[i82much]

Just trying to make some sense of things. Dyer's FAQ says you get about 1.5 HP per CID with a street blower setup:

http://www.dyersblowers.com/223/268.html

Now SD is making 700 HP with 340/350 cfm e-heads on a 500 CID engine, about 1.4 HP/CID:

http://sdperformance.com/listProducts.php?categoryID=25

Am I missing something? It would seem like an 8-71 is hardly worth it to go from 1.4 HP/CID to 1.5 HP/CID.

Do gains from flow and gains from boost "add" together reasonably well, or is it a one-or-the-other proposition? On a reasonable street setup, could you see making much more than 1.5 HP/CID with an 8-71, 350 CFM e-heads, and a 500 CID Pontiac engine (aftermarket block, etc.)?

[TIN TIGR]

are you kidding?..no n/a motor can match the snap response of a roots blown deal..and where the 500 inchers need many upgrades for more power(cam, or more head, exhaust) all ya gotta do with the roots is turn it faster..

roots make the power without the rpm, saving parts..they impress the guys, and the ladies also..nothing sounds or looks as wild..

and the price of the kit is about the same as a block ready to go 500 inches..

build the 500 and put a 10-71 on it..then u be the man..

[Tom Vaught]

Originally Posted by i82much

Just trying to make some sense of things. Dyer's FAQ says you get about 1.5 HP per CID with a street blower setup:

http://www.dyersblowers.com/223/268.html

I read the link and did the math for the 525 HP engine quoted. They are assuming that a 350 cid engine will make 1 hp per cubic inch naturally aspirated. (350 HP times 1.5 hp per cubic inch = 525 HP). If the Chebby engine was a 400 cid engine then the engine would make 600 hp at 1.5 hp per cubic inch. Still a stretch from the 700 hp number you quoted.

1.5 HP per cubic inch is a very conservative number with a blower system. It assumes that you will add slightly more than 50% more density to the engine at the same peak hp number. Depending on the engine and heads that could be 7-10 psi of "Boost" to get that density.

The engine should be very streetable at 550 hp with the blower adding a lot of "WOW" factor to the vehicle.

Originally Posted by i82much

Now SD is making 700 HP with 340/350 cfm e-heads on a 500 CID engine, about 1.4 HP/CID:

http://sdperformance.com/listProducts.php?categoryID=25

Am I missing something? It would seem like an 8-71 is hardly worth it to go from 1.4 HP/CID to 1.5 HP/CID.

Do gains from flow and gains from boost "add" together reasonably well, or is it a one-or-the-other proposition? On a reasonable street setup, could you see making much more than 1.5 HP/CID with an 8-71, 350 CFM e-heads, and a 500 CID Pontiac engine (aftermarket block, etc.)?

One HP per cubic inch on your Pontiac 500 cid engine would be 500 HP.
1.5 hp per cid would be 750 HP.

The 700 HP SD performance engine would most likely have a much different camshaft which could affect driveability of the engine.

As far as the aftermarket block 500 cid and the 350 cfm heads, you should look at the Luhn Performance engine test. A BASIC 455 engine with 2 bolt mains and less cfm heads made 861 hp with the most basic Vortech Supercharger "T-trim" unit at 13 psi of boost at 5300 rpm. If you had a 500 cid aftermarket block and the same heads with the next level up Vortech Supercharger (YSi) the engine could probably make 1000+ hp.

700 hp is a good number for the average Traditional Pontiac block to survive (if built properly). When you move to an aftermarket block like the ALL PONTIAC cast iron block you open up the door for a lot higher horsepower with any boosting device.

Some years ago, Bob, Frank, David Butler, Travis Q, Rod Butler, The old Indian Adventure Guys, Ram Air Restoration, BOP, and I had a meeting at VMP to discuss how we would move Pontiac into the Boost World. We had a Great Block, we needed a Forged crank minimum to move upward on the HP. The Forged crank happened. Forged cranks are common now. The 861 HP Luhn had a Forged crank but the 2-bolt block was still pretty basic. We did not split the block in half during testing. That says that the guys above were right about that need. The next "need" was a "Bolt on Kit" supercharger that worked. Luhn has provided the engineering on two demonstration engines now to prove that their stuff works. The 861 HP engine and BAD69BIRD's 1300 HP race engine.

While we waited for years on the Vortech brackets (which never really happened), the people interested in "Boost" started Forums, started experimenting with "home builds" with relative inexpensive diesel turbochargers and started creating their own installations. HOT ROD stuff vs Credit Card stuff (like a BDS kit).

Yep, the BDS stuff doesn't see like a very big bang for the buck but you can order the parts easily, install the parts on a decent engine in a month, (worse case deal) and be driving the car with the "WOW" factor. It just takes money or a credit card and you wind up with 1.5 hp/cid if you don't change anything.

Tom Vaught

The Luhn engine made 1.9 hp per cid with very basic available parts at only 5300 rpm. It could have probably made 1000 hp if the right bore head gaskets had been installed, which failed on one side. The "T-Trim Vortech is considered to be a STREET supercharger.

[Travis Q]

This particular engine made a tad over 900 hp with 489 inches, 9 psi boost, and pump gas:

http://www.butlerperformance.com/Fea...9ProCharge.htm

900 hp @ 489 inches is 1.84 hp/cid. With P/S, alternator, A/C, and a vacuum pump.

TQ

[Tom Vaught]

Travis, I have large copies of those photos on my wall at work to show the Ford boys what a 900 HP street car engine looks like, LOL!

Tom Vaught