Holley Avenger EFI on Budget 532 lbs-ft 383

[Bos's5.0]

I would be interested to see if anyone could find a 383 of any kind making almost 500 lb/ft @ 3000rpm.

I did some minor scouring online and nobody has anything close, not even LS1's with vastly superior heads than chinese edelbrock knockoffs .

[fastblackracing]

The cam specs and the superior AFR control of the fuel injection are helping to drive this
builds torque numbers where they are.....A lot of people seem to be afraid of the tighter
LSA cams....And yes I understand what that means...but it is the cumulative effect of the
open and close points and also the amount of overlap that LSA changes to give the engine
what it needs at the right rpm range....And not over heading the engine but making the
best use of what you have.

Could likely see that same cam but with the LSA opened 4* lose 30 foot lbs.

[jsgarage]

[quote Dang,
I come and join this forum and who do I run into...David Vizard. This is Andy Wood, I hope all is well your way. Did you ever finish that SBF book? I now have a 1971 F100 that i'm building into a gasser style build. Its going to be powered by a 393W. I'm giving a tunnel ram a try on this, should be interesting.
Andy [/quote]

X2 on the long awaited Ford (pushrod) tuning book. Plus another beg for a least a chapter using stagger-valve Cleveland heads. I get lost trying to apply the usual BBC valve motions & timing to my SVO heads!
Cheers- J DeRyke

[David Vizard]

Guys,

I see a lot of pertinent questions and comments here. I've only just picked up on this reinvigorated thread and the engine built was quite a while back.

Unfortunately I cannot remember every single detail on the build as it was almost 3 years ago that it was done and lot of water has gone under the bridge.

What I can remember with reasonable certainty is that the heads were from Liberty. For the price the heads looked pretty decent quality but what I do remember is that the intake port looked 's suspiciously like a dead ringer for a Dart intake port. The exhaust however was a little below par and I did give that a basic rework to get some halfway decent exhaust flow.

The reason this engine made good on output was because the cam was right for the cylinder head/bottom end displacement combination. For what it's worth [and this is far from intuitive] the torque output of an engine is only very loosely dictated by the airflow. When a cam selection is made for engine that has the heads already decided on than the cam must suit those heads. Obviously the less flow the cylinder heads have the less the power that can make but, as far as torque is concerned, the cam should have a duration and event points that make the most of the cylinder heads. The less flow the heads have the less RPM the peak torque will occur at if torque is the goal that's being optimized.

Remember good build consists of a combination of parts that are compatible. This is something that I stress all the time. By getting the combinations right the build will do far better than the parts used would suggest. The real trick here is knowing or being able to calculate what parts combination is likely to deliver the best. There was nothing special about this engine other than it was a good parts combination and could be built by anybody at home in the garage or failing that - in the kitchen!

Given the time I may be revisiting this engine. If that happens I'm going to give the cylinder heads of full porting job. Then cam it to suit the heads and try it both with the two-plane intake and a single plane. Please don't hold your breath here. I'm up to my ears in work but I'm far short of the energy required to expedite anything very quickly.

One thing I would like to reiterate here is how well the much 'debunked rule of thumb' 128 formula for the cam lobe center line angle worked. The success of any cam can be largely confirmed by a high Brake Mean Effective Pressure (BMEP) and that is just what the free, accurate and more to the point, extremely simple, 128 formula gives!

One other point for my put down critics to take into account - let's not forget that this is an 87 octane pump gas build!

Thanks,
DV

[RevTheory]

David,

Do you have any experience running the QXI lobe family in a SBC with 1.7 rockers?

[David Vizard]

David,

Do you have any experience running the QXI lobe family in a SBC with 1.7 rockers?

Yes!

[RevTheory]

I guess I have to call and pry it out of you like a wisdom tooth

[David Vizard]

I guess I have to call and pry it out of you like a wisdom tooth

Yes - I want to know how you are doing and that is not ST business!
Take care,
DV

[psychomotors]

David,

Do you have any experience running the QXI lobe family in a SBC with 1.7 rockers?

Yes!

That answer kills me,lol. This is a very interesting build and am glad it was brought back to life.

[user-29956]

Maybe it would make 600lbs with some more tuning and 1/2° less LSA. That is truly world class.

[NewbVetteGuy]

I would be interested to see if anyone could find a 383 of any kind making almost 500 lb/ft @ 3000rpm.

I did some minor scouring online and nobody has anything close, not even LS1's with vastly superior heads than chinese edelbrock knockoffs .

An HT383 crate motor with a good oil pan and an electric water pump manages 440 ft lbs at 3,400RPM with iron vortec heads, 9.1:1 compression, and a wild-ass-guess of a 110 or 112 LSA baby cam so it shouldn't be THAT hard to believe...

Here's a 355 w Vortec Heads, TPI intake, a DCR on the edge of acceptible for premium fuel, and a super crappy (for max torque) Comp OEM fuel injection-safe cam with a laughably wide 114 LSA and 0.531 lift -it made 458.4 ft lbs @ 3,000 on 355 cubes and a cam that's terrible for trying to hit a max torque #. -If you just increased the displacement by 33 to a 383 and only gained 1 ft lbs per cube (many on here report significantly better improvement) this engine would be at 491.4 ft lbs and that's with a cam that would be pretty terrible for a max torque build and Vortec heads...
http://www.hotrod.com/articles/hppp-091 ... ck-engine/

383, AFR 195 street heads, Comp XR288HR -.520 lift, 110 LSA, headers, stock TPI intake: 501 ft lbs @ 3,900. Upgrading to TPIS big runners, porting the intake, and extrude honing it = 533 ft lbs (@ 4.000, though). -See DV, this guy's got you beat in terms of ft lbs / cube; you need to revisit this build with AFR heads and a long-runner intake, and just give up on the HP#, IMHO; max torque per cube below 6,000 RPM build!!!
http://www.powerperformancenews.com/tec ... -upgrades/


383, 5.7 rods, 10:1CR, Motown 220cc heads (should make shit low-end torque, right?), Comp XR295HR 242@0.050" (should make really shit low end torque, right?), only 1.52:1 rrs, 110 "comp special" LSA, Air Gap intake- 491 ft lbs up at 4,000 (I'm guessing this # drops off quite a bit at 3,000, though).

---Tightening the LSA increases torque and lowers it, increasing the lift into better air and going with a faster lobe to keep the advertised duration and DCR up increases torque, using the EFI and a knock sensor with a good tune to go a bit lean to maximize torque, and having chilly dyno air and water temps to crank up timing more than you normally would with the engine in the car, should all provide a sizeable jump in torque. -In the dyno cell, I totally buy it and I think more is possible, still with a large injection of $$$$. (1mm ring pack with Mahle pistons, anti-friction coatings, dry sump+vacuum pump, TRI-Y headers that start small at step up at each "Y", a ported long-runner FIRST Fuel Injection Intake, AFR 195cc heads instead of the chinese 200cc heads, COP/CNP ignition with a 58x crank trigger, and step up to the Holley Dominator w port injection and tune each cylinder's AFR and ignition timing, go for broke and make it a 396 so you get an extra 13 cubes AND a faster piston speed at your torque peak RPM... and then cry yourself to sleep about the little gain that you got for all that $$$$, but if it was someone elses $$$$, it would be fun!)


I'm only an internet keyboard enthusiast, though. But, I do follow max torque SBC builds religiously and seek them out across the 4 winds of the internet; they're my favorite thing. I think the #'s are quite possible in a strictly controlled dyno room; not so sure in a real car having to deal with it's own heat and outside heat, at least not with more tricks and gobs of money.



Adam

[NewbVetteGuy]

The cam specs and the superior AFR control of the fuel injection are helping to drive this
builds torque numbers where they are.....A lot of people seem to be afraid of the tighter
LSA cams....And yes I understand what that means...but it is the cumulative effect of the
open and close points and also the amount of overlap that LSA changes to give the engine
what it needs at the right rpm range....And not over heading the engine but making the
best use of what you have.

Could likely see that same cam but with the LSA opened 4* lose 30 foot lbs.

GREAT post; really informative, helps a newbie like me understand how this build ticks.
-Obviously the ability to go a bit learner on the AFR and a add a bit more timing in a strictly temp controlled air and water temp environment of a dynocell helps, too, right?


Adam

[NewbVetteGuy]

...
For what it's worth [and this is far from intuitive] the torque output of an engine is only very loosely dictated by the airflow. When a cam selection is made for engine that has the heads already decided on than the cam must suit those heads. Obviously the less flow the cylinder heads have the less the power that can make but, as far as torque is concerned, the cam should have a duration and event points that make the most of the cylinder heads. The less flow the heads have the less RPM the peak torque will occur at if torque is the goal that's being optimized.
....
DV

David, Can you help me unpack this more?

My understanding was that if you had two versions of the engine, both with identical everything (except heads), and you swapped these heads for a set of heads with the same Min CSA and Average CSA, but more flow, you'll end up with higher velocity /total air mass (afraid to say "port energy"... and trigger the trolls...) because you are moving more air through the same port size which increases average velocity and therefore air and fuel in the cylinder and therefore more torque. <-This is my thinking behind my guess that moving to a 195cc AFR head would gain more torque, as there's +20 CFM at your max lift AND a decrease in min CSA, therefore, more average and probably peak airspeed & torque...

Am I confusing things, or just setting up a scenario that would never happen? When I compare 23 degree SBC heads, I like to compare the CFM flow at each lift value ALONG SIDE the min CSA for that head and use that ratio of CFM to min CSA as a mental equivalent for average port speed and therefore average torque.... -Is this a mistake to do?



Adam

[NewbVetteGuy]

David,

Do you have any experience running the QXI lobe family in a SBC with 1.7 rockers?

Yes!

I'm afraid of what the velocity of that poor valve would look like... Make an engine that sounds like a machine gun, rather than a sewing machine at 6,200RPM??

I'm assuming 1.7 rockers on these cams isn't going to be a recommended practice from COMP for street-going SBCs...


Adam

[NewbVetteGuy]

That is truly world class.

It is; I love this build. 1.39 ft lbs / cubic inch on a <6,000 RPM 383 SBC -with a DUAL PLANE intake.
Big block torque, small block prices.

Add a 700r4 or 4L60e with a 3,000 stall, lockup TC and a really nice and low rear gear and you'd still have GREAT off-the-line launches because of the torque, low first gear and stall speed, and you'd get AMAZING highway fuel economy with the low cruise speed, lockup TC, and EFI going into lean burn mode... Hmm... wonder if with all the overlap if AR headers could further help the low-end, too...

-Rebuilt SBC 383 with well over 500 hp and 500 ft lbs and 25 mpg highway fuel economy. What more could you want?
Have Terry Walters add this as another DV collaboration crate motor and partner with Monster transmission and Holley so it comes with a 500 ft lbs capable 700r4/4L60 and a Holley Sniper EFI as a $1,000 add-on. "500/500/25 Resto-Mod Special: Just Drop it in and Drive! We don't need no stinkin' LS"".
-A competitor for the GM "Connect and Cruise" LS crate motors (The LS3 430 HP, 424 ft lbs "Connect & Cruise" package with 4L65E from GM is $13,550.66; what would a run-of-the-mill 383 with ProMaxx heads, a Comp roller cam, Holley Sniper EFI, and 500 ft lbs capable 7004R sell for?)


These are my favorite engine builds bar none; I love this @#$@!


Adam
P.S. Sorry guys, I just realized I posted 5x in a row like a nut-job; didn't mean to take over the thread. I REALLY like this kind of high torque, good power, good fuel economy, street SBC builds and get... overly enthusiastic about them.
P.P.S. I forgot the link to the 220cc Motown heads 383 build that I mentioned way above and it's too late to edit it in now, so: http://www.hotrod.com/articles/hrdp-050 ... 83-engine/