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Original Message
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| FTs came in 600-series and larger trucks. |
| By Dave Shoe - 05/04/2001 1:03:11 AM; IP 216.243.158.161 |
I'd post this info to that truck forum, but that thread's about a year old.
500-series and smaller trucks got the plain old FE engine stuffed under the hood. The plain 360/390 block is a good one, however. Occasionally you'll find a heavy duty FT casting in an FE truck block, but more often it's only an FE-style block with reinforced webs, not the heavier cylinders, and most often it's the plain block.
There is most often a reversed "105" cast on the front of the FT block, and a "352" cast on the front of an FE block, but this is not a strictly reliable indicator. Also, some FE and FT blocks have neither cast on their front.
The FT block is a heavy duty casting and can sometimes be converted into the equivalent of a 428 "C-scratch" (HD) block, but only a sonic map will tell whether the cylinder cores are centered well enough to allow this without offset boring. Core shift is common in any older technology production block, the FE and FT are no exception to this. There really is no need to rush out and overbore this thing. For stronger cylinders, take the first swipe at 390+.060" or 428std, and save the 428+.030"/428+.060"(if possible) bore for the next rebuild.
I don't yet buy into the rumor that FT blocks are a special alloy, with extra Manganese and Silicon, because Ford's ferritic nodular of the period actually had LESS Manganese (<.25% vs .80%) and less Silicon (1.10% vs 1.85%) than their gray iron (MCC holder analysis info). Ford used a strong durable gray iron in FE and FT blocks (and is likely why the FTs got heavier main webs and cylinder walls), and occasionally used a softer, more hammerable iron alloy in some of it's race-only FE blocks, however this does not appear to be a nodular type of iron. From my readings, it doesn't seem that engine blocks could practically be made from nodular iron in the mid-70s, and projections from this period don't indicate a future application for nodular engine blocks. Oddly, nodular exhaust manifolds were becoming popular toward the end of the FE reign - though I doubt any FEs got 'em. This is only my understanding - I'm still learning this stuff.
Many times you will find nodular iron maincaps in FE, and probably FT, engines manufactured for heavy duty use. The 427 SOHC engineers mentioned (in their published paper) that they switched from gray iron to nodular maincaps in the Cammer (circa 1964). I have frequently found Brinell indenter markings on each nodular maincap in an FE engine, indicating the appropriate "hardness" is present in the maincap. I assume "Brinell marked" maincaps to be the nodular maincaps. So far, I've found them on 427 and some 428 "C-scratch" blocks. My FT block doesn't have the marks, but neither did one of my CJ "C-scratch" blocks. Not sure if the Brinell dude was taking the day off or if Ford just took "representative" samples from each pour.
The only significant difference I'm aware of between the 361/391 FT block and the HD 428 PI/CJ block is the FT gets a HD oil pump driveshaft, and therefore has a larger pilot hole drilled into it for the distributor. If the FT distributor is the massive and ugly "governed" type, you'll wanna toss it and bush the hole (330MD bushings are apparently still available from Ford) to fit an FE distributor. If your FT has a "normal looking" non-governed distributor, you'll wanna keep this great piece with the engine and run the big-honking oil pump drive that came with the engine. You WILL have to have the distributor recurved. Again, this is all just my opinion - I'm not the kinda person who needs facts to make a claim. Also, I haven't yet verified that the FT distributor fits the hole in the FE intake properly - I seem to recall seeing something strange in this respect, but have never checked it out.
The 391 crankshaft is made of SAE 1046 forged steel. Nothing special, but it makes a great crank. If it's got a "$" trademark symbol on it, then it was forged at the Wyman-Gordon plant. You'll want to turn the crankshaft's snout down to the FE diameter, and also thin the crankshaft's flywheel flange to the FE thickness, otherwise the flywheel will be too close to the tranny. It may not be crossdrilled like the early 427 forged cranks, but that just means you must use super-common grooved main bearings top and bottom to keep continuous oil pressure to the rods. The crossdrilled crank allowed using an ungrooved lower main bearing to better support extreme crankshaft forces generated by full-race FEs. Seasoned 427 racers often elected to NOT crossdrill their cranks, so, according to the more enlightened, you've got a "race drilled" crank (as do all of us "cast crankers").
The rods are the excellent dime-a-dozen FE-type rod used in every 390+CID FE (exc SCJ) since about 1964. Yes, I realize PI and CJ engines got the same rods drilled a bit more for the fatter bolts. I believe the steel is SAE 1041, and these suckers are well suited to high-performance street and strip action. You'll want to install 3/8" ARP bolts and resize the big-end, as it's no doubt been hammered out-of-round hauling tons of lettuce to the local grocery over the years.
The heads - well, you'd best toss 'em. They're a little different - especially on the exhaust side. Same with tossing the pistons. Valve train - it's a yawner, but you might as well keep it until you decide whether to go hyd or mechanical on the cam (go mechanical if you wanna rev, hydraulic if you're a law abiding citizen). Keep an eye on the pushrod length, as that varied a slight bit over the years (no biggie). The cast iron timing cover - keep it until you realize you don't plan to use a front engine plate - and then toss it. Oil pan - toss it if you've got a car. You definitely need to get a performance oil pan if you expect ANY fast FE to live in a car. You can probably make the externally balanced FT truck flywheel work, but I suspect you really need an aftermarket steel flywheel, as I doubt Ford intended that FT flywheels would spin really fast.
I guess that covers the basics. Hope it helps. Again, this is all my opinion.
Shoe.
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