L88 Article by Ken Kayser

[Michael H.]

Re: L88 Article by Ken Kayser

the sheets i posted about the all aluminum can am engine with the front mounted oil pump is dated 7-1-68

Yes, but as I mentioned, this sheet with the early ZL1 info was not part of the usual HD pages that the GM reps carried around with them. I'm sure your sheet was sent directly to you, the same as mine was.

The very first mention of a new aluminum block in the regular HD pages showed the well known 3952318 (?) part (or casting?) number. Not the part number for the unque block with the front drive oil pump.

[Joe L.]

Re: L88 Article by Ken Kayser

i should have kept the first set of OC i got from GM as these heads had the aluminum around the exhaust ports not contured to shape of the exhaust ports and the head bolts were down in a counter bored holes next to the exhaust ports. i think these heads were sand cast. these heads made 29 more HP even when used with closed CC pistons as i did not want to tear the whole engine down at that time.

clem-----


I believe that all GM big block aluminum heads were sand castings, including all of those cast by Winters Foundry. Even today the GMPP big block aluminum heads, now cast and machined by Edelbrock, are sand castings.

[Clem Z.]

Re: L88 Article by Ken Kayser

clem-----


I believe that all GM big block aluminum heads were sand castings, including all of those cast by Winters Foundry. Even today the GMPP big block aluminum heads, now cast and machined by Edelbrock, are sand castings.

these heads were much roughter on the outside surface than the later ones i had. maybe it was just the way they were final finished.

[Dick W.]

Re: L88 Article by Ken Kayser

I don't think the info and prints were ever in the early HD pages that came out in the late 60's. I have most of those and there's no mention of the early design with the C/S driven oil pump. My sheets for that pump came separately from engineering.
Most of the technical engineering sheets like the one that Clem has were sent to engine builders.

I also have the first HD pages that were printed on green paper and available to the general public and I'm pretty sure that would have been around late 1970 or early 71. That would have been around a time when anyone could go to the dealer and purchase the sheets. It wasn't at all that way back in the late 60's.

Below is a scan of the first page of the HD pages I received in 1969. They were just loose pages, no binder. There's no mention of the early ZL1 block with the front mounted oil pump. The regular production ZL1 block is shown though.
The sheets that discussed the early version of the ZL1 with the front mounted oil pump arrived separately.

I just remembered a lot of HP parts were in the parts catalog, very front. About 1969 maybe

[Ridge K.]

Re: L88 Article by Ken Kayser

I must have missed Ken's answer. I have been through here twice and can't seem to find it. Can someone help ??

Dan

Unfortunately, Ken has 0 posts on this site.....

Ridge

[Joe L.]

Re: L88 Article by Ken Kayser

these heads were much roughter on the outside surface than the later ones i had. maybe it was just the way they were final finished.

clem------


There are different sand casting methodologies and they might affect the surface finish. Other than sand casting, the only other major aluminum casting technologies are lost foam, permanent mold, and die casting. All of these produce a surface finish that's much smoother than sand casting.

The lost foam process was used to produce the Vega 4 cylinder blocks. Some of the current GM aluminum heads might be produced using permanent mold or die casting but prior to the mid-90's, I don't think this was used for any cylinder heads.

[Clem Z.]

Re: L88 Article by Ken Kayser

I don't think the info and prints were ever in the early HD pages that came out in the late 60's. I have most of those and there's no mention of the early design with the C/S driven oil pump. My sheets for that pump came separately from engineering.
Most of the technical engineering sheets like the one that Clem has were sent to engine builders.

I also have the first HD pages that were printed on green paper and available to the general public and I'm pretty sure that would have been around late 1970 or early 71. That would have been around a time when anyone could go to the dealer and purchase the sheets. It wasn't at all that way back in the late 60's.

Below is a scan of the first page of the HD pages I received in 1969. They were just loose pages, no binder. There's no mention of the early ZL1 block with the front mounted oil pump. The regular production ZL1 block is shown though.
The sheets that discussed the early version of the ZL1 with the front mounted oil pump arrived separately.

just found the same the publication with the cover you posted

[G A.]

Re: L88 Article by Ken Kayser

Unfortunately, Ken has 0 posts on this site.....

Ridge

Ahhh... the young Jedi learns another lesson. Thank you for enlightening me Ridge.

[Duke W.]

Re: L88 Article by Ken Kayser

clem------




The lost foam process was used to produce the Vega 4 cylinder blocks.

The Vega block was actually a (steel) die casting. That's why it had an open deck design. The high cost of the dies is why Cosworth gave up on the F2 engine development. The early blocks wouldn't take 9000 revs. Cosworth and Cal Wade recommended changes to the dies, but Tonawanda didn't have budget for new dies, and the production engines were not showing similar failures.

In one Cosworth test the block separated at the top of the crankcase and the only thing that kept the whole thing from flying apart was the timing belt.

Circa 1973 Tonawanda produced new dies for a HD Vega block that went on to some success in USAC Midget racing, but by that time, F2 had gone to six cylinders.

Sand casting surface finish is affected by the grain size of the sand used for both cores and the mold.

Duke

[Joe L.]

Re: L88 Article by Ken Kayser

The Vega block was actually a (steel) die casting. That's why it had an open deck design. The high cost of the dies is why Cosworth gave up on the F2 engine development. The early blocks wouldn't take 9000 revs. Cosworth and Cal Wade recommended changes to the dies, but Tonawanda didn't have budget for new dies, and the production engines were not showing similar failures.

In one Cosworth test the block separated at the top of the crankcase and the only thing that kept the whole thing from flying apart was the timing belt.

Circa 1973 Tonawanda produced new dies for a HD Vega block that went on to some success in USAC Midget racing, but by that time, F2 had gone to six cylinders.

Sand casting surface finish is affected by the grain size of the sand used for both cores and the mold.

Duke

Duke------


I always thought the Vega blocks were cast at Massena, NY using the lost foam process.

[Duke W.]

Re: L88 Article by Ken Kayser

John Hinckley can confirm, but the attraction of the die cast process was low cost. Tooling cost was fairly high, but production cost was low since the process was essentially automated. Workers didn't have to prepare cores and molds as is the case with sand castings.

I think the die casting machines spit out a fresh block about every two minutes.

One of the issues was porosity. About 15 years ago I did a bore scope inspection of the cylinders in my Cosworth Vega engine and saw an "anamoly" on the rear of #2 cylinder about one inch down.

A few years later when I pulled the head for a refresh at about 70K miles I was able to confirm that is was a porosity hole about .060" x .030". That cylinder was slighly down on compression and leakdown, but not enough to worry about. There was no measureable wear at the tops of the cylinders.

The block should have been rejected, but it made it through.

Duke

[John H.]

Re: L88 Article by Ken Kayser

John Hinckley can confirm, but the attraction of the die cast process was low cost. Tooling cost was fairly high, but production cost was low since the process was essentially automated. Workers didn't have to prepare cores and molds as is the case with sand castings.

I think the die casting machines spit out a fresh block about every two minutes.

That's correct - see presentation slide below; the block was a low-pressure die-casting. There were four of these machines running at Tonawanda, as we built a Vega every 36 seconds at Lordstown. The aluminum was shipped in molten form to Tonawanda from the Massena foundry in special insulated trucks.

As I recall, the original Saturn OHC 4-cylinder and the Chevy truck OHC I-5 were the first volume applications of the lost-foam aluminum casting process.