L88 Article by Ken Kayser

[Duke W.]

Re: L88 Article by Ken Kayser

Correct me if I am wrong Pat, but weren't all the Can Am blocks sleeved from the factory? I seem to remember that from the early Chevrolet Performance Manual.

I think the last version - 510 CID from 1971 - used a linerless block - same technology as the Vega engine.

I believe this linerless block was cast by Reynolds, and they may have also cast the earlier sleeved blocks that were built to 427, 430, 465, and 495 CID.

I believe these are the nominal bore x stroke dimensions, in inches:

427: 4.25 x 3.76 = 426.7 (same as production 427s)

430: 4.44 x 3.47 = 429.8

465: 4.44 x 3.76 = 465.7 (stroke may have actually been 3.75" for 464.49 CID)

495: 4.44 x 4.00 = 495.46

510: 4.50 x 4.00 = 508.9

The linerless 510 CID block allowed .060" greater finished bore dimension.

The "short stroke" 430 was higher revving, but placed greater stress on the valve train.

Duke

[Duke W.]

Re: L88 Article by Ken Kayser

A few of those very early 0- aluminum blocks had part of an oil pump from a turbo 400 transmission mounted and driven off of the nose of the crankshaft. The pump location used the large oil passages that you describe.
I may have some prints on this somewhere around here.

IIRC Can-Am engines used a dry sump system, so I assume the pump you are refering to is the pressure pump.

What about the scavenge pump - external, belt driven?

Duke

[Dick W.]

Re: L88 Article by Ken Kayser

I think the last version - 510 CID from 1973 - used a linerless block - same technology as the Vega engine.

I believe this linerless block was cast by Reynolds, and they may have also cast the earlier sleeved blocks that were built to 427, 430, 465, and 494 CID.

Duke

I seem to remember that Reynolds did the casting.

[Clem Z.]

Re: L88 Article by Ken Kayser

the easiest way to tell a CC head from a OC head on a assembled engine is the shape of the aluminum over the exhaust port. the CC heads the area is flat and the OC head the area is rounded

[Clem Z.]

Re: L88 Article by Ken Kayser

IIRC Can-Am engines used a dry sump system, so I assume the pump you are refering to is the pressure pump.

What about the scavenge pump - external, belt driven?

Duke

here are some pictures

[Patrick B.]

Re: L88 Article by Ken Kayser

Correct me if I am wrong Pat, but weren't all the Can Am blocks sleeved from the factory? I seem to remember that from the early Chevrolet Performance Manual.

The first addition Chevy Power Manual published in 1975 says the ZL-1 block (4.25 bore, sleeved) was built from 69 to 74; the first big bore Can-Am block (4.44 bore, sleeved) was built from 69 to 72; and the second big bore Can-Am block (4.44 bore, no sleeves) was built from 72 to 75). The linerless block was still listed as P/N 3965755. I think the big bore sleeved blocks looked pretty much like the production ZL-1s and had the Winters snowflake.

The 0294550 block existed before any of the other aluminum blocks or the open chamber heads. I have a picture in the book, Chapparel by Dave Friedman, showing an aluminum 427 with apparent CC heads, ordinary chrome plated valve covers, and Weber carbs sitting beside a Chapparel 2F on March 31, 1967 in the garage at Sebring 12 hrs. This was about 18 months before the ZL-1 open chamber heads and apparently even longer before they showed up on L-88s.

[Clem Z.]

Re: L88 Article by Ken Kayser

here are some pictures

better pictures ??

[Duke W.]

Re: L88 Article by Ken Kayser

Thanks for posting the higher revolution scans.

I now understand that the scavenge pump is located/driven as is the production pressure pump.

Since most road racing courses run clockwise it makes sense that the LH valve cover has two scavenge pickup points and none on the RH valve cover

What document did these scans come from?

Duke

[Clem Z.]

Re: L88 Article by Ken Kayser

Thanks for posting the scans. What document did they come from?

The resolution is too small to read the text, but I can trace the lines and it looks like there is no external scavenge pump, so I assume the scavenge stage is built into the pump mounted on the nose of the crankshaft (?).

Duke

the scavenge pump is in the pan driven by the dist. the pressure pump is in the timing gear cover. zoom the picture to 150/200 and see if you can read it

[Michael H.]

Re: L88 Article by Ken Kayser

better pictures ??

Thanks Clem. That's the system that I was talking about. I can't read most of the text but I remember that the basic design of the pump used gears from a Turbo 400 transmission front pump.

[Dick W.]

Re: L88 Article by Ken Kayser

What document did these scans come from?

Duke

I think those prints were in the booklet Chevy printed (was not even bound) about '69 or '70. I have one somewhere in my library. It had a lot of part numbers and technical information for those that were racing. I think the pages were green and about as thick as onion skin paper.

[Michael H.]

Re: L88 Article by Ken Kayser

I think those prints were in the booklet Chevy printed (was not even bound) about '69 or '70. I have one somewhere in my library. It had a lot of part numbers and technical information for those that were racing. I think the pages were green and about as thick as onion skin paper.

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.

[G A.]

Re: L88 Article by Ken Kayser

Ken, What a great article in the new Corvette Restorer magazine this month,
Can you tell me if there is a Vin or date when the " LO "
open chamber heads came out in late 69 ?
As my late 69 L88 has the LO heads.

Regards Tom

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

Dan

[Clem Z.]

Re: L88 Article by Ken Kayser

the OC heads and pistons were available 1-17-69 according to the parts sheets i have here.

[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 about 1972 or 73. 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.

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