aluminum /6 block

[Capt Jack]

found this over at http://www.valiant.org/sixup.html

Factory-performance slant sixes (Bob Scott)From mid-1961 to 1963, 50,000 225-cid Slant Six engines were produced with an aluminum engine block. These were discontinued because production was slower, more expensive, and not as reliable as with the steel blocks, according to various allpar.com interviews.

A special Hyper-Pak was available for the 170 and 225 slant sixes, with a radical cam; a Carter AFB four-barrel carburetor mounted on an intake manifold with long ram passages; steel tubing exhaust headers; higher compresion pistons and a special tuned exhaust system. Advertised at 195 hp (gross output, for the 170), Hyper-Pak engines are often said to put out even more power. They were the rulers of the lower stock classes at the drag races. The Hyper-Pak was available as a dealer-installed or user-installed option.

Hyper-Pak specs:

Overhead valve. Cast iron block.
Compression ratio: 11.5:1 (225), 10.5:1 (170)
Brake hp: 195 at 5200 rpm (225), 148 (170) *
Four main bearings.
Solid valve lifters.
Carburetor: Carter AFB 3083S four-barrel.
Larger exhaust system using cast iron hearders.

Ive never heard of these....anyone have any first hand knowledge of them?  just curious really

[NYrr496]

They exist... they usually corrode at the deck and good used ones are VERY rare.

[GTS225]

Us slant guys have known about them for ages.

The slant was originally designed for an aluminum block, but they designed it with an open "deck". (No real deck with free-standing cylinders.) With so little sealing surface at the top of the cylinder, there was serious problems with head gasket sealing and overheating. To add to it,  it was discovered late in '61 that it was more espensive than iron.  As a result, the aluminum block was dropped, but the crank/rod/block dimensions weren't changed, so the slant ended up being rather stout for a four-main straight six.

I've got a good bare block out in my garage, but just use it as a dummy for setup or head work while on the stand. (It only weighs in at about 78 pounds.)

BTW....here's something else a lot of you V-8 guys don't know. (or care about  ).  Hilborn made and marketed a mechanical fuel injection setup for the slant clear back in the late 60's or early 70's.

Roger

[Capt Jack]

thanks guys. 

I was just momentarily toying with the idea of a stout built (super or turbo charged) /6 and stumbled across that alum block note.
doesnt sound like it would be the best of choices.  nice n light doesnt count for much if it comes apart first time you go to run it.

 

[CudaSRT8]

I was over at Doug Dutra's house back around '96 or so.   He had one or two aluminum blocks running in cars and had another 2-3 laying around.   No wonder they're so scarce, Dutra has them all...