I've pretty much come to the conclusion that I need some vents in my '66 decklid to feed/cool my 1915 monster. Currently I am running with a tennis ball holding up the lower part of the decklid, however, I'd like to make the system a little more secure by adding vents and leaving the decklid locked.

So step one, basically I'm contemplating running my number plate elevated 5mm and having a hole/cutout behind it - do you think it'll flow enough extra air to justify the effort?

Also I want to run vents which'll need to be welded in. What cars provide a good source of vents for this conversion? I think AussieBug had a suggestion on the old forum. I'd love to emulate the convertible style vents so keep that in mind, however, if I have to go the S/L Bug style, I'm not too fussed.

go the hotrodders way! take it to any hotrod body shop and puch as many 2" louvres as you can fit! keep any potent motor cool! plus it it looks tough!

Those flute/louver things aren't my look. Thanks for the help though.

yeah im currently waiting for a decklid to be done for me... a 40hp decklid with slots welded in to look like a vert decklid.
and i'm only running a 1600sp

have you thought of deck lid stand offs
marcel

If you want to do it efficiently, there is a high pressure area at the sides, above the guards: Buy some back issues of "Performance Buildups" to learn about making fibreglass/composite components and make a couple of scoops/ducts. About 1 x 4 inches will provide more than any engine needs - email me if you want some accurate calculations.

What about a scoop and flexible hose under the car.The scoop uses the high pressure area at the torsion bar tubes and the hose joins onto the front tinware,flywheel end.GB Tech Art.page 18.

Bugmeister,

As Blue suggests - if you decide on the raised number plate and hidden holes you need to move the number plate out a decent amount - 15mm at least, for a good airflow behind it. Think how much gap there is between the fan and the firewall to get enough air into the fan.

For vents, if you can find a 70/71 "two slot" lid - even a damaged one with good vents, you could cut those sections out and graft them in to the 66 lid. The two-slot lids are big enough to work with the doghouse cooling fan (though VW changed to 4-slot lids in 72).

You could try importing a cabrio 66 lid from overseas - with the two sets of slots already in them. The true cabrios don't have under-window slots so VW developed the two-slot lids to provide cooling air for these cars - the cabrios are popular in the US and in Europe but we didn't see them in Aus. That means the two-slot lid is sufficient for the 1300/1500 fan all by themselves (22cf/sec), so adding that to the under-window slots should work OK with the larger doghouse fan (25cf/sec).

You could graft in sections of Kombi front air vent - the slots would be vertical but it looks good - vaguely early-porsche. I know a guy in QLD with this in is 58 (with 1915) engine and he says it works fine.

Lugnuts suggestion of an air scoop underneath into the fan inlet (through the front tinware) would work too; but I bet the fan and cylinder fins get covered in road grime rather quickly - part of the reason VW uses slots up high is to get nice clean air into the fan so the fins stay clean - a layer of dirt is an insulator and you don't want THAT in your cooling system.

Actually the 1976 Beetle that had torsion Bar front suspension and IRS rear end and flat Windscreen, also had a round hole under the number plate lamp... and a thermostatically operated flap that covered the hole in normal circumstances.... and opened when the temp exceeded.?? My 1976 NOS engine Lid has the round depression but no hole... I also have a Fibreglass Scoop that is attached to both sides of the roof gutter over the top of the Vertical air vents below the rear window... this Fibreglass Scoop catches a large volume of Air and forces it into the Air Vents which should help in the Summer Heat... I will take a pic of it ..if anyone is interested.. I don't like the look of the punched out slits... either

You could always use a 1970-71 rear deck lid with the two sets of vents. because the Genuine German made 1967-68 Beetle actually used the later flat bottomed engine lid with the push button lock... I would have the number plate at least 25mm out.... and as many holes as You can fit in... but the old "deck Lid stand off kits" take some beating... You can still lock the lid as far as I know, and add a push button alarm for the lid....

Run Hoodjacks on my '66 Beetle. They are ideal for allowing the warm air to escape the engine bay, & allowing your bigger motot to run cooler.

No need to cut the decklid, and gives your car plenty of "cal-look" apppeal.

A very cheap, but effective way to keep the engine cool @ highway speed without compromising your decklid with vents or hoodjacks. Is to run a piece of heater hose under the engine, & back up through the "emissions/warm air hole" (not the heater hose holes) of the inside tinware.

This worked extremely well in my '66 when it ran a 1600 with twin Kadrons, 009, and S&S headers, with the lid closed. According to the temp. gauge, the car ran a lot cooler @ 60 miles/hour with heater hose hooked up than without.

I guess, it comes down to the look you want for your Beetle. Hoodjacks or vents to allow the warm out, and then some type of ducting to allow cool air in.

Zayus

I've been running home made deck lid lifts that raise the top of the deck lid about 80mm. Very Cal-Look and VERY efficient!...I only run them during summer though! As some of you Sydney guys know, I have driven my bug accross Oz a few times....No reports of over heating yet (10 years on this engine)! about 120hp out of my little 1776, with a best of 14.8 quarter and she runs real cool!...get a BERG oil temp sender...Works a treat...The only time the light has flickered is when I was doing about 130kmh just north of Port Augusta on my way back to Perth from the Nationals back in 96!

did u get my U2U regarding the decklid vents?

sam