How many years ago? I'm old enough to recall the days that a pair of 1150s were all anybody could buy. Now, with the availability of billet bodies, 2.600" throttle bores are commonly available. With proper interior contouring something on the order of 1850-1900 CFM is possible.
A tunnel ram and twin 1050 doms and 1000+ should be in the bag especially if you can get more compression peak power may not go up a lot but the torque and area under the curve should go up substantially with the longer runner length.
Nice work Eric. 385’s maybe too much head for that engine however if they were offering the same compression we would’ve seen a massive difference over the Pro max. The 1250 Dominator surprised me a little.
i have a set of the 385's on a 555 and i really like them. At 12.9 CR with .810 lift. Its looking like they would like even more cam. Thanks for this dyno test Eric. Maybe you could test with the profiler tunnel ram ? thats what i'm using with a pair of 750's
i will warn you that the profiler t-ram needs work before it will even bolt on to the 385 heads. The flange interferes with a ridge on the heads just above the intake ports, and mine needed .100 milled off the end rails so that it wasn't sitting right on the block.
I may be in the minority here, but I think once you port the Pro maxx heads and add the larger valve it’ll break over 1000hp with the larger single carb. From what I’ve always heard it’s somewhere in the neighborhood of 4-6 percent per point of compression.
BBCs really take to compression, from what I hear and understand .5 can even make a world of difference on them. Bump that 11-1 to 13 or 14 and watch out.
EDIT: OK, revised my numbers after paying more attention to the video. Looks like it's currently making about 2.28HP per CFM @ 405 ...... So 1000 / 2.25 = ~444.4 CFM Tunnel ram w/ dual dominators + ported ProMax heads @ ~445 CFM..... Possibly make 1000HP? Now is there possibly ~40+ CFM to be found in massaging those ProMax heads?
This is not a tow truck engine. 😂 I think you would be shocked at the results if you asked people why they like your channel. Yes you’re incredibly well versed in your chosen profession, but its your personality that has you standing out from the crowd. Is there any chance you would be able to to do anything on say 250 or 450 mx bike? And maybe talk about the similarities throat to bowl etc Or is there another person you could recommend? Thanks for a great show.
Hey Eric. You think the 385 head would actually run quicker and faster down the strip even tho it makes a tad less on the dyno? I'm thinkin it would, I don't have experience with Chevys. But with a Mopar plenty of things show more on the strip than they do on the dyno.
@WeingartnerRacing I have heard from a couple of older builders in my area that they would run, say 1.7 rockers on the four center cylinders and run 1.8 on the four cylinders on the corners to increase the flow the further cylinders. Have heard of this or have you tried it yourself?
Extra octane doesn't make power unless your engine is knock limited and the engine needs its timming reduced from optimum to stop it from knocking. If you wanted to run the Promax heads, you'd likely need to lower the compression to stop the knock, thus reducing the power right across the rpm range.
Dude any time you are over 900 with a 24 degree head on pump gas is impressive. Would be curious to see how much with the same compression ratio 11.2:1 and same cubic inch going to AFRs 18 degree heads would be worth powerwise. Never see any real good test comparisons of how much more power could be made from more exotic heads with shallower valve angles with more efficient chambers. I.E. being able to make more power without having to have sky high compression and stuck running race gas. I know why the tests arent run because its expensive because you would need multiple engines. Just a test i was always intersted to see
@@WeingartnerRacing if the combustion chamber ( head side ) is small enough, that works. but you get a big ass 118cc+ CC in the head, you're going to be limited to what you can get away with and still make power.
Problem with pump gas is you can't rely on the octane you might be pumping 87 it happens wouldn't want to risk my expensive engine so I generally don't run more than 10.5 compression on the pump for safety
In a car the bigger carburetor will slow air speed down and go slower don’t care what the dyno says you don’t drive it with 3200 lbs of weight behind it.
I can say for a fact that is false. The Camaro had a 540bbc in it that only made 840. From the 1000cfm to 1375cfm dominator it gained on the dyno and was far faster on the track.
umm you prbably have already done it but would 1.6 on the intake of a 406 with a b&m forced induction with 10.5 comprssion,and comp cam hydraulic roller blower cam around .500 lift, and afr heads not the cheap ones
Good video Eric, lots of good information, I want to build a 575cu bbc
Nice man bbc big power is always cool
Racers used 1350 dominator years ago. 514 up to 555 cubic inch engines alot ran tunnel ram and two 1350's. 496 seemed to work well with two 1150"s.
How many years ago? I'm old enough to recall the days that a pair of 1150s were all anybody could buy.
Now, with the availability of billet bodies, 2.600" throttle bores are commonly available. With proper interior contouring something on the order of 1850-1900 CFM is possible.
@@ToddWright2 late 80's through mid 90,s. Still using such today in some setups.
Be interesting to see tunnel ram with twin Dominators
Would like to see a tunnel ram with 2 4150 1050s on that setup to see the tq and hp changes
Me too also two dominator setup
Very interesting information makes me think I am seriously under carbureted
Need some higher compression pistons to test the bigger heads with.
A tunnel ram and twin 1050 doms and 1000+ should be in the bag especially if you can get more compression peak power may not go up a lot but the torque and area under the curve should go up substantially with the longer runner length.
Impressive power for out of the box parts except for the pistons
Interesting!!
I fucking love data
I wish you'd run the air turbine so we could see volumetric efficiency and proper BSFC on your tests.
Great Video!! What was the Timing?? Thanks
Nice work Eric. 385’s maybe too much head for that engine however if they were offering the same compression we would’ve seen a massive difference over the Pro max. The 1250 Dominator surprised me a little.
Understand funds are short but it would be nice to see what the AFR 385’s would do with 12.5-13 compression
Hey do you do any big block 460. builds
385 probably too much Head at that rpm looking forward to see what the 317 head does fully ported
Great info as usual. I'm always interested in all things BBChevy. Just curious, and you may have mentioned but what head gasket are you using?
i have a set of the 385's on a 555 and i really like them. At 12.9 CR with .810 lift. Its looking like they would like even more cam. Thanks for this dyno test Eric. Maybe you could test with the profiler tunnel ram ? thats what i'm using with a pair of 750's
i will warn you that the profiler t-ram needs work before it will even bolt on to the 385 heads. The flange interferes with a ridge on the heads just above the intake ports, and mine needed .100 milled off the end rails so that it wasn't sitting right on the block.
I think people often associate carburetor size with ci when it’s really just a requirement of flow and ve
91 octane power!
I may be in the minority here, but I think once you port the Pro maxx heads and add the larger valve it’ll break over 1000hp with the larger single carb. From what I’ve always heard it’s somewhere in the neighborhood of 4-6 percent per point of compression.
BBCs really take to compression, from what I hear and understand .5 can even make a world of difference on them. Bump that 11-1 to 13 or 14 and watch out.
EDIT: OK, revised my numbers after paying more attention to the video.
Looks like it's currently making about 2.28HP per CFM @ 405 ...... So 1000 / 2.25 = ~444.4 CFM
Tunnel ram w/ dual dominators + ported ProMax heads @ ~445 CFM..... Possibly make 1000HP?
Now is there possibly ~40+ CFM to be found in massaging those ProMax heads?
This is not a tow truck engine. 😂
I think you would be shocked at the results if you asked people why they like your channel.
Yes you’re incredibly well versed in your chosen profession, but its your personality that has you standing out from the crowd.
Is there any chance you would be able to to do anything on say 250 or 450 mx bike?
And maybe talk about the similarities throat to bowl etc
Or is there another person you could recommend?
Thanks for a great show.
Hey Eric.
You think the 385 head would actually run quicker and faster down the strip even tho it makes a tad less on the dyno?
I'm thinkin it would, I don't have experience with Chevys.
But with a Mopar plenty of things show more on the strip than they do on the dyno.
Do you do Zelle? Tunnel Ram great suggestions, send em in
Curious to see the difference in air speeds between the two heads. And I think you will make a 1000 with a tunnel ram.
Eric are you going to put a dominator intake top on a duel plane intake ?
@WeingartnerRacing I have heard from a couple of older builders in my area that they would run, say 1.7 rockers on the four center cylinders and run 1.8 on the four cylinders on the corners to increase the flow the further cylinders. Have heard of this or have you tried it yourself?
Eric, could you have put some good Tape(100mph tape) Inside to make the 4.650 flow adaptor to the 4.500" yo needed ???
It seems like if an engine doesn't need more air, it doesnt need more air.
Interesting stuff for sure Eric. Just curious...what springs did you run on the 385s ? Also, is that a Super Victor II ?
Psi 426rml. Super victor 2
Can you keep that 1250 around for the LS 408 test just to try ... and who did they carb for DV
Tunnel ram will make 4 digit power
I wonder if that 1250 would help the ProMaxx 317 cc ? That be awesome test much lower cc adding 200 CFM
Well going just by a simple CFM calculation, that engine needs 1300cfm.
Hmmm……. dynamic compression without static compression.
Wonder how much HP difference was due to 2 different fuels?
Extra octane doesn't make power unless your engine is knock limited and the engine needs its timming reduced from optimum to stop it from knocking.
If you wanted to run the Promax heads, you'd likely need to lower the compression to stop the knock, thus reducing the power right across the rpm range.
Dude any time you are over 900 with a 24 degree head on pump gas is impressive. Would be curious to see how much with the same compression ratio 11.2:1 and same cubic inch going to AFRs 18 degree heads would be worth powerwise. Never see any real good test comparisons of how much more power could be made from more exotic heads with shallower valve angles with more efficient chambers. I.E. being able to make more power without having to have sky high compression and stuck running race gas. I know why the tests arent run because its expensive because you would need multiple engines. Just a test i was always intersted to see
Did he say 11.7 on pump gas? That's really pushing it in my opinion especially in a vehicle 😮
11.3. But I have no problem driving 11.9 compression around in a car if your timing is right. I did it for years.
@@WeingartnerRacing if the combustion chamber ( head side ) is small enough, that works. but you get a big ass 118cc+ CC in the head, you're going to be limited to what you can get away with and still make power.
Problem with pump gas is you can't rely on the octane you might be pumping 87 it happens wouldn't want to risk my expensive engine so I generally don't run more than 10.5 compression on the pump for safety
NO SOUND
Try again.
In a car the bigger carburetor will slow air speed down and go slower don’t care what the dyno says you don’t drive it with 3200 lbs of weight behind it.
I can say for a fact that is false. The Camaro had a 540bbc in it that only made 840. From the 1000cfm to 1375cfm dominator it gained on the dyno and was far faster on the track.
Further proof is the tunnel ram that’s on it now with 2300cfm of carb. No bog just goes.
You did not mention port energy into the equation. ?? Trying to keep video simple. ??
umm you prbably have already done it but would 1.6 on the intake of a 406 with a b&m forced induction with 10.5 comprssion,and comp cam hydraulic roller blower cam around .500 lift, and afr heads not the cheap ones