Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

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dwilliams
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by dwilliams »

I saw an article about one of Lothar Motzenbacher's (?) cars, that was supposed to have a four-bolt 351 Windsor block. I didn't remember seeing anything about that anywhere else. I wonder if it was one of those... the author of the article wasn't an engine guy.
piston guy
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by piston guy »

There sure are allot of confused people out there regarding this block. The design was known as the "377 Can Am engine , although it was likely designed for the GT40 program because of the time frame and the ASK number also used on some of them. As shown in your pictures ( that appear to be of Jay Cushman's stuff) they were made in iron and aluminum. They were cast in late '66. There were core shift issues on the iron blocks and many were deemed unusable. The block was also called the "Holman Moody 351" because Ford ''dumped" the blocks on them when the project fizzled out. A 4" stroke crank would NOT fit in the block ''back then". The earliest drag race use was in the early '70s in a 66 Mustang owned by a football player named Ralph Head and the car was called the Phantom. It used the XE 3.75 stroke crank. When Dyno Don used one , He could only fit a 3.900 crank in it. The block was in essence a "tall deck" 289 and because of that the blocks often cracked the main webs out because they were never intended to make the power that the increased cubic inches allowed. There was a VERY special "high riser" head made for that block as well. The only intake made for it was a "Weber/ Techalmite fuel injection manifold because of the anticipated use. "Some" had 273 Chrysler mains and others had Y block mains as you already know. Few people know about this engine because it was an "experiment " that didn't work well. This left unused parts "floating around" but few "complete engines". Many lessons were learned and as the 351W was being developed in '67 for '69 release , improvements were incorporated into it like 1/2" head bolts and improved bulkhead strength. I do not know of any official "Ford" pictures of this engine , a bit of a rarity in itself.
tuffxf
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by tuffxf »

Awesome mate thanks!👍
MichaelThompson
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by MichaelThompson »

BA74CEFA-ABAB-47AD-8D58-C65869979CA1.jpeg
I don’t remember if I asked this here yet I'm very curious to know if anyone has information of the very early Indy V8 engine development?

Generally speaking the program went from a sort of a conventional 260 style cylinder head to one that substituted the ball/stud rockers for the Y-block shaft mounted style to the full blown DOHC 4 valve heads that we all remember so well.

Anyhow my question is somewhere in there was a proposed canted valve head in the mix. To my knowledge the head was designed but the decision was made to go straight to the DOHC heads.

I’ve only heard about this and read one blurb about it in a book about Ford’s Total Performance era.

Any insight on this is appreciated.
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piston guy
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by piston guy »

Smokey was in charge of the "stock block" Indy program for 1969 . This was an all aluminum 351C block and heads . SK42617 was the block and SK42624 was the head. Both were cast in Oct of '68 far before the engine was known to exist. I own one block and three pairs of heads at the moment. The "criss cross" pushrod engine ( I used to own one) was NOT designed for Indy use. It was also NOT a reverse cam except for the fact that the normal intake lobe now ran the exhaust and the normal exhaust lobe ran the intake valve. the engine was designed around a hydraulic lifter use . Mine was converted to roller tappet through the use of a custom "rocker guide". There is a picture of my engine in the fall '87 Mustang illustrated and my all aluminum engine is on the cover. The heads are not like the ones in your cylinder head photos.
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by piston guy »

I ran the criss cross engine to well over 10,000 many times without valve train issues. Ti valves of course. I have not found the original intent of the design. The heads were iron and designed for bolt down ( hydraulic) rockers like a conventional 351C , and the exhaust port was standard 351C 4V. There is a note in my SK information regarding two carter carburetors "for cross pushrod engine" but I have nothing as far as an SK oe XE number for an intake. I don't think the engine on display in the Carolina museum has an intake either. Mine had a sheet metal tunnel ram needed because of the extreme port offset in the heads. They also used 14 head bolts , 5 conventional 1/2 " lower and 9 , 7/16ths "under the cover". I lost track of it after I sold it some 20 years ago. At least one guy I know is searching for it.
BTW there were NO durability issues with the Alloy (SK 42617/8) blocks. The 305ci version used the 255 indy dry sump pump system and the 320ci version used a special chain driven pump later used by Bud Moore (rip) on his Nascar engines. The Ford system was dropped for a more conventional belt driven external pump. Smokey had the plug pulled before the '69 race. Ford engineers were pissed because Smokey was given an "unlimited budget" for development when they were restricted as to what they could do. At least one of the original engineers is around and I keep in contact with him
BTW II Your caption noting a proposed "20* canted valve" is "probably" the primary angle of the valve and the "cant" would be be more like 4*s cant on top of that. A 20x20 isn't possible. The 351C is a much shallower at 8.5*s primary angle.
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Re: Shelby/DeTomaso P70 7Liter (Windsor base block race eng)

Post by piston guy »

He got the axe about the same time Knudson did. The money wasn't wasted as they actually produced parts to test. The projects simply got cancelled.
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