Check this bad boy out
LT4 383

 

I think he might be exaggerating a little on the HP #'s though, unless his 650HP # is with the NOS.

 

I think he is exaggerating the HP#'s a little though, unless his 650HP # was with NOS.

 

Dayuuuum Is that thing streetable???

 

It seems like a lot of HP for the flow, compression, and cam he indicates.

I have no doubt it is 500+ though.

 

no way this thing is 650hp. This is just a street/strip 383 LT4 nothing special about it. This is more like a 420rwhp and 11 sec motor.

You are not going to get 650hp with 300cfm heads, 12:1 CR, and near .600lift cam.

 

I was going to say damn maybe my build up in progress will end up 500+ hp

 

how does a .030 over bore cost $4700.00????????

 

That was my first thought too. Even the bill for clearancing and align boring (assuming it was done) shouldn't come near close to that, including the block price. I don't even think bowtie blocks cost that much.

 

It will, just rate in in EHP, eBay HP

 

Too true

 

Yep, that's what I was saying too. 300cfm is way too much cylinder head for the average street strip motor and way too much for that cam shaft.

 

I really don't understand this, but this site seems to support the possibility of 650hp from 300cfm.

http://www.malcams.com/legacy/misc/headflow.htm


HP=300*.257*8=616.8

or

CFM=650/.257/8=316

 

I am not arguing that it is impossible, but I've seen quite a few N/A small blocks with some pretty good heads and 650 horse power is a hefty number.

I can't recall what Ski and Jeb are making, but they are running hand-built intakes and bigger rollers (I think), and more cubes to run in the low/mid-10s. This guy claims 9's in a 3400 lb Camaro - it takes more than 650 to go 9s in that heavy of a car.

I just don't know that the cam is enough to support that kind of HP with the rest of the combo - it just doesn't look to be a perfect match. But none of us have seen the dyno sheet or the head flow charts to really know what lift they are flowing best or where the engine is making it's power.

Of course, I have been wrong before and will be wrong again.

 

I think he's double charging for stuff. I would say that the $4,700 for the boring of the block included the crank, rods, pistons and a few other things and then he separated them out to make it look like it cost a lot more than it did to try and get his money out of it.

 

Bowtie aluminum blocks don't even cost that much.

 

so 300cfm is to much flow for that cam? so if he had a bigger cam(although it would make it less streetable) it would make more power? i agree that 9s with a 3400lb car is impossible unless you put juice on that thing.(with this paticular LT4)
i would definatly like to see the head flow charts, as well as the dyno sheet to see the power band. that would show us more of what the cam is doing. he says the motor is built for NOS yet i dont see anything about the internals being forged.
im kind of surprised he is still running a regular waterpump and not an electris one to free up more power. and doesnt 36lb injectors seems a little small for that kind of power at that high of compression?
you can still run 93 octane in that motor for "street use" right? since its a reverse cooling design cant they run at higher compressions with lower octane than most motors? i would think you would want race fuel in it if you were going to wind the tach up though.
i dont know why he spent all that money and didnt get ceramic coated headers....
im also curious why he didnt just go with a 396 bore and stroke.
seems it would be a little easier to get teh power he was looking for and that way you can get a really high revving cam to get that peak HP he wanted without suffering as much low end loss cause you have more displacement to give you more tq!

 

I am assuming his head flow 300cfm @.600lift. His cam on the intake side doesn't even reach .600 therefore he won't see 300cfm.

I don't think his heads are too big for the cam but he could have choose a cam with a little more lift to utilize the good flow of his heads.

I am not good with math and I don't know how they come up with those numbers but I would think CR would be a factor in Hp as well. I am sure you can make the numbers match on paper but doing it in real world is a completely different story. Take Desktop dyno for example, it is nothing but numbers inputed into the computer but the results always fall short...by a lot.

I also think 316cfm is a huge difference when compared to 300cfm. If I had heads that flow 16 more cfm I would probably gain 50rwhp.

 

650hp noway. I would bet about 550fhp. I am compare to Phil old 401LT1 with big solid roller cam and AFR 220 heads with addtional portinng 12:6:1 C/R and made exactly 500rwhp on pump gas.


Bruce

 

phil tobin? as in the owner of "HOOVER"? hes only making 500rwhp? and hes running a 10.64? WOW DAMN! can that man launch or what?