Author Topic: ZL-1 heads- castings w/o heat crossover passages  (Read 1660 times)

Rock Crusher

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ZL-1 heads- castings w/o heat crossover passages
« on: March 22, 2009, 09:34:21 PM »
I have a set of 3946074 aluminum heads that I purchased from a guy in Michigan. They appear to have been in storage/unused for quite some time. He purchased them at auction and knows nothing of their history.

I read on the CRG- COPO page that ZL-1 heads did not have heat crossover ports. www.camaros.org/copo.shtml

The heads that I have do not have any heat crossover ports. The castings appear to be that way from the factory. Both heads have 1969 casting dates. The heads have been decked and have had port work done. They both have the stampings; Batten Heads, Romulas, Michigan (stylized company logo) and Diamond Elkins (std individual hand stamped letters). There are also some various letters and numbers stamped on them as well  (E 892 R is on one head and E 892 on the other, 71201 and H.C. is on both heads, I wonder if any of these could be serial numbers ?).  I read an article somewhere that described the H.C. markings as factory stamped signifying high compression.

All of the other 3946074 heads that I have seen appear to have functional heat crossover ports. Until I read the COPO/ZL-1 article describing ZL-1 heads on the CRG site, the missing ports had been a mystery to me.

I did a bit of research and found that C.J. Batten of Batten Heads and Butch Elkins of Diamond Racing are both renowned port and flow wizards. Unfortunately both are out of business now.

I would like to know if these heads have any historical racing provenence. If anyone has any information I would appreciate it. I can post some photos if neccessary.

Thanks in advance

Rock Crusher

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Re: ZL-1 heads- castings w/o heat crossover passages
« Reply #1 on: March 23, 2009, 09:21:23 PM »
I need to correct my previous posting...

After thoroughly cleaning decades of dust and grime from these heads. I have discovered that the ports were actually filled with something such as Devcon and then sealed with silver paint. It honestly appered to me that they were cast this way initially. I certainly apologise for misleading anyone with my prior description of these heads.

I am still curious about the statement on the CRG ZL-1/COPO page describing ZL-1s as not having these crossover passages, a heat riser valve or carb choke... Is this actually true ???

I am still interested if anyone may have some info about the work done on these heads by Batten and/or Elkins or where these heads may have been used. I think they may have an interesting story to tell if I just knew who had used/raced them in the first place.

Again, I apologise for the confusion.

I attached some pics if you are interested.  I hope that you will be able to see the details.
The Batten Heads logo is located just above the 71201 stamp. It is extremely fine lettering and was stamped very lightly, so it is somewhat difficult to see well in the photo. There are some additional numbers that I neglected to mention before, they are 3372 and 3373. One of them is stamped onto each head. The numbers 1 and 2 is stamped on them as well. Could any of these (or others) be useful serial numbers ?

Thanks again, Rick
« Last Edit: March 23, 2009, 09:41:36 PM by Rock Crusher »

william

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Re: ZL-1 heads- castings w/o heat crossover passages
« Reply #2 on: March 27, 2009, 03:01:08 PM »
I was primary author of the COPO article on this site.

The wording should be changed to state there was no manifold heat. ZL-1s did not have a choke or heat riser. I have a poor copy of a prophetic internal memo dated 12-17-68 from Engineering asking Chevy to "Find some method of restricting sales of the COPO so that its purchase for street use, either intentional or inadvertent, is impossible. Our previous experience with this type of release has been very poor [probably the '68 L-88 Corvette] in that some jobs will find their way into the wrong hands and driveability complaints are inevitable." Marketing rarely listens to Engineering and the ZL-1 Camaro was unleashed on the public as is, complete with both 12/12 and 5 year/50,000 mile warranites.

It did not take long, 2 weeks to be exact, for "driveability complaints" to become a reality. As the story goes ZL-1s #1 & #2 were delivered to Fred Gibb Chevrolet on NYE 1968 and neither would start; both had to be winched off the transporter.