zl1 motor

[sebs]

hi ,i may have located,what seems to be a all alluminium zl1 engine from ,what the owner says was the late sixtys,i willbe viewing the motor soon but need to be sure what im looking for .Could anyone tell me the block numbers or any other ways to identify this as the genuine article.He has already mentioned the snowflake symbol,but i am keen to know of any other distigushing marks ,many thanks

[william]

Chevrolet did a number of aluminum BB castings back in the day; not all were ZL1s. If it has provision for a mechanical fuel pump it is likely a ZL1. However they did some castings in the '80s in a much darker alloy.

Get the casting number off the back of the block, the casting date near the LH motor mount tabs. Also check the pad on the pass side of the block deck for a stamping. ZL1 blocks can have numerous problems so be careful.

[sebs]

great thanx ,jst the sort of info i was after

[ds1]

Factory engines have the Winters  foundry logo on the front above the timing cover.  The cast date should be cast on it and on the back deck  behind the distributor  should be stamped numbers that match the main caps if they are still  original.

[Nikke]

Casting # Aluminum Big Block

0-321270  4.440 430-465 Can Am Experimental Prototype 67-68 no boss for mechanical fuel pump
0-294550  4.250 427 Can Am Experimental Prototype 68 Dry sump
0-326711  4.440 430-465 Can Am Experimental Prototype 68
3946052  4.250 427 ZL1 68-69
3946052  4.250 427 Yenko 69 LC Casting
3946052  4.440 430-465 Can Am 69
3946053  4.250 427 OTC Replacement 70
3946053  4.440 495 Can Am 70
O-399204 4.500 510 Can Am Experimental Prototype 70-71
O-495102  4.500 510 Can Am Experimental Prototype 71-72 no Sleeve
3946052  4.250 427 Yenko
3946053  4.250 427 Yenko

[Kelley W King]

Never knew there were so many. Was there a number specificly for the 69 Camaro factory ZL1

[Nikke]

3946052  4.250 427 ZL1 68-69 is the Casting # for Camaro / Corvette Production Cars.  I think it was about 250, 052 blocks cast 68-69.

[Nikke]

There is a CanAm block from 73-74 but I have lost the the Casting number

[william]

The 3946053 block was used in a few production ZL1 Camaros. One of the first cars built had one. The ZL1 castings done in the late '80s are 053s.

ZL1 casting dates are on the LH side of the block near the motor mount tabs.

'0-' casting numbers were Chevrolet R & D part numbers, not marketed. Some ended up in race cars that were later sold.

[Nikke]

So you really think that # 3 had 053 block from factory?
053 was a stronger block than the 052 so I find it strange that # 3 got it and not the others.

[william]

I did not need to question the source for the information on the original block for the #3 ZL1. He would know. I'm sure other production ZL1s used it.

Why would an 053 block be "stronger" than an 052?