427 with 4.280 pistons?

[NIsaacs]

I know most builders will not recommend anything larger than .030 over, but I see Summit offers .040 and .050 over pistons. Has anyone ever went over .030 on a 427 with a good sonic test?

I also know most builders don't like to sleeve them, however I think in Steve Christ's Big Block Ford Book, they built a marine 427 with 8 sleeves? I can't find my book, I think one of my boys has it, lol.

We have a 427 side oiler with some damage on 2 cylinders, one on each bank from a wrist pin keeper that fell out. We are not sure yet if even a .050 will fix them so most likely sleeves will be needed.  Can we save this block and still have a dependable engine? Looking for at least 500 hp, with the 3.98 crank currently in use. It will be going back in a 1970 F-100 short bed 4x2 for some bracket racing. 

Thanks, Nick

[Joe-JDC]

Raced my 427 at +.040 for many years.  Joe-JDC

[Tboggus]

Personally, I would sleeve those two cylinders and keep the bore as small as possible. If the rest of the block will clean up at .030, that's where I would stop.
Travis

[gt350hr]

    Sonic check it . Very important to know where and how much metal is where. Pistons can be made in ANY size that rings are available for. Lots of .040+ 427s out there . Use a sleeve as a last resort.

[MeanGene]

Always gotta check it- especially sideoilers. I have two at .040, both centeroilers- one needs a small crack in the valley repaired, has flattops, C4 iron crank and big bolt rods, basic rebuilt V-drive engine, had a 324/500 cam in it. Also has scores in one cylinder, looks like it lost pin clips. The other is in my Galaxie, was built for a Falcon drag car in 1975, ran 3 years running 10.80's around 126, no maintenance. Sat unassembled for a year, got put back together with the same rings when I needed an engine for my F250 Highboy 4x4, was in there for many years (and smoked a 911S one night), and has been in my Galaxie for a long time, still with the 1975 rings, still thunders pretty good. I do have a set of custom big dome Wisecos at .050, got them at a swap as they were installed in a sideoiler that lasted 6 passes before splitting a cylinder wall

[jayb]

The 427 stroker that was used as the dyno mule in my book is 0.060" over.  Beaten the tar out of that thing many times, no problems.  The book has the sonic test data, which is a little scary, but with the cloverleafed cross section of the 427 bores, they are stronger than you think.

[NIsaacs]

The 427 stroker that was used as the dyno mule in my book is 0.060" over.  Beaten the tar out of that thing many times, no problems.  The book has the sonic test data, which is a little scary, but with the cloverleafed cross section of the 427 bores, they are stronger than you think.

That's good news! I went back and read the story, that was one dangerous "492"...

The block is at .030 over now so it is going to be close if .050 will clear it up, I haven't seen it yet but my son don't think so, so maybe .060 will.

The 428 in my sled pull truck is at .060 over with no problems. It don't have a lot of miles on it but I freshened it up last in '95. The 428 in my dually was .060 over also with no problems and I have beat them severely over the years.

The machine shop said bring it down, so we will see I guess.

Nick

[My427stang]

My 63 center oiler reminds me of that joke, "looking for lost dog, deaf, 3 legged, missing one eye, tail cut off, goes by "Lucky"

I have run Diamond pistons at 4.277 on the street since 2006.  Blowby is zero, doesn't burn any oil, quiet when cold, and leakdown numbers are tight.   The block has 4 sleeves, remainder sonic checked fine, sleeves were in their when I got it due to damage when it scattered twice.  You never know, but if you have to sleeve them, it's really no issue, just need to make sure all machining is done right

That being said, I eventually plan to build a blower motor for this car, but I probably wouldn't push much harder on this block, although I'd say it has moved as much as it every will at this point... it is truly a "seasoned" block LOL

[Stangman]

Mines at 4.265 don’t know what cubic inches are I’d imagine 485 but my sonic check was
90 in one spot Barry said it was ok so I’m good with it then. I have about 1200 miles on it
And 20 1/8 mile passes on it and runs cool so far so good. He says there are a bunch of 427
Blocks out there at 90. And like My427Stang my motor is a 63 center oiler

[blykins]

I'd sonic and check it.

I've checked two 351C blocks in the past few months that had cylinder walls under .050" thickness.  On one I did a half fill and then proceeded to make over 600 hp with it at 8500 rpm. 

I'd be comfortable with .090-.100" thickness on a 427 block.  I've ran them that thin with no problem.

Overheating because of overboring or a thin cylinder is actually a wives' tale and has no merit.  The only con to a thin cylinder is that it will flex and you may lose ring seal.

[NIsaacs]

The machine shop has the block and after just a visual of the damaged cylinders, they are recommending 8 sleeves, stock bore. The original thought was a mild build due to thin cylinders....now my son is thinking full roller/stroker build, 482. Maybe I can cabbage some of the castoff parts for my 428, Lol.

He is looking at the Trick Flow heads and stroker kits from Summit, hasn't got to the cam and valve train yet. His cam for his 501 BBF sled puller was from Cam Research, so probably go back there.

Nick

[CaptCobrajet]

I would not recommend sleeving all eight, or even adjacent holes in a 427.  The deck will usually split between the cylinders.  I sleeve all eight back to 390 and 428 bores with flanged sleeves often, and that works well, but we are 4.300 or 4.380 OD with light press on those.  To get .090 wall in a 427, there is not much left behind the sleeve, and some hit water.  You might think about a BBM block if you are going for big power.

[cammerfe]

Sleeve quality and material makes a difference. Carl Holbrook did a lot of sleeving, including even some furnace-brazed combinations, and told me that using the right steel is critical.

KS

[billtroth]

My marine block 427 stroker is .040 over and block filled to the bottom of the water pump holes and so far no problem. That said I did blow the first race motor that was also a marine block 427 that sonic checked good but broke through the side of the bore on #4 cylinder.  It happened at about 7200 r.p.m. so the motor was trashed.  That' why I block filled the motor I run now.

[NIsaacs]

Well, the block now has 8 new sleeves, with JE, 4.25, 12.5 to 1 Pistons on order and a set of Trick flow heads. He is going to keep the 3.98 crank and maybe the Holly Street Dominator intake. I would post a picture of the new paint job on the 1970 F-100 4x2 short bed, but I can't anymore. He went with the original oem Royal Maroon.  I bought the pickup new in 1969.

Nick