ZL-1 Block Marking Help

**SuperNovaSS** · #1 05-11-2013, 12:58 AM

I recently picked up a ZL-1 block and am trying to find out more about it. It is a large bore block that has cooling passages and a fuel pump boss. It had a winter's snowflake but was ground off by the original owner so the block would appear to be a cast iron block once painted. There is a stamping on the deck pad and by the oil filter that reads,"Jumbo's Racing Engines Torrance, CA".'Vince and Kim Jamara" is also engraved by the oil filter area. Under the timing cover is stamped SY and SY DJ as shown. The block has no casting date anywhere and has never been ground on or polished so there never was one.

Does anyone have any insight on any of these stampings? The rods were also engraved, "Jumbos".

Thanks,

Jason

**SuperNovaSS** · #2 05-11-2013, 01:00 AM

**SuperNovaSS** · #3 05-11-2013, 01:02 AM

**SuperNovaSS** · #4 05-11-2013, 01:04 AM

**PeteLeathersac** · #5 05-11-2013, 03:35 AM

Googled up a few things but only this below item for sure from the same group.
Note it has Jumbo Racing, not Jumbo's also the ad refers to F1?
http://www.delcampe.net/page/item/id,202...language,E.html

Try and you may get lucky asking someone @ Shaver Racing in Torrance CA?
http://www.shaverengines.org/index.html

[img]<<GRAEMLIN_URL>>/dunno.gif[/img]
~ Pete

**iluv69s** · #6 05-11-2013, 09:03 AM

I believe that is a later 'Yenko' block. They made big-bore and high deck versions. Ive seen them with a snowflake but I believe typically on a Yenko block, it would not have a 'w' for winters..If I recall it would have had a snowflake with an L... going by memory

Interesting as it has screw-in freeze plugs, typical of production blocks, but I have Yenko blocks had them both ways.

**iluv69s** · #7 05-11-2013, 09:03 AM

Neat oil filter too !!

**bergy** · #8 05-11-2013, 01:42 PM

Those big milling cutter sweeps don't look like they came from the Tonawanda CNC machining center - IMO.

**SuperNovaSS** · #9 05-11-2013, 02:21 PM

Thanks for the replies guys. It could be a Yenko block but I also had a winter's block years ago that had large bores just like this one. It is a bummer about the snowflake because the block is cherry otherwise. It was assembled as a shortblock when I got it. I believe the 4.5
inch bore amd 4 inch stroke makes this a 510. It has nice Ross pistons, a 3521(LS7) 454 crank that had been internally balanced, a Summers Bros timing cover with a cam access hole, and Isky roller cam.

The story goes that it was in a 70 el camino that the owner hoped to run 10's in. The camino was setup safety wise as a 10 second car and broke into the 9's on the first run. The track asked the owner to go home. The engine was pulled and a smaller engine was put in the camino. This engine was either sold or given to the current owner who was a good friend when the past owner past away.

Jason

**iluv69s** · #10 05-11-2013, 05:03 PM

my belief that it is yenko block is because of the markings, nothing to do with the bore size.

as far as the snowflake missing, that's no big deal. My original block from my ZL-1 had the same thing. Early in lfe it was separated from my car and then eventually ended up in a circle track car. It had the snowflake ground off and was painted all orange so the competitors would not know any better !!! The goood news is JM restored the motor and he also restore teh snowflake. His website has a pic of my block. Fortunately, aluminum can be fixed.

I'll take it off your hands if the missing snowflake bothers you too much !! Cool Piece !!!

Better yet, YOU SHOULD BUILD SOMETHING OUT OF IT !!

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