ZL1 block I.D.?

[Igosplut]

I wonder if the people on this site could help me with IDing this block....

I've had this block since the 90s. It came by way of the late Al (big Al)Maynard, to a friend of mine, then to me. My friend has also passed, so in order to ID what it is I've been asking different people if they have an idea. Talked to Jerry MacNeish, and Chris white (who suggested I post this here). After following ZL1 blocks on Ebay for twelve years, I've seen about four that by description seem to match this one, but only one shed any light on the origins. One was a complete motor that a guy built, the block he said he bought directly from Yenko (he still had the shipping crate). That block(and mine)had no Yenko crest, or Yenko cast on the front. So hopefully someone here has knowledge of these being sold without Yenko crest's, or markings. Or whatever...

Here's a description of the block

It"s the same cast number:3946052 with the 2 being sightly smaller.
The snowflake is there, but has an upside-down "LC" instead of a "W" (some have said "Lockport" foundry?)
NO date code, or any markings on the sides of the block.
NO pad stamping (it's been decked)
In the timing chain cavity, it has "SYEQ" stamped twice.
"875" stamped twice on bell housing flange.
Press-in freeze out plugs instead of threaded solid (has solid in the lifter galley)
No numbers on the machined pad at the top of the bell housing flange.
Has "EQ" and 875 stamped on the main caps ( the latter indicating a assembled block?)
On the boss below the fuel pump (like if looking at the oil pan flange) there is stamped "+-20" with an arrow below it pointing towards the front of the block.
Conventional cam freeze plug, and no tapped holes (bosses are there though)
On left side top of bell housing flange (opposite of casting number) there is a cast pad with "KPT-CST" (area where the later iron blocks have the date codes).
Main caps are 964 cast

The rest of the block looks just like the run of 052s that came in the cars/CE blocks I've seen. Two extra head bolts, oil filter/dry sump fitting, webbing, etc.

I know GM did alot of experimental stuff, and have heard of Al's back door connection to GM so who knows? But I figure somebody somewhere should know (as a side note, Jerry said that the person to ask would have been Bill Jenkins, but sadly that time has passed also)

I can put more picture up if someone likes. And thanks for and help in advance...

[black69]

Mike Gillipse (spelling may be off) in indiana that used to work at the dealer, has a listing of all the engines produced. You can find him through the yenko stinger connection search. I have an engine with similar attributes, and the key is that stamping in the timing cover area. Not many of these I have seen out there. Some without the stamps would be the engines cast without Yenko approval (and this supposidly happened due to yenko not meeting the forcast he predicted for these). I dont think many of these exist or survived.

[Igosplut]

Thanks for that, I sent a post through that site. That would also jive with the Ebay auction stating he bought the block from Yenko. It's surprising that more is not known (by more people that is) about these motors. I understand that they're rare, but I figured that more people would have been exposed to them. I will definitely post the results for my search here...

[olredalert]

----Joel,,,Would that friend who passed be Wayne McCabe?.....Bill S

[Igosplut]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: olredalert</div><div class="ubbcode-body">----Joel,,,Would that friend who passed be Wayne McCabe?.....Bill S </div></div>

Yes it was...A year this November

[bergy]

Lockport Casting was a small aluminum sand casting shop. Tonawanda often used it for prototype work, for casting changes, and for producing parts for machining trials due to its' proximity to the Tonawanda complex (where the foundry pattern shop was located). The CNC machining center for the ZL1 blocks at the Tonawanda Motor Plant was really cutting edge back then &amp; quite a few blocks were required for machining trials (also for production casting changes). The &quot;LC&quot; in the middle of the snow flake is just on a piece of dyno-tape which was stuck onto the core box. Chevrolet didn't let vendors make changes to patterns or core boxes - the equipment had to be returned to Tonawanda &amp; changed. If the alteration was significant, a trial run on the updated equipment would be made at Lockport Casting before returning the equipment to the production supplier. In the case of the ZL1 blocks, most of the core making equipment never left the Tonawanda Foundry because the aluminum casting vendors didn't have the big Sutter and Osborne machines required to produce the cores.

[Igosplut]

Stating that about the dyno tape makes sense, it sure looks like that. So then is it safe to assume these particular block ran through Lockport?

[olredalert]

----I met Wayne in 1968 when he and some friends came to look at my 67 SS Chevelle in Hyannis. He didnt buy it but we quickly became good friends. Im pretty sure one of his buddies did buy my 69 red 396 SS Camaro, and Wayne bought my brothers 64 black/red gut Corvette convert. He restored it for Carol. He also bought my 74 maroon/silver gut Corvette that I totalled with only about 150 miles on it from the insurance company and rebuilt it with an LS6. I spent many a Carlisle with those crazy guys (way too many beers). I hope Carol is doing OK. Sorry to go off topic....Bill S

[Igosplut]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: olredalert</div><div class="ubbcode-body">----I met Wayne in 1968 when he and some friends came to look at my 67 SS Chevelle in Hyannis. He didnt buy it but we quickly became good friends. Im pretty sure one of his buddies did buy my 69 red 396 SS Camaro, and Wayne bought my brothers 64 black/red gut Corvette convert. He restored it for Carol. He also bought my 74 maroon/silver gut Corvette that I totalled with only about 150 miles on it from the insurance company and rebuilt it with an LS6. I spent many a Carlisle with those crazy guys (way too many beers). I hope Carol is doing OK. Sorry to go off topic....Bill S </div></div>

No problem, I just sent you a PM.

[markus37]

Yes, I do have records on the Yenko ZL 1 blocks. I can probably interpret the coding on your block, casting , machining data , etc. Complete history will be in my book which I hope to have available at MCACN in Nov. Mark Gillespie