Engine Compartment Air Intake (Manometer test)

I was never successful enough to be anywhere near a C level meeting! 

 

But I like chicken pot pie! 

 

…and I hate when stuff doesn't work the way its supposed to..

Wow.  I see myself in that ad several times.  Jimbo, you are a wonderful person for sharing this f%&$&%g piece of s$#t.

 

 

Oh and Senior kahuna, I am an engineer and I contribute.  So there.  Nyah!

What's a C level?  Back in school, I was always taught to strive for an 'A' myself.

 

 

There, that's my contribution.

 

 

You may be slightly behind the curve on that one, Noel. A strong plurality of oil, car, and obviously tech companies are run by engineers. In fact, as of 2012, 7 of the top 10 Fortune 500 companies were run by engineers.

Our company is currently run by a former engineer...

Wow, this thread needs popcorn! Me, I don't have a Speedster, I have a Spyder, so all this stuff about vents and air doesn't apply to me. But it is still interesting, if you have a technical bent. If you don't, there's the door, go live on another site, thread, whatever.

 

As far as non-paying members having less rights than paid members, I say pfffft! I pay over at Spyderclub, but I won't pay here. I try to help people, and occasionally crack a joke or two. Plus, I call a lot of guys on here friend. Certain people on here that don't pay offer way more worth in their comments, kindness, engine parts, telephone calls, and yes, sometimes even organize teams that descend on someone's problem and fix the darn thing! For free, nothing expected or asked for in return.

 

Sometimes I'll have a brain fart come out that helps somebody. Sue me!

I started my own company in 1997, in part because I was tired of working for ex-shoe salesmen who didn't (or wouldn't) understand what exactly it was that we did.

 

I'm not an engineer. I'm a beat up old service tech with a unique skill-set and customer base-- but I'm pretty good at what I do, and my customers all love the no-BS approach to something they need to have. I don't live in Tahoe, but I'm comfortable.

 

On a larger scale, companies around the world are finally figuring out that making stuff that works beats being run by a pointy-haired boss and his bean-counter minions.

Bob; Perhaps....Cabinet  level or Corporate level??  I'm not sure either.

Art

All the cooling in the world wouldn't have helped my engine.  In normal traffic my oil cooler fan in the rear driver's fender was on all the time.  The fender got so hot I couldn't rest my hand on it.

My new mechanic took the engine apart and said everything looked fine.  We're not sure why it ran so hot.

 

 

As Stan mentioned these temperature gauges can be off by quite a bit.  When my gauge read 210 it was actually 240!  I trusted my dash gauge until I did some temperature comparisons with a digital temp gun and a dipstick thermometer.

Nope. I've got a 96 plate cooler and fan in the driver's side rear wheel-well (aft of the wheel itself). If I could figure out where to go with it, I'd add another. The passenger's side wheel-well is filled up with my dry-sump tank.

 

I agree with Al and Tony and pretty much everybody else in the world-- these cars seem to be a bit starved for air. The manometer test was a great effort, but I'm concerned about where in a moving car you can get "clean" air for the base-line pressure (the other side of the manometer). The area behind a vehicle is typically a massive low pressure zone, so I'd suspect that the hood vent actually discharges air, but I don't know if the engine bay is an even lower pressure zone or not.

 

An engine is just an air pump. The air supplied to the engine needs to be >/= the sum of exhaust flow and whatever the cooling fan uses. The "folklore and common knowledge" figure people throw out is that the fan uses 7- 10 hp. That's a LOT of air, as the VW cooling fan is a fairly well developed fan wheel. In total, a 2L+ engine is using a lot of air.

 

If you've ever looked at a real 4-cam engine lid on the inside, you can see evidence that the Porsche engineers were concerned with getting clean air to the carbs as well. The lid actually creates a "breather box" around each carb, fed by the oh-so-cool vents we all love. It indicates to me that they were concerned (like Tony mentioned) about the temperature of the engine bay, as well as the fan robbing air that the carbs badly needed.

 

Regardless of anybody's personal opinion or experience with smaller engines and cooler climates, I do think there's a real problem here once a certain threshold is crossed. For my bubble-top AL cased 9.5:1 2110, that threshold was 80 mph and 105* for 2+ hours. Somebody else's may be different. It's irrelevant-- there's not a single one of us that wouldn't benefit from more air. Holes in the firewall don't seem to provide it. Popping the deck-lid does.

 

Short of the massive duct coming from teh front of the car in Al's race-car picture, I'm not sure how to do it. The trick here is to keep air flowing through the engine bay (in and out). It's probably the biggest weak link of Dr. Porsche's design, and one we are not likely to overcome without a lot of work-arounds.

Holes behind the license plate may help.

This guy may be on to something...ugly as it is.

 

Anybody tried running a fan on the firewall hole blowing air into the engine compartment ? Derale 16508 8" 500cfm looks like it will fit . 500cfm should be better than 0cfm .

 

Yes. I know I'm not the first, but I had one of these mounted in the compartment in front of the firewall, blowing air through the 8" hole that's now standard on all Vintage Speedsters:

 

http://tinyurl.com/pcwepn3

 

It seems to do nothing to help engine temps - in fact, the engine seems to run hotter when the fan is on.

 

Why? I've got an external oil cooler mounted in that same space (this is where VS puts them) and the heat generated by the cooler is largely trapped there. Turning on the firewall fan just blows hotter air into the engine compartment than would otherwise be there.

 

This winter, we're moving the oil cooler out of that space and into the driver side rear wheel well. I'm hoping doing that will dissipate the oil cooler heat better. But, it should also allow the firewall fan to do something useful - blow COOLER air into the engine compartment.

 

I won't know how this all works until our 100-degree days return again - probably sometime in May.

 

 

 

 

Thanks I just re-read your earlier post about running hotter with fan . I hope moving oil cooler helps , does your oil cooler have a fan ? I have a 1915 now with no cooling problems , but want a 84 x 92 engine without cooling problems .

As you know in a Beetle, the motor gets clean air via vents that are just below the rear window. I have tried various ideas as to how to get proper cooling in a Speedster. There are three things .... oil cooler with fan mounted AWAY from the fan intake ....and two $10 fixes, a 6 inch piece of corrigated black plastic hose routed from the air intake on the bottom of the chassis, this allows clean air to be directed to the fan. The   choice is to leave a 1.5 gap between the firewall and motor , add a piece of sheet metal angled 

down at the chassis to catch air forcing it into the motor bay and fan intake. The enemy is slow speed or stopped in traffic as on a hot day the motor will pick up the hot pavement air....just my .02..

Hi, i hope, its o.k, if i also write something about my Experiences in this forum in my Brocken English ;-)

there are a lot of things about which you should consider when it comes to the optimum engine temperature.

And since there are still some things about not yet been written.

For example, the carburetor settings and jetting has a lot to do with the engine temperature. set Them on lamda 12.5... also help little things like the rubber on the spark plugs if they are correct and mounted.

The blow box should be completely sealed so that no air can escape.

Very important it is in my opinion the all plates that separate the top of the engine from the bottom of the engine are completely sealed and the rubber seal perfectly mounted.

The small blechel mounted below the cylinder witch should blow the air to the the rear necessarily should be installed.

There was also nothing said about the timing oft the ignition this should not be too early 7.5 degrees absolute maximum reaches 28 degrees at 2000 revolutions per minute. also this helps to geht the Temperatur down...

 

I know, you all are Experts in these engines and you know about things i wrote but

if all of this homework is done perfectly and everything is tight and the carbs are set correctly a little bit fat...), there are, in my experience, even for large engines hardly no temperature problems.

 

Many aircoled greetings from Germany, Jan

I've got two 9" holes with fans sucking from that space, and blowing straight onto the air filters. My oil cooler is in the drivers side rear fender, so I'm not picking up hot "oil cooler air". I'd love to say it makes a difference.

 

It does not.

 

It's no worse, but no better than when the firewall was sealed up. Popping the deck-lid makes a difference-- 10*, anyhow. A water mister on the oil cooler would make a huge difference.

Boy are you guys having fun.  One thing I have learned here is that air cooled engines need air to be cool.  What a surprise.

 

I also believe that everyone who visits here should be a contributing member.  Isn't that the way it should be?  You drop in, poke around, see what goes on, and if you like it and want to participate, you pay.  It ain't much $$, and just seems right to me, regardless of how cool your knowledge is, and how much you contribute.  Just sayin' . . .

 

Also, the thing about manometers.  29" (inches) of water is supported by one atmosphere of pressure, which is about 14.7 psi, not 1 psi.  Owing to its larger density vs. water, a column of mercury (Hg) ~30 mm (not inches) high will be supported by the same one atmosphere.  mm of Hg is what is mostly used to quote barometric pressure.

 Thanks for replies , I was thinking the fan would help . How about facing fan blowing out to draw cool air from grill ? 

Frazerk1....Thanks for catching that typo. I meant to say 1 ATM not 1 PSI. That makes a big difference and I do appreciate you catching it

I have been too busy with the Holidays and traveling out of the State and Country to continue testing on my car but will in the Spring. I did, however, do a little testing on another members car. His is a Intermechanica model (i think), and we found that he was drawing 1 inch of water at 65mph. We went back to my house and propped the engine lid up about 3 inches and that eliminated the vacuum. We compared the size of the air channel between the underside of the grill into the engine compartment and found that my car (a 2014 VS) has a larger opening in that area. This directed us to suspect that area as the restriction. Since that inner panel is multi-function, (keeping water out of the eng. compartment etc.) I think it would be very difficult to modify it to allow more air in. I think it can be done but I haven't taken a closer look yet. It's possible that my car will pull a vacuum at higher speeds/RPM.   More testing to come........Bruce

I'm by far one of the least knowledgeable about these air cooled engines vs heat. I'm just wondering if it would be any benefit in drawing cooler air into the engine bay via ducts mounted facing forward on each side of the frame then up through the firewall and exiting at or near the fan shroud?

The reason I ask this is on the Cobra the side vents on the front fenders are actually hot air exit points. During early development of the racing Cobras the engineers, drivers and mechanics found that the engines were running far hotter than they were meant to and the front disc brakes were prone to overheating. By simply making a pair of about 4'' dia. flattened aluminum vents and mounting them under the front of the car with ducting t'd to vent on the brakes and in front of the engine the problem of overheating of the brakes was solved and the engine heat was significantly reduced and the side vents on the front fenders actually functioned as they were supposed to do. Also to further reduce engine heat the radiators, Harrison standard Corvette type, were replaced with Harrison 4 row 'Desert Cooler' Corvette radiators which further reduced engine heating.

 

Just curious if any one has tried the under car ducting?

 

It would be interesting to find out how long incoming air stays in the engine bay before it's sucked into the shroud and carbs.

I imagine the longer it hangs around the hotter it gets, which is not a good thing.

I like my idea of propping the engine lid open 4 inches for hot weather driving.  I have a simple extension arm, and it takes me about 3 minutes to raise my engine hood and lock it in place.  Eventually, I would like to install an actuator, so I could raise and lower the hood while sitting in the driver's seat.

Mind you, that may not be necessary, as I'm also planning on installing side vents by the air cleaners.

Think about this:
The way of the Air is, that it goes through the engine lid into the cabs and the fan.
While driving. behind your car, you alway have a underpressure. If you open the lid while driving with open lid the underpresure will makes the air flow in the wrong directinon...
imagine how mutch air the engine pulls through i think the air stays in the engine bay not even for seconds at higher rotations.
one more example: i ve got an karmann ghia typ 14 in the karmann commuity every one knows if do not close your engine lid ore also if you dont mount the engine lid ruppers it can cause sussen engine exidus cause of this effect

Bruce wrote: "Since that inner panel is multi-function, (keeping water out of the eng. compartment etc.) I think it would be very difficult to modify it to allow more air in. I think it can be done but I haven't taken a closer look yet."

 

If you go to the classified section and see the rear view of the JPS Blue coupe for sale, you'll see how John Steele removed a huge area under the grill and installed a screen to let lots more air in.  Not bad looking, and the engine doesn't (or shouldn't) care about rain getting in there.

 

 https://www.speedsterowners.com...9#431817394449723409

If the grill is located over the alternator pulley I suspect a fair amount of water could be flung all over the engine compartment by the spinning pulley.

So what?

--I'm surprised the video at the top has made it through the Theron-screening --