Is it possible to 'deck' a block and retain a shallow (faint) imprint ofthe original block number? If anyone has seen this done, please send me a photo (if available). When I got my '67 5 years ago, I didn't know any better (didn't join the NCRS until last year) and had the motor rebuilt. There is only a faint imprint of the number on top of the head, and it is painted over with paint, filling in what shallow imprint does exist. It is the correct number, but I'm trying to determine if it is the remainder of the original casting, or if it was re-stampted (if that's even possible).
-
-
Re: '67 327 block number
when the machine shop decked your block, the broach marks almost certainly were removed. depending on how much of a cut their broach took off the deck of the block, some or all or none of the vin derivative and some or all or none of the machine assembly data will remain on the stamped "pad" of the block.in 1969, i bought a 20K mile 65 FI roadster that had spun a rod bearing. i decided to send the original engine out of the 65 to a speed shop/machine shop in Baltimore Md for a "blueprint" rebuild of the engine. still got the car but the vin and mach data are all that's visible. boy, did i screw up on that one. if all that's missing on your pad and assuming its the original cast # and cast date, you'll only loose 38 points out of 4500 for the absent broach marks. mike -
Re: '67 327 block number
How many points can you lose before you become ineligable for a top flight? Can cars with decked blocks actually get Top Flights, and do point values differ between local, regional and national top flight scoring for this particular infraction? What if you present documentation, or are there numbers on other parts of the motor that would substantiate the decked block as original to the car? It seems a shame. I know it's the original block (is it the block or the head...I'm using the terms interchangeably here but I'm thinkin' I'm wrong).Comment
-
Re: '67 327 block number
Keith: Search for "broach" in archives, as I recall a post from a member with number of points lost for lack of such marks...
The numbers you are talking about are on the "top front surface" of the block, or "right deck" where the heads attach. Also, my right side is passenger side.
Tom Dingman
4889
MI Chapterhttps://MichiganNCRS.org
Michigan Chapter
Tom DingmanComment
-
Re: '67 327 block number
Hi Keith:
You are probably in better shape than you think. When cars are Flight judged they start with 4500 points and then "deductions" are made for things that do not meet the judges' criteria for operations, originality, or condition. In the case of the block, the allowable deductions are standardized and documented in the Judging Reference Manual. I believe the total points assigned to the block is 350, with the majority allocated to the casting number and the casting date.
A total of 88 points are allocated to the pad: 25 for the VIN derivative, 25 for the engine assembly code, and 38 for the broach marks created from the factory machining of the block surface.
Assuming that the casting number and casting date are correct, you already have 262 of the 350 points, even if the numbers on the pad are completely gone. If the numbers on the pad are still legible, you may pick up another 50 points, losing only the 38 for the broach marks.
You need a 94% overall score (4230 points out of 4500) to get Top Flight. So, even if your pad is completely blank (88 point deduction), you can still get Top Flight as long as the other aspects of the judge well.Comment
-
Re: '67 327 block number
Hi Keith:
Per my earlier description of the point allocations for the block, here are some photos of my 67 block to help you check out what you have.
This is the casting number 3892657, located on the rear flange on the driver's side:
This is the casting date, located on the rear flange on the passenger side. The code C177 means March 17, 1967. Note that there is a relationship between the casting date and the car's serial number. For instance, a car assembled in April 1967 can not have a block that was cast in June 1967. This is why the NCRS checks the casting date.
This is the pad. The left hand number is the last several digits of the car's serial number. The right hand one indicates the type of engine and when it was assembled.
If you can check what you see on your block and post it to this board, we can help you determine how the block would judge. We would need to know the approximate serial number of the car to evaluate the casting date.
You may want to carefully strip the paint off your pad, using only chemical stripper and no abrasives. That may allow you read what was stamped there. If you could post a photo that would be great. Sometimes, the digits are easier to make out under magnification and careful lighting conditions.Comment
-
Re: '67 327 block number
Can someone explain to me why you deck a block and exactly what it is? Been reading about this for over a year now and really don't understand exactly what it is/means. Sorry for the silly question, but I'd like to learn! Thanks.Comment
-
Re: '67 327 block number
Hi Kirk:
Decking a block is done to "true up" the surface that the head mounts to, and renew the finish that the head gasket seals against. It is a routine operation at a lot of engine rebuilders. Many rebuilders deck all of the engines they rebuild, "whether the block needs it or not." Decking involves removing a small amount of material from the deck surface, typically .010 inches or so.
Sometimes the block surface is slightly warped due to thermal cycling of the block afer the original machine work was done at the factory. Also, sometimes the original factory machine work was slightly off, so that the deck is higher in the front than in the back, or higher on one side than the other.
Typically, the amount of deviation on a used block is small enough that decking is not absolutely mandatory. When having a numbers-matching engine rebuilt, it is important to ensure that the machine shop does not just automatically deck the block, but instead carefully measures the deck height and evaluates whether decking is needed. If major problems are found, it is sometimes possible to correct them without damaging the pad.Comment
-
Re: '67 327 block number
Kirk -
Photo below is a typical automotive machine shop setup for decking a block; the block is mounted on a mandrel through the main bearing saddles, and the rotary cutter at the top revolves while the block traverses laterally below it. This shaves the deck surface of the block parallel to the crankshaft centerline, and leaves telltale circular machining marks on the deck (and the pad, which is an extension of the deck surface).
Comment
-
Re: '67 327 block number
Thanks. Now I understand.Comment
-
Re: '67 327 block number
Thanks for the great info Joe. The numeric style and alphabetical font of the numbers and letters which, per your description, indicate the type of engine and the date of assembly on my pad number are identical to the same "VO3I7HO" series of numbers and letters on your pad number. The imprint is very faint (partially due to the paint), but your number doesn't appear to be that much deeper. I wonder if the machinist would have (or could have)re-stamped this information taking care to re-create the same style/ font of lettering (seems unlikely) or was he actually tuned-in to the importance of the number and able to leave just enough to read it. I tried to contact him through the shop that did the engine rebuild, but it apparently has gone out of business.
I will photograph the numbers on the engine and post them for you as soon as I can. Maybe that will help (if I can get them as clear as yours). In the mean time, I am greatly relieved to learn that a missing broach mark will not, by itself, prevent a car from attaining Top Flight if everything else is in order.
Best Regards, KeithComment
-
Re: '67 327 block number
Hi Keith:
This is very encouraging. Did you also check the casting number and casting date of the block? These are far more important, point-wise, than the pad. We also need to know the approximate serial number of your car to evaluate the casting date and the engine assembly stamping on the pad.
It would be great if you could post a good photo of the pad (with the paint chemically removed). Use the camera's macro mode for good focus at close range, and experiment with different lighting angles to help highlight the surface. The photo I posted is the best one of about 20 that I took when I was trying to photograph my pad.
Regarding your question about the machinist trying to re-stamp the pad, it's really hard to know. Most machinists are not tuned in to collector's concerns about the pad issue, but some are. A really well done restamp is very hard to distinguish from an original.
There is a good chance that your stampings are original, and it's not yet clear to me that your pad has definitely been decked. Sometimes the original stampings are rather faint. A good photo of the pad would be very helpful.
If you don't know how to post a photo, contact me offline and I will post the photo(s) for you.Comment
-
Re: '67 327 block number
Hi Joe;
I will definately look into it at my first opportunity. May need some assistance posting photos as I recall having trouble in the past, and appreciate the offer. What would you reccommend to remove the paint? Dab some paint thinner on an old wash cloth? I will experiment with light, etc., but not sure if wife's camera has 'macro' button (maybe time to break down and buy my own, eh?) You're photos are great examples. Well done!
Regarding the numbers, I have the old judging sheets from a Joplin, Missouri regional meet back in 1988 (courtesy former owner), and so can provide comparison between photos and judge sheet. Maybe I can photo the sheet itself and use it as a guide. Hopefuly this will help put things in a better light. I wish I had close-up photos of these numbers from 1988, or earlier. I could do a split screen/ forensics sort of comparison to prove it's the real McCoy!
Will get back to you in a couple of days. Thank Again!
Happy New Year (@ work and actually forgot it was N.Y. Eve for a minute!?!)
Best Regards, KeithComment
-
Re: '67 327 block number
Hi Keith:
Try lacquer thinner first, but if that doesn't do it, a paint stripper such as Stripeeze (sp?) from the hardware store will work. The main thing is to avoid anything that might scratch the surface.
I think that almost all digital cameras have a "macro" mode that is intended for focusing on objects that are only a foot or so from the lens. Without a macro mode you can't really get a close-up photo with good detail.
My Canon S410 is NOT very good at this, since the auto focus has trouble converging in macro mode and there is no manual override on the focus. I have to make several attempts to get one good shot.Comment
Comment