BBC casting #1X157129AC still a mystery.

6T9chevelle · 02-06-2010, 12:03 AM

I posted this last week trying to find some info on this mystery casting number but have come up with zilch, like they dont exist. They have CFD cast in them as well as HI PERF. The date code is only 58. They are rect port iron BBC heads with 2.25 valves and bronze guides. The main reason I need some info on them is I would like to sell them but I dont know which class can use them. They are fresh with new valves and guides and triple springs. Any info would be appreciated.

Ron Miller · 02-06-2010, 02:56 PM

I think your question was answered here. Their are way more Sharper Guys on this site that live & die by casting numbers. Suggest for you, spend some time over on the NHRA Engine Blueprint Specifications. That head will not be legal for any traditional Super Stocker or Stocker.

Jim Cimarolli · 02-06-2010, 06:23 PM

Is that an open or closed chamber head? What spark plug does it take?
I knew you said it had a 2.25 intake valve, what size exhaust valve?
Thanks, I wonder if Dwight Southerland can chime in on this one?

tj310 · 02-06-2010, 06:43 PM

I suggest you try and sell them on the Yenko or a Corvette site cause there not legal in stock unless you grind the numbers off and carefully weld on different numbers. Thanx Trevor

6T9chevelle · 02-07-2010, 02:38 AM

They are open chamber with a taper plug. I believe the exhaust are 1.88.

Jim Cimarolli · 02-07-2010, 10:40 AM

The little plug has to mean post 1970, and the open chamber almost has to lead me to believe it is a prototype of an over the counter item. Somebody correct me if I'm wrong, but I don't think there was ever a production engine built by GM after 1970 that had a big port open chamber iron cylinder head on it.

Chris Cogan · 02-07-2010, 01:34 PM

Bowtie Froggie is correct. These heads are from Central Foundry Defiance. The wagon wheel was the old logo. All Central Foundry Sites became part of GM Powertrain in the early 90's, so I would guess that these heads are service replacement heads from 1988. The date code uses a letter for the month (we didn't use I so it wouldn't be confused with a 1), then 3 numbers. First 2 numbers were the day and the last # was the last number of the year. maybe 058, 158, 258, who knows. looks like the pattern had a "sticker" and the numbers didn't get imprinted in the mold. Defiance finished production of the Mark late last year. (8.1 liter block, head and crank) The end of an era for sure. I will try to find out more about the casting #. Take care guys.

Dwight Southerland · 02-07-2010, 05:28 PM

Quote:

Originally Posted by Jim Cimarolli

Is that an open or closed chamber head? What spark plug does it take?
I knew you said it had a 2.25 intake valve, what size exhaust valve?
Thanks, I wonder if Dwight Southerland can chime in on this one?

Jim - I can't shed a lot of light on this that hasn't already been said. The CFD marking indicates to me these are from the '80s. Maybe this was done at the same time the replacement 291 closed chamber heads were done. I know the late casting 291 heads (which were also CFD castings from the '80s) used the same intake port and exhaust ports as the 188 & 990 heads and were machined for the 5/8" spark plugs. What throws me is the 2.25" valves. Chev had 2.30" valves in their HP catalog about that time, but not 2.25" valves. It would be nice to have a bunch more pictures.

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

02-06-2010, 02:56 PM	#2
Ron Miller Member Join Date: Mar 2002 Location: Brownstown, Mi 48134 Posts: 196 Likes: 35 Liked 13 Times in 7 Posts	Re: BBC casting #1X157129AC still a mystery. I think your question was answered here. Their are way more Sharper Guys on this site that live & die by casting numbers. Suggest for you, spend some time over on the NHRA Engine Blueprint Specifications. That head will not be legal for any traditional Super Stocker or Stocker.

02-06-2010, 06:23 PM	#3
Jim Cimarolli Senior Member Join Date: Mar 2002 Location: Sulphur Springs Texas Posts: 742 Likes: 144 Liked 166 Times in 46 Posts	Re: BBC casting #1X157129AC still a mystery. Is that an open or closed chamber head? What spark plug does it take? I knew you said it had a 2.25 intake valve, what size exhaust valve? Thanks, I wonder if Dwight Southerland can chime in on this one?

02-06-2010, 06:43 PM	#4
tj310 Member Join Date: Sep 2009 Location: Dresden On. Canada Posts: 460 Likes: 0 Liked 0 Times in 0 Posts	Re: BBC casting #1X157129AC still a mystery. I suggest you try and sell them on the Yenko or a Corvette site cause there not legal in stock unless you grind the numbers off and carefully weld on different numbers. Thanx Trevor

02-07-2010, 02:38 AM	#5
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. They are open chamber with a taper plug. I believe the exhaust are 1.88.

02-07-2010, 10:40 AM	#6
Jim Cimarolli Senior Member Join Date: Mar 2002 Location: Sulphur Springs Texas Posts: 742 Likes: 144 Liked 166 Times in 46 Posts	Re: BBC casting #1X157129AC still a mystery. The little plug has to mean post 1970, and the open chamber almost has to lead me to believe it is a prototype of an over the counter item. Somebody correct me if I'm wrong, but I don't think there was ever a production engine built by GM after 1970 that had a big port open chamber iron cylinder head on it.

02-06-2010, 12:03 AM	#1
6T9chevelle Junior Member Join Date: Oct 2006 Location: Lincoln Posts: 39 Likes: 0 Liked 0 Times in 0 Posts	BBC casting #1X157129AC still a mystery. I posted this last week trying to find some info on this mystery casting number but have come up with zilch, like they dont exist. They have CFD cast in them as well as HI PERF. The date code is only 58. They are rect port iron BBC heads with 2.25 valves and bronze guides. The main reason I need some info on them is I would like to sell them but I dont know which class can use them. They are fresh with new valves and guides and triple springs. Any info would be appreciated.

02-07-2010, 01:34 PM	#7
Chris Cogan Junior Member Join Date: Apr 2007 Location: Defiance, OH Posts: 47 Likes: 0 Liked 0 Times in 0 Posts	Re: BBC casting #1X157129AC still a mystery. Bowtie Froggie is correct. These heads are from Central Foundry Defiance. The wagon wheel was the old logo. All Central Foundry Sites became part of GM Powertrain in the early 90's, so I would guess that these heads are service replacement heads from 1988. The date code uses a letter for the month (we didn't use I so it wouldn't be confused with a 1), then 3 numbers. First 2 numbers were the day and the last # was the last number of the year. maybe 058, 158, 258, who knows. looks like the pattern had a "sticker" and the numbers didn't get imprinted in the mold. Defiance finished production of the Mark late last year. (8.1 liter block, head and crank) The end of an era for sure. I will try to find out more about the casting #. Take care guys. __________________ Chris Cogan

02-07-2010, 05:43 PM	#9
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	#10
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