Berger ZL1 Drag Test
 

This is a great article because of the reference pictures of the engine compartment, engine and underbody. I believe the one change they made to chambered exhaust actually hampered performance since it was found to be a more restrictive exhaust vs the transverse.

Bill Porterfield did a series of dyno runs on a 'blueprint' ZL-1 engine rebuild many years ago. Engine did 444 hp with headers, no accessories and full chambered exhaust. Removing the chambered exhaust; 524 hp. Chambered was not a performance exhaust system.

The article is interesting for other reasons. Rear axle and sub frame are glossy black; floors appear to have little black paint. Built with standard N10 muffler/resonator exhaust system. Car was final assembled March 4, 1969 and has 1st design rear spoiler. Missing mounting nut on alternator bracket.

ZL-1 specific details: no heat riser; coolant pump, lift hooks, manifolds, TC cover, oil pan painted black. Standard production plug wires. Was built with production L72/L78 #4346 Holley carb, probably all of them were.

#3 still exists, mostly in original condition. Lowest body # [211785] of all ZL-1 Camaros; 1st car ordered. Rumor has it Berger initially ordered it [and #211786] as L72s and later changed the order. One of 2 ZL-1s built with COPO 9737.

Also the orig. engine for it sits in a basement in Michigan.

Charlie care to share any information about this motor that’s in a basement in Michigan? Why is it not with the car? The person that has the motor holding it ransom or the cars current owner not interested? Just curious!

The last thing this circus needs is more clowns. Let it be.

More clowns ?

William, the N10 exhaust looks like it has resonators, were resonators removed on later cars?

When NC8 was dropped as standard equipment, the 1st recall notice stated Camaro SS L34 & L78 would be produced with the standard N10 muffler/resonator dual exhaust system. The parts in question are the BB exhaust pipes [grp. 3.609] from the manifolds back. The 67-68 deep-tone pipes [no resonators] are 3912596 and 3923573. They are also listed as the exhaust pipes for the 69 L35 396 in an 11/68 P & A manual. The '69 L34 & L78 396 lists different part numbers, 3958409 & 3958410. There is a note stating they run from the manifolds to the 'front' muffler. In production, the resonators were welded to the exhaust pipes. When serviced, the parts were separate.

However, the AIM lists different numbers: 3923567 & 3912592. The rev box as of June 13, 1969 shows "3923567 was 3923573; 3912592 was 3912596." This contradicts the 11/68 P & A manual which implies L35 396s did not have resonators. PNs #3923567 & 3912592 are also listed in the '67 AIM under N10 as L78. Probably resonator pipes.

The April recall notice has a parts list to convert a BB built with NC8 to "...a regular muffler system." The exhaust pipes listed are 3912596 and 3923573. That means any recalled BB was fitted with a single muffler no resonator system.

So, what did they do in production? ZL-1 #3 and the recent L78 survivor, both built early ’69, had the muffler/resonator system. I know of two later production L35s built w/o resonators. My guess, the clue in the 11/68 P & A is telling: L35 cars were built w/o resonators, L34, L78 & COPOs had the full muffler/resonator system. We did a ZL-1 resto many years ago, full N10 system. Had a nice sound, not at all loud. Another ZL-1 resto was done w/o resonators and was obnoxiously loud. L72 & L78 cars w/o resonators have an unpleasant, raspy tone.

Wish I had more Chassis Broadcast Copies. Box 198 lists an exhaust system code.

L35 built 10/9/68...FR probably no resonators
L78 built 11/10/68...FT probably chambered
ZL-1 built 12/30/68, L78 built 1/2/69, L34 built 1/13/69, COPO built 5/7/69, L78 built 6/23/69...FS probably muffler/resonator.

Great site and there is a wealth of automotive knowledge here! I frequent the site multiple times a day to see and learn. There are some great people here I’m not sure Iv ever encountered a “clown” or a circus on this site which is what makes this site stand tall.

The clown comment was totally uncalled for (arrogant) and completely out of character from what Iv experienced and seen from members here .

Long story short... The owner of the engine bought it out of the car before Porterfield owned it. Owner was running a small block in it. He was planning on getting the car but Porterfield beat him to it. He wanted the car, Porterfield wanted the engine. Stalemate. Guy with engine bought # 26 ZL1. Porterfield found the engine for 26 and tried to trade. Nope. I bought 3 from Bill and later bought the engine for # 26 and tried to trade. Nope. I then put 26 engine in 3 figuring someday people would come to their senses.... I think William just didn't want this long story added to this thread.