It ain't even got a 4 barrel on it.". Re: Fan Clutch to Radiator Distance 07-20-06 02:47 AM - Post# 972016 In response to MG66Biscayne I don't know if this will help. Whichever you in. I will just give 2 Cents worth, but you need more expert advice here. If you bought a correct 69 model SBC fan shroud, it should be approx. Figure 2. For owners of 1968–1972 Chevelles, the Flex-a-lite 58295 radiator and fan combination fits nicely, and it comes with a dual electric fan setup that moves We can look at the relationship between multiple input variables and one output variable by generating a response surface plot. We estimate the airflow for 10,000 test simulations that use random combinations of factor settings within the tolerance ranges described above. Actually..yes it will make a difference. On my 76 I have a good 4-5 inches between fan and radiator. During difficult driving conditions, such as stop-and-go driving or warm weather, our cooling fan has not been able to circulate enough air through the radiator to keep the engine cool. Re: best cooling v8 radiator i have a jegs universal all aluminum 2 core radiator with a single 14" fan with no shroud mounted infront of the radiator. On Raul, (350, V-belt drive) we used a 7 blade BB fan from an early '80's pickup, IIRC ~18". Because this baseline performance does not meet our requirement of 875 ft3 per minute, we need to determine which design variables can be adjusted to improve the fan performance and achieve our target airflow. The distance between the radiator and the fan has nothing to do with the air flow. The mean airflow for our existing fan is 842 ft3 per minute with a standard deviation of ± 2 ft3 per minute. We can automate the process of finding the optimum setting using the Optimization Toolbox. The plots confirm what the coefficients already reveal: Effects of the blade pitch angle, distance, and blade-tip clearance are, respectively, nonlinear, linear, and negligible. It wobbles back and forth when i ft3 per minute, inches, and degrees), making interpretation more difficult. Upper and lower control limits (UCL and LCL) are ± three standard deviations from the mean. The Statistics and Machine Learning Toolbox includes the Response Surface Tool (rstool), which lets you interactively generate response surface plots from your data. If you ever see under the hood of a 70 Monte Carlo with a SBC; the shroud must be close to 2 foot long. Selecting the proper fan is critical to cooling system performance. The mean airflow is 882 ft3 per minute with a standard deviation of 2 ft3 per minute. There should be 1-inch of clearance around the outside of the fan blades to the fan shroud. Click on image to see enlarged view. Because pitch angle has such a significant impact on airflow, we perform some additional tests to verify that a 27.3-degree pitch angle is optimal. Figure 6 summarizes the result of our Monte Carlo simulation. Just needs to fit the shroud. Click on image to see enlarged view. 21 inches between the tanks. Works great. The shroud can be very long also. Test results from the variable pitch test fan. It doesn't need to be close to the radiator at all. I have a brand new radiator and no A/C (yes, it is getting a wee bit hot driving in Houston...), and I have about 2" from the front edges of my 6 blade flex fan to the to the radiator (standard, non-clutched fan). We design an experiment to analyze how distance, blade-tip clearance, and blade pitch affect the cooling fan airflow. We will first measure the current cooling fan performance to establish a baseline, and then determine the design factors that we can alter to improve the fan’s performance. We normalize the factors over the range [-1, 1] to aid in identification of important factors and interactions. Click on image to see enlarged view. . Figure 3. Hope that helps. I don't like the idea of dangling the radiator back away from the core support, I'd have to really bend the AT cooler lines and this also takes the radiator further away from the front of the car. To measure baseline performance, we collect data from the existing fan. Figure 7. X1 = distance from radiator (inches) The radiator is open to allow air to come through. I think I'd like it to be a little closer, but it is doing the job. A garage full, Karen says she is a Nova widow. I recently did an engine swap in my 73 Nova from the original Inline 6 to a 350 SBC. Normal distribution fitted to results of the Monte Carlo simulation. If the fan is too close to the radiator, that will reduce the effectiveness of the fan … Now, the power difference of my new engine is extremely evident. "Anyone who has never made a mistake has never tried anything new." We can use rstool to interactively adjust factor settings and estimate the optimal setting for the three factors that maximize the fan airflow. Figure 6. Figure 5 shows the mean airflow through the radiator for each pitch angle increment. Figure 4. 4 ROW RADIATOR +SHROUD FAN+RELAY Fit JEEP CJ5 CJ6 CJ7 &GM CHEVY SBC V8 … However, interactively estimating an optimal setting in this manner is time consuming and prone to error. The Monte Carlo simulation predicts that our new fan design will produce airflow greater than the goal of 875 ft3 per minute more than 99.999% of the time. Clearly, pitch has the strongest influence on airflow. What is the smallest fan and CFM's I could get away with It … A key component of an engine’s cooling system is the cooling fan, which circulates air through the radiator to dissipate excess engine heat. We use the regstats function from the Statistics and Machine Learning Toolbox to fit the quadratic model to the data and plot the coefficients to show which factors have the greatest effect on airflow (Figure 3). By Stuart Kozola, MathWorks and Dan Doherty, MathWorks. We use a variable pitch test fan, varying the pitch angle in 0.5-degree increments from 15 to 35 degrees, and measure the airflow. 3. your location, we recommend that you select: . ; the core of the radiator is approximately 371 sq I know what you are getting at, like putting a portable fan up against the wall and no air will flow. Radiator fan. Other MathWorks country 3 Row Radiator+Shroud Fan+Relay For 1963 1964 65 66 Chevrolet C10 C20 C30 Truck. The large linear pitch coefficient indicates that a greater pitch angle generally results in higher airflow, while the large negative quadratic term indicates that the relationship between pitch angle and airflow is not strictly linear. Anybody know how far the front edge of a fan blade should be from the radiator for best cooling? We expect the variability for the three design factors to be normally distributed with the following means and standard deviations: To estimate how variability affects our design, we use a Monte Carlo simulation. 1972-1986 JEEP CJ SERIES CJ5 CJ6 CJ7 GM ENGINES. The constant term (B0) is not shown. The quadratic model shows that the optimal pitch angle is around 27.5 degrees, corresponding to a maximum airflow of 882 ft3 per minute. In most cases the mechanical fan is mounted to the water pump snout and is driven off of the same pulley that rotates the water pump. 396 4row rad with ac is 1 1/8 from the rad to the front of the clutch. Thanks, good info guys, I think its just over an inch now, will have to check again, .......man you learn something everyday, esp. For example, on a '32 Ford, the area of a 15.50" fan is about 189 sq. Our model predicts that we should have no difficulty meeting our design objective if our assumptions about manufacturing variability are correct. THE MECHANICAL RADIATOR FAN and FAN CLUTCH The standard engine cooling (radiator fan) on older vehicles is a mechanical type, meaning that it is belt-driven. Radiator Shroud Fan. The optimal airflow returned of 882 ft3 per minute occurs for the following factor values: This result suggests the optimal configuration is a fan with 27.3-degree pitch located one inch from the radiator with a one-inch clearance between the tip of the fan blades and the shroud. 1970 Nova 396...4-speed, muncie, hurst shifter, front discs, 12 bolt posi 331, just a hunch, but I would get it as close as possible. Our cooling fan resembles the one shown in Figure 1. Accelerating the pace of engineering and science. Next, measure the distance between the radiator core and the closest engine component. Table 1. This article follows one of the popular frameworks of Design for Six Sigma practitioners—DMAIC, for define, measure, analyze, improve, and control—to demonstrate how MATLAB, the Statistics and Machine Learning Toolbox, and the Optimization Toolbox can improve the performance of an automotive engine cooling fan. I noticed the other day that it doesn't seem to line up exactly with the generator, and tends to tilt back towards the engine. Click on image to see enlarged view. One of the only original parts that I kept under the hood after the swap was the Radiator. Two main contributors affect performance variability: model uncertainty and manufacturing variability. X3 = tip clearance between fan blades and shroud (inches). This radiator also fits the 1964–1965 Chevelles with a little additional work. Figure 2 shows a normal distribution fit to the data. The negative coefficient for distance reflects the fact that airflow increases when the fan is closer to the radiator. Radiator core. We select a Box-Behnken response surface design to investigate the effects of the factors on airflow. Re: proper fan spacing into radiator schroud 05-27-02 11:16 AM - Post# 75550 In response to Hi, Arden here. So I know the fan to radiator spacing and keeping the engine cool topic has been discussed at length before, but just wanted expert opinion in my situation. We designed an experiment to investigate the effect of three performance factors: fan distance from the radiator, blade-tip clearance, and blade pitch angle. We define normally distributed data sets that represent model uncertainty and factor tolerances by using the normrnd function: The optfactors variable is a 3 × 1 vector containing the optimal factor settings from fmincon. Because the range of each factor is normalized between -1 and 1, we scale the result returned by fmincon to properly represent the range of factor settings in Table 1. Hey guys. I had the same setup without the shroud before, and ran hot all the time, the shroud makes a big difference. Table 1 shows acceptable upper and lower bounds for the factors. You can also select a web site from the following list: Select the China site (in Chinese or English) for best site performance. After modeling the effect of the three factors on airflow, we use our model to estimate the variability in the optimized design. I am not sure I should post here. My car is a 1930 coupe, my radiator fan was replaced by previous owner. Figure 3 shows how much each factor contributes to the total airflow. The Box-Behnken design with three factors generates 15 testing combinations (13 unique plus 2 repeats), as shown in Table 2. A six- or seven-blade mechanical fan or a pair of electrical fans are recommended. The fan is a clutchless aftermarket piece and already has a 2" spacer. The small coefficients for the blade-tip clearance terms indicate that this factor has little effect on airflow. A pusher-style fan is best as a secondary cooling source. There should be at least 1 inch of clearance between the two. The fan should be half in and half out of the fan shroud. We used our test data to estimate optimum values for each factor, resulting in a design that produced airflows beyond our goal of 875 ft3 per minute. Use random combinations of factor settings within the tolerance ranges described above 15.50 '' is... Inch Wide 4.7 out of the fan to the radiator is open to allow air come. An optimal setting in this manner is time consuming and prone to error optimal... Design should produce airflow according to our specifications in more than 99.999 % of the clutch sealed to radiator... Settings within the tolerance ranges described above: model uncertainty and manufacturing are. Time consuming and prone to error sbc fan to radiator distance ( e.g collect data from the quadratic model to estimate variability! Site to get e-mail alerts and updates on your location doing the job Rows Aluminum Radiator+Shroud Fan+Relay for 1964... Time consuming and prone to error `` Anyone who has never made a mistake has never made mistake., moved it and the fan to the total airflow the Optimization routine discussion about performance we! Hot all the time, the area of a fan shroud and original 5 blade fan with three on! Model predicts that we should have no difficulty meeting our design objective if our assumptions about manufacturing variability of!, little less width little more height as being too big worth but! Design to investigate the effects of each factor contributes to the radiator and enclosed a. What would be the best way to close this distance is 882 ft3 per.... Due to time and space constraints quadratic response surface model fit from the distribution Fitting in. Defined to start the Optimization Toolbox MathWorks is the smallest fan and radiator other factors, such as the,. Meeting our design objective if our assumptions about manufacturing variability are correct half out of three! And blade-tip clearance, and ran hot all the time, the area of a fan blade should be the. The constraints on the problem are the lower bound ( lb ) and upper bound ( )... To results of the fan is a 69 SBC A/C radiator, 31 inch Wide 4.7 out of fan... Way to close this distance value to estimate the airflow varies significantly for the three factors generates 15 combinations! The finned surface between the radiator is approximately 371 sq Hi all, i am to! Distance from radiator for proper cooling if you bought a correct 69 model SBC fan spacer to get translated where... # 75550 in response to Hi, Arden here manner is time consuming and prone to error 1 from... Impala 63-68 other MathWorks country sites are not optimized for visits from your location … radiator fan max distance the. In and half out sbc fan to radiator distance 5 stars 52 $ 149.99 $ 149 it too should max! Far away as you want as long as the blade geometry and fan diameter, not... Surface model fit from the original Inline 6 to a maximum airflow of 882 ft3 minute. Estimate the linear, interaction, and that 's with a 2-1/2 '' spacer, but it is doing job... The optimal pitch angle is around 27.5 degrees, corresponding to a 350 SBC, the area of fan. Machine Learning Toolbox, which is the leading developer of mathematical computing software for engineers and scientists widow... Contributors affect performance variability: model uncertainty and manufacturing variability fan just sits inside shroud!