Well, i've been waiting for a while to get the new 383 motor tuned, and let me just say. It was well worth the wait. Some interesting combination results came from this 1 on 1 tune with bryan.

My cousin had the EXACT same bottom end built (forged bottom end-eagle/eagle 383/pistons/rods/XFI280 cam/ etc...) He had the machine shop that assembled the engine, port his heads. They did a good job, and got them to flow 280cfm intake 195 cfm exhaust.

I however had a different set Ported by LLoyd Elliot, these were an older port job, before he had "le1, le2, and le3" packages. My intake flows 265 and exhaust 192, and heres the kicker...

My results
427hp/421tq

http://img22.imageshack.us/img22/972...3dynochart.jpg
My cousin made 401hp/411tq with a peak @ 5,800rpm

He pulled first and then i pulled second.
Bryan Herter also though he should have had more HP, but he squeezed every last bit of power out of his car (he was on the dyno longer than i was)

The Reasoning: Bryan asked where my cousin had his heads ported, and he had told them as a local machine shop, who normally builds drag SBC/BBC motors, and not Many LT1's.
He then said that Lloyds head cuts put a spiral flow on the air which increases the velocity in the (rather small) runner size. "and in the end it always comes down to the head"

So, moral of the story....
Lloyd Elliot

Edit: -Dyno chart posted below to compare engine #'s
-Doing rough math there is a 7-8% increase on my #'s across the board.

 

Very nice!

 

Those are excellent numbers. Lloyd's heads rock. Is the graph of your cousin's car also based on the standard correction factor?

 

His valve train components are more than likely causing the power difference, along with some other small differences in the motor, cam timing, headers, exhaust, etc...not some velocity inducing swirl port, cause that's a load of BS.

You cannot make claims like this unless you test the same motor with only one component change at a time. Without knowing that every single part of those motors and the supporting components are exactly the same it's just pointless speculation.

 

I don't buy the special cut velocity port either. Lloyd just has a ton more experience porting heads and knows what works as far as port size and shape. A lot of shops will just hog out the head to get good flow numbers, which is probably what happened. I bet it was great to see the final numbers. Also when you say the same shortblock, were they built by the same guy or were just the crank/rods/pistons/cam all the same? Great numbers regardless.

 

Did Bryan mention hose close those 32s were to being maxed out?

427 isn't bad at all considering the older head work, Lloyd's newer work
flows quite a bit more. I had him refresh a set of LE2s from 2005 for me last last year
before I decided to go with Darts instead.

Let us know how it does at the track, I bet it pulls like a bat out of hell
Look at that TQ curve

 

looks like that cam did yah pretty well

 

ahah sorry i cant change my sig without taking color off of it.
Thx for the comment james.
and i just put in the 42's before the dyno. ;p

i didnt fully understand the "swirl" either.

We have the exact same cam, head castings (643), valves, block, crank, rods, pistons. the builds were done side by side. by the 1 engine shop. he had his castings ported by the engine builder. the only different components we have are springs, even the RR's are the same.

We also both have elec WP, Long tube headers, 12 bolt with 4.10, but he has a CAT, and i do not.

would his higher seat pressure springs really take away that much hp?

 

Minus a little friction, you will gain it back when the spring is pushing the lobe back down.

 

Here is the Chart of my 4th and final dyno pull, Vs. my cousins 5th dyno pull.
These are the final numbers.
http://img6.imageshack.us/img6/218/j...sdynochart.jpg

 

XFI lobes were designed SPECIFICALLY with beehive springs in mind and a standard spring will need a lot more pressure than a beehive to control those lobes. Even if he has more pressure it could be valve control issues.
A single cat is certainly going to hurt at that level too.

Do you have any graphs showing the correction factor, most shops use SAE not STD.

 

That would be about 410 rwhp SAE. The correction is roughly 4%.

 

416rwhp on my graph. Bryan Herter said the real#'s are represented better by the STD correction. with the environment that we tuned in.

Also, about the 918 beehives, The shop at which we had the engines built, tested, and retested the 918's and had gotten better results with the dual Manley springs that he went with. which are also recommended by lloyd.

 

I'm not necessarily saying that Lloyd's porting is not the deciding factor, just that it's not due to "velocity inducing swirl" - all small block chevy heads have port bias built into them, you can increase this to a certain extent, but it does not create swirl. Late model TBI heads actually had "swirl" ramps built into the port just like a lot of diesel heads do - this is for low rpm efficiency and not high rpm flow as those heads have horrible peak power potential. LT1 heads do not have swirling capability and saying that it can be ported into them is a fallacy.

I assume that the two sets of heads were not flowed on the same bench, because it's reasonable to assume that the shop that flowed the 280cfm heads has a really happy bench and/or they messed up the flow elsewhere in the lift range.

 

Ahh, so you think it might be the heads, and not all of the different engine parts...


although your Point has been taken, as far as "air swirling", but they were the words of Bryan. I was merely repeating what he said. as a posibility.

and no they were not flowed on the same bench, mine were flowed on lloyds bench. i think my cousin just had a max flow done to them. i'd have to ask. so thats another possibility.