Anyone ever seen this?
http://cgi.ebay.com/ebaymotors/1969-CHEVROLET-Z-28-CAMARO-CROSSRAM-Hemi-302_W0QQitemZ4653005729QQcategoryZ34202QQrdZ1QQcmd ZViewItem

Cool isn't it? One of the guys here use to own a yellow Z/28 with one of the prototype engines in it. Also Reggie Jackson has/had one on display in his shop.

Yes, I read some older links that JimM posted about this ,,, The Forge museum shows that motor in a car along with Reggies car. I would be curious of the internals and head design. Haven't found much yet.. I am sure the motor will sell quick but why would someone remove it(comments from ebay listing) from the car its in? Seems the combo would be worth more.

Doesn't Clill own one too that if I recall right came from Smoke's garage sale??

pdq67

Paul - Charley's was the one I was referring to. They all came from Smokey's Garage at some point. The Yellow Z/28 was a really cool car, I hope it wasn't the one they pulled the engine out of.

DD- none of the engines started out in cars so even thought having a Smokey engine under the hood is major cool I think the all alum 302 would be rare and just about, not quite though as cool...

According to Smokey Yunick's Chevy Engine Guide (S-A Design number 2575-4) from the Hot Rod Magazine's High Performance Series Volume 4 Number 3; which are a compilation of old reprints from Hot Rod's Mags prior to the 1987 copyright date:

Chevy made six different Hemi head prototypes over a period of 17 years for the small block Chevy. One was a dual overhead cam (DOHC) variant, two were a single OHC version, and the other three were push rod engines. According to Smokey, who was one of six engine builders that GM trusted enough to experiment and report back their observations and opinions (Da Grump was another), none of the engines showed a very large advantage in horsepower, tuneability, or reliability to meet the needs of (in his case NASCAR) the racer, compared to the cost to manufacture.

Because Chevrolet was in a the midst of a corporate racing ban, all of these heads were developed and cast in the engineering labs and snuck out the back door. This deniability allowed these racers to keep the parts as their own personal property with the understanding that no one know about them (except for Hot Rod magazine in Smokey's interpretation of the deal).

This picture appears to be a push rod variant.


Larger Dave

Dave, You keep excellant records. You work at the courthouse? wow.

Larger dave,aren't you retired or semi retired...If so you really should put your talents to use doing research or be one of those reference guys for Hot Rod magazine articles...You truly are a wealth of information and I absolutely laugh out loud at some of your off color jokes...what was the one where someone called it a pvc valve instead of a pcv,and you quoted the chemical name for pvc....funny, man ,if I could remember the context

He, He!!

"Poly Vinyl Chloride"..

Good one, Big Guy!!

pdq67

DD there is a lot written on this engine and a lot of pictures are available if you are curious about the internals. The dyno sheets of one of the motors Smokey tested showed the 302 made 485 horsepower, but I believe the rods would fail on the endurance testing. There is an individual in Michigan who has/had complete motors and some spare parts. John Hooper's 69 Camaro book details this collection pretty thoroughly.

Besides Charlies former car, there is a silver 69Z featured recently in one of the magazines, Musclecar Review I believe, that also had one of these in it. I've spoken with several people regarding these and if all the claims I've heard, plus the 3 that I'm aware of that ended up in Camaros, there is probably more than the 6. But I've also heard 5, I've heard 6. I've heard the GM Tech Center in Warren had one, I've heard Talledega had one (that one I'd question, they'd have no interest in one). The individual in Michigan who had a couple, plus all the parts, it starts to add up to more than 5 or 6. The engine was listed in the 1969 SCCA prelim documents with the head package many refer to as Hemi 302 (actually not a hemi), but so was the TH400 trans and that never made it into a 302 car either. The number of 5 or 6 is probably accurate though. I'd assume there is a lot of rumors to the where abouts of the motors and where they ended up, everyone knows someone who knew someone who knew where there might be one. You see how it can end up appearing to be more than 5 or 6 when all the rumored engines are thrown in.

I purchased a left over set of the pistons from Trisha Yunick Brown before the auctions. At that time I was told there were no more "hemi 302" head package parts left lying around in Daytona, except for a couple more sets of the pistons. I'll send you a picture of that set of pistons and the part numbers assigned to them. If I get my photos posted on a host site I'll post them here, but I'm pretty busy this week between work and trying to get a 68 SS Camaro home that I purchased Saturday. Give me a few days.

I know about 15 years ago in Hemmings there was a 68 Z28 for sale in the 35K range that claimed to have installed one of these motors in it. I did not call on it to verify what it was, at that time I was not interested in it.

It's an interesting engine topic though.

Dave

According to Smokey they cast about 25 pairs of each design in total (18 were shared out side of the GM labs with persons who showed enough expertise to continue development work). Each engine builder got three each, so there should be a total of about 10 or 12 left (some of the tests were destructive, and the broken parts were returned to GM for analysis.

Yes, I am retired from Engineering; but I still teach. And yes I do have every issue of Hot Rod going back to '69, and a lot of Chevy High Performance, Supper Chevy, Rod & custom, Kit Car, and Car Craft. I also have a bunch of old High Performance Cars magazine (Magnum publishing) which document the East Coast scene, and all of John Diana's Chevy Rumble mags (Buckaroo Publishing). I used to keep the National Dragster but they are just to prolific. Even a pack rat like me throw them out now.

I also keep about forty-five reference books next to the computer to refresh my sagging memory. Plus all my engineering text are in the computer room in shelves, if I need to dust something off.



Larger Dave

Yes I saw one last summer sitting in Reggie Jacksons shop on display. The silver Z with one is Reggies old car.

There was a set of these heads, valve covers and cam for sale on Ebay about 2-3 years ago. I think they are in PA right now but the owner was looking for an intake to go with the stuff.

Believe it or not they often used to use hardwoods to carve patterns for the intakes for these engineering research designs; out of separate pieces, that would bolt together to form a new intake design. They occasionally never bothered to get around to actually casting the different variants, and gave out the hardwood patterns for people to try with these one of a kind heads. So he may be in for a long wait trying to find an aluminum casting that might not even exist.


Larger Dave

Pistons purchased from Yunick were ESK2528 CL-C D 316937. Trisha refered to them in her original ad as EPCR bolt on Hemi pistons. They were standard bore, with a slight convex dome and a slight wedge cut on opposite sides for the valve reliefs. Once I realized the parts could not be procured to build a complete motor (the intake base is not available, the intake lid is the same as the standard part 3941130 I've been told) I swapped them for a standard set of 302 pistons from her. However Smokey had so heavily modified that set for racing that I elected not to use them for a motor that would see regular duty, a lot of material had been removed to lighten them up, particularly the balance pad beneath the pin bore.

To throw a little more fuel on the fire, I've been told Daytona as well as Talladega has a motor in their museum, I haven't verified this and I would be surprised if it's true. I've also heard two canted valve 350 motors were sold, again I can't verify that either except that the second buyer is the person who told me this along with the two supposed museum motors. I heard the price paid at the 89 Yunick garage sale was $17,000 for one of the hemi motors.

One of the 69 cars that ended up having the canted 302 put into it I've been told had the later version GM performance parts canted (hemi) heads 24502517 castings, but again I don't know if that's true either. Those castings were recently still availble for $1750 each bare, had 8 mounting bolts for the covers. However no rocker hardware or valves were available for them and according to GM when I called none ever were offered or listed. Moroso makes a valve cover for that head Moroso number 68342 listed as a fabricated aluminum cover for small block splayed valve heads. They have 8 mounting bolts, the Yunick tested heads had 7 and the covers were magnesium. The cover part number I have listed was 314684 for the magnesium 7 bolt covers. The pistons that Yunick played with according to Maynard's documents were 3965534. So I don't have any idea how to decipher the number on the set I'd purchased ESK2528 CL-C D 316937.

I could put names to the rumors above, but since I don't personally know the individuals I don't feel it's proper for me to do so. Maynard's name appears along with credits in Hoopers book, so that is already public knowledge. Trisha offered many of her dad's items for sale and it's obvious her name would be involved in discussion with these rare parts. But I will respect the privacy of the others, they don't need the attention.

It would be really neat to see a documented history on the development and some real history on where everything ended up. Wayne Guinn's book "Untold Secrets" does detail some of the background on the motor as well.