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Lindsay, they look good. I have the chrome boxy filter on now, waiting trying to figure out How Otto mounted his air box for a set of Weber 40dcoes sidedrafts. He sent me a picture many years ago , no picture attached. Strange indeed. Waiting now on what ITB says. I do have original Carb tops, can go that route or upgrade to what Gordo has, but money is tight here on the Farm, and I have a 7400 series Jd 4wd, that may have to go to the shop, for transmission problems. Read "NOT Cheap" to pull Cab etc, just to get to a 3 doller switch in the tranney. Damn it. So, I can live with what I have for the time being. Thanks for providing the links though, Jarrell
 

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Can Opeler
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Lindsay, they look good. I have the chrome boxy filter on now, waiting trying to figure out How Otto mounted his air box for a set of Weber 40dcoes sidedrafts. He sent me a picture many years ago , no picture attached. Strange indeed. Waiting now on what ITB says. I do have original Carb tops, can go that route or upgrade to what Gordo has, but money is tight here on the Farm, and I have a 7400 series Jd 4wd, that may have to go to the shop, for transmission problems. Read "NOT Cheap" to pull Cab etc, just to get to a 3 doller switch in the tranney. Damn it. So, I can live with what I have for the time being. Thanks for providing the links though, Jarrell
Otto used the top of an air box for a 1986 (I think) Datsun 300zx. He cut it down to fit and made a custom adapter plate. I’ll try to remember to find a photo of how to do it for you. I gave it a try, but it was much too large on my 40DCOE setup and not worth fiddling with more.
 

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Otto used the top of an air box for a 1986 (I think) Datsun 300zx. He cut it down to fit and made a custom adapter plate. I’ll try to remember to find a photo of how to do it for you. I gave it a try, but it was much too large on my 40DCOE setup and not worth fiddling with more.
Thank you Kyler, you answered my question, and the photo is probably what he sent Harold and I. What did you use for your 40 DCOEs and how did you set up your accelerator? Sorry Tom for hijacking your thread. Thanks, Jarrell
 

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Just Some Dude in Jersey
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I was looking over the owners guide on the controller that you have. That’s really a nice one, I really like the soft start feature, it looks like you mount it in front of the radiator? Set the temperature and let it do it’s thing. 3,000 CFM’s for our 4 cylinder surprised me. That’s a very good price on the fan. Looks like a good value. I’ll have to do more browsing through the links posted earlier. Thanks for posting the information.
I'm very pleased with both devices.

PJ is one of our smartest guys and he usually buys very good well researched stuff. That type of 14" fan was his suggestion. I was using a 12" fan with straight, unconnected, blades and was pretty happy, but still had some overheating incidents. This type of 14" fan seems exponentially better, it really blows the air. I think that the ring around the outside that connects all the blades is a VERY good thing. It keeps the blades in balance and reduces the amount of air that might be inclined to go out sideways.

The fan controller I chose is really sweet. It has that slow start feature, but it also has an "overdrive" feature where it will overfeed power to the fan for a short time if it's normal speed doesn't start to bring the temperature down to the target point. Additionally, it has a self check function at start up: When you first turn the key to Run the fan will turn on for 2-3 seconds. This lets you know that your fan is operational without you having to wait until your car overheats and the fan turns on. I've had fans fail long ago and when you have them set to only come on when your car overheats, it's hard to tell if you have a functioning fan. Often times you can't hear them running with the engine on and the shrouding of them makes it tough to look inside to see if the blades are spinning. That self test let's you hear the fan kick on before you start the engine. There are multiple terminals to plug in wires for various applications, one of which lets you turn the fan on whenever you want to with a switch. It also has enough power to control 2 or more fans, as long as you stay below it's max amperage. I have it hooked up to turn on both my auto tranny cooler fan and my engine fan simultaneously. Not the most accurate set up, The thermostat probe is inserted into the radiator fins near the top hose inlet, so it only reacts to engine coolant temp. I have no idea if, when the engine coolant gets too hot, the tranny fluid is also too hot, because I don't have a temp probe in it. It's a very oversized tranny cooler, probably WAY more than I need, but I only overheat in backed up traffic and that's one of the conditions where tranny fluid gets really hot. The other time being when the car is under extreme load, like climbing a hill. I figure that if the engine coolant gets too hot, then it's likely that the tranny fluid could use some cooling also.

There are other controllers that I'm sure have the same number of features, if not more, but it has a beautifully integrated design, it's nice to look at, and many other controllers look like someone cobbled them together from junk in their basement. Considering how catastrophic and inconvenient it is to have your car go to crap or even stall in backed up traffic, ANY price you pay to put an end to that is worth paying.

Unfortunately, my computer with it's 6000+ Opel pics is on the fritz and I'm forced to use my lap top from work, so I don't have any pics from my archives to show where I mounted it. I put it on the radiator wall just above where the brake booster support is. I dressed it up a little with some mirror stainless steel slid over the cooling fins.

Here's a pic from my archive of photos on this site showing the controller when my engine was yellow. I don't have the Stainless cover on it. You can see it just to the left of the MSD box.

 

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Opeler
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Cooling

Anything you use that brings the air in from the front of the radiator works,for the street car I use the one Gill sells,for the race cars something that moves the filter down by the battery.
I think we can all agree that mixing colder air with fuel can increase HP. And god knows we all need it,plus it help brake stuff,
 

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Anything you use that brings the air in from the front of the radiator works,for the street car I use the one Gill sells,for the race cars something that moves the filter down by the battery.
I think we can all agree that mixing colder air with fuel can increase HP. And god knows we all need it,plus it help brake stuff,
Yep I agree esp with the Brake issue. I need to get with Gill and see what filter you are talking about. Many,Many years ago,I was told the original air cleaner/filter was the best as it being smaller in the front would ram more air into the carb. I often wondered about that. The Mantas had a small line to the front on the right side to an opening that pushed the air into the cleaner/ filter. I liked that idea and never had a problem, except that it was a Solex Carb. I later found a Solex, mechanical linkage, that worked for a while, then onto "The Weber '' Thanks for the tip, Jarrell
 

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Discussion Starter #49 (Edited)
The goal has been to keep the fuel temperature in the float bowl of the carburetor under boiling point which I’ve found starts around 135° using our California summer blend, premium top tier 91 octane pump gas. Before I made the changes, mainly eliminating the stock exhaust manifold assembly I used the little 200 CFM cooling fan to see what difference it would make, with the stock manifold set up with the OGTS stainless heat shield on a 70°- 80° day, what it was able to do was eliminate the severe boiling after shut off, keeping the carburetor under the 135-140° mark but it was unable to keep the temperature down while waiting at a drive through or extended periods of idling time (5-10 minutes). I recorded the different temperatures after shutdown with the hood closed after making identical drives in similar outdoor air temperature conditions. I also wanted to see if I’m getting a good value for spending the money on eliminating the stock exhaust manifold. When I started this thread I was going with the stainless steel header in the meantime I got an offer to buy the Sprint manifold. Since my wife and I like quiet, I could separate the exhaust from the intake and I didn’t want to give up the low end torque. I Installed the Sprint, I had it sandblasted, cleaned it up inside and out and used the Eastwood DIY ceramic coating on the inside and got the outside lightly coated with I think more of a powder coating they claim it was done with a ceramic coating but I’m not about to remove it and argue since the cost was only $100. I went to the DIY method because I didn’t want to spend very much money and as it were I’d be surprised if I saved $20 in the process compared to a company like Jet hot. The end result was nothing spectacular but an honest effort was made to bring down the temperatures and preserve the manifold. So I installed it with my son over the weekend last week. I used stainless steel studs and copper coated self locking nuts with washers and lock washers (see pic) to preserve the Sprint for re use. I used stainless steel studs for the carburetor mounts and the same self locking nuts which I highly recommend. Micro Trader 12pcs Exhaust Manifold Nuts Head Stud Nut M8 Hex Copper Self Locking Car Parts https://www.amazon.com/dp/B07GJHDLQY/ref=cm_sw_r_cp_api_i_vMFpDbHSJ0QYB
I drove it with just the same stock style heat shield, it did cool down better after engine shut off but nothing else improvement wise. I picked up and installed some good heat shielding:
Design Engineering 050517 Form-A-Shield Hi-Temp Heat and Sound Insulation, 21" x 48" - Non PSA https://www.amazon.com/dp/B072MG5844/ref=cm_sw_r_cp_api_i_DbOZCbGGE8P26
It was easy to work with, I bolted it up to the bottom of the intake using the same bolts with 8mm x1.25 threaded lock nuts and ran the shielding right up to the cylinder head flanges underneath the intake runners. I doubled it up from the intake manifold out and extended it out so it meets up with the passenger side wall. I also re installed the stainless steel stock style heat shield underneath the carburetor too with the phenolic spacer. Now the outdoor temperatures are in the mid 90’s so it’s very difficult to get a side by side comparison. I did get one recorded temperature drop but it wasn’t in my garage where all of the other ones were recorded it cooled down in half the time. The last thing left in my arsenal thanks to the guys here that have fought this battle and won is to install the electric radiator fan to come on as a pusher at idle when the stock fan doesn’t get the job done, I installed an additional fuse block on the little shelf above the clutch cable to handle the extras thanks again for your suggestions on that great idea. On a separate post I’ll post up the recorded temperatures. Gotta do some more driving, right now the inside of the car is much cooler and quieter with the DE heat shield on the passenger side of the transmission tunnel where the old stock heat shield was. Heading in the right direction on this heat reduction business I believe. If the pusher does better than I think I may just eliminate the little cooling fan altogether and go to the set up in the pic courtesy of another post here on the forum. I just realized after I posted this that I may need the little cooling fan after shut down so I’ll have to figure out a way to incorporate it. In the meantime I’ll clean up the metal shelf that the fan sits on.
 

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Opel Rallier since 1977
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I have not read every post, TC, but is/has a fuel system change to re-circulate the fuel with a return line and electric pump a part of your plans?
 

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Discussion Starter #51
I have not read every post, TC, but is/has a fuel system change to re-circulate the fuel with a return line and electric pump a part of your plans?
Yes, there’s discussion about it earlier in this thread. It’s the last step that I’ll be doing especially if the steps taken so far aren’t enough as it seems all of this is necessary. I am interested in insulating the fuel line inside of the engine compartment as well. I think the fuel stays more stagnant and collects more heat than you’d think without the return line. I had in mind a fixed metered return line teeing in right before the carburetor the 73’ used a return line off the 3 way fuel filter but if I’m not mistaken it was a different concept before the fuel pump. There’s a way to calculate the known capacity of my electric fuel pump and the proper sized metered orface to allow the right amount of fuel back to the tank, it seemed like a good reliable inexpensive way to return the fuel but I have to do some more reading up on it. Excellent suggestion and if you have any input or feedback it’s certainly welcome.
 

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Not sure what fuel pump you have or if you already have a pressure regulator, but a bypass pressure regulator is old hat, and is that 'metered orifice' you speak of but which automatically adjusts in size to accommodate changes in carb fuel flow. Seems like the no-brainer way to accomplish that.

Holley and Aeromotive make them for the lower pressures of carbs. Aeromitive has one that supposedly goes down to 3 psi.
https://www.speedwaymotors.com/Aeromotive-13301-Bypass-Fuel-Pressure-Regulator-3-60-PSI,40596.html
(Not sure if that part matches your pump flow range.)
 

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Opeler
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Thought Fan Switch Kit might be a good way to control a secondary cooling fan that is not dependent on radiator (core) temperature.

https://www.summitracing.com/parts/dcw-dc-0444?seid=srese3&gclid=EAIaIQobChMIkPqR1aid5wIVRQF9Ch2mWQf_EAEYASAFEgLFGfD_BwE

Davies Craig Digital Thermatic Fan Switch Kits DC-0444 $66.42

Q: I understand that this controller turns the fans on automatically when the desired temperature is reached, but what I would like to know is it possible to also have a toggle switch to turn the fan on manually at any time I would like? Basically I would like it to work like it normally would, but if I flip the toggle switch it will come on and stay on until the switch is turned off. A manual override switch.

A: Yes, green wire for the AC override wired to a manual switch.
 

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Just Some Dude in Jersey
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Well, I've already stated that I don't think that fuel in the line, routed logically away from or insulated against the engine heat, heats up any real noticable amount.

I feel that the problem is entirely that the carb heats up and that you could have fuel the temperature of ice water and still have carb boiling of the fuel.

Before resorting to all sorts of highjinx like return lines, boxes of ice, and whirlygigs, why not first PROVE that your fuel is getting excessively warmed up while still in the fuel line?

Go out on a hot day, drive around until you're pretty sure that your car is starting to show signs of vapor lock, then pull over and remove your fuel line from the carb and put the hose in a soda bottle and crank your engine to pump some fuel into the bottle or if you have an electric pump just turn the key to Run for a few seconds. Then put a thermometer in the bottle and test what the temp is. I'll betcha that that it won't be much more than ambient temperature.

As another experiment, after you've got the car all warmed up, try measuring the temperature, in various ways, of the carb itself. I'll betcha it will be 200*-300*. Then measure the temp of the intake manifold. It will be even higher.
 

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Perhaps it's time for someone to develop an intake made of a plastic ?:) And a carb body too, like on the Carter Thermoquad and Street Demon 635.:)
 

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Go out on a hot day, drive around until you're pretty sure that your car is starting to show signs of vapor lock, then pull over and remove your fuel line from the carb and put the hose in a soda bottle and crank your engine to pump some fuel into the bottle or if you have an electric pump just turn the key to Run for a few seconds. Then put a thermometer in the bottle and test what the temp is. I'll betcha that that it won't be much more than ambient temperature.
FWIW.... it only takes a short section of hot fuel to boil in a line and cause vapor lock, for a mechanical pump setup. It'll be hard to find that few inches of overly hot fuel at the flow rate of any pump into an open container. All you'll measure is the the average temp of the fuel in several feet of line... probably not useful info.

Now if you have a mechanical pump, and it has sputters or trouble pumping fuel into an open container, then you can pretty much count on fuel boiling in the line before the pump. The same may apply for an electric pump.. look for sputtering and air out of the line.

My 1st exposure to vapor lock was in 1967, in my dad's new '67 Dodge Monaco wagon. We stopped on a 100F day at a small rural gas station and a few minutes later, no start. The issue was in the fuel line running close to the exhaust just behind the engine.
 

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Living in the past
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Vapor Lock Problem

Fuel temp. is a problem, and anything you can do within reason helps with starting and driving these cars. I ran the fuel line from the tank using 5/8 braided line incased in conduit along the inner rocker panel on the race car then ran it up into the wheel housing and through the inner fender panel using a bulkhead fitting to the cool can (insulated guart can filled with ice) to the filter and to the carb. so you might say it was chilled better than ice tea. I always tried to go to the starting line with the engine temp. at about 160 and it was at about 180-190 at the end of the run. Compression was 13 to 1 and we ran high octane racing gas that was 115 octane and had to pass a specific gravity check in order to be legal. The best I remember on street driven cars if you route the fuel line away from heat, as much as you can, and INSULATE the line in the engine compartment it goes a long way in eliminating vapor lock. Back in the old days hotrodders would wrap tinfoil around the fuel line in the engine compartment and put two or three wooden clothespins clipped on the line as heat sinks, not pretty but the were the sign that you were a rodder:lmao:
 

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FWIW.... it only takes a short section of hot fuel to boil in a line and cause vapor lock, for a mechanical pump setup. It'll be hard to find that few inches of overly hot fuel at the flow rate of any pump into an open container. All you'll measure is the the average temp of the fuel in several feet of line... probably not useful info.

Now if you have a mechanical pump, and it has sputters or trouble pumping fuel into an open container, then you can pretty much count on fuel boiling in the line before the pump. The same may apply for an electric pump.. look for sputtering and air out of the line.

My 1st exposure to vapor lock was in 1967, in my dad's new '67 Dodge Monaco wagon. We stopped on a 100F day at a small rural gas station and a few minutes later, no start. The issue was in the fuel line running close to the exhaust just behind the engine.
question
I ran all new copper line for fuel lines from tank to mechanical pump and to 3 port filter then to carb. I also wrapped the copper line at the front around the valve cover area with id rubber fuel line that was a perfect fit for od of my copper line
Does this set up help at all to avoid this boiling and vapor lock?
Or can this happen well before it gets to pump?
 

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question
I ran all new copper line for fuel lines from tank to mechanical pump and to 3 port filter then to carb. I also wrapped the copper line at the front around the valve cover area with id rubber fuel line that was a perfect fit for od of my copper line
Does this set up help at all to avoid this boiling and vapor lock?
Or can this happen well before it gets to pump?
My understanding is you want to avoid using rubber around the engine as much as possible as it hold the heat. Metal lines are much better at disapating heat.
 

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Opeler
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Question
I ran all new copper line for fuel lines from tank to mechanical pump and to 3 port filter then to carb.
I also wrapped the copper line at the front around the valve cover area with id rubber fuel line that was a perfect fit for OD of my copper line
Does this set up help at all to avoid this boiling and vapor lock? Or can this happen well before it gets to pump?
Hope that you used automotive rated Copper/Nickel Alloy Tubing. Also known as Cupronickel, Cupro Nickel, Nicopp, Cunifer and Nickel-Copper.

DO NOT USE soft copper refrigeration coil from Home Depot for automotive? Refrigeration copper coil will eventually work harden and stress crack.

A wise (older than myself) Opel Owner suggested covering metal fuel line with black, split wire loom material.
Unknown, it it reduces vapor lock, but it looks slightly better than formed metal (steel) line that I replaced decades ago.

Now , Google / Amazon is showing Heatshield Products (or DEI) 3/8" ID, 1/2" ID etc. Hot Rod Sleeve Roll that is supposed to reduce vapor lock. It may or may not reduce vapor lock?

https://www.amazon.com/gp/product/B00FS6CIA6?pf_rd_p=ab873d20-a0ca-439b-ac45-cd78f07a84d8&pf_rd_r=YQVS010AQTR0G8FDQNXT
 
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