would appear that Saito makes the 1.70 in 3 cylinder only now a days.
I appreciate all who have answered, whatever side they're on.

Anyone see the youtube video of the 1/4 Zero with the working cockpit and pilot that turns his head? Looks real nice with the cockpit lights on and so forth.