From Modified Mustangs and Fords
April 30, 2014
New FE Blocks
When we received the call from Bear Block Motors (BBM) announcing the arrival of its new reproduction 427 cross-bolt side-oiler blocks, it was like an answer from heaven. We anticipated another high dollar all-aluminum FE block few could afford, but that’s not what we saw. Imagine an all-new 427 cross-bolted, side-oiler iron or aluminum block with casting and machining quality way beyond anything Ford did in the 1960s. This is not marketing hype, but cold hard iron or aluminum virtually identical to what Ford was producing back in the day.
What makes the new 427 block better is vastly improved technology and a high-standard casting technique for starters. The BBM FE 427 block is cast with high tensile diesel grade iron with a super thick .750-inch deck. Siamese cylinder walls allow you to bore to 4.440-inches. Out of the box, bores are 4.245-inches, to be finish honed to 4.250-inches. An optional 4.150-inch bore will be available for the 428 crowd. Cross-bolted main caps are a perfect interference fit amid the block skirts without spacers. Locating dowels in the main saddles “lock” the forged and heat-treated 8620 steel main caps in place.
Down under are heavier, thicker main webs and pan rails for superior strength. What’s more, these redesigned FE blocks accept both FE and Cleveland main bearings, which gives you a wider choice of performance bearings. Water jackets are cast solid, right up to the bottom of lower core plugs, to maximize cylinder strength and support. You may use standard ARP FE head bolts or studs. Main oil gallery passages are larger than the factory originals for increased oil volume. These BBM FE iron blocks tip the scales at 250 pounds. Prices have not yet been announced.
New FE Aluminum Block
BBM is producing an FE aluminum block for just $1,200 more than the iron that weighs just 125 pounds. Made from virgin high-density aluminum using the best casting technique in the world, the BBM aluminum 427 is a dry sleeve block, and sports centrifugally spun, high tensile strength, nodular iron flanged sleeves. Maximum bore is 4.320-inches, with decks finished to 10.155-inches. All this block needs is finish honing and you are good to go.
The 428 Cobra Jet cylinder head, as one example, is virtually identical to the 427 Low Riser casting—and this is what Bob Tasca plucked off the shelf when he was developing the KR-8 (Cobra Jet) for his own Mustang in 1967.
Cylinder Head Duo From BBM
Bear Block Motors introduces its new FE aluminum cylinder head for 390, 427, and 428 big-blocks with 2.150/1.680-inch intake/exhaust valves with lightweight 11⁄32-inch stems. Combustion chambers are engineered for optimum swirl and quench right out of the box. Intake ports offer 295-plus cfm. Exhaust ports yield 225-plus cfm of flow. High-swirl/high-quench chambers allow for more aggressive ignition timing on today’s more unforgiving pump gas. Also available are CNC-ported FE aluminum heads with 2.25/1.71-inch valves, which calls for 4.230-inch minimum bore size. Expect to see 355-plus cfm intake and 250-plus cfm from these CNC-ported pieces.
Reproduction FE Series 427 Crossbolt – Blockbuster!
Bear Block Motors introduces reproduction FE Series 427 crossbolt, side oiler blocks in iron and aluminum
If lightweight aluminum is more to your liking, Bear Block Motors has your FE block. In paint, it is challenging to tell the Bear aluminum 427 block from iron because it is cast basically the same way cosmetically with all of the correct markings. It weighs just 125 pounds, remarkable when you consider the weight of an iron block at 250. What’s more, the Bear aluminum FE block is priced just $1,200 higher than the iron, which is somewhere around four grand. If you perceive the new FE as pricy, price a used 427 side oiler block and be ready for sticker shock. Prices on both iron and aluminum blocks have not yet been confirmed.
With such a grand slam block casting for FE enthusiasts, you’d expect Bear Block Motors to complement this block with a world-class cylinder head. It has with the high-swirl aluminum FE cylinder head in as cast and machined or in CNC ported. This is the FE cylinder heads brought to current engineering standard high swirl, good quench 72cc chambers, 11⁄32-inch valve stems, 2.150/1.680-inch intake/exhaust valves, 300/225cfm intake and exhaust volume, and bowls cast to match valve seats perfectly. Extra thick port walls allow for additional porting if desired.
There’s also a CNC-ported FE head available from Bear Block Motors with 2.250/1.750-inch intake/exhaust valve sizing that offering a whopping 355/250cfm intake/exhaust volume. These heads mandate a 4.230-inch bore.
When you compare the Bear Block Motors castings to original Ford, they aren’t in the same league because casting technology has changed significantly in 50 years. Here are examples of original 427 castings.
15. The Bear Block Motors FE cylinder head is available in “as cast” and optional CNC ported. This high-quality casting is engineered for high-performance use and, as such, has been well thought out in every respect. We’re talking the more common 11⁄32-inch valve stem, 2.150/1.680-inch standard valve sizing (2.250/1.780-inch optional), high-swirl 72cc chambers with excellent quench to where you can run these guys on pump gas. Exhaust bolt patterns accommodate Ford compacts and intermediates as well as fullsize.
16. Check out these high-swirl 72cc chambers, which are the result of years of development to achieve the most optimum power-making FE chamber. Good valve shrouding. Large 2.150/1.680-inch stopcocks are standard. CNC porting optional.
17. Look at the evolution of Bear Block Motors cylinder heads through development. The GEN 1 head was a more traditional FE shovel chamber. With a lot of engineering time invested, the shovel chamber evolved more into the GEN 6 high-swirl chamber that made the final cut. A lot of time and thought have gone into the development of these heads