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I 3D printed some bell mouth intakes for my HS4 and K&N filters.
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I 3D printed some bell mouth intakes for my HS4 and K&N filters.
#1
 This topic is about my 1966 MG MGB GT |
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Topic Creator (OP)
Apr 21, 2024 02:14 PM
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 Joined 8 weeks ago
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The sharp angle inlet to the HS4 carbs on my MGB was totally outrageous to me so I had to design something more aerodynamic. I made them so that they are held in by both the posts and the filter when it's clamped in. I think it'll be enough that the filter clamps them on so I'll let the posts pass through on the final version to make installation easier.
My only way to test is to do a 4th gear pull from 50 km/h up a hill. Before the bell mouth I got a bit over 70 km/h at the top. With the bell mouth I got a bit over 80 km/t. Clearly the improved aerodynamic is going to help but that sounds like too much of an improvement. It was on two dirfferent days as I forgot to incorporate that hill into my drive before I got to working on the car today. The large difference means I have to redo the test.
Don't mind my janky choke cable setup. My previous owner did a lot of strange things to the car that I've been rectifying. I'm replacing both choke and throttle cables soon.
Edited 4 time(s). Last edit at 2024-04-21 02:52 PM by Lynxman.
My only way to test is to do a 4th gear pull from 50 km/h up a hill. Before the bell mouth I got a bit over 70 km/h at the top. With the bell mouth I got a bit over 80 km/t. Clearly the improved aerodynamic is going to help but that sounds like too much of an improvement. It was on two dirfferent days as I forgot to incorporate that hill into my drive before I got to working on the car today. The large difference means I have to redo the test.
Don't mind my janky choke cable setup. My previous owner did a lot of strange things to the car that I've been rectifying. I'm replacing both choke and throttle cables soon.
Edited 4 time(s). Last edit at 2024-04-21 02:52 PM by Lynxman.
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Apr 21, 2024 11:55 PM
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Apr 22, 2024 06:54 AM
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In reply to # 4787839 by Lynxman
Won't the carbs add more fuel automatically? After all it's not making the air denser, just flowing more.
Not necessarily, a chassis dyno with AFR hook up at the tailpipe will tell the story, set up for about 12-12.5 at WOT in 4th gear
Hap Waldrop
Acme Speed Shop
864-370-3000
Website: www.acmespeedshop.com
hapwaldrop@acmespeedshop.com
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Apr 22, 2024 06:05 PM
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In reply to # 4788085 by Sean Brown
You can use new spark plugs and do a clean cut at the top of the hill, pull over and check the plugs, it'll tell you a lot if you know what to look for.
Those look very good. We have modified those style of K&N backing plates before to increase flow into the carb mouth and it is very helpful. As stock, they are very bad, so I think you did a good job.
I don't know if your test results are totally accurate, but I will say that the improvement does not seem unlikely to me.
Those look very good. We have modified those style of K&N backing plates before to increase flow into the carb mouth and it is very helpful. As stock, they are very bad, so I think you did a good job.
I don't know if your test results are totally accurate, but I will say that the improvement does not seem unlikely to me.
One of these can come in handy if one does not have a bunch of clean plugs.
https://www.amazon.com/Sunex-3912-Spark-Plug-Cleaner/dp/B002RVRKJO/ref=asc_df_B002RVRKJO/?tag=hyprod-20&linkCode=df0&hvadid=312158556601&hvpos=&hvnetw=g&hvrand=6749536702995877290&hvpone=&hvptwo=&hvqmt=&hvdev=c&hvdvcmdl=&hvlocint=&hvlocphy=9010658&hvtargid=pla-491000178933&psc=1&mcid=ff759e8f12273d19a32a39d067cf93b1&gclid=Cj0KCQjwlZixBhCoARIsAIC745CIk45ZrVe7J5XbvwCK-gX327lwsoJyCGpTdYFulCQPioTBIHXzpyUaAoUaEALw_wcB
Hap Waldrop
Acme Speed Shop
864-370-3000
Website: www.acmespeedshop.com
hapwaldrop@acmespeedshop.com
Member Services:
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Topic Creator (OP)
Apr 23, 2024 03:06 AM
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Joined 8 weeks ago
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It runs great. I'm gonna just leave it and inspect the plugs after a while. 
Nice work! I'll have to give that a try.
I machined a proof of concept for my car. It definitely changed the torque curve by the seat of the pants feel.
TD19746 British Racing Green
I machined a proof of concept for my car. It definitely changed the torque curve by the seat of the pants feel.
TD19746 British Racing Green
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Apr 28, 2024 03:41 PM
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I use one similar to this on my 67’s HS6 carb. Aftermarket air filter clamps to the O.D.
Pogo is right.
—————————————————————-
The power of reasons is an illusion. The belief will not change when the reasons are defeated. The causality is reversed. People believe the reasons because they believe in the conclusion.
Pogo is right.
—————————————————————-
The power of reasons is an illusion. The belief will not change when the reasons are defeated. The causality is reversed. People believe the reasons because they believe in the conclusion.
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Apr 29, 2024 05:48 PM
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