Common block identifying?????

[HybridCuda]

OK my question is in Common blocks I have a 1990 Omni with a 2.2 TBI all factory and I assume it will be a common block, but I thought that common blocks have a large "C" Stamped on the block in the front under the thermostat housing general area, I went out to check my block today to see if the "C" was there it is not there so I am wondering it the common block only refers to turbo engines? cause mine being a 90 and not have the "C" on it ,or is this "C" not referring to a common block.......

Thanks

[135sohc]

Some do have the big letter 'C' and some dont. FWIW I have never seen one in the all years I have been going to the yards and in buying/selling engine cores. If its all original and factory then its 99.999998% for sure a common block as chrysler switched to the CB for the 1989 model year and that would have started in august/september of 1988.

A few quick checks to ID a CB.

The rear block rail where the oil pan bolts up will be flat vs scalloped like an early engine.
The front seal housing where it joins with the pan will be a half round shape. On a non CB its the same shape as the rear
No fuel pump block-off plate.

[4 l-bodies]

The "C" does not refer to common block. It is only there to identify that particular casting. Your 90 should be a common block. 88 was the last year for the early style block with the exception of the Chrysler TC's which there was a delay in using up parts due to assembly location. The early blocks will have a provision for a fuel pump, which is a cover held on with two bolts. It is located between the waterpump housing and the distributor. If you can't find that on your omni, that would be another clue that you have a common block. The rear bottom of the block also has a straight line at the oil pan bolt rail. This is added material that the early blocks don't have. Pic below shows early and common block from bottom. There are other diffferences too, but for an external visual inspection. These are easy ways to tell them apart.
Todd

[HybridCuda]

ok Thank you I will look at it After Welding class today.

[Khajjathefang]

I think the c's were the Mexican blocks. I remember theory back in the day was that they were stronger

[135sohc]

I think the c's were the Mexican blocks. I remember theory back in the day was that they were stronger

I have a mexico cast block, its plain in that area.

[Khajjathefang]

No idea then, lol

[4 l-bodies]

I think the c's were the Mexican blocks. I remember theory back in the day was that they were stronger

Yeah I remember that thread. They were thought to be the Holly Grail until several of them failed (cracked waterjacket). Another urban legend shot down (lol)!

[Khajjathefang]

2

Yeah I remember that thread. They were thought to be the Holly Grail until several of them failed (cracked waterjacket). Another urban legend shot down (lol)!

Doesn't shadow run a regular old t2 block? Really makes you question some of the old facts

[turbovanman²]

C's aren't the holy grail, mine cracked, but after it was cold welded, it was fine. The best blocks are TIII or later TBI blocks.

http://www.turbo-mopar.com/forums/kn...ck-Differences

[roachjuice]

Didn't top fuel bender run an old 85-86 block into the 10's? All the C blocks I've seen were 2.5 89 blocks. But that's just my experience. All the old blocks are blank. There is a build date on the bottom back passenger side of them. Just above the oil pan.

[4 l-bodies]

2

Doesn't shadow run a regular old t2 block? Really makes you question some of the old facts

Rob is running block # 4501851 It looks like a early block but has webbing of the common block. These were cast in the early 90's in Mexico. I have one as well. Uses early crank, oil pan, etc. Cast in 93, long after early blocks were done in US. Here are a couple pics.
Todd

[turbovanman²]

Rob is running block # 4501851 It looks like a early block but has webbing of the common block. These were cast in the early 90's in Mexico. I have one as well. Uses early crank, oil pan, etc. Cast in 93, long after early blocks were done in US. Here are a couple pics.
Todd

Oh really!!!!!!!!!!!!!!

[Tbird232ci]

Are the mexican blocks cross drilled?

[turbovanman²]

Are the mexican blocks cross drilled?

Yes, turbo of course.

[Shadow]

Rob is running block # 4501851 It looks like a early block but has webbing of the common block. These were cast in the early 90's in Mexico. I have one as well. Uses early crank, oil pan, etc. Cast in 93, long after early blocks were done in US. Here are a couple pics.
Todd

Is this a joke? Did you actually check this out when I was at SDAC? (cause I don't remember talking about it?)

If not, your timing is impeccable my friend! Was just talking to a Bud and telling him I didn't have the balls to drop my pan and look at the webbing to check if it's the older or if it's like the CB because it would scare the $hit out of me, and just before I'm about to go out and run! lol

So If what your saying is true, it would not only make good sense (otherwise how am I still together?) It gives me a Ton of confidence back that this Beast is going 9's!!!!!!

[Shadow]

Damn! Ya had me going there! lol Bu11$hitter!!!!!!

[4 l-bodies]

Rob,
I remember talking about this on this forum a couple few years back. Thought we concluded you also ran this unusual block? Remember seeing that your car had the fuel pump blockoff when I last saw the car in Waukegan, IL. I did not crawl under car to verify block #'s though. Without a jack, your car is a bit too low for that (lol)! Easy enough to check without dropping pan, just look for that straght edge (added material) where oil pan bolts up (like common blocks) and of course the block casting date and casting #. It will be identical to pic is post #3. Gary Donovan told me has one of these blocks. At least a couple others on this forum also have them. They are rare, but they are definitely out there. They where used in US as replacement warranty blocks for early TII applications after CB's were in production.
I also run the garden variety early block in one of my GLHT's. Not making the HP you are, but hardly a low HP car. Quacks GLHS Masi also ran early block that was a easy mid 11 second car on very low boost. Of course both have steel cranks in them. Yes, Bruce Bender was also running early block and running in 10's. I have no issues running early block along with steel crank in a street car. I've seen exactly one early block crack in the #3 main journal area. I've also seen a couple CB let go in this area. Think Brian Slowe hurt one of his blocks in main webbing area years ago.
Todd

Is this a joke? Did you actually check this out when I was at SDAC? (cause I don't remember talking about it?)

If not, your timing is impeccable my friend! Was just talking to a Bud and telling him I didn't have the balls to drop my pan and look at the webbing to check if it's the older or if it's like the CB because it would scare the $hit out of me, and just before I'm about to go out and run! lol

So If what your saying is true, it would not only make good sense (otherwise how am I still together?) It gives me a Ton of confidence back that this Beast is going 9's!!!!!!

[cordes]

C's aren't the holy grail, mine cracked, but after it was cold welded, it was fine. The best blocks are TIII or later TBI blocks.

http://www.turbo-mopar.com/forums/kn...ck-Differences

Most of those which I've seen have been mexican castings.

[zin]

Are those "odd" blocks the tall deck TBI blocks? I'm thinking I'd like to find one of these tall deck blocks, but I imagine they'd be pretty hard to find, so if these are more common, perhaps I would do well to set my sights a bit "lower" so to speak...

Mike

PS Does anyone here know if the "tall deck" blocks had the same pan rail as the CB? I'm trying to hone my JY, "tall block" vision!