Boredom 391FT thoughts

[chris401]

In doing a little research, last night, I found is, citing a FordFE.com post:

This one test is the single best way to quickly identify an assembled FE block, and credit for it goes to FordFE.com forum member David “Shoe” Schouweiler. You only need the simplest of measuring tools– some drill bits.

Remove the center freeze plug from the side of the engine block. Using common drill bits, then slip the shank portion of the largest possible bit in between the center cylinder cores through the freeze plug opening. The size of this largest drill bit indicates which water-jacket core was used to cast the block.

If you can only fit a 1/8- or 9/64- inch drill bit shank between the cylinders at the largest gap position on the block, and a 10/64-inch bit doesn’t fit anywhere, then they are 427 water jackets.

406/428/DIF361/DIF391 blocks allow a 13/64-inch drill bit shank to fit into the gap at the largest position.

MCC361FT/MCC391FT blocks (MCC = “mirror 105” marking) allow a 14/64-inch bit to fit between the cores.

Regular 360/390/410 blocks hang around the 17/64- to 19/64-inch water-jacket space at the largest position on the block.

These are only approximations, but tend to be close.

I've included the TRW warning. It applied to 359, 361, 389 & 391, truck engines. There are no warnings of this nature, for any car engines. By that, I'm not saying car engines were thick wall, just that TRW had a reason to relate is info for FT engines, only.

I remember Shoe's post. That is what got me into checking them for potential with a drill bit. That TRW foot note goes hand in glove with my posted theory. Remember Steve Christ printed an excellent book, only the identification chart has since been proven incorrect. Seems either Shoe, Kevin or another with official Ford documents mentioned Mr. Christ info matched what Ford provided at the time. It is possible TRW was using the same inconsistent documents.

Heck, for all we know a former TRW engineer and fellow forum member could have prank printed those on his way out the door.

Kidding Mr. BR

[blykins]

Yeah that document is incorrect. 

[plovett]

Ah, never mind.

[Dr Mabuse]

...
Manufacturers, and the internet in general, are full of wrong, misguided and generally stupid information. You can go to nearly every website or forum that doesn't cater to FE's, and when the subject comes up on a project about FE's, you will see bad information given as gospel. Only here, or the other forum, will you get good solid information that you can rely on and trust ...

I just read another FE specs website today that started out well written, until I got to the "high nickel" iron in FE block reference. Along with all of the incorrect casting number crossover references in printed books, they will never go away.

When I worked for a large Ford car and truck dealership from 1969 to 1976, I occasionally tried to use the large quantity of O.S.I. (Obsolete * Supersede * Interchange) reference books we had on hand. In those pre-computer days, Ford regularly came out with (quarterly?) new issues.

 They were just part number and engineering number lists that were supposed to show if a certain part number that was no longer in the price book had been updated with a new part number. They would also have some engineering numbers with cross references, but as a general rule, they were not very useful.

[chris401]

...
Manufacturers, and the internet in general, are full of wrong, misguided and generally stupid information. You can go to nearly every website or forum that doesn't cater to FE's, and when the subject comes up on a project about FE's, you will see bad information given as gospel. Only here, or the other forum, will you get good solid information that you can rely on and trust ...

I just read another FE specs website today that started out well written, until I got to the "high nickel" iron in FE block reference. Along with all of the incorrect casting number crossover references in printed books, they will never go away.

When I worked for a large Ford car and truck dealership from 1969 to 1976, I occasionally tried to use the large quantity of O.S.I. (Obsolete * Supersede * Interchange) reference books we had on hand. In those pre-computer days, Ford regularly came out with (quarterly?) new issues.

 They were just part number and engineering number lists that were supposed to show if a certain part number that was no longer in the price book had been updated with a new part number. They would also have some engineering numbers with cross references, but as a general rule, they were not very useful.

I started with Ford in 2004 as a tech just as the parts man was coming to his twilight years. Wes just about said the same thing you did when I was looking for a good set of iron FE heads.

Brent I wasn't asking if it was correct but was playing the unpopular middle man that figures out a common ground.

[cleandan]

I have a TRW reference, that says that 1971 and earlier blocks, both 361 & 391's, have thicker cylinder walls.

Frank, this is my perspective after reading all the posts up to this point.
Your initial post, in this thread, stated you have a TRW reference indicating thicker cylinder walls in 1971 and older blocks.
Nothing wrong with this post and statment. It is a neat "fun fact" kind of thing.
Really though, this is a general assumption type of statement, not a measurement.

Next you go on to challenge the abilities and validity of those who are literally builders of FE engines, either currently or in the past.
While there is no harm in asking questions when trying to verify certain things, the manner in which you have gone about asking in this thread is more a challenge of validity and worth, rather than a question of mechanical measurements and determination of cylinder wall thickness.

You then continue to hammer the TRW reference information into the ground while seemingly ignoring the actual, hands on, useful, and prudent, information that basically says "don't trust the books, measure what you have to be sure."
Keep in mind, even if the books were spot on correct, it is still good machining practice to measure what you have in order to know what you are working with prior to doing any machine work.

What is it you are trying to help others learn with your statements and direction regarding this TRW reference?
You have an old TRW reference...Good...Neat to have, and a nice general idea, but hardly a direct measurement of the literal FE engine block currently being machined, and evaluated, in order to know what is there to be worked with.

There are MANY things to take into consideration when it comes to anything FE engine.

There are plenty of books and reference materials out there to be had, some of which have been directly found faulty in certain aspects.

There is a plethora of wives tales, it worked for me anecdotes, and poor practices being used to guide those who don't know unfortunately in a wrong...or at least lesser, direction.

When it comes to measuring an FE block cylinder wall thickness in order to help determine a safe overbore capacity, NOTHING any reference book, technical sheet, engineering drawing, or other written words will be better than literally measuring the block as it is, on the bench, directly in front of you, right now in the present.

Currently the most useful method of making this determination is a sonic test.
A sonic test is relatively cheap, relatively easy, relatively quick.
A sonic test is what some of the members are recommending as a better measure than your TRW reference...Because it is better.

This all boils down to two questions I ask of you directly.
1) Why so cemented in your TRW reference as to argue about a sonic test recommendation?
2) What is your reasoning for not performing a sonic test prior to machining the cylinder walls of an FE block during a rebuild?

[blykins]

...
Manufacturers, and the internet in general, are full of wrong, misguided and generally stupid information. You can go to nearly every website or forum that doesn't cater to FE's, and when the subject comes up on a project about FE's, you will see bad information given as gospel. Only here, or the other forum, will you get good solid information that you can rely on and trust ...

I just read another FE specs website today that started out well written, until I got to the "high nickel" iron in FE block reference. Along with all of the incorrect casting number crossover references in printed books, they will never go away.

When I worked for a large Ford car and truck dealership from 1969 to 1976, I occasionally tried to use the large quantity of O.S.I. (Obsolete * Supersede * Interchange) reference books we had on hand. In those pre-computer days, Ford regularly came out with (quarterly?) new issues.

 They were just part number and engineering number lists that were supposed to show if a certain part number that was no longer in the price book had been updated with a new part number. They would also have some engineering numbers with cross references, but as a general rule, they were not very useful.

I started with Ford in 2004 as a tech just as the parts man was coming to his twilight years. Wes just about said the same thing you did when I was looking for a good set of iron FE heads.

Brent I wasn't asking if it was correct but was playing the unpopular middle man that figures out a common ground.

Yes sir, I was replying to Frank.  Didn’t mean for you to take collateral damage.

[frnkeore]

This all boils down to two questions I ask of you directly.
1) Why so cemented in your TRW reference as to argue about a sonic test recommendation?
2) What is your reasoning for not performing a sonic test prior to machining the cylinder walls of an FE block during a rebuild?

Ok, here we go again. I was going to leave a sleeping dog lye after posting the finding of "Shoe", showing that the core thickness of FT blocks is the same as 406 & 428's.

My only defense of the TRW reference was that there must have been a reason for them to add that to the FT engines only, for them to have wasted the ink, to do so.

Please cite my post, where I say that I do not recommend sonic testing prior to boring! Core shift can effect the amount that you can bore a engine but, core shift is random and effects all FE's and all other engines that are cast, using sand casting.

When I post something on this forum, it is immediately "suspect" by some! But, there are people on this forum, that are well respected people, held in high regard, that do such things as bore a 427 to 4.280, giving a maximum cylinder thickness of .110. With that, there will be some overall core shift, using a sonic tester, that will give areas of under .100, not to mention the erosion of 55 years. If I suggested that "some people" would be all over me. If it is acceptable to have .100 cylinder walls on a 427, why is it not, on a 390.

I was a mechanic, for 8 years, in the 60's. I was also, a hot rodder. When I first joined this forum, I asked about boring FE's and suggested that the early engines had thicker cylinder walls. I was told NO! But, there was this one response:

ThatDarnCat:
I just went to the garage and popped a core plug from a EDC-6015-C 1958 model year block I have. Date code is “7 0 B”, which is 1957 October 2nd. So a pretty early FE. A 1/4” ( 16/64” ) drill bit fits totally loose between the cylinders, the same as pretty much every other 352-390. You could easily get 17/64” or 18/64” in there.

There was a picture with it. It showed that 1/4" drill, with no side clearance so, I'll call it 17/64 or .265 (the shanks are slightly smaller on drills).

In that thread, I said that it was common, to bore 352 blocks 1/8", to 4.125, as well as most early V8's. So, w/o core shift, boring a early 352, .125 would leave .120, thick walls. 427's, commonly bored 4.26, leaves cylinder walls of .120. Factory walls are .133, on that engine, based on a gap of .13, between the cores.

In my 8 years, I only saw 2 cracked blocks, a unrelated 312, cracked from the main to cam bores and a 350 sbc, std bore, with a cylinder wall crack.

I ran with all the "racers" in my area (Orange Co, up to South LA) and heard no reports of cracked cylinder walls, from boring 1/8". Maybe racers were luckier in those days, I don't know..........


 

[cleandan]

Thanks for the answers Frank. I do appreciate your efforts.
1) You did not directly state that sonic testing is not recommended. I will admit my perception of your arguements seems as if you are trying to give reasons for not sonic testing...but you did not directly state such words verbatim.

2) EVERYTHING else in your reply is nothing more than great bonfire talk. All the drill bit tests in the world give an approximation of what might be, rather than a useful measurement prior to boring.
All the anectdotes from some past event have ZERO bearing on the actual measurements of an engine block being machined at the moment.

I guess my real perspective on this situation is one of wonderment.
I am wondering why go to all the trouble of your round the bend examples when the usefulness, validity, and sense of a sonic test are tangible and apparent?

I think you simply want to make a point, but you are not able, or are at least unwilling, to understand your point is mostly pointless specifically because of what a sonic test provides.
The methods you are fighting for are all approximations and guesstimates, where the sonic test is far more precise when it comes to direct measurements of what you have to work with.

Your methods are useful when you find a block laying on its side in a wrecking yard, in the back corner of a garage, or at a swap meet. They can help you determine what MIGHT be there.

But, even after the drill bit tests, TRW reports, and technical papers encouraged you to give this block a try...the sonic test will tell you exactly what IS there.

Because of this, and because of the way you are addressing this thread, I just don't understand your point.
I'll move along now. No need to get up. I'll close the door behind me.

[wayne]

To day we have sonic checkers and they are a good thing but 40-50 yrs ago no one had them.At least small town shops did not they just bored what ever it took to keep them on the road.My friends dad owned a machine shop i seen a lot of 352-390 at .060 over  some 289 also with no problems.

[frnkeore]

Dan,
All I can say, is that I lived through the "hay day" of the FE. I was 14 when the FE was released and I was 32, in '76, when I had to throw my LR, long block, in a scrape pile, TRW forged pop-up's and all, because I couldn't sell it before moving to Nor Cal (sold the heads & intake, cheap, to my brother for his 390 GT)!

As you exit, have a very nice day and don't let the door hit you, where the good lord split you

[wayne]

Read Jim Doves ( tips on building a fe) its on the web he has done a lot of them. It talks about a 352 .080 over for a street engine.

[blykins]

...

[blykins]

Read Jim Doves ( tips on building a fe) its on the web he has done a lot of them. It talks about a 352 .080 over for a street engine.

That would essentially be a .030” over 390 bore which isn’t too far out of line but I think I’d still get a sonic before setting up the boring bar.

[DubyaTF]

   Mr Dove goes on to say "This method does not check for core shift, but it does qualify the block for further interest and inspection, such as a sonic test, which will find thin spots from core shifts or broken cores."

  Just curious- when was the TRW material published?

   I'm no expert in anything but it just seems to be proper procedure to not short cut any machine process including inspections, cleaning, measurements and setup before hitting the power button on any machine.