Re: Raw Casting ZL-1 Block
 

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

Re: Raw Casting ZL-1 Block
 

<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;
https://www.yenko.net/ubbthreads/pics...1-img_4515.jpg
https://www.yenko.net/ubbthreads/pics...2-img_4517.jpg

Re: Raw Casting ZL-1 Block
 

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.

Re: Raw Casting ZL-1 Block
 

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

Re: Raw Casting ZL-1 Block
 

Do zl 1 cylinder heads interchange with L 88 heads if so how do the heads get coolant circulation from a zl 1 aluminum block to a L 88 cast iron block.Yes they use dry blocks for drag racing because the engine only runs for 2 or 3 minutes,no need for coolant.Thanks marc.

Re: Raw Casting ZL-1 Block
 

<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?!).

Re: Raw Casting ZL-1 Block
 

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

Re: Raw Casting ZL-1 Block
 

<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!

Re: Raw Casting ZL-1 Block
 

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.

Re: Raw Casting ZL-1 Block
 

Did any of these blocks have a high silicon content such as the Vega 4 bangers so they did not require sleeves? TAZ