BBC casting #1X157129AC still a mystery. - Page 2

6T9chevelle · 02-07-2010, 05:43 PM

I'll take some more good pics and post them later tonight. I appreciate the info so far.

Jeff Cuppy · 02-09-2010, 06:34 PM

Hello,

Its been a while but it seems that I have seen similar heads used on Mercruiser versions of LS-6-7 engines in the 80s.

The ones I saw had closed chamber style domed pistons, that looked very similar to a 1970 LS-6 forged 11.0 to 1 (with a closed chamber head), but used the open chamber rectangular port head.

Im not sure about the intake valve size but the exhausts were 1.88".

Maybe these have a marine origin?

Competition Products, in Wisconsin used to do a lot of work on Chev marine engines in the 80s, and would sell a lot of take off stuff in the Dragster. I bought "L" rockers, cams, intakes, balancers. etc.. Maybe they would know a little about this?

Jeff

02-07-2010, 05:43 PM	#11
6T9chevelle Junior Member Join Date: Oct 2006 Location: Lincoln Posts: 39 Likes: 0 Liked 0 Times in 0 Posts	Re: BBC casting #1X157129AC still a mystery. I'll take some more good pics and post them later tonight. I appreciate the info so far.

02-09-2010, 06:34 PM	#12
Jeff Cuppy Junior Member Join Date: Dec 2001 Posts: 6 Likes: 0 Liked 0 Times in 0 Posts	Re: BBC casting #1X157129AC still a mystery. Hello, Its been a while but it seems that I have seen similar heads used on Mercruiser versions of LS-6-7 engines in the 80s. The ones I saw had closed chamber style domed pistons, that looked very similar to a 1970 LS-6 forged 11.0 to 1 (with a closed chamber head), but used the open chamber rectangular port head. Im not sure about the intake valve size but the exhausts were 1.88". Maybe these have a marine origin? Competition Products, in Wisconsin used to do a lot of work on Chev marine engines in the 80s, and would sell a lot of take off stuff in the Dragster. I bought "L" rockers, cams, intakes, balancers. etc.. Maybe they would know a little about this? Jeff