A "what will it make" thread in the boost section
 

In other sections time to time folks post up their engine projects to see what it may make on the dyno. We thought we would try it here in the boost section as well to give it, the boost section, shall we say some ...boost.

It is a 1969 400 two bolt main block 4.180" bore, 4.00" stroke (440)

1977 6X-4 cylinder heads (93cc), SS valves, no port work, mild exhaust "hump" clean up with Crower 1.5 roller rockers, Isky valve springs

MLS head gaskets

Custom Ford/LS-1 firing order hydraulic roller camshaft 249/261 @.050 .382" lobe

Hooker 1 5/8" D port headers W/Pypes reducers and 6" dia. x 24" Magnaflow street mufflers W/multiple O2 sensors

Our new passenger side 8 rib serpentine belt drive Vortech V-7 series supercharger kit with the mating Vortech 360 degree Power hat.

No inter cooler or water-meth injection

Hurricane single plane intake manifold 4150 carb flange

Holley Super Sniper 1250 throttle body EFI system with their Hyper spark ignition and the dual sync HE distributor

Mechanical water pump and a 64 amp GM alternator

We will be limiting the rpm to 5500-6000

At what boost level??

Yeah, how much boost? And I sure would like to have that supercharger set up...

What was the cam?Tom

I will guess 829!Tom

The previous Luhn Performance Dyno testing with a 440 engine years ago made 862 ho at only 5300 rpm but it had an intercooler on it and a carburetor (way too small carb 750 cfm), and the carb was not perfectly dialed in.

It made that HP at less than 6000 rpm, but had Edelbrock heads, and I believe this engine has cast iron barely touched heads. Depending on the Belt Ratio of the Supercharger you can move the Supercharger vs Engine rpm around a bit.

So a rpm number does not mean that much.

I was told that they were going to use a new YSi supercharger that I sent to Mark, years ago. Marks Supercharger Bracket and Pulley/Belt work has always been really good.
He said something about sticking with a 8 rib belt and that is what the pictures showed I believe. We are not talking about a cog belt deal that is 50mm wide driving the supercharger. Just a real "street friendly" Pontiac set-up probably at 6000 rpm or less for best power. The other engine made that 862 HP at only 5300 rpm charlie.
Best torque on that engine was 4800 rpm.

This Engine with the larger supercharger, YSi vs the T-Trim supercharger used on the previous test should be a very happy unit making very low discharge temps to the Vortech Bonnet. Air Distribution to the Sniper EFI should be very good too.

Tom V.

Tom S, you number should be really close but just so I don't pick the same number as you I will bump it up a couple of HP numbers to 834 or 835 and around 750 on the torque. It should be really close for either guess, in my opinion.

I hit Mike Leech's (RIP MIKE) HP numbers with-in a couple of numbers I think 3 times when he was on the dyno.

Other guesses, Guys?

I have a little advantage because the Supercharger came from me, I have the Supercharger data from the Vortech Engineering Supercharger Stand Testing, and I have done Boost for a while.

Tom V.

How about some guesses from Jim and George, they run superchargers!

Tom V.

The engine will use a set of Crane hydraulic roller lifters set at .025" pre-load or better known as a half turn on a 7/16-20 stud. 3/8" thick wall push rods.

The valve springs have been installed at 1.800" 180#'s on the seat, 420#'s open.

The cam is what we call the pump gas 750 Hp cam. This will be the target Hp based on one atmosphere of boost pressure. The 1000 Hp cam has a few mods to allow it to breath above 6000 rpm.

The target will be around 400/410 Hp N/A based on the 8.7:1 compression ratio.

The base setup will use a 8.1" diameter crankshaft drive pulley and we will test with a 3.4" and a 2.95" supercharger driven pulley diameter.

https://vortechsuperchargers.com/col...ant=7813351297

I think Tom hit it really close right off the bat. I'll say 800 for the under...

Scott,

We generally always target one atmosphere when utilizing a stock block. We will know a lot more after we test this engine, it has all of our current "boost" essential stock block parts and modifications.

It seemed to run very well when it was on the run in stand where we set up the initial EFI parameters and checked for leaks.

the LS-1 firing order really made it calm and smooth.

Does the "rule of thumb" for close to doubling power at one atmosphere apply if the air charge isn't cooled? Is that even an accurate rule of thumb? One of those things I read somewhere, but have no boost experience, so I don't know what's true...

Its not a rule of thumb, it is basic physics, given STP.

Air charge temperature and velocity can be handled in a couple of different ways. We figure the throttle body and it's spray pattern design will cool the charge coming in from the blower, hence the reason for no inter cooler or water meth on this build.

We also picked a larger more efficient blower (means denser, cooler charge) and we will be running it at half speed 13-15 psi of its possible 22-26 psi output capability.

This is the main reason for the duration numbers on the camshaft. We learned on the first build that too small of a cam, the motor literally shuts off because you cant feed it.

Good questions, thank you.

Thanks for answering. I'd be nothing short of dangerous trying to mess with one of your supercharger systems, but I want one nonetheless...

Most "Rules of Thumb" are really not set at a specific number.

One "Rule of Thumb" that is directly related to your question is this one

One Pound of Air mass will make 10 horsepower. Double the air mass you double the horsepower.

The deal is, depending on the weather conditions, that pound of air mass might make 9.5 horsepower or 10.5 horsepower.
So in one case 100 pounds of air mass gives you 950 horsepower and in the other case it gives you 1050 horsepower.
You have a 100 horsepower window. So you really can't go much by Rules of Thumb except in simple discussions.

Vortech tests superchargers at 68 degrees F and 29.23 HG pressure on their supercharger flow stand.
Not 29.92 and 59 degrees vs the normal STP quoted numbers. They decided that was more real world vs a 59 degree day and being by the sea.

Tom V.

Believe me, Tom, all my discussion around boost is "simple". I find it very intriguing, but know little about it. Thanks for your example, that does simplify the numbers, and the reasoning around the "rule of thumb.

Very Nice Mark!!

Steve Page
475 Cubic Inch, 4" Stroke
DCI Ram Air V Heads
8.5 to 1 Compression
Anticipating a Supercharger install!

Would running e85 with port injection get roughly the same ability to run without meth or an intercooler on this engine you're testing? Or is that too late in the intake tract to get it done?

Intake "Air Charge Temperatures" should be the reason why you use or do not need a Inter-cooler/ methanol injection, etc to keep the intake temps within a specified number.

If you have a Efficient Boosting Device that has an efficiency of .78 vs say a Roots Supercharger that is in the .56 range you possibly do not need a different fuel like Methanol to keep the engine alive or an inter-cooler.

Some Boosting systems have been used with Inter-coolers, others with water/methanol injection like the Snow Injection Systems.

To answer your question, Scott65, take a look at what Charlie66 has on his 4 cylinder Turbocharged Pontiac Engine. He has Fuel Injection, runs E-85 Fuel, runs an Inter-cooler, and has boost levels in the 30 psi to 43 psi range.

A engine at 12 psi might get by with just a different fuel and careful tuning.

NOS systems made great power but you were constantly tied into the Bottle Refilling
"Trap" where when the bottle was empty, you had less power.

Belt driven devices and Turbochargers eliminate that situation for the most part.

A good Street Centrifugal Supercharger can be mounted under the hood, make 1000 HP easily, and no one is the wiser. Same deal with a Proper Turbo System.

John Clegg has a 2400 hp Centrifugal Supercharged "Pontiac Race Car".

Tom V.

Intake "Air Charge Temperatures" should be the reason why you use or do not need a Inter-cooler/ methanol injection, etc to keep the intake temps within a specified number.

If you have a Efficient Boosting Device that has an efficiency of .78 vs say a Roots Supercharger that is in the .56 range you possibly do not need a different fuel like Methanol to keep the engine alive or an inter-cooler.

Some Boosting systems have been used with Inter-coolers, others with water/methanol injection like the Snow Injection Systems.

To answer your question, Scott65, take a look at what Charlie66 has on his 4 cylinder Turbocharged Pontiac Engine. He has Fuel Injection, runs E-85 Fuel, runs an Inter-cooler, and has boost levels in the 30 psi to 43 psi range.

A engine at 12 psi might get by with just a different fuel and careful tuning.

NOS systems made great power but you were constantly tied into the Bottle Refilling
"Trap" where when the bottle was empty, you had less power.

Belt driven devices and Turbochargers eliminate that situation for the most part.

A good Street Centrifugal Supercharger can be mounted under the hood, make 1000 HP easily, and no one is the wiser. Same deal with a Proper Turbo System.

John Clegg has a 2400 hp Centrifugal Supercharged "Pontiac Race Car".

Tom V.