Maximum Stage II Horsepower

[ijames]

Billy Anderson once posted here that the best flowing Stage II heads he had ever seen topped out at about 360 cfm, and he put those heads on his car .

 

[Alky V6]

So far up just under 1800HP.
BMEP 680.
Max cylinder pressure around 3500.
130 octane gas.
85% eff. intercooler.
Knock numbers on the hairy edge.
Torque curve flat from 6400 to 8000 rpm. Looks impressive.
Is it practical to run twin 76s at 45 psi? Would they surge before getting in the power band?
Looks like a single T-106 at 45 psi would be a piece of cake.

 

[Big Stu]

Here are the Chapman Heads that I had, these are the same units Kenny went 6.8s with!
Please keep in mind I was going to use a cam bigger than .700 inch!!!

Intake Port Volume: 247cc
Exaust Port Volume
Chamber Volume 40.5cc
Valve sizes and Lengths
Intake Valve 2.100 x 5.540
Exhaust Valve 1.625 x 5.560
Flow Figures @28"
Intake Exhaust
.100 68 53
.200 145 113
.300 221 174
.400 281 213
.500 321 229
.600 336 241
.700 341 247
Extra Info NOTE: This program will only work on select castings. Please call for more information.

Who got those heads?

 

[Big Stu]

So far up just under 1800HP.
BMEP 680.
Max cylinder pressure around 3500.
130 octane gas.
85% eff. intercooler.
Knock numbers on the hairy edge.
Torque curve flat from 6400 to 8000 rpm. Looks impressive.
Is it practical to run twin 76s at 45 psi? Would they surge before getting in the power band?
Looks like a single T-106 at 45 psi would be a piece of cake.

I really wanted to run a lencodrive with twin custom 78's but money is holding me back. If i had unlimited resources, that is what I would do. I like the idea of a 106 at about 45psi but that would be a bitch to spool using anything other than a stick/ or nitrous/automatic combo. The having to run the equivalent of 130 octane is where the nitro would come in handy I think. I wonder if I would have to run two magnetos?

 

[Big Stu]

Billy Anderson once posted here that the best flowing Stage II heads he had ever seen topped out at about 360 cfm, and he put those heads on his car .

Yes, those were the Bennett ported heads. I have heard of over 368cfm intake but I couldn't tell you for sure if that's true or not.

 

[Alky V6]

I really wanted to run a lencodrive with twin custom 78's but money is holding me back. If i had unlimited resources, that is what I would do. I like the idea of a 106 at about 45psi but that would be a bitch to spool using anything other than a stick/ or nitrous/automatic combo. The having to run the equivalent of 130 octane is where the nitro would come in handy I think. I wonder if I would have to run two magnetos?

Nitro would require a totally different engine setup. Nitro's octane number is horrible and the fuel is harsh. I'm going to switch the combo to alcohol, optimize the CR and see what we get.

Have you considered a Bruno? I hear some fantastic things about them. Oh wait. Is the Lencodrive the torque converter drive setup?

 

[Alky V6]

Very interesting results.
Peak BMEP 691@7200
Peak cyl press 3813@7450
Peak exh temp 1247 degrees F@7950
Lowest intake port temp 36 degrees F between 4700 and 5200 rpm
Compressor eff 69% between 7200 and 7950, peaking at 7700 rpm
Turbo is spooling quicker and the torque curve plateaus earlier (5950) and remains flat to the end.
Peak torque 1255@6950
Peak Hp 1774@7700
Exhaust is looking restrictive. I'm going to try opening it up a tiny bit.
The impressive thing at this point is that the knock numbers look fantastic. Not even a concern.
I'm still using the head example John gave me.

 

[Alky V6]

Opened the primaries on the exhaust 1/8".
Slowed the spool up slightly, shifting the torque curve to the right just a bit with a new peak HP of 1810@7700.
Knock numbers still an absolute dream. Even with the low knock numbers, I suspect the BMEP and peak cyl press numbers will be over the capacity of the vast majority of rods available. Maybe a custom built pro mod design with a thicker I beam? Steel or titanium?

OK! Where can I get a set of heads like those? They're on my must have list.
One thought. If your running alcohol, you can forget about any internal water passages so a head flogged from billet is very do-able, bypassing the casting setup and production process. Anyone interested? Can anyone supply me with Stage II head blueprints? That would be the best starting point. Does anyone have proven intake and exhaust port dimensional draw ups that they want to sell?

 

[Big Stu]

Nitro would require a totally different engine setup. Nitro's octane number is horrible and the fuel is harsh. I'm going to switch the combo to alcohol, optimize the CR and see what we get.

Have you considered a Bruno? I hear some fantastic things about them. Oh wait. Is the Lencodrive the torque converter drive setup?

There the same basically, the lencodrive is something lenco came up with where as the bruno can be mated to a g-force/lenco/liberty, etc. They all use a converter which i think is the way to go. I can't come up with the $8000 for a used unit though.

 

[Big Stu]

Opened the primaries on the exhaust 1/8".
Slowed the spool up slightly, shifting the torque curve to the right just a bit with a new peak HP of 1810@7700.
Knock numbers still an absolute dream. Even with the low knock numbers, I suspect the BMEP and peak cyl press numbers will be over the capacity of the vast majority of rods available. Maybe a custom built pro mod design with a thicker I beam? Steel or titanium?

OK! Where can I get a set of heads like those? They're on my must have list.
One thought. If your running alcohol, you can forget about any internal water passages so a head flogged from billet is very do-able, bypassing the casting setup and production process. Anyone interested? Can anyone supply me with Stage II head blueprints? That would be the best starting point. Does anyone have proven intake and exhaust port dimensional draw ups that they want to sell?

I'm sure the heads that john is talking about belong to me now, got them from tyson along with the car. Mine are 2.125 intake though, not 2.10. They were a specific casting run and it's pretty rare to find a set from what I have been told. I think any good set of aluminum stage heads will do after being sent to chapman to work their magic on them. Or bennett like bill anderson did. As far as rods, probably billet titanium would do the trick, I agree on the I beam, they can and will take a serious beating. I think I'll run race gas for the time being after the engine assembly and see what kind of numbers that will produce. I'm sure it should be plenty for a car that should weigh in the neighborhood of 2400 lbs, loaded.

 

[Alky V6]

I thought we were talking about max setup? Com'on, step up. I've heard some impressive things about these converter drives. And with the new Pro Mod converter technology that's out now. NO Problem.
I'm up to 1837hp on the calcs with room still to tweak.

 

[John Wilde]

Stu,

I did not want to say anything but I think your set flows more than quoted.
Please keep in mind several shops quote numbers high for marketing reasons.
Chapman does not!

 

[Alky V6]

Even at the flow numbers already plugged in, port velocity is still at the low side with plenty of room for more. The larger intake size is good. The flow coef graph was showing some room for a larger valve in relation to port flow. I'll plug in the new valve diameter.

Well, a little more. 1839@7700

 

[Alky V6]

Turbine housing size looks to be very critical with the T-106. I choked it down slightly and lost a pinch of peak HP but gained a bunch of meat under the overall torque curve. One drawback being that the knock numbers are starting to creep up.
Max hp 1828.
Max trq 1317 and getting broader and is flat.

 

[Big Stu]

Turbine housing size looks to be very critical with the T-106. I choked it down slightly and lost a pinch of peak HP but gained a bunch of meat under the overall torque curve. One drawback being that the knock numbers are starting to creep up.
Max hp 1828.
Max trq 1317 and getting broader and is flat.

The torque is impressive, this is pretty informative.

 

[Alky V6]

Hey Stu, it looks like at a level like this, you don't want the turbo/s spooling up by the midrange. You want it to build up through the midrange and settle in at the top range. Large single turbo setups are good for that. It looks like that will be the best way to stay away from detonation problems. Also, keep in mind that your still talking about 800 to 900 HP at around 5000 rpm with a long boost build up. It can only help a lot in keeping good traction at the launch.

 

[John Wilde]

Don,

Are you still running the 4.11 Gears?
If so I think the car would do much better with something in the 3.4 to 3.7 range.

 

[Alky V6]

Don,

Are you still running the 4.11 Gears?
If so I think the car would do much better with something in the 3.4 to 3.7 range.

Yes, I'm presently using 4.11s. If anything I'll move up in tire diameter. That way I can lower overall ratio and gain a bit more traction. I had 3.73s in it before, but was only running the 1/8 mile. The switch to 4.11s really wasn't that impressive. If I remember correctly, maybe a tenth. That was very early on in the development of the engine tuneup, so the results of the gear change weren't clear. I know the turbo spooled slightly quicker. I was not injecting the nitrous at that period. The calcs say to stick with the 4.11s. Vegas was the first time on the 1/4 for that setup and the tach read 7,800 at the finish. You can bet I was chanting, hurry up finish line, hurry up finish line, the last bit of the track!!!
The engine and car ended up performing better than all calcs had pedicted. Once I had the data from those runs, I was able to change some variables in the programs to simulate the performance of the car and engine exactly. When it comes to any sims, garbage in, garbage out. The more detailed and correct the input, the better chance of getting realistic results. Then, the more exact your variables are, the more realistic the results are when you start trying different tire sizes, cams, torque converters, etc. The more you play with it and compare it to real testing, the easier it becomes to see patterns in certain changes. Real interesting stuff. The good thing that has come out of my engine mishaps is that it has given me the opportunity to confirm the limits of certain pressures and fuel limitations. And also test the program's alerts as well.

 

[Dusty Bradford]

Yes, those were the Bennett ported heads. I have heard of over 368cfm intake but I couldn't tell you for sure if that's true or not.

When were these done? I know several guys at Bennett if your talking about the shop here in Alabama. Were these numbers from Bennett or from someone else flowing them?

Also. If a rod can be made to take the abuse I would think an alcohol motor with billet head without water ports would be the best way to go. You see these in the diesel tractor arena and they take a serious beating.

 

[Big Stu]

When were these done? I know several guys at Bennett if your talking about the shop here in Alabama. Were these numbers from Bennett or from someone else flowing them?

Also. If a rod can be made to take the abuse I would think an alcohol motor with billet head without water ports would be the best way to go. You see these in the diesel tractor arena and they take a serious beating.

Those are numbers I got from a few other people. Bill talks about having his heads done in a thread that i would have to hunt for. Bennett didn't claim these high numbers. I will see if i can hunt it down and make sure i know what I am talking about.