Another good day of dyno'ing the 352....JJ never disappoints.

[blykins]

Took off to take the 352 to the dyno again today, with the only changes being the new custom 660's and some shear plates.

First pull out of the gate was 512 hp @ 7000, just like last time, but this time the new carbs were rich on the driver's side.  Pulling 2 numbers out of both carb secondaries got us back to 12.5-13:1 A/F ratio and picked us up to 523 hp with 449 lb-ft of torque.  Another pull backed that one up with  524 hp. 

I'm pretty sure I either had 30W break-in oil in it or 20W-50 when I put oil in it months ago.  My gut is leaning towards 20W-50 Brad Penn.  Either way, I dumped all the oil out and filled a new filter with a quart of Driven 5W-20, then put another 6 quarts of Driven in the engine.   Cranked it without the ignition on to get the oil pressure up, then lit it off again.  Right off the bat, I noticed the oil pressure was quite a bit lower than the old oil was when we started it for the first time this morning.  However, we were still getting 80 psi at the top of a 7500 rpm pull.  The oil change was worth 6 hp.  We were now at 530 hp. 

From that point, we started playing around with different spacers.

I had originally installed the carbs with a Magnafuel 1/2" shear plate on the bottom and a Moroso 1/2" open spacer on the top. 

Pulling those off and putting on two 1" Super Suckers got us 529 hp and 450 lb-ft. 

Using a 1/2" Super Sucker (it has 1/2" of "fingers" that stick down into the plenums) and a 1/2" 4-hole top got us 530 hp and 452 lb-ft. 

Using the Magnafuel 1/2" shear plates and 4-hole 1/2" spacers on top of those got us to 531 hp @ 7200 and 457 lb-ft at 5600.  This combination also had the highest average hp and torque measured from 5000 rpm to 7000 rpm. 

We were making pulls to 7500 each time.

I hope to be able to free up an engine stand in the next couple weeks and pull it all down.   A couple of forum members have dibs on some rods and some other parts, so I need to get it all apart.  My goal for the next iteration with more compression and different rotating assembly parts will be 575 hp. 

I can't say enough about this little 352.  It has completely pulled through for me each time and just keeps on singing to 7500 rpm, over and over again.  I think we estimated 50-60 dyno pulls so far.  I wish I would have kept track.  1.48 hp/ci is nothing to sneeze at.  If it had been a 390, that would be 577 hp and if it had been a 445 pulling that ratio, it would be 658 hp.  Pretty proud of the little feller.

For those who are wanting to keep track, we picked up 19 hp and 11 lb-ft over last time. 

[Falcon67]

That's just excellent and way much fun.  Can't wait to see the next iteration. 

[wowens]

Amazing numbers from a 352 and the throttle linkages are a lot nicer.

[WConley]

Very cool Brent!  That puts a lot of bigger "built" engines to shame 

[Stangman]

Very nice Brent sounds like alot of fun. And JJ sounds great I heard her on Instagram.

[Rory428]

Brent, I don`t know if they would clear the dyno cradle, but it would be interesting to try a couple of sets of production unibody (Mustang/Fairlane) headers, to see how much power they would cost, compared to those great looking dyno headers. Even the big tube Hooker multi piece race headers have severe port exit angles to fit the shock towers, curious how badly that affects the power.

[Tommy-T]

Cool motor.

At the risk of sounding more ignorant than I already do...what are shear plates?

[blykins]

Brent, I don`t know if they would clear the dyno cradle, but it would be interesting to try a couple of sets of production unibody (Mustang/Fairlane) headers, to see how much power they would cost, compared to those great looking dyno headers. Even the big tube Hooker multi piece race headers have severe port exit angles to fit the shock towers, curious how badly that affects the power.

That's the only thing I don't like about this dyno.  Very rarely will chassis headers fit.  I have to have them specially made, where they come off the head by 6-8" before they start to turn downward. 

I'm sure Barry and Blair have some header dyno data that would probably be better served for you. 

[blykins]

Cool motor.

At the risk of sounding more ignorant than I already do...what are shear plates?

Tommy, a shear plate is a type of carb spacer that is designed to fight reversion.  Most of them have an underside that's made to keep it from happening.  On intakes that have a very straight shot to the valve, like a tunnel ram, a big cam with lots of overlap can cloud up the signal.  The shear plates try and fight that. 

[blykins]

So, I was talking to Ross last night, and he's like...."Are you gonna try that other cam?"

He shamed me into it. 

At 08:00 this morning, I tore the front and top off of JJ and swapped/degreed camshafts. 

I had bought another cam a couple of months ago because in the beginning I had wanted to turn a lot more rpm with JJ than what I'm doing.  I had that cam ground with those specs/overlap in mind.  With the current cylinder heads, I thought I could *maybe* make a few more ponies with a different cam, so I suppose now's the time to try it. 

[1968galaxie]

Higher lift cam? Near .750"?

Fun project to witness - through the internet.
Must be awesome to hear that 7500 rpm on the dyno.

Love rpm. I recall a quick drive around a not well populated suburb in my boss' 1969 Porsche 911 race car. 2.0 liter six 906 camshafts and 906 titanium rods.
Open megaphone exhaust. 1900 lb car. Unreal exhaust note at 5500 to 9000 rpm - fast too lol.