Trouble is each engine is different, and these vids can help get in the ballpark, but to maximize YOUR COMBO, you'd have to test it, and without back to back drag strip runs or a chassis Dyno you can easily cost yourself power. What I'm saying is you can't get their results and have it be optimized unless you do the same tuning/testing. Go out and buy a carb spacer thinking it's going to add 10 hp, and in your combo it could cost you 14 hp until you optimize your engines air fuel ratio, timing, etc. And keep in mind these are wot tests with very low coolant temps that are precisely controlled. In your car at operating temp with full exhaust, stock stall converter etc it will most likely behave very different due to the way the engine is loaded on the Dyno vs your car/truck. So don't rush out and buy a four hole spacer thinking you'll gain power and acceleration. The difference between a good engine and a GREAT ENGINE.. is this kind of testing, gathering data, and optimizing the car.
@@b.c4066 so good to see someone say exactly what i say! Lol! Ive been at the track and heard the argument that “this spacer added 20hp for my 440, it’ll add 20hp toy your 5.0” I’m like “ummm, that’s necessarily true…”. And the fight is on!
@@heathermiller2917 spent years reading forums, where guys are asking what timing, what jetting. Blah blah blah, put in the work, pay for Dyno time, gather data, learn to read plugs and they'd realize how absurd it is to ask for info like that, even if building a damn near identical engine, sure you can offer a ballpark suggestion, but ultimately THEIR combo will want what it wants. It amazes me that kind of mentality is still alive in this day and age.
I'm not even a dodge guy but I do too! Gives some options for guys who want to do something other than an LS in a classic Mopar without spending lots of money
I’m eating up these magnum videos. Building a drag week truck and planning to stick with the magnum that came with it. Not a ton of stuff out there so loving all the attention you’re currently giving it 😁👍🏻
This whole series is great. I keep going back to the tuning myths we had 45-50 years ago, and now it makes much more sense why some things worked and many didn't. Keep up the good work. PS: If we only would have had the heads back then that are available now........
Thanks Richard for the Mopar videos, 5.9 magnum, and 440. All the Mopar folks are very happy I'm sure! We gotta get you a 440 to Big Bang! LETS MAKE SOME NOISE!
Man you are the best with this video i ran an open spacer on my 302. I will take your advice because down low is where i want my power. Thank you for doing this test
From personal experience, I went from an RPM intake to a Victor Jr on a 400 HP 383. 9.8:1 compression, 236/242 hyd roller, Victor heads. The loss of low end torque was noticeable. On a suggestion, I tried a 1 inch 4 hole spacer to get some low end torque back. It did help, but should have left the RPM intake for what I was doing. The four hole spacer helped with carb signal.
I'm not surprised about the jump in power from where you had the timing set, and shifting it to where I said. I didn't even have to get out of my chair.
Interesting but one big data point missing. Results w/No spacer! I heard the part that the carb wouldn't fit without one, but it would have really interesting to see if it would have fell between the two in terms of power or who knows, maybe it would of had the best power of all.
Dude, thank you so much. I have been fighting this weird richness problem, and knowing that my ride, while modest, still highly rodded, should pull more than it does. All the temp, vac, and load readings line up with this (haven't installed the AFR yet, still just need to take a day to do that) sure enough, I have a performer rpm intake - thus dual plane, and a giant open phenolic spacer between it and the carb. I will swap that **it in the parking lot of the parts store and give an earball tuning to the thing on the spot. thanks again man.
Which is totally fine - the phenolic thingy can go on the torker I just picked up for my 425. I already had one for it, but expanding the plenum with a second on a single plane? how terrible...works for me! Stacking! Obviously a different nightma...project
Recently I have built my sbc [40 over 4 bolt 350 with custom grind 488/488 roller conv cam,906 heads and a holley 750dp sitting on edelbrock air gap] and I had installed a 1 inch open spacer. I soon realized there was a noticeable negative power difference and after watching this I have a 1" 4 hole spacer and 1/4" phenolic spacer on the way. I hope to see improvements...
Thank You, Richard for the Magnum Series!. Too bad the M1 dual-plane intake had such a limited production run. They were around $300 each back in 2006. The water heated intake makes for good driving in cold weather- some vehicles are more fun when the snow starts flying. When these M1 dual -planes sells used for 2X what they cost new here is definitely interest. A Edelbrock Performer or Performer RPM for Magnum would be easy-borrow from the Magnum AirGap the intake to head section to bolt to the Magnum heads. The 5.9 Magnum had a production run of almost 20 years, millions made, going to scrap. All for the want of a bolt-on Performer, Action Plus, or Contender intake. Glad to see the Magnum get some attention. Go make some Magnum noise!!
@@blueduster74 Another year later.... No Change on the manifolds. Ma Mopar's last two owner groups come from non-hot rodding cultures. Ramcharger's are always fun.
The torque curve on these engines makes you run them at part throttle to keep the revs down in the power range. I noticed it dropped 100 ft lbs above 4K rpms.
Just a couple days ago I posted a vid about putting a four hole phenolic spacer on my friends 76 D100 318 with the stock cam advanced 4 degrees, an Edelbrock SP2P low RPM torque intake for heavy vehicles and a Qjet. The four hole spacer severely outperformed the open 1/4 inch gasket we had before hand. Without the four hole it would only leave about a foot of rubber and slowly accelerate away but with the 4 hole installed it leaves several feet of rubber and accelerates much more aggressively.
@@jrdmotorsports9718 They also split the carb in half only letting each individual cylinder see half the CFM it would see.This can be good or bad depending on the specific application. I tried a 4 hole spacer on my solid lift 235 HP 273 thinking I'd gain some much needed torque to get through the low RPM bog of my 2.76 gears and it did help a little bit down low, but it hurt so bad up top that I swapped back to open after one drive. Funny how some engines completely defy your expectations.
@@Impactjunky It's ALL application specific. They are tuning aids. The magic isn't from the spacer, but what the spacer is doing for the combination, and how it is affecting the manifold. Put a 1" open on the manifold, and put the 1" 4 hole on top of it. Watch what happens.
@@jrdmotorsports9718 I've heard a 4 hole on top of an open spacer makes really good power, seems like we may have been reading the same article or at least a similar one. I wish I still had that little 273 around to experiment with but I tossed it out for a cammed, carb swapped 6000 RPM 5.9 Magnum years ago. Getting ready to see if the Magnum likes a 4 hole tapered spacer as a compromise for a 4 hole on top of an open because my velocity stack/air cleaner combo doesn't offer me any extra hood clearance.
@@Impactjunky It's not from any article bud, 35 years in the business, and have tested my fair share... on the dyno, and on the track. Back when HVHs weren't even around I used to make my own spacers, and combined different styles. I know what they do and why. In your application, feeling it lose top end says it needs plenum volume, hence why the open works. Putting a 4 hole on that will help bottom end without sacrificing top end. The reason why you lost top end with just a 4 hole, is due to the plenum volume being too small. All they do is help tune a manifold.
Every engine is different. I put a 1 inch open spacer on a basically stock 383 roadrunner engine with a Holley vacuum secondary 780 carburetor and gave a tremendous seat of the pants boost!
I use a spacer under my sniper 2 reasons. 1 to help keep sniper throttle body cooler, 2 to increase plenum length, with the holley sniper it needs to be 4 hole it whistles with open spacer
I love that the old Dodge engines are getting some attention, thanks Richard! Have you ever done an intake test of Vintage intakes? Like the old Eddy Tarantula manifolds?
Just out of curiousity, it would have been nice to see what the AF ratio was with carb to intake before the 4hole and open hole spacer was added.... either way, i see there will be a slight leaner mixture because of the simulated added intake plenum that the spacer provides, allowing more air without a change in fuel delivery.
Thanks for this video. I don't have a dyno,so i use throttle resonse by ear and feel. I was going to buy a super sucker 4 hole off ebay,but im just going to stay with my 4 hole Mr. Gasket Aluminum outside plastic 4 hole insert. I'd love to see a 4hole stacked on top of the open just for giggles.
Why did you not Retune the Carb for the Open Spacer to match the FA Ratio Power would have been closer if you did? its good to know that will happen but we need to see the Open Spacer Power after retune of the carb for it, if it makes it act like a single plane up top it would be beneficial to the power band of the Duel plane for those who want the best of both worlds!
It should have made the most power with the leaner A/F ratio. But it was leaner because it had a weaker signal. Richening it up with the open spacer would have made even less power.
@@1967davethewave not necessarily, I seen too lean low rpm get rich and make 35 lbft of torque 2700 - 3700, this happened when using a spread bore carb and adding an air cleaner with a short spacer between base and top of carb
@@erikturner5073 shallow spacer has benefits , can help idle circuit with some carburetors, there can also be benefits of a spacer between carb and filter base ,
4 hole beats an open design, WITH THAT PARTICULAR carb and intake. I would like to see the results when using an AFB or AVS in the 750cfm range. My 30 over 9.0 to 1 360 with a MP 450/455 cam and now Edelbrock spread bore dual plane instead of an M1, consistently made 8 hp and 14 lb ft more with an open spacer, than just sitting on the manifold. It made an average of 6 more hp with the 4 hole but only 5 lb ft, (that had to be mildly machined to accept the secondaries), over just the carb on manifold. Timing was using an MSD set at 34* at 2800, no vac adv. I will say this. The AFB did need some jetting and rod tuning because out of the box, it was lean down low, but way rich WOT. The AVS was better at low and mid range, but still rich WOT. Anyways enjoy your vids!!
Really good info here! I’m wondering if there’s a fuel distribution issue with that M1 manifold. Individual EGTs or 8 O2 sensors might show the engine likes an overall rich mixture because of a few lean cylinders. Just a guess… Bottom line is dual plane manifolds work best for every day street use. Don’t mess it up with an open spacer unless you’ve got a whole different usage in mind. Thanks again Richard!
What this test shows me, which I suspected from the start, is that if you change your intake manifold, spacers or otherwise adjust the signal to your carburetor, you have to tune your carburetor. After the swap to open spacer, tune your carb to work properly with that setup and run the test again. Then I'll say you changed the carb settings and that caused the difference, lol.
BTW I'm about to flash up a fresh rebuilt 383 and tuned my edelbrock a little rich on the single plane intake, so your video is making me think that was a good choice in calibration of the jets and rods.
Open spacer? Carb to open spacer then open spacer to 4 hole (4 hole to open then back to 4 hole). Turbulence possibly? I always thought that the open spacers worked best with single plane intakes but I could be wrong. Note the torque curve: Max torque is exactly where you need it in a pick-em-up or heavy van that might be pulling a load. Possible that the MoPar engineers designed it that way for a reason? I had a 98 Ram 1500, 5.2, 5 speed, 3.23 gears and it would pull an all steel car hauler with a Duster on it just fine in 4th gear. Cruise at 65 all day with cruise set.
This question is a bit off but .... ZL1 Lid spacer for a Eaton 1.9, I have the convertible so fitting would be close does this increase volume enough to make a difference? Then there are spray connections....hmmmm
What I am seeing is the open spacer did made the motor more efficient in that it lost a small amount of power and torq but ran on quite a bit less fuel. If you had put in bigger jets wouldn't it most likely brought the torq/hp figures up?
@@richardholdener1727 Am I miss reading the graph - with spacer , roughly it was down .03 in torque and hp but was using .9 less fuel. I guess I don't understand how that relates to signal, bigger jets would not have helped that lean condition while increasing P&T?
No, 4-hole or directly on the intake. Radical cams with lots of overlap love the extra carb signal, especially if you have a carb with annular boosters, they can be worth close to 100 ft/lbs down low.
You seem to be the expert on Induction. Please tell me if you can use a Carburetor setup with Fuel injection? Will the fuel injection take away lean spots in a carb system? Working via the Co2 sensors????
Something I don't think you have: a comparison in powerband between big cam/stock heads, mild/mild, stock cam/big heads, all making around the same power. Is the powerband better at the same power level with the big heads/stock(ish) cam?
Richard , I had the opposite results from a sbc 350. The 4 hole on my stock silverado gen 1 motor and a boat anchor cast iron intake. And it lost a BUNCH of everystuff...then the open one I really couldn't tell the difference in that and no spacer.
great and informative content as always 🤘 However, please try to work on focus fluctuation when you film the computer screen, gets dizzy after watching the graphs closely :) thanks in advance ;)
I really would like to know what applications the headers were designed for. Reason being is that it would have been much easier to build the header shown if the destinations on the collector had been swapped for the front and rear positions on the mounting flange.
Excellent video, short, sweet, and to the point. My experience, back in the day, was that 4-hole spacers were best for street applications and could actually improve low RPM throttle response. Open spacers were good for high RPM race applications.
I'd love to have that engine for my 1977 dodge w200. Richard what about the height of the spacers. Then what if you put the open space then put the 4 hole then try the 4 hole then open??????????????
Great video and info, it a four hole spacer for me. If you can, I have a question, I’m thinking to put 2v closed chamber heads on a standard 351 Cleveland to increase compression, no other changes, am I going to run into tuning issues or maybe other issues you may know of.
I have always run 32-35 total in all my LA's Why the pulsing on the videos of the grafs ? I will be starting a 416 build in a few months as the kit has arrived .
What about fuel atomization, What about a tapered 4 hole spacer upsidedown. I see on UA-cam some power gain along with the restriction and maybe some fuel atomization. It combined low end and top.
Thank you for this! I usually use phenolic or resin spacers and fuel return system on carbs to try and keep the carb and fuel temps low. We all know that carbs hate modern fuel and the cooler we can keep them the better the engine will start.
Interesting.. what if you put bigger jets on the open spacer? Maybe more power on the top end? Now I’m wandering if freiberger was using a rich carb for his test and that’s why he showed more power with his test… using a open spacer and milling his intake.
Whats up Ricky, i know this is old but thought id rewatch these on the Dodge Magnums because im going to add some HP to one in my retired work Truck, i plan to port match and some bowl work, blend the valve guides because im too cheap to buy decent heads. I appreciate the data you provide. Hey ive adked before but forgot what you said, do you tune? Hahaha
What about spacer plate on supercharger engine like thermal spachers is it worth? Need to be tested want be very nice With and without spachers to watch ita temperatures if its working or not
These are the videos I like! Head to head comparisons on dirt cheap parts, something anyone could change in a couple minutes.
Trouble is each engine is different, and these vids can help get in the ballpark, but to maximize YOUR COMBO, you'd have to test it, and without back to back drag strip runs or a chassis Dyno you can easily cost yourself power. What I'm saying is you can't get their results and have it be optimized unless you do the same tuning/testing. Go out and buy a carb spacer thinking it's going to add 10 hp, and in your combo it could cost you 14 hp until you optimize your engines air fuel ratio, timing, etc. And keep in mind these are wot tests with very low coolant temps that are precisely controlled. In your car at operating temp with full exhaust, stock stall converter etc it will most likely behave very different due to the way the engine is loaded on the Dyno vs your car/truck. So don't rush out and buy a four hole spacer thinking you'll gain power and acceleration. The difference between a good engine and a GREAT ENGINE.. is this kind of testing, gathering data, and optimizing the car.
@@b.c4066 so good to see someone say exactly what i say! Lol! Ive been at the track and heard the argument that “this spacer added 20hp for my 440, it’ll add 20hp toy your 5.0”
I’m like “ummm, that’s necessarily true…”. And the fight is on!
@@heathermiller2917 spent years reading forums, where guys are asking what timing, what jetting. Blah blah blah, put in the work, pay for Dyno time, gather data, learn to read plugs and they'd realize how absurd it is to ask for info like that, even if building a damn near identical engine, sure you can offer a ballpark suggestion, but ultimately THEIR combo will want what it wants. It amazes me that kind of mentality is still alive in this day and age.
These videos are so helpful because not everyone is rich
I love that the magnum is getting some love, and wow, the afr is crazy interesting!
I'm not even a dodge guy but I do too! Gives some options for guys who want to do something other than an LS in a classic Mopar without spending lots of money
Yeah I have a Durango and been looking into building a new 5.9 magn
I’m eating up these magnum videos. Building a drag week truck and planning to stick with the magnum that came with it. Not a ton of stuff out there so loving all the attention you’re currently giving it 😁👍🏻
This whole series is great. I keep going back to the tuning myths we had 45-50 years ago, and now it makes much more sense why some things worked and many didn't. Keep up the good work.
PS: If we only would have had the heads back then that are available now........
Keep doing this stuff you are saving a lot of time and money for people trying to pick a combo.
Thanks Richard for the Mopar videos, 5.9 magnum, and 440. All the Mopar folks are very happy I'm sure! We gotta get you a 440 to Big Bang! LETS MAKE SOME NOISE!
Man you are the best with this video i ran an open spacer on my 302. I will take your advice because down low is where i want my power. Thank you for doing this test
From personal experience, I went from an RPM intake to a Victor Jr on a 400 HP 383. 9.8:1 compression, 236/242 hyd roller, Victor heads. The loss of low end torque was noticeable. On a suggestion, I tried a 1 inch 4 hole spacer to get some low end torque back. It did help, but should have left the RPM intake for what I was doing. The four hole spacer helped with carb signal.
I'm not surprised about the jump in power from where you had the timing set, and shifting it to where I said. I didn't even have to get out of my chair.
Love the Mopar content!
Interesting but one big data point missing. Results w/No spacer! I heard the part that the carb wouldn't fit without one, but it would have really interesting to see if it would have fell between the two in terms of power or who knows, maybe it would of had the best power of all.
Great comparison. Thanks for sharing this vital information! Cheers!
The best engine videos on UA-cam period!! Loving the mopar content!
Yes! This is what I have always wanted good data on!
It would be interesting to see if re-jetting the carb (with the open spacer) would regain some of that lost power.
My thought exactly.
Neat comparison on JUST a one inch carb spacer. Significant difference.
Thanks to your video I chose the 4 hole over the open spacer!
Dude, thank you so much. I have been fighting this weird richness problem, and knowing that my ride, while modest, still highly rodded, should pull more than it does. All the temp, vac, and load readings line up with this (haven't installed the AFR yet, still just need to take a day to do that) sure enough, I have a performer rpm intake - thus dual plane, and a giant open phenolic spacer between it and the carb. I will swap that **it in the parking lot of the parts store and give an earball tuning to the thing on the spot. thanks again man.
Which is totally fine - the phenolic thingy can go on the torker I just picked up for my 425. I already had one for it, but expanding the plenum with a second on a single plane? how terrible...works for me! Stacking! Obviously a different nightma...project
Great video I actually figured out some of the problems that I might be having from a carb spacer thanks Richard 👍
Thanks I’m going to order a 4 hole for my 347 with 750dp and air gap. Cool video. Simple and effective.
Good stuff! I have always preferred 4 hole spacers, but never really tested it.
Recently I have built my sbc [40 over 4 bolt 350 with custom grind 488/488 roller conv cam,906 heads and a holley 750dp sitting on edelbrock air gap] and I had installed a 1 inch open spacer. I soon realized there was a noticeable negative power difference and after watching this I have a 1" 4 hole spacer and 1/4" phenolic spacer on the way. I hope to see improvements...
Thank You, Richard for the Magnum Series!.
Too bad the M1 dual-plane intake had such a limited production run.
They were around $300 each back in 2006.
The water heated intake makes for good driving in cold weather- some vehicles are more fun when the snow starts flying.
When these M1 dual -planes sells used for 2X what they cost new here is definitely interest.
A Edelbrock Performer or Performer RPM for Magnum would be easy-borrow from the Magnum AirGap the intake to head section to bolt to the Magnum heads.
The 5.9 Magnum had a production run of almost 20 years, millions made, going to scrap.
All for the want of a bolt-on Performer, Action Plus, or Contender intake.
Glad to see the Magnum get some attention.
Go make some Magnum noise!!
Love mine on my Ramcharger. Thing runs so good I’m hesitant to put efi on it.
@@blueduster74 Another year later....
No Change on the manifolds.
Ma Mopar's last two owner groups come from non-hot rodding cultures.
Ramcharger's are always fun.
The torque curve on these engines makes you run them at part throttle to keep the revs down in the power range. I noticed it dropped 100 ft lbs above 4K rpms.
Surprising. Great knowledge and numbers don't lie.. open spacers have been a gimmick for years
Just a couple days ago I posted a vid about putting a four hole phenolic spacer on my friends 76 D100 318 with the stock cam advanced 4 degrees, an Edelbrock SP2P low RPM torque intake for heavy vehicles and a Qjet. The four hole spacer severely outperformed the open 1/4 inch gasket we had before hand. Without the four hole it would only leave about a foot of rubber and slowly accelerate away but with the 4 hole installed it leaves several feet of rubber and accelerates much more aggressively.
That's what they do. More signal at the carb, better it pulls fuel=more torque.
@@jrdmotorsports9718 They also split the carb in half only letting each individual cylinder see half the CFM it would see.This can be good or bad depending on the specific application. I tried a 4 hole spacer on my solid lift 235 HP 273 thinking I'd gain some much needed torque to get through the low RPM bog of my 2.76 gears and it did help a little bit down low, but it hurt so bad up top that I swapped back to open after one drive. Funny how some engines completely defy your expectations.
@@Impactjunky It's ALL application specific. They are tuning aids. The magic isn't from the spacer, but what the spacer is doing for the combination, and how it is affecting the manifold.
Put a 1" open on the manifold, and put the 1" 4 hole on top of it. Watch what happens.
@@jrdmotorsports9718 I've heard a 4 hole on top of an open spacer makes really good power, seems like we may have been reading the same article or at least a similar one. I wish I still had that little 273 around to experiment with but I tossed it out for a cammed, carb swapped 6000 RPM 5.9 Magnum years ago. Getting ready to see if the Magnum likes a 4 hole tapered spacer as a compromise for a 4 hole on top of an open because my velocity stack/air cleaner combo doesn't offer me any extra hood clearance.
@@Impactjunky It's not from any article bud, 35 years in the business, and have tested my fair share... on the dyno, and on the track. Back when HVHs weren't even around I used to make my own spacers, and combined different styles. I know what they do and why.
In your application, feeling it lose top end says it needs plenum volume, hence why the open works. Putting a 4 hole on that will help bottom end without sacrificing top end. The reason why you lost top end with just a 4 hole, is due to the plenum volume being too small. All they do is help tune a manifold.
Every engine is different. I put a 1 inch open spacer on a basically stock 383 roadrunner engine with a Holley vacuum secondary 780 carburetor and gave a tremendous seat of the pants boost!
I use a spacer under my sniper 2 reasons. 1 to help keep sniper throttle body cooler, 2 to increase plenum length, with the holley sniper it needs to be 4 hole it whistles with open spacer
I love that the old Dodge engines are getting some attention, thanks Richard! Have you ever done an intake test of Vintage intakes? Like the old Eddy Tarantula manifolds?
Kool vid. I'd like to see that same test on a single plane manifold.
Thank you for showing the timing deal so that guy could 👀
Just out of curiousity, it would have been nice to see what the AF ratio was with carb to intake before the 4hole and open hole spacer was added.... either way, i see there will be a slight leaner mixture because of the simulated added intake plenum that the spacer provides, allowing more air without a change in fuel delivery.
I bought phenolic resin blanks for making adapters, spacers, and heat barriers for all sorts of stuff. Its cheap to find and make a nice piece.
-Side note. You are such a hype man. Got me "wooooooooooo'ing" for a Dodge Magnum lol
Thanks for this video. I don't have a dyno,so i use throttle resonse by ear and feel. I was going to buy a super sucker 4 hole off ebay,but im just going to stay with my 4 hole Mr. Gasket Aluminum outside plastic 4 hole insert. I'd love to see a 4hole stacked on top of the open just for giggles.
...and what is about this dual Edelbrock spacer which is waiting for installation of my chevy performer manifold 😧
Why did you not Retune the Carb for the Open Spacer to match the FA Ratio Power would have been closer if you did? its good to know that will happen but we need to see the Open Spacer Power after retune of the carb for it, if it makes it act like a single plane up top it would be beneficial to the power band of the Duel plane for those who want the best of both worlds!
It should have made the most power with the leaner A/F ratio. But it was leaner because it had a weaker signal. Richening it up with the open spacer would have made even less power.
@@1967davethewave Exactly right. Fattening up the AFR might pick up a little torque, but you would lose power.
@@1967davethewave
not necessarily, I seen too lean low rpm get rich and make 35 lbft of torque 2700 - 3700,
this happened when using a spread bore carb and adding an air cleaner with a short spacer between base and top of carb
Open space on a dual plane defeats the purpose of a dual plane. You just compromise the purpose of the dual plane in using the open spacer.
@@erikturner5073 shallow spacer has benefits , can help idle circuit with some carburetors,
there can also be benefits of a spacer between carb and filter base ,
i would like to see a tapered spacer test.
4 hole beats an open design, WITH THAT PARTICULAR carb and intake. I would like to see the results when using an AFB or AVS in the 750cfm range. My 30 over 9.0 to 1 360 with a MP 450/455 cam and now Edelbrock spread bore dual plane instead of an M1, consistently made 8 hp and 14 lb ft more with an open spacer, than just sitting on the manifold. It made an average of 6 more hp with the 4 hole but only 5 lb ft, (that had to be mildly machined to accept the secondaries), over just the carb on manifold. Timing was using an MSD set at 34* at 2800, no vac adv. I will say this. The AFB did need some jetting and rod tuning because out of the box, it was lean down low, but way rich WOT. The AVS was better at low and mid range, but still rich WOT. Anyways enjoy your vids!!
Please do more magnum test love it
i feel like running them stacked with the four hole spacer on top of the open spacer would be good
Really good info here! I’m wondering if there’s a fuel distribution issue with that M1 manifold. Individual EGTs or 8 O2 sensors might show the engine likes an overall rich mixture because of a few lean cylinders. Just a guess… Bottom line is dual plane manifolds work best for every day street use. Don’t mess it up with an open spacer unless you’ve got a whole different usage in mind. Thanks again Richard!
What this test shows me, which I suspected from the start, is that if you change your intake manifold, spacers or otherwise adjust the signal to your carburetor, you have to tune your carburetor.
After the swap to open spacer, tune your carb to work properly with that setup and run the test again.
Then I'll say you changed the carb settings and that caused the difference, lol.
BTW I'm about to flash up a fresh rebuilt 383 and tuned my edelbrock a little rich on the single plane intake, so your video is making me think that was a good choice in calibration of the jets and rods.
It would be nice to see you repeat the test, with an open plenum manifold.
but how did the engine do without the spacer?
Open spacer? Carb to open spacer then open spacer to 4 hole (4 hole to open then back to 4 hole). Turbulence possibly? I always thought that the open spacers worked best with single plane intakes but I could be wrong. Note the torque curve: Max torque is exactly where you need it in a pick-em-up or heavy van that might be pulling a load. Possible that the MoPar engineers designed it that way for a reason? I had a 98 Ram 1500, 5.2, 5 speed, 3.23 gears and it would pull an all steel car hauler with a Duster on it just fine in 4th gear. Cruise at 65 all day with cruise set.
Richard this thing needs more cow bell !
This question is a bit off but .... ZL1 Lid spacer for a Eaton 1.9, I have the convertible so fitting would be close does this increase volume enough to make a difference? Then there are spray connections....hmmmm
What I am seeing is the open spacer did made the motor more efficient in that it lost a small amount of power and torq but ran on quite a bit less fuel. If you had put in bigger jets wouldn't it most likely brought the torq/hp figures up?
incorrect assumption-the signal changed making the motor less efficient
@@richardholdener1727 Am I miss reading the graph - with spacer , roughly it was down .03 in torque and hp but was using .9 less fuel. I guess I don't understand how that relates to signal, bigger jets would not have helped that lean condition while increasing P&T?
A really interesting test!
why did you not fatten the carb up for the open spacer ??
Carb linkage plate with 4 holes, instead of open plate, might show a measurable gain...
I'm curious if the open spacer would do better with a more agressive cam shaft
No, 4-hole or directly on the intake. Radical cams with lots of overlap love the extra carb signal, especially if you have a carb with annular boosters, they can be worth close to 100 ft/lbs down low.
Why 1/2? Do you think there would be any advantage if you had hood clearance for a 1 inch, or 2 inch, what point would be negative return?
You seem to be the expert on Induction. Please tell me if you can use a Carburetor setup with Fuel injection? Will the fuel injection take away lean spots in a carb system? Working via the Co2 sensors????
YOU CAN RUN BOTH
I love the intro music
Something I don't think you have: a comparison in powerband between big cam/stock heads, mild/mild, stock cam/big heads, all making around the same power.
Is the powerband better at the same power level with the big heads/stock(ish) cam?
Richard , I had the opposite results from a sbc 350. The 4 hole on my stock silverado gen 1 motor and a boat anchor cast iron intake. And it lost a BUNCH of everystuff...then the open one I really couldn't tell the difference in that and no spacer.
Doesn't Edelbrock, who makes these, too, state to not use an open spacer with their carburators? I have the amazing AVS2 and their spacer.
great and informative content as always 🤘 However, please try to work on focus fluctuation when you film the computer screen, gets dizzy after watching the graphs closely :) thanks in advance ;)
Would it be possible to put the part numbers in the description so we can source them if we want
can you please test the difrence in power after adding total seal piston rings in a na ls?
i appreciate your videos . Thanks for all you do
How about a test with a Weiand Team G or a similar single plane?
not a good choice for this rpm range
Fantastic video and education. Thanks!
Try recurving timing and blocking heat cross over
I really would like to know what applications the headers were designed for. Reason being is that it would have been much easier to build the header shown if the destinations on the collector had been swapped for the front and rear positions on the mounting flange.
Excellent video, short, sweet, and to the point. My experience, back in the day, was that 4-hole spacers were best for street applications and could actually improve low RPM throttle response. Open spacers were good for high RPM race applications.
What about anti reversion / shear plates though?
I'd love to have that engine for my 1977 dodge w200. Richard what about the height of the spacers. Then what if you put the open space then put the 4 hole then try the 4 hole then open??????????????
1/2 INCH THICK
@@richardholdener1727 awesome, what about 2in thick spacers
Great video and info, it a four hole spacer for me. If you can, I have a question, I’m thinking to put 2v closed chamber heads on a standard 351 Cleveland to increase compression, no other changes, am I going to run into tuning issues or maybe other issues you may know of.
2" spacer next?
How is the tapered carburetor spacer do?
I have always run 32-35 total in all my LA's Why the pulsing on the videos of the grafs ? I will be starting a 416 build in a few months as the kit has arrived .
What about fuel atomization, What about a tapered 4 hole spacer upsidedown. I see on UA-cam some power gain along with the restriction and maybe some fuel atomization. It combined low end and top.
there is no magic-sometimes spacers work and on other combos they don't
Have you tested a tapered spacer. If not I would love to see the results.
Wanna see same video, but on a SBC or BBC
I Ran two different Black 4 hole spacers, but Both Cracked, I now run a 1" Aluminum 4 hole spacer.
Should have tried a HVH spacer (tapered one) great video tho
OK so I just watched Eric weingartner Do the same test and have the opposite results so now I’m confused what are you guys doing to me?
spacers are not universal-they don't do the same thing on every combination
Right on
Whatever happened to the video to either prove or disprove UTG (Uncle Tony's garage) theory of switching the pistons around
Waste of time really. It does nothing.
Thank you for this! I usually use phenolic or resin spacers and fuel return system on carbs to try and keep the carb and fuel temps low. We all know that carbs hate modern fuel and the cooler we can keep them the better the engine will start.
Interesting.. what if you put bigger jets on the open spacer? Maybe more power on the top end? Now I’m wandering if freiberger was using a rich carb for his test and that’s why he showed more power with his test… using a open spacer and milling his intake.
Would the same apply to fuel injection , I have keg intake with aem open spacer ?
I like that your showing what happens to the air/fuel ratio. Very interesting to me.
How about the difference on a single plane intake
less of an effect
Only reason I have a spacer is so I can clear the egr on the factory intake with a Holley.
What would a say 2” 4 hole spacer do on a single plane intake
might help carb signal, but single plane would still act like a single plane
Run 2 or 3 inches of the 4 hole spacers until you have maximum effect.
Keep going with your videos 👍
You’re the man! Keep it up.
Isn't the M1 dual plane a pretty small intake?. I bet an RPM airgap might show a jump in power by itself
I think that if you removed the material between two of the four holes you would continue with the duel plane manifold
What about 1 inch 4
Whats up Ricky, i know this is old but thought id rewatch these on the Dodge Magnums because im going to add some HP to one in my retired work Truck, i plan to port match and some bowl work, blend the valve guides because im too cheap to buy decent heads. I appreciate the data you provide. Hey ive adked before but forgot what you said, do you tune?
Hahaha
What about spacer plate on supercharger engine like thermal spachers is it worth? Need to be tested want be very nice
With and without spachers to watch ita temperatures if its working or not
your engine bay is hot so the spacers will do very little
Richard. Would you use a open spacer with a singlepplane.
I would love to see a 4.0 mustang engine 05 and up and or 4.0 ranger. Run it till it pops. Can it hang with the 4.3 gm? Or can it run away?
Great video
What about on a single plane manifold ?
NOT A GOOD CHOICE FOR THIS MILD COMBO
Is there any difference between a 1/2 inch and a one inch spacer ?