Hi Alaska,
Re: Not sure what a type 4 is...but mine was air cooled.
VW used the Type 1 engine from the beginning to about '72 or so in the bus. And the Type 1 was always used in the bugs. Both the Type 1 & the Type 4 were 4-cylinder, flat, opposed, air-cooled engines. The Type 1 was very reliable & the Type 4 was completely unreliable.
Now, with that info, 25 yrs from now when someone asks, you call tell them all about the differences. :yes:
Jerry Baumchen