Lotus Europa Community
Lotus Europa Forums => Garage => Topic started by: Polopharm on Saturday,September 24, 2022, 06:17:29 PM
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I have tried to search this on the forum to no avail.
Are the vents on engine cover outlets to expel heat or inlets for fresh air.
I have seen people make some crazy roof high ram air ducts into them, but the design seems like an outlet as it doesn't look like a place that would get a lot of fresh air.
If it is an outlet how is fresh air channeled in?
Looking at some europa race cars they have naca ducts on the b pillar which I assume are ducted to the intake?
On the mk 1 mr2 the engine cover vents, similar location to the europa, and are outlets, many people add fans to actively push out hot air. Cold air is channeled under the car and enters from below the rear bulkhead. So any ram type intakes on the engine cover are not productive.
Radiator- why would stock radiator not be directly behind the grill, which would seem to get most airflow?
Reading older posts seems like a lot of talk about over heating , how many people have added oil coolers?
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I don't know what the NACA ducts on the 47 are for (for that matter, I don't know what the ducts on a Ferrari 308 GTB or any number of cars are for) but I do know that the vents in the TC engine cover suck air from the engine compartment into the area behind the rear window. I think the S2 is similar but the screen between the tail/brake/backup lights could alter things. Here is a video I took of the air flow in my car (https://www.youtube.com/watch?v=aqHFg4q7jxA). I had figured that a low pressure area would form behind the back of the car but the area behind the rear window provides a much stronger low pressure area (https://www.youtube.com/watch?v=1L4F4dEc2BQ). Possibly, if it weren't for the engine cover vents, the rear would have a stronger low pressure area.
I also understand that, as counter intuitive as it seems given the previous paragraph, that the snorkels are designed to provide cold air for the carbs actually do the job for which they are intended. In fact, a member here (Sandyman) made his own snorkel that seemed to cool the engine compartment and presumably also cool the intake charge. Here is part of a thread that discusses that (http://www.lotuseuropa.org/LotusForum/index.php?topic=3062.msg57530#msg57530). For intake charge cooling, there are other options. One that is very effective is to snake the intake air cleaner down near the bottom of one of the fuel tanks. Here's a thread (there may be others) about it including a pdf attachment describing how our own pboedker did his (http://www.lotuseuropa.org/LotusForum/index.php?topic=2658.0). Since I have to guess, I would guess that the NACA ducts on the 47 provide a similar function to the snorkels...
I think the idea for the radiator is put it on one side to make room for a spare tire and jack. I would also guess that Lotus sized it and decided in front of the right front tire was a good place for it. People with more aggressive engines sometimes put a larger radiator that exhausts out the top of the bonnet. This is efficient but I would imagine their spare tire is a tire patch kit and battery operated compressor or a bottle of Slime.
As I stated before, I assumed that the car would form a low pressure area behind the car so that's where I put my oil cooler. That turned out to be a mistake. An oil cooler would be better placed in front of the radiator or if you really want to get fancy, you could fence off some air for an oil cooler in front of the left front tire - the idea being not to steal too much air from the radiator. I figured that I didn't want air warmed by an oil cooler to be used to cool my water but I was too cautious in that regard. Dave Anderson had an interesting oil cooler arrangement (https://www.prevanders.net/europa/oilsystem.html). He isn't specific about how efficient it is though. The plain fact is that I have an oil temp gauge and my oil has never been really hot. I have an oil thermostat and I'm sure it's been opened but I don't think it is a common occurrence based on the oil temp readings I see. If I knew what I know now when I built my car, I might not have bothered with an oil cooler. If my car had a lot of track time, I would probably be glad to have one, though.
As for overheating, I've never had a problem with it. I don't do much downtown stop and go traffic driving which would be harder on the cooling system. I really think that is the only time the cooling system is really marginal. I use Red Line's Water Wetter and distilled water (It rarely freezes hard here and the car is in the garage anyway so it never experiences a freeze at all) and I have an aluminum radiator with the highest CFM fan I could find. Other than that, my cooling system is not remarkable.
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+1 The air flows up out of the vents in the engine cover.
Adding “ram” air down through the same vents actually does work as the ram air effect is much stronger than the vacuum drawing air up. Ram air would pressurize the engine compartment and push air down and/or back and out.
NACA ducts do not flow much air. One lister hooked his air intake to one NACA duct and the lack of air flow choked off the carbs at high rpm. They look cool and do flow some air, but not that much.
The first mid-engined cars started out smooth and sleek. Then they discovered all the air flow issues and ram air intakes started appearing, for good reason.
The front plenum is “sealed” and pressurizes at speed greatly increasing air flow through the rad. It all actually works very well. The issues arise at slow speeds and stopped in traffic where air flow is insufficient. The stock rad fans are poorly implemented. Fit the biggest CFM one you can find.
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Very informative replies. Ive often wondered would the air filter be better off taking air from the luggage tray which surely must be cooler than the engine bay.To BDA the ducts on the 308 gtb are for fresh air to the carburettors and on the other side for the oil cooler.
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Very informative replies. Ive often wondered would the air filter be better off taking air from the luggage tray which surely must be cooler than the engine bay.
There was a thread about this a while ago. It started off about air temperatures and wandered into changing the location for the air filter on the TC engines.
http://www.lotuseuropa.org/LotusForum/index.php?topic=2658.15 (http://www.lotuseuropa.org/LotusForum/index.php?topic=2658.15)
Despite the fact the original location has worked for umpteen years without any obvious problems, I was inspired by Peter's article and changed the air intake on my car so that if collected air from down by the petrol tank. I can't honestly say I've noticed any more power but on the plus side the filter seems to stay clean enough and the engine bay looks tidier.
Brian
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If the radiator is in the front wouldn't you always get warm air coming through the dash ducts?
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Yes, unless the warm air is ducted out through the front cover..
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…To BDA the ducts on the 308 gtb are for fresh air to the carburettors and on the other side for the oil cooler.
Thanks!! :)
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For an oil cooler installation, I'm thinking of placing it in the rear opening (license plate area) with a small electric fan or under one of the openings of the rear deck lid. I'm suspecting the PO had thoughts had the same idea with the rear section cut out. Any thoughts on either option?
Joji Tokumoto
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My car has air filter in luggage compartment, clearly it gets some fresh air, not sure how and obviously not great flow. For my application with the 4age and injection, not many alternatives, I guess you could somehow duct air into the luggage area.
Oil cooler, I was thinking of the same location. My consulier gtp race car has the radiator in a similar spot. I would think with the 47 race car the ducts go to oil cooler on one side and intake on the other.
When I get back to Florida will have my race mechanic and fab guy evaluate what I do to get my car functional so I can decide what to do with it- keep or sell.
For sure electric water pump, use old water pump location to have more room for better alternator mounting. Change slave cylinder to pull type a la JB.
If I keep car I would look into feasibility of top mounted pedals, has anyone done that?
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For an oil cooler installation, I'm thinking of placing it in the rear opening (license plate area) with a small electric fan or under one of the openings of the rear deck lid. I'm suspecting the PO had thoughts had the same idea with the rear section cut out. Any thoughts on either option?
Joji Tokumoto
Depending on where your exhaust is routed, here's another area of opportunity.
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PO modified the front of my S2 to incorporate an air-dam.
He never quite finished it so I have work to do there.
I have wondered about incorporating ducting to run inside the sills for colder air to the carbs.
But I seem to recall reading somewhere that too long of ducting stacks air until it has very little flow.
Answer becomes larger diameter ducting, but that would not be possible with the limited space inside the sills.
Anyone tried this?
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Air flows in at the rear. Even with a fan to push it out, warm air from a rear mounted oil cooler would probably just flow back in again unless you have air flowing in from elsewhere to pressurize the rear compartment to push it out.
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Richard, I also thought that getting the air from the front was a possibility. The thing that stopped me was how to get the duct through the front wheel area. My scoop was the easiest idea.
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Yes, just came back in from looking at it.
Could conceivably pull from the rear of the front wheel arch via a modification of the shut panel.
But then it's still an issue to find space to route the duct at the rear ahead of the tire. :headbanger:
Now considering a scoop low on the body behind the door.
Under is probably simpler and less visible.
I have an idea for that but I'm one of those guys who can probably fabricate it faster than I can draw it.
Basically a wide shallow scoop directed to carb air box ducting.
Similar to what was posted above in a link.
I might try to do one on each side to cool the engine compartment as well.
My car has been lowered so space is pretty tight.
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Some pic's.
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Side scoops at the lower sills?
Looks pretty good.
Having some trouble comprehending the bottom pic.
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NACA ducts do not flow much air. One lister hooked his air intake to one NACA duct and the lack of air flow choked off the carbs at high rpm. They look cool and do flow some air, but not that much.
Curious - do we have any numbers on this?
I've previously calculated the inlet area of the 47/Banks NACA duct and it's 20% greater than the area available from 3" dia trunking.
I was thinking to utilise one duct to feed a commonly available flat panel filter box with trunking to a 2xDCOE mounted air box.
The consideration there was not so much air flow, which as you say is perhaps not much, but merely to access to the ambient air stream. In that respect, a simple hole in the bodywork would be fine.
With that said, the 47/Banks NACA duct looks weird. For anyone who's read the rather long and esoteric NASA article on submerged ducts . . well, I can't see that it's even long enough.
I also wonder if one couldn't mount a counter argument and suggest that a Bernoulli effect might be in play and that the duct actually extracts air due to it being somewhat at an angle to the air flow! I dunno.
I'd like to see a wool tuft video on that duct.
On oil cooler mounting, I thought David A's installation looked promising. (pic below)
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Just how many 12v fans may we reasonably run using a standard alternator and battery?
Seems some of us may need radiator, oil cooler, and intake air.
The first two can be thermostat actuated.
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I use a jw coolant oil cooler. These coolers are small, need no thermostat, and heat the oil when it is cold and cool the oil when it is hot.
This is the model I use. https://www.laminova.com/products/oil-coolers/complete-oil-coolers-c43
I have a c43-180.
I have never had a problem.
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Here is a better picture of what I did with the under car air duct. Does seem to transfer quite a bit of air to the end of the tunnel and into the engine compartment, at least with my leaf blower. LOL. How well it works in actual operation is the question, but it was fun building it. Cannot use the anti-sway bar in the stock location as it fouls the inlet, but I relocated the bar atop the T-section. You are correct, the other pictures are the rocker sills with corresponding openings in the body to direct air up and into the fuel tank wells.
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I think I may try to do some CAD work on this.
Cardboard Aided Design.
Wondering if a simple louvered cover under the fuel tanks, louvers down and forward, would work at all.
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I use a jw coolant oil cooler. These coolers are small, need no thermostat, and heat the oil when it is cold and cool the oil when it is hot.
This is the model I use. https://www.laminova.com/products/oil-coolers/complete-oil-coolers-c43
I have a c43-180.
I have never had a problem.
I forgot about the Laminovas. It will solve the problem of installation in a spot with air flow at the expense of more heat input into the coolant system but it appears you don't have an issue with that.
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Anyone experimented with Scoops/Ducting similar to this?
Low profile and might prevent the hot air recirculating back into the engine compartment?
Really need my S2 running but not painted so I may do my own yarn testing.
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My car has air filter in luggage compartment, clearly it gets some fresh air, not sure how and obviously not great flow. For my application with the 4age and injection, not many alternatives, I guess you could somehow duct air into the luggage area.
When I get back to Florida will have my race mechanic and fab guy evaluate what I do to get my car functional so I can decide what to do with it- keep or sell.
For sure electric water pump, use old water pump location to have more room for better alternator mounting. Change slave cylinder to pull type a la JB.
If I keep car I would look into feasibility of top mounted pedals, has anyone done that?
On my S2, I pull intake air from a boxed in area fabbed with ABS sheet, next the the gas tank. I've logged everything possible on the ECU. My MAF air temps are always about 10-15 degrees higher than ambient depending on speed. It's not ideal but it's that or the rear wheel well. Non boxed I would be 20 degrees higher. When my car was N/A, it wasn't boxed and I didn't care. I didn't have detonation concerns then. I would worry about air pick up in the back as long as you aren't near the exhaust. Air is always moving around in there, it's just a little warm.
On the front. Mounting a radiator right in front of the opening isn't the best. You will get hot air in the cabin too. I eventually ducted out the hood to solve it. If you need a fan, Spal list the CFM and pressure drop. Run the largest and highest flowing you can. If you are warm at cruise it's not the fan. Click English if it's in German. https://www.spal-vertrieb.de/en/catalog/?durchmesser=305. A 10mm/h20 drop is about .4" H20 and about the max you would see from a radiator restriction with big fans. They list as Push or Pull. Don't trust Ebay fans, they lie on specs. If you have a 4age you you should have a 70A alt. I run a 100A alt and 2 big fans, an intercooler fan (was 2), aftermarket ac always on high in the summer, and a big electric fuel pump. No problem at idle.
I didn't run top mount pedals but made a bolt on tandem twin brake master cylinder mount. If you have a fab guy, I have drawings. The top mount is really probably easier though. If your brakes work. I wouldn't bother. I did it for other reasons. If you want pics of anything I did let me know. We all like to help.
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If I keep car I would look into feasibility of top mounted pedals, has anyone done that?
47’s had a top mounted pedal box, replicas of which are available. Banks also did their own top mounted pedal box which meets more modern race regs (UK and FIA at least). Both versions have twin master cylinders with balance bar adjustment along with provision to run a hydraulic clutch if desired.
Pic below of the Banks pedal box with its lid removed (not running a hydraulic clutch)
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I made the engine compartment much more smooth, so that the air does not stall in the engine compartment.
Better flow, better cooling
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As for the pedalbox, I cut the fibreglass corner and put it as much as I could to the left.
So I could move the pedals about 1 inch to the left.
Also went to hydrolic clutch.
By doing this I made a standing pedal for the gaspedal (I have shoesize 12)00
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Any pictures of the banks pedal set up in the car? I saw a europa race car years ago and with the top mount they were able to spread apart the pedals more.
Your engine compartment looks great. I was thinking about doing a similar abs plastic box ducted same as yours. Would love to see it.
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Wow looks great. Is it right against the frame rail ?
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Foto
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Any pictures of the banks pedal set up in the car? I saw a europa race car years ago and with the top mount they were able to spread apart the pedals more.
Not the best picture but you can see the spacing between the pedals, if you have a hydraulic clutch then the top mount clutch pedal wouldn’t be interfered with by the step at the end of the footwell on your lhd car - as I mentioned in previous post, mine has cable clutch and retains an original style floor mount clutch pedal.