Wrong Again..... only time fuel mileage sucks is when the right foot hits the floor! Lol. This car has perfect street manners
Edelbrock Performer RPM dual plane 1500-6000 RPM range. Torquer II Single plane 2500-6500 RPM range (street intake) Victor JR. race single plane 3500-7500 RPM range. Apples and oranges. Willpower and Torquer II use smaller cross section ports for higher velocity. Willpower intake has flowed close to the bare head when it was tested.
The BBB has so much low end torque that the SP1 makes no discernible difference in low end power or gas mileage. This is especially true with the right torque converter. The SP1 is worth a good amount of HP over the dual plane Edelbrock intakes. That being said, the smaller the engine, the more loss of low end you would feel with a single plane intake, or a bigger cam for that matter. I can't imagine why anyone would want such an intake on a 300 unless you planned to scream it to 7000 RPM with the right supporting parts. Even the SP3 acts much differently on the 350 than the SP1 on a 455. My Quadrajet is seamless everywhere on the SP1. From everything I have read here, the SP3 likes a Holley DP 4150 carb. The Quadrajet has some flat spots when going from part throttle to full throttle quickly. Not sure anyone has been able to tune that out.
You did not share details about your application. All I did was make the general statement that, in general, single plane manifolds are made for WOT racing applications. If you dyno the same engine with both single plane and dual plane manifolds the torque curve will be different, the single plane will suffer at lower RPMs. This is why the manufacturer went to the trouble to make a dual plane manifold since it's more broad banded. It's much easier to cast a single plane manifold then a dual plane, why would they go to the trouble do it if there is no advantage. I'm 69 years old, grew-up in a racing family, my uncle ran in 3 Indy 500s, my sprint cars won the USAC East Coast championship in 2018/19/20, I am not whistling in the dark, I've been doing this a long time. If you want to have scientific civil conversation about this I'm willing, not interesting in "your wrong, your making assumptions", be civil.
larry, you are getting old and soft. the challenge is building something that everybody is scared of and know nothing about. some of us just like to make our own roads.
You made the assumption my friend...... not me. Many are running the single plane manifold without issues & not just track cars that run WOT. Fox's Den, Mark Demko, Mart & I'm sure there's more. That's my only point....... So when you say they are good for WOT only, not for street use, I was simply correcting you because many of us run them on the street without issue.
I didn’t make any assumptions or cast a broad comment about the dual plane in any way. We are simply sharing our experiences. Most of your comments were gross generalizations without any detail so we added clarity. When you make a comments like you did it doesn’t help make constructive discussion, people just call out the flaws in your generalizations. We are hot rodding these things, some mods work and others don’t. We dont know till we try. Back when GS Johnny was the only one making single planes for these engines we learned they could rev to 8500 RPM and survive and that it really woke up the 350. Then I paid mark Burton to start making a few single plane intakes and it was a success. Eventually TA made the SP-3 and we were thankful to have an option. Each engine design likes something different than another brand may like so that’s what we are doing. Experimenting with different cams etc. That’s the fun of it, making power and keeping street ability. when my car was last ran it had a 8:1 compression buick 350 with a Poston 114 cam (2500-6000 rpm), blow through turbo carb, overdrive trans. It had perfect street manners, the combo of the 4.56 gears with a tall tire works out more like a 3.73 and the 4000 rpm stall converter isn’t that loose when driving around but it will flash up when floored. The gears and converter don’t make it undrivable on the street. On this combo it was the single plane intake that helped even out the fuel distribution, otherwise it wouldn’t be an advantage on this combo, especially if it wasn’t boosted. The new combo is a different animal, and it will take advantage of the single plane for sure. Girdled with forged internals, 10:1, E-85 fuel, cam setup for 3000-7500 RPM. Same turbocharged and driveline combo.
Don't forget guys even though the singleplane is working very good for us the Dual plane intake will work very good all the way to 6200 rpm. If you are running a 212 or less the D/P intake is fine. Mine was port matched to my ported heads so it had no problem spinning to 6200 at the rev limiter. I remember the first time I took my car out after the engine rebuild and that TA 510 cam would go all the way to the 6200 rev limiter, no problem. So, there is no problem running that D/P intake. A ported TA D/P intake is better than the stock intake and if you take the stock one off, you will be happier putting the aluminum intake on the engine, plus lighter means faster. I was still making 390 hp at 6200 rpm so that TA D/P has no problem getting there. As the statement that was made earlier. The singleplane intake will not work on a stock engine. From the actually been there done that files. G out
Great article on stroking the 300 Buick... https://www.motortrend.com/how-to/hrdp-1103-how-to-hot-rod-any-engine/
Rather dated. Much more relevant information is available on the threads here, on BritishV8 and MGExperience. I would be reluctant to use cast pistons in any engine that will be expected to spin over 6000 rpm more than once or twice. Just too many reports of broken piston skirts for my liking. I've done that myself also and a few hundred extra spent for custom forged is a worthwhile expenditure especially as you get to specify exactly the piston that you want. If you are going to run a single plane it is generally safe to make the assumption that the engine is going to see more than 6,000 rpm, therefore the need for the forged pistons. Then to go with that perhaps a roller cam is not out of line. And then to top it off possibly a set of TA heads. Now you have an engine worth building. Need I even mention forged rods? When building a stroker 300 the only sensible approach is to use ex-nascar rods since they are so cheap and of such good quality. It now appears a SBF rod is available in a 2" journal and about a 6.32" length. That works out pretty nicely with the new thinner ring package and slipper style piston. Now you have light weight internals that the late 350 crank will allow you to internally balance if you wish, making it easy to run a light weight steel flywheel as there is no balancing cavity. Then a 4bbl type TBI setup and an electronic mappable distributor rounds things out nicely. Of course with the proper respect paid to oiling and clearances. By now of course we are talking about what is basically a $10K engine, less if you build it yourself, but depending on what you are doing with it that can be reasonable. And in a 300 sized package it can be quite potent. Ideal powerplant for an MGB for instance. As a final note, this build can be staged to spread out expenses. Because the TA heads have chambers that are 2 or 3 cc larger than the late 4.6L Rover heads the engine can be built using the Rover heads which are selling for around $200 each on ebay and then the TA heads are basically just a bolt-on swap. (Check that the rockers can be used.) The Rover heads will not flow as well as the Buick irons but they are about the same as the Buick alloy heads which really isn't bad. Jim
Its got an overdrive trans, and the tires are 32" tall by 18.5" wide tires, twin turbo, the single plane helps with distribution under boost. Its 2600 RPM at 80 MPH with the lockup engaged. The car only weighs 2980 pounds and it drives around nice at part throttle.
Johnny, I think it is done and Brian is waiting to get the prototype from Australia so he can trial fit.
These type of conversations always intrigue me. I'll go with my experience any day rather than what most tell me. I have a basically stock Buick 350 in my Opel with a comp cams 268 cam and headers. At the time of my intake swap it had 3:08 gears with a 29" tall rear tire so pretty much a highway cruiser. I changed out the stock q-jet dual plane for an SP-3. Had a few guy's tell me the usual loss of low end, mileage, blah blah. It actually is more responsive off idle than ever, no difference in mileage on highway and more to end. Another "test" was a SBC 307 w/same cam ^in a 62 Nova. Performer vs Holley strip dominator. Slightly noticeable off idle difference but more top end with the single plane. Mileage not a significant difference. Then I tried a tunnel ram with the carbs setup progressive. Off idle and all throttle response improved over both single carbs and highway mileage no difference. Daily drove it for a few years doing field service work, took it on Hot Rod Power tour 99, any many vacation miles with the t-ram.
I didn't lose anything either with the SP3, actually starts up better no choke needed. I used a Comp 268 cam in a stock engine in the 80's I liked it I needed more stall than stock and the 373 gear change later on did a big improvement. It was the best we had that I could find back then, didn't know about Ken Bell at the time. I wooped a lot booty with that cam on the street.
