Oh yeah, but take it from me, any time you put cams on even a lower 9.2" deck height I6, it becomes physically larger than the old 300 Ford F150 truck engine.
IMHO, here's THE engine to add twin turbos to...the 5.0 Windsor Fuelie engine on the right.
Care of engine afficinado gb500 at Ford Forums dot com dot Aye Ewe.
The I-6 Barra, well, Its just H-U-G-E.
Yeah, a bigger I6 cammer sounds a heck of a lot nicer than any Skyline GTR or 2JZ engine. but its even bigger than the Jappa boat anchors.
Sell it, and buy a Ford V8....
Since you talked about the Barra, for a few years, the DOHC Barra took the US market French Bordeux 55R5 N, S, E and W parts, (Explorer, Ranger, Mustang 4.0 or 4.6 gearbox) and you can fit those transmissions to the Aussie 2008-2010 bellhousing, and a 5 speed auto Turbo 4.0 Barra or C4 or Powerglide with maybee a Overdrive kit would capture 1000 hp with some ease. Ther is a C4 or Powergild auto bellhousing kit for the 4.0 I6.
But did I say how H-U-G-E the I-6 was?
Any cammer I6 or V8 engine conversion trades off about 100 cubic inches of bore spacing to pull more revs for the same power.
Since a good US OHV I6 or V8 engine can easily make 1.5 to 2 hp per cubic inch, OHC cam operation is just like saying Nyet to 150 or 200 hp right off. Nice to know you....Goodbye....
The size limitatations of any Overhead cam six?.
Well, having an Overhead Valve pushrod engine with , say, a 4.38 (SBF), 4.40 (SBC V8 or in line Chebby or GMC 250/292), 4.46 (LA SB Mopar), 4.47 (Ford 300 /4.9 inline six) to 4.625" (FE 390/427/428) bore spacing makes more power than the same size OHC engine with 3.8125 (Jag XK), 3.76/3.95 (Datsun Nissan/BMW) to 4.08" (Small Ford in liner Six) bore spacings. The size of in line sixes with cams is just H-U-G-E.
My 188 hp 2.5 liter Nissan Neo DOHC Variable Valve timing engine is a huge blott on the landscape. It sounds like a TR6 Triump, revs like a VTEC Honda to over 7000 grand, and , well its a piece of cattle crap compared to any 351, 352 Windsor, Cleveland or FE engine. There is nothing romantic about the Ford DOHC Barra. It piles parts on parts, and forgoes size to yeild the same power as a 5.0 liter supercharged DOHC Miami engine.
Henry Ford was right....the in line six is a great big turkey that needs a really special chilli sauce to spice it up. Any time youy have a high mounted camshaft system, you loose about 3.4" on engine space in the front, and gain a 100 cubic inch capacity penalty.
Which is why Chevrolet copied the last 351 Windsor overhead valve engine features (fireing order, head clamping, tappet diameter, block depth and two valve per cylinder valve angle. oling system) because in the Windsor 351 to perhaps 400 to aftermarket 454 cubic inch range, the combination is the most compact and most powerfull on a size to weight basis.
And thats from a guy who flat out loves Modular Cammer 3.937 bore spacing Ford V8 ohc's of any denomination.
They cut off about 200 thou from the ages old 250 ohv in line six block just to get it under the low hood of every 1987 to 2017 Ford Falcon. It was Honda front drive depth, seriously slammed, MN12 Tbird style.
For the OHC or DOHC, it is a very tall engine. It amazing a little 5.0 Windsor EFi fits under the hood of a late 90's Ford Falcon Pickup, but they savagely cut down the in line OHC CFi, Mutipoint, Intech, and the later DOHC Barra intake parts to package it all.
Spare a thought for us in Australia and New Zealand.
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From the 1966 Falcon pickup and Sedan based vans till 1984, it was all pretty tall hoods. Clevelands, Big Block FE's, and even 460's went in okay. A 250 would go anywhere, and you could slap a 4-bbl 650 on a 2V 250 and your dough was bread.
Pretty soon, hoodline crumping was a Ford pandemic....and we had to deal with the nasty OHC engines and everything under hood became a festooned cluster of disaster.
In the old days, right up till the last Fully Fox based Lincoln LSC and even the Fox 4 SN95's and New Edges had an abundunce of hood height.
So you know, you can do what you want with a Fox.