66-427 CX no casting #?????

[SCOBRAC]

I found an FE block with no production code. It has vertical ribbing on the skirt, additional webbing on bearing supports ala CJ, SCJ and 427's. It is marked 66-427 on the right rear and CX on the left. The freeze plugs are press in.

It's date code is J16 (October 1, 1966). I have been told that the extra ribbed blocks got a C scratched in them. What if anything was the X for???

Anyone seen a block like this before? It seems to be never assembled standard bore. What would it be worth?

[FFR428]

The "X" was just a way to tell a HD block from the regular. And the CX blocks are really thick. I had one and it had much thicker walls compared to the regular CJ block. Pop out a freeze plug and check the wall thickness using the drill bit test. Also look for the 428 cast inside. I been reading up on service blocks and that sure sounds like one. Look for a number with a couple of dots under it before the J16. Also the J is September not October. The foundry skipped the letter "I" in the date codes as it could be confused for a "1". Also no production blocks had the ribs only service blocks. Thtas why you see no casting or production number. The 66-427 is just the rear bulkhead of the 427 used in casting and it's on lots of other FE's besides. The sandscratch "C" was to designate the CJ block and was not a cast in letter like the "CX". The "A" blocks are the std 428 without the extra crank webbing. The best I can figure with the "CX" is it's to designate a CJ HD replacement block but that's just a guess. Checkout www.428cobrajet.org and also an archive search on www.fordfe.com for service blocks and you will find lots of info. Gotta run, G.

[SCOBRAC]

Thanks. Yea I figured it was a service block with no production code. I didn't know they skipped I... It is a really thick wall block. I can see the difference at the bottom of the cylinder / wall. it looks a good 1/16" thicker all around where the bore meets the area around the bore. It actually flattens out before it turns up.

I knew all the C blocks I'd seen had additional webbing, so maybe CX is additional webbing with thick walls. As you suggest a HD service block.

Well. it seems I have a check to write. Thanks for the insite.

[FFR428]

You will find most HD blocks have the crow's feet webbing as your CX. Also more girth underneath the crank support area as well. The CX blocks just had thicker walls and are rumored to be race blocks as well. I can't confirm the race block thing but they are thick walled for sure. Sounds like you scored a nice one! G.

[SCOBRAC]

Two actually. The guy has a std bore C6ME-A 428 too. I will be selling that one and some other parts. Anyone in N. Calif need a nice 428 block? It's an A code but would be a nice street motor. It was suppose to have been an early CJ but at this point there's no way to verify that.

A code motors were used in the 1967 GT 500's... Not saying it was. Just saying it could have been. ;-)

http://www.carmemories.com/cgi-bin/v...erience_id=597

[FFR428]

T-birds also had the A blocks as well others. Know a guy who just fished out a complete running "A" 428 from a T-bird for $200. There have been a few A blocks found in CJ cars over the years that were stock. Seems supply and demand played a big part in production. G.

[SCOBRAC]

Doh...

It seems my initial measurements were off a little. It turns out the CX block measures 4.09 not 4.13.

How funny is that. What would this thing been used in? I guess it would have been a heavy duty replacement for a 390.

It will obviously go to 4.13 so I can go to a stock 428 piston, netting a 406 CI. What about going to 4.23? Only a sonic check will tell the tale, but this is the same block family the 1968 427 hadraulic engines came from, high nickle content reinforced crank saddles, etc.

Anyone done this? But then again why do it... If I kept it 4.13 It would be an excellent performer with a mild cam and 10:1 compression likely to put out 450 hp and still be done using standard sized piston$. Any future rebuilds would be equally inexpensive compared to custom pistons.

Any thoughts?

[FFR428]

I think it will go 4.13 no problem. 4.23 might be a stretch but do the drill bit test between the cyl walls through the freeze plug holes. A 17/64" bit will fit between a 390 wall casting a 13/64 between a 428/406 casting and 8/64" and 5/64" for the 427's. You can convert the sizes as needed. The 64" are just a universal standard given. This is a fairly quick and accurate way to tell the wall thickness as far as casting. That 390 might fit the 428 13/64" bit wall thickness and would prove good to 4.13+. A sonic of course the best way but this is just a quick field helper. Use the shank of the bit to gauge between the cyls. Some guy's use the allen wrench test to the same effect but I feel the round bit shanks are more accurate. See what you can find. G.

[FFR428]

Oh and FWIW there is a guy on the www.fordfe.com forum who is building a 427 from a 352 block. He cut out and bored the entire cyl wall and installed eight sleeves for a 4.503! bore. See "Poor mans 427" threads. Pics as well and pretty cool idea. Machine work is fantastic. G.

[SCOBRAC]

I saw the poor mans 427 whan I was trying to figure out what this engine was from. It seems pretty ambitious but given the cost of good 427 blocks, even at $3995 from genesis it might pay off. I'd be worried about all the heat needed to get the sleeves welded in. Hopefully he does a good job preheating the thing and takes care not to warp it.

I'll try the drill test. I'm pretty sure I'm not going to try to take it beyond 4.13 just given the nature of the project. I have a set of Arias pistons in 4.25 but I am not going that far even if I could. If for no other reason that would be the final time the thing could be comfortably be taken out even under the best conditions.

The good news is the price was contingent on it being a 428 (the owner though it was a 427) now that it is a 390 despite the high nickle content and HD nature of the block it has a greatly deminished value.

I'm going to build it for a restomod mustang. It's either that or a non cobra component car with all year drivability, top speed, handling and reliability being the goal. Something that draws limited attention especially from the masses but will smoke a corvette in a straight line or a corner.

[FFR428]

Yep I'd say much cheaper being a 390 block. That 352/427 project has only cost him $160 out of pocket to date. The block was free and doing the machine work at his uncle's shop also free. G.

[FFR428]

Hey while your over there look in the classifieds at the capsaddle thread. Dave Shoe has been working very hard on this for the last few years and while it's not new technology it fairly priced compared to a ladder bar. I'm going to try one myself. G.

[Excaliber]

The Arias pistons will only work if the compression hieght of the piston (position of the wrist pin) will place the piston at or near zero deck hieght with the block at TDC.

The 427's were originally specd -.035, that pretty deep in the block, relatively speaking.

I have to order new pistons for my ribbed 427 block because the block HAS been decked to a non standard number.

[SCOBRAC]

Good point X. These are 14:1 and after living with a 12:1 side oiler for 6 months I'm ready to have an ashtray blowout sale.