Viet Nam Vett

I was watching Horse Power TV and they were putting together a "SHAFIROFF" ... SB Motor which dyno-ed out at 675HP.!!! This is a Pump Gas Street Motor... So I went to ther web page and found some of there motors..check them out..
They also have a buch of Outrageous BB mill's also..

I guess when you start looking at doing a BB conversion you can get info overload. So many choices out their. What do you guys think?? I still want to do BB for that low end low RPM torque..
http://www.shafiroff.com/sportsman_engines.asp

L79vette

Uhhh... the website says the 675HP engine has 14:1 Wiseco pistons. I suppose it depends on what gas station you go to.

If you want that kind of power on pump gas, you need to use forced induction or nitrous. You can get 550+ HP from 434 inches on pump gas naturally aspirated, though. That's really more than plenty with street tires anyway.

I looked around a bit more, and they do have a 625HP version that they say runs on 94 octane. Interesting stuff, but danged expensive. Especially when you add on the 950HP or Barry Grant 1090CFM carb options that add close to another grand to the price.



[Modified by L79vette, 9:51 PM 3/22/2004]

SWCDuke

On a street engine, torque bandwidth is key, not peak power.

Assuming this SB is naturally aspirated I can imagine that the bottom end of the 80 percent torque bandwidth curve doesn't start until well over 3000 revs.

This would not make a very pleasant street engine.

Duke

L79vette

On the other hand, Duke, if the motor pumps out 500 lb-ft of peak torque, then it really wouldn't matter if it was only giving you 60% of peak torque at 2000RPM. Not that I've seen the dyno sheets, but it is something to think about. We're accustomed to thinking about motors that peak at maybe 370-400lb-ft of torque.

SWCDuke

Peak torque on a NA engine is a function of displacement and CR, and I don't think and "normal " SB could make anywhere near 500 lb-ft without boost. An unlimited NASCAR 355 makes around 750 HP at 9000, but it would be very cantankerous for street use.

I notice this "small block" has a four-inch stroke, so the bore must be about 4.15". I don't know how they do this and make something that lives, but for the prices they charge you should be getting something.

Yeah... 434 SB, 14:1 CR, roller cam - just your average street high performance SB. ;)

Even if it will flash 675 HP on a lab dyno, by the time you put it in a car with a real street exhaust system, etc. you can be assured that it won't make much over 400 SAE corrected RWHP, the low end torque will be poor, and the driveability even worse.

To get that kind of specific output from a pushrod engine it will need TONS of overlap, and when you add exhaust backpressure from a reasonable street exhaust system half the chamber will be full of exhaust gas instead of fresh mixture, so the power will evaporate!

Duke




[Modified by SWCDuke, 11:27 PM 3/22/2004]

PatsLs1vette

i used to buy all my parts when i was building circle track motors from scott.NIce company to deal with.

Subfixer

I watched this show also. The Small Block they built is 478 Cubes!!. They did that using a custom short block with .300" raised decks and the cam centerline is located .300" above normal also. Necessitates the use of a special timing chain and .300" longer pushrods. All this so they could use a huge stroker crank (forgot the stroke; 4.25" I think). The block has siamesed bores to support the large bore as well. Is quite an interecting piece, but I'm sure it takes "interesting" $$$ as well.

achapman

Hey VNV,

I see us "house bound" guys are watching the same channel. Yup, that small block mouse sure pushed the limits. The neat thing about it was that it was built for the street and able to run on pump gas. And the torque came on in the low RPM's and stayed pretty much flat across the board.....

I think I'll have a BB for lunch.... :lol: :jester :lol: :jester :lol: :jester

66427-450

I agree..... that's why I like the highly tuned BB's, you still have SB torque levels for low RPM/intensity street driving.

six-T-six

Building a massive small block eems like alot of trouble to go to when you can get a stock 502 right from GM with plenty of parts. For the street, it just doesn't seem worth it except for the exclusiveness of it. Of course if someone wanted to give me one... :lol:

66427-450

hey, better be careful :-) ..... how about we do the same mods to a BB and then see who eats who ? :lol:

Subfixer

Here's a link to the show products from HP TV. Look for the Shafiroff Episode March 6 and 7th. All the parts for the engine are listed here. The block was a Dart piece. CR is 10:1, Brodix M2 Heads, etc....
http://www.horsepowertv.com/showproducts/

JL66REDCPE

Mark

Dig up a couple cans in the back yard and go buy a Big Block car.

:D :D :D

Viet Nam Vett

:lolg: :lolg: :lolg: :lolg: :lolg: :lolg: :lolg: :lolg: :lolg: :lolg: :lolg:

You know...I have to check all this gack out before I spend my buried money..

________________________________________ ________________________

And Andy..Where you been???? Your still house bound..Just for a Little bump.

Always Use The Propper Tools..!!





[Modified by Viet Nam Vett, 12:39 PM 3/23/2004]

achapman

Hey VNV,

What was your quote...... "I get no respect...... :leaving: "

I'm looking better now.... :jester

kyosho

That is some serious power. As was stated before, questionable how 'streetable' it is, but at any rate, very impressive. :D

garagedweller2

:eek: Define streetable :D

JohnZ

Idle quality/stability, progressive throttle response, no flat spots, low-end torque, freedom from detonation, abililty to run on pump gas, etc. - all the things the "magazine dyno tests" pay no attention to whatsoever :rolleyes:

Viet Nam Vett

On the show they were working with the Pump Gas version of the motor in which they stated ..that it was streetable as far as pump gas goes.

Of course...Low end torque and the other items you mention were not covered on the show.

That's why I like the BB's.. I'm interested in Low end torque Plus HP ..and streetable performance under 5500 RPM. I'm really not into the 6500 RPM rod throwing Valve floating RPM range.

That's waht I like about my 86 Vette L98. It develops it's max HP and Torque at 3400 rpm. :cheers:

66427-450

Well .... we're all different, and some of us have different priorties when it comes to engine performance. And if someones engine is not designed/setup for high RPM use (worry about throwing a rod at 6500?) then I agree, he better keep the RPM's down.