Raw Casting ZL-1 Block

[markus37]

A couple dozen unmachined raw castings were shipped to Smitty at Yenko Performance and Marine in the early 80's. My records indicate that he thought some racers might want to do their own block prep.
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[Verne_Frantz]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: markus37</div><div class="ubbcode-body">A couple dozen unmachined raw castings were shipped to Smitty at Yenko Performance and Marine in the early 80's. My records indicate that he thought some racers might want to do their own block prep.
. </div></div>

The raw Yenko blocks were identified as &quot;Yenko&quot;

[ds1]

How many were cast and how many made it through machining in 1969?

[markus37]

Many of the Yenko blocks had no Yenko I d, only the GM part number. This was done to satisfy racing organizations who did not allow aftermarket blocks...SCCA for one.

[markus37]

Again, I reference my new book &quot;The Yenko Era..
Continued.Canonsburg and Beyond &quot;

[bergy]

<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">[/quote]The cores in the cooling cavity of the block are usually made of silica sand,when the block is machined the sand exits from the frost plug and cooling holes.They usually go on a vibrating machine to loosen the particles of sand.Theres more to the process then i mentioned.[quote]</div></div>
Good point Marshall - I'm sure that you know this, but just for discussion - The same resin core binder was used for aluminum and iron. The problem was that aluminum is poured into the mold at a much lower temperature then iron. So, the binder didn't break down (burn up) completely in the aluminum castings; thus the core wouldn't completely exit the casting during shake out. The cores that remained in cooling passages of aluminum castings caused huge problems. At Messina (Vega 390 aluminum blocks) we actually built dedicated, individual shaker fixtures to &quot;rattle&quot; the heck out of the blocks. I did my thesis in graduate school on cleaning of castings and removal of core sand (how anal is that?!).

[JoeC]

The solid core Yenko blocks may have been for drag racing ?

filling blocks was for dedicated drag racing to keep cylinders round and keep them from cracking. Some drag racers still do it

They make block fillers such as &quot;Hard Blok&quot; and others

[Xplantdad]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: bergy</div><div class="ubbcode-body"><div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"></div></div>The cores in the cooling cavity of the block are usually made of silica sand,when the block is machined the sand exits from the frost plug and cooling holes.They usually go on a vibrating machine to loosen the particles of sand.Theres more to the process then i mentioned.<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body"></div></div>
Good point Marshall - I'm sure that you know this, but just for discussion - The same resin core binder was used for aluminum and iron. The problem was that aluminum is poured into the mold at a much lower temperature then iron. So, the binder didn't break down (burn up) completely in the aluminum castings; thus the core wouldn't completely exit the casting during shake out. The cores that remained in cooling passages of aluminum castings caused huge problems. At Messina (Vega 390 aluminum blocks) we actually built dedicated, individual shaker fixtures to &quot;rattle&quot; the heck out of the blocks. I did my thesis in graduate school on cleaning of castings and removal of core sand (how anal is that?!). </div></div>

Your knowledge never ceases to amaze me!

[MarcDant]

Another interesting fact i came across by one of mould making engineers at a casting facility quite a while back,was that they did not use steel liners in the bores of the Mclaren cars,they had the forged piston iron plated.I thought he was crazy but came to find out it was true.Thanks marc.

[firstgenaddict]

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: marshall</div><div class="ubbcode-body">Another interesting fact i came across by one of mould making engineers at a casting facility quite a while back,was that they did not use steel liners in the bores of the Mclaren cars,they had the forged piston iron plated.I thought he was crazy but came to find out it was true.Thanks marc. </div></div>

Yea this is amazing isn't it... I was in awe when I found out as well!