Carrera cooling?

Whatever happened to Darios Carrera look-alike cooling shroud endeavour for type 1 engines? Did it die aborning or is it still in the works? Just curious...

Along those lines, how are you finding your deck louvres? helpful, no big deal but not adverse, etc?

The 2,387 runs very cool considering its BHP output; the louvers are probably a big help in getting cool air into the fan and carburetors.

Around town on a hot day (90's) oil temp is 180 to 185 F, cruising at 70 it gets up to 212 F; this is with the 356/912 alternator pulley. Haven't checked cyl head temps yet.

Jetting is still just a tad rich, but I'm working on it...

The reason I ask is on my big adventure atKnotts, the oil cap came loose...I saw oil film up underneath the decklid... I resecured everything, cleaned it up and in a conversation with John Steele, he expressed the thought that the louvres don't draw air in as much as they pull warm air out. He used some airplane sounding talk about negative something or other...

Before the big engine went in, I ran a few days with the decklid down snug as opposed to propped open at the top edge as I usually do, I noted the engine temp was a little warmer, decklid down.

I'm thinking as sexy as those louvres are, they are not the be-all, end-all cooling assist I had hoped they'd be...I'm thinking about getting Mr. Sawzall out and looking for some other avenues of fresh air in.

Probably better you're running rich than lean.
It wass neat having these gauges to get a look-see at what is happening under the hood. When IDA gets back from Utah, more travel time for me...

The Louvers have caused many VW guys with beetles problems... My own personal car is mine and has been for 15 years because of those louvers..

The guy baked 4 engines in a year, all died the same way.. I taped up the louvers and have ran a 11.2: engine with 48mm carbs and it didn't run hot- in the same engine bay.

I am thinking the Carrera GT louvers purpose was to connect the carb induction boxes (or whatever they are called) to the louvers for fresh source of cooler outside air for the carbs. I don't believe their purpose was for additional cooling for the engine compartment --every photo I recall shows the induction boxes covering the entire louver opening, though I may be wrong.

You are exactly correct, Erik.

Not a louver expert here, but while at Gary Emory's Campout I noticed a recuring theme on their outlaws and raceing cars. An I am thinking that Gary and his team know what they are doing. Anyway, his louvers are inverted, not facing forward instead of to the rear, but put on the inside of the engine lid, opening forward and out, like they were stamped from the outside of the lid. Pictures for your clarification.

I saw those inverted numbers up at ThunderHill, particularly on that dark 356 coupe, the dude who has the matching speeder too. Very racy, but on metal decklids there are more options. Hmmm, maybe I'll start sifting through my decklid collection (seven maybe eight) and see if there are any that near fit my car's engine opening.

In the mean time, those rascally 48 IDA carbs are at Art's place for repair and training. They are supposed to be as civil as fuel injection upon their graduation...I think I'll go back to keeping the lid up a bit. With the surface mounted hinges it is just a matter of a spacer.

Paul, another option that was used on the carrera's was to open up the area under the rear engine grill. I was able to creat an opening that is 2/3's again as big as the stock opening without using the louvers. The louvers really have a very small overall area open to the outside, the area created by opening under the grill is over 10 times the size. You can see in the pic the modification. To go one step further, some carrera's even have a large oval cut directly under the grill opening to further enhance the air flow to the fan and carbs. I would look into this if I had your engine.

Or drill a 3 inch hole behind the license plate for additional cooling air.

Eddie, great looking work. Nicely done lid and detailed engine compartment. Did you use a dremil tool to modify/enlarge the bottom of the lid opening? I reckon I will copy what you did.

This got me to thinking -- when these cars were designed the German engineers weren't factoring-in engines with the hp output of today's monsters. Can one grill opening supply enough outside air to cool the engine and supply the carbs when they are sucking air?

It would be interesting for someone with oil temp and head temp gauges to take two identical summer spirited drives, one with the lid on / the other with it removed and compare the two baseline temps.

The performance figures attained in a climate-controlled environment like Jake's dyno room may be different than in a stuffy engine compartment if the engine can't get enough air.

Yeah I definitely see some Sawzall sessions upcoming...My engine temps are good, no problem there, I just want lots more air going into those carbs

Paul,
Art did a pair of IDFs for me about 5 years ago. Very satisfied with his work, even if you have to ship them to Utah. Hope they work well on the beast.
Joel

This post reminds me of the post we had a few weeks ago, about propping up the engine deck lid a few inches when extra cooling is needed. Maybe a little electric motor that can raise and lower the deck lid two or three inches....wouldn't that be nice.
Ron

Guys, their is plenty of space under the engine grill to get all the air you need to feed those big webers without doing any cutting behind the lisence plate or cutting louvers, or jacking up the lid IMHO. Eric thanks for the kind words, the pic that showes the opened up lid is an early stage before I re did the engine compartment, check the other pics in my file. If you figure the square inches that you can utilize it's amazing. I didn't cut the oval out right under the grill, but if I had an engine like Paul's, I'd pull out the dremmel again. What I did was to mask off the area with masking tape, then drew out the openings I wanted, then cut them using my dremmel tool. Eddie

I just remembered what my engine builder told me about cooling. He's been building performance engines for dune buggies, drag cars and race cars for ten years. He said that he has seen cars that had such a negative pressure area in the engine compartment that it actually sucked the oil out of the rear pulley, and sprayed the engine compartment with oil. When they cut openings or jacked up the lid on VW sedans it eliminated the oil leak at the pulley altogether. So I guess it just goes to show you can't get too much air. Eddie

The oil was probably being misted due to crankcase pressure... The pressure increased because the engine was expanded too much from excess heat... The engine probably ran cooler with the deck jacked a little, which made less expansion and equaled no oil from excess crankcase pressure...

Just an observation.

Really hard for me to imagine GENERALIZED negative pressure in a replica's engine compartment when the fan is ingesting 400 litres per second (or more) of air and the carbs are also gulping their fair share. There might be localized low pressure areas, but I doubt very much that Carrera style louversw in the rear deck lid would cause this; otherwise Porsche would not have used them on Carreras.

Only the GT/GS Carreras for competition had the baffling for carb air intake; the GT's that I have seen did not.

There was a similar thread a few weeks ago. I was surprised how many (few?) Speedsters had a hole in the firewall in front of the shroud/fan inlet. Seems like this would improve air flow, especially with the louvres in the lid.

Jake, good observation, hadn't thought of that.
George, maybe I didn't make myself clear, what I ment was that with all that sucking going on by the fan and carbs, and not a large enough vent opening it would suck oil from the rear crank seal. I'm not saying it's true, I was just told this. It had nothing to do with the louvers.
Bruce, I don't know about that hole your talking about, but I think if I had a choice between cutting a hole right under the engine grill and sucking in clean cool air from above the car, or cutting a hole in front of the fan under the car and sucking in warmer air as well as road debris, I'd try the former first. Either way, if it rains the engine is going to get wet. Eddie
P.S. some Carreras had a big oval cut out right under the engine grill.