Any idea WHAT this block is?

[Chevy454]

We found a block, but we can't find the number listed anywhere: #3952318

It's supposed to be an aluminum block.

[Rowdy Rat]

I show 3952318 as the original PART NUMBER for a big block Chevy aluminum cylinder case CASTING NUMBER 3946052... Your run of the mill ZL-1 block.

Regards,

Stan Falenski

[Edited by Rowdy Rat (10-30-2001 at 04:03 PM).]

[Chevy454]

Hmmm...guess I could have looked THAT up! It's supposed to be a "Can Am" block. What #s did they use?

[sYc]

Stan; Thanks for the quick reply. Now, for a couple of more questions. Could the block be a Yenko block? std. or tall deck? would the part number --2318 be on the block? thanks; Tom

[Rowdy Rat]

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>It's supposed to be a "Can Am" block. What #s did they use?<HR></BLOCKQUOTE>

I show two additional part numbers for service replacement aluminum blocks. The first, 3992038, was made from the same 356 T6 alloy as the "regular" ZL-1. It was equipped with dry cylinder liners (again, like the ZL-1), but with a bore of 4.440" instead of the typical 4.250" bore of the standard ZL-1. I show this block as available beginning in 1969.

The second, 3965755, was a linerless block made from a high silcon Reynolds 390 alloy (pretty sure that this is the same material that the Cosworth Vega engines were cast from... hopefully, the big blocks received better quality control ) with 4.440" bores. I show this block as being available in 1972.

I'm sorry that I can't provide casting numbers for either of these blocks, but I'll keep digging and see what I can turn up.

<BLOCKQUOTE><font size="1" face="">quote:</font><HR>Could the block be a Yenko block? std. or tall deck? would the part number --2318 be on the block? <HR></BLOCKQUOTE>

Tom,

My initial thoughts are that if it has a Chevrolet part number, it is unlikely a Yenko block. I have no hard evidence to support this, so if your research uncovers evidence that it is, I'd sure like to hear about it. I do know that Yenko's tall deck block was very well received by the racers (the three blocks mentioned above are all standard deck height blocks to the best of my knowledge) and I would imagine it to be quite valuable should you uncover one.

There was some sort of tie in between Don Yenko, GM, Alcoa, and Winters that resulted in Don getting these blocks cast in the first place, but I'm not sure what part each played in this business relationship. I'd be curious as to what details others can provide.

Regards,

Stan

[Edited by Rowdy Rat (10-31-2001 at 01:00 AM).]

[JoeC]

Stan, My understanding is that the ZL1 and the CanAm block are different castings. The ZL1 is similar to the iron BB design and has "wet" liners meaning coolant passes in between the adjoining cylinders. The CanAm block has a 4.440 in. dia. bore with Siamese cylinder design (like the 400 SB) where coolant does not pass between adjoining cylinders (dry liners). The other CanAm block has no liners and used a special coating on the pistons to control wear.

[Rowdy Rat]

Joe,

The three part numbers that I listed may very well be three different castings... The fact is that I only know of the "052" casting (the production ZL-1) at this point, but I'm researching the other two part numbers at this time. The 3992038 block might possibly be the same casting (although I highly doubt it), I'd bet the farm that the 3965755 block is a different casting.

I think that you're confusing "wet" and "dry" cylinder liners with siamesed cylinders (like the production 400 cid small block). A dry liner is one that is still surrounded by block material - a cylinder within a cylinder so to speak. A wet liner has very little material support from the block; it is directly in contact with the coolant and must be sealed to prevent coolant from forcing its way past the press fit between the liner and the block. For simplicity, a dry liner is pressed into the cylinder, a wet liner IS the cylinder. Both the 3952318 and 3992038 blocks are listed in GM literature as having dry liners.

Both of the 4.440" bore blocks may very well be siamesed cylinder design (makes sense that they would be)... None of the sources that I referenced mentioned it though.

The 3965755 block is as you described. The block was cast from a completely different alloy with a very high silicon content and used specially coated pistons (the coating was a nickle alloy I believe). The combination of the two kept the aluminum piston from trying to weld itself to the linerless cylinder.

Regards,

Stan

[Mr70]

Rob
I also found this part# 3952318 in my Chevrolet Special Equipment Catalog dated March 9th 1972.
It says it is a Bare Aluminum block for the 427 and 454 application in 1969.
This was the block was also used in that DEALER made ZL-1/LS-6 1970 Chevelle SS that I had posted here earlier this year.
It was from Ray Ridge in Trenton Michigan,which is now Pam Rogers Chevrolet.

[William]

The Can-Am block is easy to ID - no provision for a mechanical fuel pump.

[Chevy454]

So...did Chevrolet EVER produce an aluminum tall block? Was the Can Am block a tall block? And, was the Can Am the ONLY block NOT to feature a fuel pump boss?