Single plane vs Dual plane 300 stroker with TA heads.

[mgb260]

Goofing around with the Desktop Dyno.300 with 350 crank, TA heads and Crower 50233 cam. 10.5 compression. Here is the interesting part. Input Chevy Edelbrock Performer RPM vs Edelbrock Victor Jr intakes. Check out the graph:

[mgb260]

This graph with the Torquer II would be more like the new Willpower intake compared to a good dual plane:

[mgb260]

Now I've put in LT4 "HOT" cam specs:

[BlownMGB-V8]

Interesting Jim. Can you extend the 50233 graph up to see where it peaks out?

Since I have essentially the LT1 Hot grind the last one is relevant but with around 4-5psi of boost it will be extended.

Jim

[MGBV8]

The first graph shows why I chose a Victor Jr 30 years ago when rebuilding the 350 in my Camaro.  Works better on the street than most would give it credit for.

[Airwreckc]

Jim, those are really interesting results.  What options do you have for intake and exhaust?  For instance, is there an option for the Rover EFI or some sort of throttle body sizing?  And I wonder about different exhaust manifold options--for instance, I've heard that the original 300 exhaust manifolds actually flow pretty well.

[mgb260]

Jim B I can extend the graph but it drops off at 6000RPM. That cam is retarded 4 degrees to move power band up. Eric, I can input thousands of variables but it takes time. I use open headers, no accessories and electric water pump for flywheel HP & TQ. Deduct about 20% for rear wheel numbers. I have access to real dyno numbers and specs of different intakes, cams, heads etc.

[mgb260]

Jim B, 50233 drop off at 6000RPM. I'll work on Eric's Fuel injection and closed exhaust next.

[mgb260]

Eric, Willpower type intake with throttlebody, port fuel injection. 50233 cam. 300 exhaust manifolds, dual exhaust 2.5 pipes with H pipe. Dynomax mufflers. The chart above has same specs except 650 double pumper carb and open headers.

[mgb260]

Eric, Brian is going to sell his extra Willpower intake.

[Airwreckc]

That's great Jim, thanks.  As an aside, I am building a custom intake plenum with 350 CI of capacity (about 50% larger than the standard Rover plenum) for the Rover EFI system and was thinking of using a larger 75mm throttle body than the standard Rover 65mm.  I'm thinking that I might limit my CR to 10 :1 and likely go with a 50232 or 50233 cam (not sure yet).  And regarding the exhaust manifolds--trying to decide how much I get (or give up) by using tube headers (not block huggers) vs. the original cast iron (which are *free*) and a lot quieter--and I've read aren't much different in weight than the tube headers.

[Airwreckc]

And thanks for letting me know about Brian's intake--yet another option to consider

[mgb260]

The Buick 300 manifolds probably flow about the same as the shorty headers. The open long tube headers don't gain a lot with no backpressure except noise. A good free flowing exhaust with long tube headers will gain more. I'll change to a sheetmetal intake with
75mm throttlebody.

[mgb260]

Not much difference, A little more power at peak. Both types of throttlebodies can flow 1000cfm.

[Airwreckc]

Interesting how similar the numbers are (and how good they all are).  This looks like nearly exactly the result I was shooting for.  Thanks for putting these together.

[mgb260]

Eric, Results on Desktop Dyno's are very optimistic. This program starts with a stock baseline and I add improvements. I can set elevation, temperature, and humidity.There is a huge database library of real results. I haven't messed with the program for a couple years and started playing with it and it becomes addictive. I figured out how to print to PDF and convert to jpg for the graphs on my laptop. .Bottom box colors are the single plane. you can hover with the mouse and it reads actual numbers ,I could have typed in the peak numbers but I was lazy.

[Airwreckc]

Jim,  good to know.  However, it does give me a better picture that the wild guessing I've been doing so far.  I'd be interested in knowing what variables you've used so far.  If you want some more fun, I might change a few

[mgb260]

I can change everything from mild to wild. Turbo's, Superchargers, port size, runner length. I have the experienced user, Pro edition.
I forgot to mention I used 1.9 IN and 1.6 EX valve size. 1.6 rocker ratio. I used Chevy examples on the intakes because few HP intakes are available for the 300.

[mgb260]

On the above all were very similar and the changes were intake, cam and exhaust. I have also done Ford V6 and V8, Buick 215/Rover V8 and Buick and Chevy V6.

[Airwreckc]

Jim, nice--good to know.  Thanks.

[Roverbeam]

I suspect "Pipemax" software might not be as robust as your stuff, but for a 302ci rover block/Buick 300 heads that flow 180/150-ish, it spits out:

Camshaft = Hydraulic  Roller  Lifter
      600 RPM/Sec Dyno Test                                Level=5        Level=6        Level=7        Level=8
Peak HorsePower    @  6200 RPM      383.7           388.6            393.5            398.5
Peak Torque Lbs-Ft @  4800 RPM      357.4            361.9            366.5            374.2

[mgb260]

Chad, I've got similar results with the Rover 4.6 with 300 crank and 300 Iron builds. on my program with more radical cams. I usually tame it down a little to more streetable results.

[MGBV8]

Might be a bit optimistic to expect the OEM rocker arms to be a 1.6 rocker ratio.  Or maybe you expect to use aftermarket.  Even those are not always on the money.

I would be surprised if the OEM Buick rockers measured more than 1.55.  I think that is one of the reasons that Dan LaGrou recommended the larger 50232 cam for 3.5-3.9 engines.

[Roverbeam]

I asked Woody for as aggressive a cam as he'd be willing to spec, and got a 226in/ex @ .050, 112 separation jobbie. I expect it'll be more streetable than I wanted!

T&D rockers from TA are 1.6 ratio.

[mgb260]

Carl, I used aftermarket roller rockers in the simulation. Chad, I like around the same rear wheel HP as engine cu in size usually for the street. I'll do the specs for a 50233 but roller cam in a 300 stroked Rover V8 and see what I get with this program.