519" SOHC Build

[jayb]

What size diameter are your stacks? I have a set of stacks that I doubt I will ever get around to using.

The stacks are Kinslers, 2 5/8" OD.  They are aluminum, and a lot nicer than the steel stacks that came with the Hilborn setup.  If you have a set of aluminum stacks that are 2 5/8" OD, send me a picture Howie, I might be interested in those.  Thanks, Jay

[jayb]

Still planning to stick the 519" into the Galaxie and then build up the 585" SOHC for the Shelby clone?

That is the plan.  Unfortunately, I'm currently waiting for parts for both the High Riser and the big SOHC, and those are the two Drag Week engines.  The Galaxie isn't going, although I hope to have it reassembled and running by the end of the month.  Hopefully those other engines will be together long before August...

[cammerfe]

I found myself waiting for that last pull to start with almost 'wedding night' anticipation.

Now, when you get a pair of turbos putting about 40 pounds into it...

KS

[philminotti]

Jay, that is awesome!  I'm with Howie...you're graphs start where i hope my motor ends up!  Sounds simply amazing.  I hate to sound like one of my spoiled kids, but I'm still dying to see how the 545" hi-riser turns out.  Sorry...

Phil

[machoneman]

Way cool Jay! Good guess on the stacks as well.

Love the upside down USPS looking plastic bins that form the dyno's air chamber....I won't tell if you don't...LOL! 

[jayb]

Did a little more fine tuning on the engine today.  It seems to like a little less timing on the top end, and the power curve hung in there for a little longer as a result.  I fined tuned the EFI map a little more and picked up another 3-4 HP, but nothing real substantial.

One thing I had noticed was that the engine was creating a fair amount of exhaust backpressure at the top end of the pulls, close to 1 psi.  Here's a graph of the back pressure data from the dyno:



Keeping this in mind, for the last pull of the day I decided to run with the exhaust open in the dyno room, and hope that my neighbors would forgive me LOL!  This netted the best peak horsepower number of the day at 878 HP at 7300 RPM.  Here's a graph of the data:



In the end I decided not to run to 8000 RPM; I'll save that for the track.  Tonight this engine is coming off the dyno, and during the week this week I'll pull the oil pump and get to the bottom of the oil pressure issue.  As long as I have the pan off I'll look at the bearings as well, and provided there are no problems, this engine is going in the Galaxie next weekend.  I'll update this project with some track numbers when I get the Galaxie to the drag strip.

[WConley]

Very cool stuff Jay! 

I really noticed that torque bump around 4,700 rpm.  Simulations I've done with various flavors of cammers on Engine Analyzer Pro seem to produce such a bump.  I'm guessing it's the header primary scavenging?

[jayb]

I'm pretty sure the torque bump is related to the individual runner manifold.  When I first ran an SOHC back in 2007 with all the different manifolds, the fuel injection manifold was the only one that had such a lumpy power curve.  It may also be that it is a combination of the header scavenging and the IR intake working together to produce that bump in the torque curve, but I don't know for sure.  All I know is that this manifold is difficult to get tuned right in the midrange, because the torque curve is going up and down like a roller coaster, and the other manifolds I tested didn't show that behavior.

[Hemi Joel]

Jay, the motor sounds great, congrats!

[fetorino]

I'm pretty sure the torque bump is related to the individual runner manifold.  When I first ran an SOHC back in 2007 with all the different manifolds, the fuel injection manifold was the only one that had such a lumpy power curve.  It may also be that it is a combination of the header scavenging and the IR intake working together to produce that bump in the torque curve, but I don't know for sure.  All I know is that this manifold is difficult to get tuned right in the midrange, because the torque curve is going up and down like a roller coaster, and the other manifolds I tested didn't show that behavior.

It really is a shame you couldn't test the sheet metal intake and dual Holleys.  It would have been very interesting to see the difference between the two intake combos.  As always your build is an impressive combo.  I can't wait to see the high riser on the dyno.

[Barry_R]

I would like to see the data from my 527 overlayed with the 519 - - since peak power is similar it might make a nice comparison between the IR and a tunnel style 2x4.

I don't have your "numbers" so you get to key in mine 

[Cyclone Joe]

Hi Jay,

Awesome video- thank you for sharing.  I did have a quick question: during the dyno pull video there is some vapor coming off the left side of the engine.  Is that fumes from the vacuum pump or something else?

thanks
Joe

[jayb]

Hi Jay,

Awesome video- thank you for sharing.  I did have a quick question: during the dyno pull video there is some vapor coming off the left side of the engine.  Is that fumes from the vacuum pump or something else?

thanks
Joe

That's the exhaust of the vacuum pump that you are seeing.  It goes into a can with a breather on top, and typically it will smoke a little bit during a pull because you get condensation in the can, and water vapor will come out of the breather.

[Cyclone03]

Jay understand I know little to nothing.....
Would running 2 different length stacks maybe flatten the torque curve?
My Sprint Car racing cousin does that on a slick track with a SBC says it widens the torque curve.

[jayb]

I would like to see the data from my 527 overlayed with the 519 - - since peak power is similar it might make a nice comparison between the IR and a tunnel style 2x4.

I don't have your "numbers" so you get to key in mine 

Here's the data, with both ram tube lengths on my engine plus your engine:



Your motor is a torque monster compared to mine below 5500 RPM, but after that they come in a little closer.  Gotta be the induction setup.  Although the tunnel wedge setup isn't known for a lot of low end and mid-range, it must be better than the Hilborn setup down there. 

You can sure see the effects of the ram tube length on the torque curves on my engine...