FE Power Forums
FE Power Forums => FE Technical Forum => Topic started by: 427Fastback on October 09, 2015, 02:06:29 PM
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Its been around since 1989 as far as I know...Ron Miller of FPP takes credit for it as it was big news and I believe it was Super Ford who did a big front cover thing on the New boring sequence of the 427 Ford..
There however is another story.Its a little more interesting..
So does anybody here have other info to the origin of the .017 over bore or know of it being done before Ron Miller stepped up...
Its been over 25 years since the article and its common practice now...
I will share the other story shortly...
Cory
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I always thought it was just to use BBC bore sizes. Looking forward to the mystery :)
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It's the same bore size as a big block scrub ( don't say the C word ). It's enough to clean up the bores and makes it easy to get rings. There wasn't much need in the '60's & '70's and most people just went .030 over when they needed a rebuild, but as 427's became harder to find and more valuable it became prudent not to excessively over bore them. I'm sure others knew this back in the day, I did.
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No mystery...just a story that has never been shared on the internet..I am well aware the bore size is the same as a BBC..Up until the Ron Miller thing I had never read of it being done before..In 1989 I was 30 years old and owned my 2nd 427 that was now in my 68..I read everything I could get my hands on about 427's since I first heard of them in the late 70's..I had never heard of it being done before..
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Son of a gun, I was hoping for some drama....Bunky Knudsen, Grumpy Jenkins or Carrol Shelby swapping BBC pistons during Lemans to slow down a little or something like that :)
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The story is...In 1988 I built the 427 for my 68..It was shortly stored where I was working (building cobras)Somebody dumped something in the engine and by 1500 miles it had torn .007 out of the cyl and done other damage.The engine was std bore and std crank..To say I was pissed was a understatement...The evidence was in the oilpan of what they had done...
I refused to bore it .030 and things came to a halt...One sunday I met up with a friend who owned a engine shop (I used to work for him) and we talked about what to do..The idea came up to have pistons made at BBC size and use std BBC rings..I would have the pistons custom made by Ross..
The following day I phoned Ross and talked to one of the owners (not Ken)after explaining to him in detail twice what I was trying to do he finally grasped it and the pistons were made.
About 8 months(lag time for a magazine) later the article came out with the new boring sequence for 427's.Ron Miller took the credit for it..I took a copy of the magazine to my friend and we just had a good laugh about..I didn't really care..The plan worked and my engine was running again..Didnt take a genius to figure out a conversation occurred between Ross racing and Ron Miller...
The rest is history..Pistons are still in my engine and the invoice is in my drawer..Date on the invoice is much earlier than the magazine..
That's my story.....
Cory
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I bought my first 427 block in 1984 at a worn standard bore. I took it to Ron Miller to have it checked out and he said to take it .017 to 4.250. It needed one sleeve at that. I was the first I'd ever heard of a 427 Ford at .017.
I think he had a deal with Arias, as that's the pistons he ordered for me.
Greg Foreman was working there a FPP at the time. A former A/Stock record holder with his Fairlane, he was a great help getting this rookie acquainted with his new 450 inch Hi Riser street racer motor.
I was a fearless 24 year-old trolling the streets of the San Fernando Valley.
Still have that motor today, although it's .030 now. I walk by it now and then. If that motor could talk....
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Interesting..I don't disbelieve it.I just had never heard any mention of it anywhere before I ordered them.Information didn't spread around then as fast as it can now..
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It was done since the 60s and everybody did it,
017 over is a convenient piston ring size and aftermarket piston size. The narrow race rings were more available in a popular step too, like DYKES and lo tension oil rings, and narrow 1st and 2nd rings
Here is a good example, Kalitta raced his blown Cammers out of Stroppe's when he was out West. He had no crew, our guys helped him in any way because he is awesome
He was well known, since around 66, as were others, for honing the block hole by hole to the size she needed. Then mixing sizes to work. And this happened too, if the 4240 hole got loose due to the bore scuffing or wearing faster, but the piston was still in tact, it could get moved down to a hole that needed honing to the next step. Pistons could get shuffled
The factory service manuals for the FE's also allowed such a practice. And FORD sold oversize stem valves for service use. No new guides needed, you reamed the head to plus 003 on the guide and started over
So his average block might go like this so did ours STD then plus 001 then 002 then 003
This is all about ring sizes and what rings you can buy
So his blocks, and many Drag blocks got freshened a lot, and many blown SOHCs could 4.234 and 2 holes could be 4.240 some 4.250 some 4.260 and depending on the piston co, you could get , say a 4.24 plus 001 or 002
Ron is an old pal and we dig him. I sold him parts way before he ever had a shop.
Always cool and a nice guy
He would tell you that a lot of us did 017 over for a real simple reason, you could find the latest and greatest ring combos in 425. This is a very popular bore, due to it being on a million 426 HEMIS, 427 Rodents, 454's and so on
guys went to 017 over at the suggestion of the piston companies. It was easy to make slugs off tooling for the chev and dodge guys set ups
But the race teams took several steps on the bore size way before going to 017 over ,,,,,to maintain as much wall as you could
It is a nice step, 017,,,,many more rings available, and when Total Seals were popular, they factored in to the choices too.
So funny, we did the original Dyno R and D for Total Seal before they formed their business. They started with a small ad in a magazine and an article or two
The Dyno results showed less blow by, yes, but little to no power at first. After more testing and tricks, they did show gains, for later guys
But you guys know, maybe some don't...so, our Pro Stock Clevelands? We did std, then 30-50 runs, hone it, taper, then all the Pro Stocks could get the 1st step pistons 003 over
More runs, honing, then 006 over,,,,,more passes, then 009 over,,,,,,then 012,,,,,then junk it and start over
If you call a good piston company, they will make you a standard size, and usually any step you want within the rang of the rings, often plus or minus 001,002 003
On a 427 FE 4240 is still a step too
When SHELBY standardized the next generation all aluminum 427, and that helped many later FE parts follow to us, this same ring availability issue, and the reduced cost of a 4.25 piston, and sleeve availability was a factor in their choice to make these blocks 4.25 to begin with
PS, on the use of a race FE with 3 or 4 different size pistons, they all got balanced within 1/4 gram to each other and if blown, the slight difference in cubes hole to hole is not an issue
If injected the FE ran fine
On a Pro Stock style FE, or a NASCAR style FE, compression balancing was very popular and kind of key we felt, for an endurance race. Same deal on Off Road and the GT or Pantera race builds
And for history, only TRW pistons came in the shop miking within a tenth, or 0001
All trick aftermarket pistons, which were great and fast and awesome, usually ranged in size up to 0015...that is 15 tenths We fit to the tenth. So the range on many trick pistons was , usually about 0007 7 tenths So we select fit them anyway. Number them all then hone to fit right, and the block might end up with 5 slightly different size holes anyway
I have a 427 here, a famous one
Order 003 over pistons, from std FE
I can get 4240s plus 001 002 003
I would advise you do not jump to 017 over unless you have no other choice
Take the baby steps and save the bore and metal. Just call the good piston companies
ARIAS for example will make these, so will VENOLIA and many more
On 390s and 428s, we NEVER go 030 as a 1st step We order customs in the same small steps if possible
A few of our best engine men here stock such pistons at times, so check with our engine sponsors here too. They can provide more logical and less wasteful choices
Thanks
Just a little background in case it helps a new guy
You old fast guys got this all 45 years ago ! maybe 50 !
Geritol please