probably 8 or 9, but the ole 352 is tired, and i constantly struggle to keep the fuel pressure consistent. I need to replace the fuel pressure diaphram in the throttle body.

not to mention its all setting on top of the original 2bl intake, i would imagine a good 4bl would help too

Joe

 

Sure. Change out the cam recommendation from above to a Crane 344361.

I ran it wrong last time too. I used a 750cfm carburetor to model it, and the throttle body is 1000cfm. Changing that, the results would have been 494hp @ 5500rpm, and 518ft-lbs @ 4500rpm.

With the Crane 344361, the results are 511hp @ 6000rpm, and 500ft-lbs @ 5000rpm.

There's an interesting part to comparing these two cams, that Desktop Dyno cannot model. Look at this:

Crane 344361:
Seat-to-seat duration: 294 degrees
.050" lift duration: 227 degrees

Crane 340321:
Seat-to-seat duration: 284 degrees
.050" duration: 244 degrees

Desktop Dyno has standardized acceleration rates for cams, based on lifter type (hydraulic, solid, or roller). Clearly these two solid lifter cams are not equal. I used the seat-to-seat duration in the simulations. When I used the .050" duration, the power and torque curve for the 340321 do not move at all. They lower significantly for the 344361.

I'd be happy with 494hp. Taking the mufflers off takes that number up to 514hp, so some low restriction performance type mufflers and you'd probably be at 500. Additionally, I'm using flow data for ported D2TE-AA heads with CJ valves. If you do an exceptionally good porting job, your flow numbers could be higher than what I'm using. That's where the power is at; in the heads.

 

Someday after I get all this for it, I might end up throwin a turbo on it.. or a centrifugal supercharger.. who knows.. I just want to see how much I like all motor first. How many mpg do you think I'll get with the MPFI?

How do you have a desktop dyno?

 

Desktop Dyno is a computer program. The full name is Desktop Dyno 2000. You put all the variables in, and it spits out a horsepower and torque curve, as if the motor were built and on a dyno. You input cam data, cylinder head flow data, compression ratio, and a multitude of other options.

You know what, if I was going the forced induction route I'd just build a 390 and let the super/turbocharger do the work. Then you could run a small cam and get your low end torque back. Plus, you wouldn't be spending $2000 on a stroker kit.

If I was building the motor, here's what I'd build:

1. 4.080x3.784" bore x stroke, 396ci
2. Ported D2TE-AA heads, CJ valves, figure 72cc chambers
3. KB150 pistons, 8.77:1 compression
4. Victor intake, fuel injection
5. Crane 343901 cam, some form of adjustable rockers.
6. Mirror 105 block, D3TE or D4TE
7. ARP hardware (rod, main, and head bolts)
8. Paxton Novi 2000 centrifugal supercharger. I believe this will be a lot easier than a turbo.
9. Headers.
10. Some form of intercooler, I figured 80% efficiency.

That motor would make 606hp @ 6000rpm, and 625ft-lbs @ 4000rpm. Then at some point down the road if you wanted more you could swap the pulley on the supercharger. You would have to be careful to avoid detonation, as those KB150 pistons are hypereutectic, not forged.

With the other build, any kind of forced induction is a non-starter. The compression is still too high. You'd probably need to get custom pistons made.

 

Do you think a ATI Procharger would do the job? With the EFI should I be getting around 15mpg?

 

It might. I dont have data for an ATI Procharger. If it's similar in capabilities to the Paxton, you could expect similar results.

There was one guy on here who built a mild 390 with a single pattern Crane cam, and was getting (IIRC) 17mpg. He also beat a new Silverado in a stoplight race. And his wasn't even fuel injected!

My old 360 would get 15mpg on the highway, with headers and a Holley 600cfm vacuum secondary carburetor. This is through a C6, with 3.50 gears, in a 1970 F100. The new 390 has gotten about the same mileage on a trip, but it has a bigger cam than the 343901 that I mentioned above. So yeah, 15mpg is a reasonable expectation, assuming everything is tuned right and you can keep your foot out of it.

 

Would it hurt to still run a stoker? Would it help out my performance ontop of the supercharger? I'm assuming it would, but how much would I expect if I did get the stroker aswell?

 

http://www.procharger.com/models.shtml

There are the models, I am thinking the D-1 style procharger. My power all motor would be between 300-500, and then it bumps me upa bit to around 925 possibly? If I got a mirror block, and kept my compression low enough, it would be a pretty stout motor. Maybe I will have to run forged pistons?

 

We'll figure the same 8.77:1 compression for both the stroked 444 and the 390, for ease of comparison. If you were running forced induction with the 444, you would need to run custom pistons anyway AFAIK.

Using the same build as above, changing only stroke, naturally aspirated:
3.784" crank: 412hp @ 5500rpm, 447ft-lbs @ 4000rpm
4.250" crank: 406hp @ 5000rpm, 481ft-lbs @ 3500rpm

And with the Paxton:
3.784" crank: 606hp @ 6000rpm, 625ft-lbs @ 4000rpm
4.250" crank: 578hp @ 5000rpm, 676ft-lbs @ 3500rpm

I could not enter the information for your selected ATI procharger. They do not list the data necessary.

Forged pistons would definately be a good idea, but I think it'll be rather difficult to find dished forged pistons. There again, you'd be looking at custom pistons.

 

Ok so with a stroked motor I am looking at less hp more tq. What exactly do you need to run the DD2 for the ATI procharger? I will see if I can dig up some more stuff for you. Where could I possibly pick up or have custom pistons made for me? $$$?

 

Things I need to model a centrifugal supercharger in Desktop Dyno 2000, copied pretty much straight out of the users manual:

1. Flow - This is the flow rate at which the supercharger is most efficient, also called the Island Flow.
2. Pressure Ratio - This is the ratio of compressor pressures at
the Island flow point (ambient vs. output).
3. Speed - This value is the rotational speed (rpm) at which centrifugal
superchargers reaches peak efficiency.
4. Efficiency - This is a measure of the power consumed by the supercharger compared to the increase in induction pressure at the point of highest efficiency.
5. Internal Gear Ratio - Centrifugal superchargers are driven by a mechanical
connection to the engine crankshaft. Internal rotor speed is increased by
the external belt ratio, but this speed increase is not a sufficient for most centrifugal superchargers to reach their optimum operating speeds (35,000rpm and higher). An internal gear train is commonly used to further
increase rotational speed. The ratio of this internal gearing determines how
much faster the turbine rotates over input-shaft rpm. To determine the internal speed of the centrifugal turbine, multiply crankshaft rpm by the Belt Gear Ratio, then multiply that by the Internal Gear Ratio.

On the custom pistons:
I've never had to get a set made, so I can say nothing about who makes good ones. I do know there are quite a few places that will do it. One that comes to mind is Ross Racing Pistons. http://www.rosspistons.com/

I would hope that we are not the only two reading this thread. Maybe someone who has some experience in this area can recommend a manufacturer?

 

Ok, I'll see what I can find..

Ha I think we are the only ones' reading this thread... No input from anyone else.. at all. :/

What should I ask them to do so I will have the right compression?

 

Well first, you need to know the exact CC's of the heads you'll be using, and the head gasket you'll be using. You also need to know the compression height you'll need. Then you can figure how big the dish needs to be to get your desired compression.

Say you wanted 8.75:1 compression, you had 72cc heads, were using a Fel-Pro head gasket with a 4.4" gasket bore and .041" thickness. Say the engine dimensions were 4.080" bore and 4.25" stroke.

First, we go back to the Survival Motorsports site, and we look at some dimensions. The crank has a stroke of 4.25. It uses 2.2" rod journals. Ok, so it uses BBC rods. They include 6.7" rods in their kit. At this point, you're not buying the kit, so that's immaterial.

For the point of illustration, lets say you wanted to use 6.8" rods.

Now, we'll figure up the compression height you'd want.
Deck height = 10.17"
Crank throw (1/2 stroke) = 2.125"
Rod length = 6.8"

So we simply subtract it out. 10.17 - 2.125 - 6.8 = 1.245" compression height for zero deck.

So now we figure up required dish volume. This is a lot easier with one of the online calculators: http://www.kb-silvolite.com/calc.php?action=comp

Plugging in the numbers, using a trial-and-error approach, we end up needing a 35cc dish to obtain our desired compression ratio.

Then in ordering, you go back and say you want a piston with a 1.245" compression height, and a 35cc dish, otherwise identical to their PN 09024080.

Does that make any sense?

 

rusty, where is this piston # 09024080 located at?
At 1.245" the wrist pin between the oil and second ring?

 

Rusty, how much pressure is in the intake in these tests ? A boosted stroker would make a great trailer pulling engine. What compression before boost ? How about 10 to 1 static and then add boost running E85 fuel ? DF, @ work on lunch