Raw Casting ZL-1 Block
 

Raw Casting ZL1 Block on eBay

Is there any way the bids on this block could be real? Even if all the machining was done, wouldn't the block still not have cast in water passages?

Jason

Re: Raw Casting ZL-1 Block
 

Simply a display item..

Re: Raw Casting ZL-1 Block
 

That would be one expensive coffee table!
Buddy

Re: Raw Casting ZL-1 Block
 

I have records on many solid blocks that Yenko cast, typically for drag racers.A lot of that history is in my newest book.." The Yenko Era..
Continued. Canonsburg and beyond "

Re: Raw Casting ZL-1 Block
 

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.

Re: Raw Casting ZL-1 Block
 

I see, that is interesting. Thanks for explaining.


Jason

Re: Raw Casting ZL-1 Block
 

They show a picture of the part number on the back of the block. But there is no casting date on the driver side of the block. Another tall Ebay story? It could be true. But event preproduction parts have casting numbers and dates. I checked my pictures of the block I had to confirm my suspicion.
https://www.yenko.net/ubbthreads/pics...7-im000169.jpg

Re: Raw Casting ZL-1 Block
 

I too would believe the core still has sand in it. Isn't there a way to check to see if there are hollow cavities? Tapping would surely give some type of indication.

Were the Aluminum blocks broached or did they use a rotary cutter?

Re: Raw Casting ZL-1 Block
 

There is no water jacket core - if the core was there, it would have printed at the freeze plug. Aluminum blocks were milled (rotary cutter)

Re: Raw Casting ZL-1 Block
 

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.
.

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

Re: Raw Casting ZL-1 Block
 

<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!

Re: Raw Casting ZL-1 Block
 

When does Bergy's book come out. Bruce's vast knowledge of the engine casting process and Tonawanda engine plant would be a great read.

Marty

Re: Raw Casting ZL-1 Block
 

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: firstgenaddict</div><div class="ubbcode-body"><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!
</div></div>

I believe the block alloy was Reynolds 390 (same as Vega), and they did run without iron sleeves. I believe (but not 100% certain) that production Porsche 928 blocks were the same alloy and they also did not run sleeves.

Click on link and read this old newspaper article from 1971 where the McLaren team said the aluminum cylinder walls wore LESS than iron cylinders.

https://news.google.com/newspapers?n...2868&amp;hl=en

Re: Raw Casting ZL-1 Block
 

Walls SHOULD wear less than iron. The silicon precipitated out of solution before the matrix aluminum solidified; leaving lots of extremely hard silicon nodules. After the bores were machined, the walls were etched to eat away the aluminum matrix and expose the silicon nodules. So, the piston rings actually contacted the silicon &amp; not the aluminum.

That's the Cliffs Notes version - it's a little more complicated. I worked with Jon Jorstaad (Reynold's chief metallurgist) in development when I was at Warren R&amp;D. Also interesting that we received the aluminum in LIQUID form at the Messina plant.

Re: Raw Casting ZL-1 Block
 

It would be nice to see if the seller would disclose what the buyer is going to do with this block. With CanAm cars being so valuable, I have to wonder if someone is buying this as a backup block to be machined later. I have to wonder if machining it could be easier now with wetliners (spun cast) being out there. Just plain curious.