Can you settle an argument?

Paul Ceasrine · 09-25-2010, 07:20 PM

Jeff,
On the small-journal versus large-journal.
The 67' blocks were 2-bolt mains, and utilized connecting rods with 5/16" bolts.
Also pistons with pressed-in pins.
The theory is the 4-bolt mains and larger-journal cranks are stronger.

This one can be debated until eternity.

pc

Adger Smith · 09-25-2010, 08:38 PM

Paul wrote:
On the small-journal versus large-journal.
The 67' blocks were 2-bolt mains, and utilized connecting rods with 5/16" bolts.
Also pistons with pressed-in pins.
The theory is the 4-bolt mains and larger-journal cranks are stronger.

This one can be debated until eternity.
I say:
Yes, Paul it can be debated, but as an engine builder that lived and work through that era of cars/engines I can say with authority it is a theory that is true. One major change that came about with the large journals is the overlap of the main and rod journals increased in the crankshaft. It was so much stronger it reduced flex and you could reduce bearing clearances. The small journal cranks and 2" rods with 11/32, not 5/16, rod bolts you had so much flex in the crank and rod distortion you had to have insane bearing clearances. Since that time period the improvements in metallurgy have also improved the strength of both factory and aftermarket race parts. Wow, no more co-plated rods for floating pins!!! (remember them?)

Paul Ceasrine · 09-26-2010, 07:49 AM

Adger,
Excellent evaluation.
The later 68' and 69' 302 engine internals had more mass and were better due to engine development.

But back in the day, I don't remember any 67' 302's blowing up, as a result of internal deficiencies.

Dwight Southerland · 09-26-2010, 10:19 AM

Also, the RS package morphed during the years '67-'69. It was originally conceived as a suspension-handling package in '67 with a "European flair", hence the HD suspension pieces (Springs and shocks, unless it was ordered on a 6-cyl car, then it included a front sway bar.). The hideaway headlights were included to give it a "European rallye" look, since taping the headlights or covering them was a common part of prep for competing in rallys. The hideaway lights also were an identifying element of the RS package, but the visual effect was so popular that the original intent of the package was lost by 1969. In fact, a lot of the 1969 production was really geared to what the public was asking for, so you end up with a lot of combinations of options that were not in the salesman's order book.

This is a quote from a September 1967 published "Camaro Facts" sales brochure:
"Rally Sport - Includes special black grid grille with 'RS' emblem, concealed headlights, wide lower body side molding, color-keyed body side accent stripes, roof drip cap molding (Sport Coupe), wheel opening moldings, 'RS' emblem on front fenders, steering wheel, and fuel filler cap, black accented taillight bezels, F41 suspension package, parking lights and directional signals located below front bumper, and backup lights mounted below rear bumper." It was designated as the Z22 option package and cost $100.

In the same brochure, reference is made to the "Camaro Rally Sport SS", which is described as "the special features of all (except that the RS emblems are replaced with SS identification) . . . plus Camaro interior features and appointments."

I owned a 22,000 mile original '67 Z-28 that was purchased to make a TransAm racer in the early '80s. The window sticker showed the car was ordered with the "Special Performace Engine Package", which included the "302-cid V8 engine, closed positive ventilation, dual exhaust with deep tone mufflers, special front and rear suspension, heavy-duty radiator and temperature controlled fan, quick ratio steering, 15x6 wheels, 7.35x15 nylon red stripe tires, 3.73:1 ratio axle and special paint stripes on hood and rear deck.". Additional options were "M21 close ratio 4-speed transmission", "J56 heavy duty front disc brakes", "J50 vacuum power brakes", "G80 positraction w/special 4.10 ratio", "C48 heater and defroster deletion". The original Z28 package required ordering the 4-speed and disc brakes, but were not included in the package. Positraction was recommended.

Spoilers were not available as factory-installed option on '67 models, but were available OTC later in the year. Fresh-air induction was not listed as an option, but that car had one and it looked to have been installed at the factory. Also, that car had a tach in the dash, but no console, and no indication on the sticker. No bumper guards, no chrome trim, no BS.

09-25-2010, 07:20 PM	#1
Paul Ceasrine VIP Member Join Date: Apr 2009 Posts: 2,546 Likes: 0 Liked 10 Times in 10 Posts	Re: Can you settle an argument? Jeff, On the small-journal versus large-journal. The 67' blocks were 2-bolt mains, and utilized connecting rods with 5/16" bolts. Also pistons with pressed-in pins. The theory is the 4-bolt mains and larger-journal cranks are stronger. This one can be debated until eternity. pc

09-25-2010, 08:38 PM	#2
Adger Smith VIP Member Join Date: Dec 2001 Location: Texarkana Ark/TX Posts: 2,446 Likes: 575 Liked 880 Times in 311 Posts	Re: Can you settle an argument? Paul wrote: On the small-journal versus large-journal. The 67' blocks were 2-bolt mains, and utilized connecting rods with 5/16" bolts. Also pistons with pressed-in pins. The theory is the 4-bolt mains and larger-journal cranks are stronger. This one can be debated until eternity. I say: Yes, Paul it can be debated, but as an engine builder that lived and work through that era of cars/engines I can say with authority it is a theory that is true. One major change that came about with the large journals is the overlap of the main and rod journals increased in the crankshaft. It was so much stronger it reduced flex and you could reduce bearing clearances. The small journal cranks and 2" rods with 11/32, not 5/16, rod bolts you had so much flex in the crank and rod distortion you had to have insane bearing clearances. Since that time period the improvements in metallurgy have also improved the strength of both factory and aftermarket race parts. Wow, no more co-plated rods for floating pins!!! (remember them?) __________________ Adger Smith (Former SS)

09-26-2010, 07:49 AM	#3
Paul Ceasrine VIP Member Join Date: Apr 2009 Posts: 2,546 Likes: 0 Liked 10 Times in 10 Posts	Re: Can you settle an argument? Adger, Excellent evaluation. The later 68' and 69' 302 engine internals had more mass and were better due to engine development. But back in the day, I don't remember any 67' 302's blowing up, as a result of internal deficiencies.

09-26-2010, 10:19 AM	#4
Dwight Southerland VIP Member Join Date: Dec 2001 Location: Arkansas - In the middle of everything. Posts: 2,001 Likes: 64 Liked 780 Times in 194 Posts	Re: Can you settle an argument? Also, the RS package morphed during the years '67-'69. It was originally conceived as a suspension-handling package in '67 with a "European flair", hence the HD suspension pieces (Springs and shocks, unless it was ordered on a 6-cyl car, then it included a front sway bar.). The hideaway headlights were included to give it a "European rallye" look, since taping the headlights or covering them was a common part of prep for competing in rallys. The hideaway lights also were an identifying element of the RS package, but the visual effect was so popular that the original intent of the package was lost by 1969. In fact, a lot of the 1969 production was really geared to what the public was asking for, so you end up with a lot of combinations of options that were not in the salesman's order book. This is a quote from a September 1967 published "Camaro Facts" sales brochure: "Rally Sport - Includes special black grid grille with 'RS' emblem, concealed headlights, wide lower body side molding, color-keyed body side accent stripes, roof drip cap molding (Sport Coupe), wheel opening moldings, 'RS' emblem on front fenders, steering wheel, and fuel filler cap, black accented taillight bezels, F41 suspension package, parking lights and directional signals located below front bumper, and backup lights mounted below rear bumper." It was designated as the Z22 option package and cost $100. In the same brochure, reference is made to the "Camaro Rally Sport SS", which is described as "the special features of all (except that the RS emblems are replaced with SS identification) . . . plus Camaro interior features and appointments." I owned a 22,000 mile original '67 Z-28 that was purchased to make a TransAm racer in the early '80s. The window sticker showed the car was ordered with the "Special Performace Engine Package", which included the "302-cid V8 engine, closed positive ventilation, dual exhaust with deep tone mufflers, special front and rear suspension, heavy-duty radiator and temperature controlled fan, quick ratio steering, 15x6 wheels, 7.35x15 nylon red stripe tires, 3.73:1 ratio axle and special paint stripes on hood and rear deck.". Additional options were "M21 close ratio 4-speed transmission", "J56 heavy duty front disc brakes", "J50 vacuum power brakes", "G80 positraction w/special 4.10 ratio", "C48 heater and defroster deletion". The original Z28 package required ordering the 4-speed and disc brakes, but were not included in the package. Positraction was recommended. Spoilers were not available as factory-installed option on '67 models, but were available OTC later in the year. Fresh-air induction was not listed as an option, but that car had one and it looked to have been installed at the factory. Also, that car had a tach in the dash, but no console, and no indication on the sticker. No bumper guards, no chrome trim, no BS.