Patron

Tony made over 620+ 383ci 550 fwhp I have the OLD*mag. RPM limited to 6500 let me find it. Some of you guys have been reading 1 to many pro- stock builds with all the reduced friction stuff. Simple question 440 big bore 406 big bore who"s kicking as? You have the bore.

speedtigger

iTrader: (16)

That 383 would be interesting with the new MAST "L93" heads. They are a reworked version of the Mast 240cc small bore LS3 heads with an improved port and combustion chambers reworked for a 4" bore. Those heads and the FAST mid-length runner manifold.

Patron

https://ls1tech.com/forums/dynamomet...-included.html

Patron

Your wish and I'll find it LOL!!!!!

NAVYBLUE210

I have that mag as well in fact, probably every LS build that Tony or
Richard Holdener has done also.

Tony's 383" with AFR 225s & solid roller, 242/248, 114 LSA
Made 611 HP on the Westech Dyno @ 6800 starting to roll over @
7200+, 523 lb'
Made 530-540 RWHP in a Very efficient C5.

Hammers 388" 630 RWHP @ ~7200 carrying to 7800+
80+ RWHP from 5" & +40-60 CFM From ~.300"-.700"
and I think Hammer would have liked another 4-6* intake
Duration.

My 396" same Dyno as Tony, 11.7 VS 11.0 Comp
243/249 LLSR , 115+3 .680" VS .650" Lift
Similar cam specs (some would say small & or incorrect)
+40-70CFM from ~.300"-.700"
690 HP @ 7100-7300 RPM, Carrying to 7600+,
VS 611, 543lb' VS 523lb'

Advantage of studying builds for Many Years.

You are correct in that Most here with a Big Bore would use
A 4.00" or at least 3.9" Stroke.

For me it wasn't what I Wanted or Needed, not trying to convince
Anyone differently for 95% of most builds.

My friend 64 Post is building a wicked 416"
With a 4.0" stroke, that will make some
Serious Steam here pretty quick (6-8 weeks)

Patron

They all will make ball park numbers depending on RPM. 416 to 7400 = around 740 depending. Less cam less hp and choice in intake. Now I will say this what I have now with less than 410ci using a factory block will make over 740 on just camming and heads/carb intake. 7500 Peak Rpm. If you know one build you pretty much no them all. Camming/rpm with intake choice will decide how much and where it's at on the rpm chart. I call it ball parking it to get a general number which is not perfect but reading between the lines to know where we're at in the basic sense.



For a 4 inch stroke I know where a solid roller 250/260/270/280 would place me at in terms of RPM. A given lift and compression. We have a Ball park as there are other builds doing 416 which to reference.

NAVYBLUE210

I figured about 750, but I think only Dyno will be in car.
With LLSR, High Comp, E85, and Powerglide targeting
620+ RWHP & Easy 9 second times @ 138+.

pantera_efi

iTrader: (1)

Hi Patron, thanks for the PM.

The EAP model is based on OEM level LS-3 with a Cam Spec of 244/256 .621"/.612" with a 114 C/L (a common spec) AND 24" exhaust primary. (shorties)

WE ALL KNOW different parameters will create big changes.

Your quest is Bore/Stroke performance.

Thus : 408 = 6000 RPM Torque of 589 and 6500 RPM HP of 677.
406 = 6000 RPM Torque of 588 and 6500 RPM HP of 676.
MODE : 408 = 5000 RPM Torque of 575
406 = 5000 RPM Torque of 572

What we know is a 4.00" crankshaft is "shelf"
What we know is a 3.75" crankshaft is custom at 2X cost.

Piston Speed = 408 6500 RPM of 4333
Piston Speed = 406 6500 RPM of 4063

What "new" specs Patron ?

Lance

my406cid

Wow. Thanks pantera

Patron

Thank you so very much Sir! If you could for these same people take that thang on up to 7500 or 8k so I can have a laugh. They say they wanna rev well let's rev since it's so easy with the shorter stroke. We know about the bigger bore. Yet similar cubic displacement. A Good set of piston rings does Wonders against wear along with a good builder.

Darth_V8r

iTrader: (4)

That's an awesome read for sure. One thing - it shows how truly good the AFR205 was and still is. I honestly suspect that 98_WS6_M6 383 might end up slightly better, because he has the 220 heads and the MSD short runner intake. Both should be slight upgrades vs that motor. Although, lets face it, that thread was from 2005, and it's still better than many of the 383's you see today.

I do see that the 383 made more power than the 346 with the same basic configuration, so I see where the stroke did add power and torque vs the 346.

But, Also, that motor made less at the crank than Big Hammer did at the rear tires in his 388. That's why I'm so interested to see 98's results. Even so, Hammer's got a bigger cam and solid vs hydraulic.

I love threads like this.

big hammer

They'll have similar peak TQ but at different RPM's. the 406 will have more hp potential

Patron

Engine that would be the 383 would need a cam like 247-251@ .050 along with a MSD intake. To help with the RPM, fair is fair. I'd say every 4 to 6 degrees with a hydraulic roller is worth 20 hp with a slight loss in Tq. Solids need a hair more. The crank as we know would eat up the same cam as we see with 242 at .050 move the duration up and dial in the LSA to Peak where it's wanted. Boom more rpm that peaks early or at the desired rpm of say 7400. I try to keep things as Simple as possible as with the 4 in crank no matter the bore give me the rpm & intake used. They all will generally make around what's been read or built. And that's a lot. You guys remember Tim's 454 hydraulic roller 775 hp with Factory Ls3 heads. Add a solid roller that is 800 at 7500. That was as simple as cookies and milk.

blk00ss

iTrader: (66)

Please don't call him. He'll be in here telling us about 58t TW's and only his cooks can handle that rpm and how you need to gap your plugs at .075"

NAVYBLUE210

Biggest and most important Difference.
Airflow CFM Delta between MAST LS3 Heads &
MMS 220s, followed by the Intake Runner Length
Difference between FAST Mid Length & FAST
Long Cat Runners or Even MSD Cats, which are
Still longer then the Mid Lengths.

Patron

No just stating facts. Did the 406 out do the 408 Yes or No? Who spent what to accomplish what and it's around the same. Don't be foolish blk00ss. Money spent to have what a junkyard stroker does? I understand being different and I can accept that. It's the it's gonna be so much better with the bigger bore shorter stroke is what I don't get. When there about the same size? Here's another 4 inch revving to 10k I guess it doesn't work on typical ls engines just for shorter stroke ls engines.

http://www.yellowbullet.com/forum/sh....php?t=1156026

pantera_efi

iTrader: (1)

Hi Patron, SURE 8K IS FAIR.

The Camshaft, Intake ???
You Specify, it would then be simple.

You, Patron use your brain, THUS NOT A BLACK "00" *** !

Lance

Patron

Cam it around 274 to 280 duration 750+ lift, with a carb style intake. Let's max each head not limit it. Thanks again Lance.


Darn good topic took most of my evening..... let me see the last parts of this preseason NFL game. Had fun. I'll be bac.

speedtigger

iTrader: (16)

This is not a generalization that you can make. It depends on the combo and the size of the existing camshaft. In the example you are working with, 20 peak HP from 4-6 degrees would be very generous.

Patron

Speed that's a generalization(of what I read a long time ago) that was used for a sbc with the same stroke etc..., only a cam change. Engine made x amount 6 degrees in duration were added and it picked up around 20 at the crank it did lose some Tq *add some comp. Old old old Hot Rod mag. 383 gen 1 style chevy with Brodix heads 11:5 comp. Maybe 10:5 compression very old read. Still got the old mag along with around 300 others LOL.


I'm waiting for Lance. We seen 6000 rpm and it's the same for more $. Let us now see what happens with RPM. Big bore heads flow 400 and small bores flow around 360 to 390 depending on CSA and heads used.