Day 2 67 Camaro restoration

[SMS]

What size are these rear tires?

[Chuck_Burg]

The Cragars have ProTrac L60s. 275/60-15. Bias Ply available through Coker Tire

[Chuck_Burg]

On Tuesday, July 2nd, I brought the Camaro to Westech Performance for a dyno day. Before going, I eliminated the rear power valve and upped the secondary jetting to 88s and put 80s in the primary. I also put a new set of plugs in the engine.

The first pull showed the engine was rich, low 11 air/fuel. We swapped in 85 jets into the rear and dropped the primaries to 77s. This yielded a nice conservative 12:1 AFR.

The main reason for going to the dyno was to make sure the AFRs were safe at WOT throughout the RPM range.

Most pulls were done through the exhaust with the cutouts closed. After the jet change and playing with timing, we discovered 34 degrees total timing was the sweet spot! Through the exhaust the engine delivered 424hp and 454lb/ft at the rear tires. With the cutouts open, it made 433hp and 474lb/ft! No only were the peak numbers higher with the exhaust opened up, but the torque curve was even more impressive! It gained substantial torque throughout the curve. Peak power was made at 5,365 rpm, but does carry pretty nice for GM 781 oval port head out to 6000rpm where it still made 420hp. I was really pleased to see this because the engine would fall on its face at 5500rpm with the old fuel system, it just didn't want to go any higher... I should've known there was fuel delivery issues from day one!

Even though the numbers aren't earth shattering I am pretty happy considering this is a pump gas, "781" iron headed 496 with an out of the box stock 1970s era Edelbrock Tarantula intake, a very mild hydraulic roller cam, 9.2:1 compression, and an 850 Holley. The guys at Westech really liked the car and were pretty blown away with the vintage speed parts on the car, especially the points ignition

[Chuck_Burg]

Here is the overlay on the screen, black lines are with the cutouts open and red lines indicated closed exhaust cutouts.

[napa68]

The thing carries at least 400lbs of torque from 2900 to 5400 at the tire???

[Chuck_Burg]

It's a bit like driving a turbo diesel

[dykstra]

Way cool Chuck!

[Chuck_Burg]

Since my mishap at the drag strip, many preventative measures have been taken with the fuel system to hopefully make sure I don't repeat what happened last year: 1/2" fuel pickup, 1/2" and -8AN line, bigger fuel pump, and a dyno tune. Jose, JBTech, sold me this seemingly new old stock Stewart Warner fuel pressure gauge, cup, and mount. The chrome is in very good condition considering it's been around since 1973... The gauge works perfectly. I see 6psi on the mechanical pump only and 7psi when I turn on the electronic Carter lift pump.

Thanks Jose, you've contributed so many awesome period correct speed parts to my car!

[AnthonyS]

...I've met both Chuck and Jose in person and have to say they are really good guys who get it, as most of us do here, and watching both of their 67s be built through the lens of this forum has been pretty cool to say the least; kudos guys!

Anthony

[R68GTO]

very nice work. It's really satisfying to see this kind of transformation with just a little (well, actually a lot) of elbow grease.