I wish you were buying my head, I know it would help you.
(obvious sales pitch(hehehjoke).
well if your talking about vw air-cooled engines, they have a serious problem when you add racing before name of motor or after. you see the problem right there, its right in front of you, pretty obvious, yep you got it,,its -the
cooling. you have a stock air-cooled motor, stock shroud, stock fan setup (w/generator or alt), no cooling problems, then again its rated for about 4500rpm, springs i think, cam stock isnt any better. mild performance, not many immediate cooling problems, put this guy on a track, (hi-performance) and about 4grand (4.5k i think) the fan belt just slips. so cooling efficiency gets very low. and these guys are easily getting up to 7k rpms and more, i mean there were a slew of CA shops with performance cams, and extensive setups. all you needed to start up above 4.5k rpms to 7k rpms, was basically a set of high-rev springs. so some 'racers' used a power pulley, well it wasnt very good for the street, and for the track maybe marginal, and well youd get air, but at a reduced speed, amount. so the majority of speedsters deleted main fan shroud, and fan, pulley, take a pair of electric fan blowers, one to each bank of cyls, well youd get some air for cooling, and iirc none to oil cooler, then again for a 1/4 mile volume of oil getting hot, or overly hot isnt the problem. cause your running an extra 'oil pan'(too). this is most bug, typeI racing, drag, 1/4 mile, so they went in many spots to 1/8 track racing. i dont know what they did for specs for the kaffer cup racing they did, but the drags, would get hot spots, for a stock case, and you now over-bore for (foolish) over-big jugs, you may not get a couple of runs, you could shoot out of the starting blocks(first time), and blow the base of a cylinder. it just adds up. and your guy there is trying to do what a 3mile run, a good few runs in a weekend. i havent seen type4 motors punched out, or hopped up, then again the T4 motor i had had i looked like a direct drive fan, fan may have been part of cam, well that may just limit you right there, you cannt direct-drive-drag crank(&cam). so you can only get so much cooling off this set-up. porsche had a good fan set-up, it was single v-belt, with a generator. motors could rev up to oh about 7grand, i never had a cooling problem. then again (and these were early 70s models) if you were a kid, you might want to stick you hand down fan and see,,,well, old set-up.