My other 'job'

[AlNyhus]

Spent two days this week on the dyno with a new build NHRA Stock Eliminator '69 396-375 HP aluminum head engine. The builder is one of my best pals and we work together a lot.

Camshaft was broken in with light springs and then changed over to race springs.

Engines are instrumented for everything from cylinder temperature, air/fuel mixture, manifold pressure, oil temperature and other critical areas. The wiring goes up here.....

...and into the electronic brains of the dyno. From here, it's routed into the control room.

The control console is where the art of dyno work comes into play. Most critical is the servo load and when the water brake 'grabs' the engine to load it. Each engine if different due to the torque curve, power rise and even how the engine responds to the carb(s) as it goes to WOT (wide open throttle). As you can see, the control room window is multi layered, meshed reinforced shatter proof glass. Parts, pieces and parts of pieces from the 'unassisted disassembly' of an engine at high RPM is nothing to be taken lightly....you can get hurt, big time. Since the exhaust is routed out the building, the biggest things you hear are all the mechanical sounds. It's eye opening, believe me.

Finally, the data is displayed on this monitor. The computer than takes the raw data and adjusts it for barometric pressure, temp, etc. to get a standardized power, torque and BSFC (brake specific fuel consumption). The BSFC is an area that we use quite a bit for tuning.

This one made very, very good power and torque and never dinged up a single component.

Good shootin' -Al

 

[Krogen]

Very cool! I'd love to see a video of the operation. (hint hint)

 

[Pawnee Bill]

Nice set up! No more guess work, the computer does it for you. Amazing.
Here's a set up I spent some time around:

 

[SKWERLZ]

I rebuild and 396/375 motor for my old boss’s 56 150, it was a nova motor with matching M22 transmission.
Love the older BB’s.

 

[Bob3700]

Al,
I knew that the 67-69 Corvette's BB had an aluminum head option L-88 and L-89 but am not familiar with the Al heads on the 396. Was this something special for the Chevelle's , Camero's and Nova's?

 

[ebb]

They run up a lot of jet engines close to me at Patt & Whitney's Florida plant. Thake it from me no hush house is involved at all. When the wind is right they can be heard at my home occasionally. The ranv]ch i work at every time they fire one up you can hear them, and not just a little. The lengths they go to to build the house where the test engineers monitor the tests are bomb shelters.

 

[Ggmac]

Spent two days this week on the dyno with a new build NHRA Stock Eliminator '69 396-375 HP aluminum head engine. The builder is one of my best pals and we work together a lot.

Camshaft was broken in with light springs and then changed over to race springs.

Engines are instrumented for everything from cylinder temperature, air/fuel mixture, manifold pressure, oil temperature and other critical areas. The wiring goes up here.....

...and into the electronic brains of the dyno. From here, it's routed into the control room.

The control console is where the art of dyno work comes into play. Most critical is the servo load and when the water brake 'grabs' the engine to load it. Each engine if different due to the torque curve, power rise and even how the engine responds to the carb(s) as it goes to WOT (wide open throttle). As you can see, the control room window is multi layered, meshed reinforced shatter proof glass. Parts, pieces and parts of pieces from the 'unassisted disassembly' of an engine at high RPM is nothing to be taken lightly....you can get hurt, big time. Since the exhaust is routed out the building, the biggest things you hear are all the mechanical sounds. It's eye opening, believe me.

Finally, the data is displayed on this monitor. The computer than takes the raw data and adjusts it for barometric pressure, temp, etc. to get a standardized power, torque and BSFC (brake specific fuel consumption). The BSFC is an area that we use quite a bit for tuning.

This one made very, very good power and torque and never dinged up a single component.

Good shootin' -Al

Love it . Ive taken the last few yrs off of shooting to try and finish my 14 hot rods . Ive done alot but NOTHING like that .
Nice work and $$$$$
My most recent motor build will hopefully make 200 hp . Flat head 3 3/8” x 4 “ flathead merc

 

[Judd]

That’s awesome…it’s cool you enjoy your job so much.

 

[SKWERLZ]

Al,
I knew that the 67-69 Corvette's BB had an aluminum head option L-88 and L-89 but am not familiar with the Al heads on the 396. Was this something special for the Chevelle's , Camero's and Nova's?

There were L-89 Camaro’s, chevelle’s and nova’s.
Very rare.

 

[jackieschmidt]

Well Al, you know I’m a die hard “Rat Motor” man.

Question. In Super Stock, do you have to run a flat tappet cam?

Also, what are the specs on those heads?

 

[AlNyhus]

In Stock Eliminator, you have to keep the stock cam lift for the engine specs. In this case, it's .520 intake and exhaust. The profile of the lobe is open as is the duration. Because of that, the lobe profiles are extremely aggressive. Valve springs can be any spring that fits the head w/o enlarging the spring seat.

These heads are the GMPP #401 heads which NHRA accepts as substitutes for the original 3919842 alum. heads...which are horrible things from a race standpoint. The #401 heads carry a factored HP penalty so if you run them you end up carrying a bit more weight. Combustion chamber, intake and exhaust ports must be OEM volume and valves sizes must be as produced.

Lifters must be as OEM produced. Hydraulics can be replaced with solids. No roller unless the engine originally was equipped with the. The compression ration has to be as produced and there are accepted pistons that you must run. Crank, rods, pins (the rotating assy) must remain stock as per NHRA specs.

Carb and intake must be OEM for the engine claimed. NHRA accepted replacements are allowed. The intake on this one is a GMPP unit. It doesn't make any more power than the original ome.

 

[jackieschmidt]

Al, I misread your original, I thought it was a Super Stocker.

Are those heads cast by Edebrock or GM. They have about the same flow characteristics as the AFR 290 CNC heads on my 540.

I saw quite a few 375 HP 396 Rats in my years, probably one of the underrated engines Chevy produced. With better valve springs, they would rev to 6500+ rpm.

This engine is basically the same platform we ran in APBA Super Stock, except we were allowed 430 cubic inches. (L-88 +.030). Amazingly though, we preferred cast iron heads because since you could not run a stud girdle, it wasn’t uncommon to pull the rocker stud boss right out of the head Because we had to run the stock Rocker Arms. They would get hot, gall, bind up and pull the hole boss out by the root.
you simply keep them cool in 5 lap competition at 6500+.

Those old OEM Snow flake heads were terrible about that. Plus, the original round exhaust port would not flow as well as the cast iron rectangle. It was a toss up on the intakes. Also, keeping head gaskets sealed in that gap where there is no head bolts was a ongoing problem, since the rules prohibited adding a boss to the block and placing a bolt in the port.

Since weight wasn’t that big of an issue in the boat, cast iron was simply a lot less hassle.

Great project. I might have missed it, but what were the dyno numbers? I have seen several “stock“ L-78 396‘s top 480 on the dyno at close to 7000 rpm.

 

[Bill Score]

Pretty awesome set up.

 

[Bob3700]

My 1970 Corvette had the original 390/454 pulled and the dealer installed an LS-7 crate engine in 1971. That engine is in it today. Recently purchased a 454 HO crate engine to replace the LS-7 ( OC alum heads, intake n water pump) Need something that will run on pump gas , have a no maintenance hyd roller cam and be more friendly to my non-mechanical off-spring. Will have to give her a crash course on Holley carbs but the ignition is a factory transistorized unit And pretty trouble free. Love those BB Chevys!

 

[JSH]

Dang you guys! Bad enough with gun porn, now y’all start with the XXX rated stuff.

 

[9146gt]

When I was at Roush wish I had a beer for every motor we put in a car that was still warm from the last Dyno run.
Tom

 

[AlNyhus]

Great project. I might have missed it, but what were the dyno numbers? I have seen several “stock“ L-78 396‘s top 480 on the dyno at close to 7000 rpm.

Jackie, each customers program is treated as intellectual property. They work hard and put a lot of resources into finding crumbs...a few here and there until it adds up. Which is a big reason they come here to dyno...they know their program info won't be shared or leave these walls. While I can't specify exact numbers, I can say it's north of 600 h.p.

 

[jackieschmidt]

Jackie, each customers program is treated as intellectual property. They work hard and put a lot of resources into finding crumbs...a few here and there until it adds up. Which is a big reason they come here to dyno...they know their program info won't be shared or leave these walls. While I can't specify exact numbers, I can say it's north of 600 h.p.

Amazing what every attention to even the smallest details can all add up to big numbers.

several years ago we had a guy in the Houston area who had a rather competitive A Econo Dragster.

He used to joke that there was nothing “Econo” about the class, and he should just switch over to A Dragster so he didn’t have to spend so darn much money.

 

[AlNyhus]

Amazing what every attention to even the smallest details can all add up to big numbers.

And that's the thing with these rules restricted engines. The number one thing to have is a dyno that will repeat within 2 hp (this one does) so you know if you're making progress or if the changes (good or bad) are getting lost in the noise of dyno repeatability. Most of our gains aren't found by simply bolting on a new piece. Often, a new component doesn't make as much power as what you replaced. But by looking at the other factors like BSFC you can often get a glimpse of possibilities. So you swap back to the original component and get after the carb air bleeds a bit...even 'leading' them a bit. Then you go back to the 'new' component and bingo...power and torque picks up for a nice gain of 3-4 hp. The shop owner is very, very savvy on data analyzing data. He's taught me so much that's just incredible.

We do that with every system in the engine...intake, oil, cam timing, header design...you name it. Bit by bit you grab a few crumbs and they all add up.

A good example is my 327-275 hp Stock Eliminator engin in my '68 Chevy II. The dyno would always show a nice power increase when I got the circulating oil down to 2 qts. (3.5 total). By working with the oil pump and adding a way to internally bypass the excess oil volume, we made another 4 hp and 4 lbs/ft of torque and I could run it safer with 5 qts. of oil and better oil control. It took a bit of doing and some special instrumenting of the engine to evaluate bay to bay crank pressure and equalize it to reduce pumping losses in the oil pan. Here's it is instrumented up with the system I fab'ed for the initial testing on the oil system. It would actually run into the negative pressure area in the pan with excellent bay-to-bay equalization and markedly reduced pumping losses. It also meant tweaking the oil ring tension a bit to bring it around. Turned out great.

 

[jackieschmidt]

Al, you are definitely living “The Life of Riley”

(Those of the younger generation probably don’t know where that comes from)