1954 Nash Dual Jetfire Le Mans

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MotionMachine
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1954 Nash Dual Jetfire Le Mans

Post by MotionMachine »

I'm doing the machine work on this engine. This model came with the same aluminum head used on the Nash Healey, which makes it on the rare side apparently. Someone in the past had bored it .125" over and used the oe head gasket, so it had burned it in many places. The engine was severely stuck, head seized to the studs, pistons seized in the bores. I sleeved it back to .030" oe bore size. The rods were bastardized on the small end to make them floaters in the cast iron rod, and one was .007" oversize. Pistons were out of who knows what. Anyway, it's all sorted and assembly starts soon. I have no specs on torque, valve adjustment, etc. Does anyone have access to any of this?
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Re: 1954 Nash Dual Jetfire Le Mans

Post by PackardV8 »

MotionMachine wrote: Mon Jul 27, 2020 5:58 pm I'm doing the machine work on this engine. This model came with the same aluminum head used on the Nash Healey, which makes it on the rare side apparently. Someone in the past had bored it .125" over and used the oe head gasket, so it had burned it in many places. The engine was severely stuck, head seized to the studs, pistons seized in the bores. I sleeved it back to .030" oe bore size. The rods were bastardized on the small end to make them floaters in the cast iron rod, and one was .007" oversize. Pistons were out of who knows what. Anyway, it's all sorted and assembly starts soon. I have no specs on torque, valve adjustment, etc. Does anyone have access to any of this?
Brings back some bad memories of one of the first cars I ever worked on; a 1952 Nash Ambassador. It needed a valve job and the head was seized on the studs. I hooked a chain hoist to the head and it picked up the front of the 4000# car without loosening the head. The engineer who decided to use head studs on that long, thick 6-cylinder head was an incompetent idiot. I ruined four scrapers driving them into the gasket to loosen that head.

Is the exhaust pipe on the aluminum head the same as the OEM iron head? It's just a piece of muffler pipe with slots cut into it and bolted to the semi-circular side of the head. They always rusted through; again, an idiot engineer with no understanding of the properties of materials.

Wonder if the head torque spec would be the same on the aluminum head as the iron?
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Re: 1954 Nash Dual Jetfire Le Mans

Post by pdq67 »

Will an old Motor Manual help out here? I have one that was my F-i-L's that is pre-55 that lists almost all of the old engines.

And btw, I didn't know that aluminum heads were put on these old off-beat engines back then. That aluminum head would be a, "scrappers", dream!!!

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Re: 1954 Nash Dual Jetfire Le Mans

Post by MotionMachine »

Mentioning those old motor manuals your F-I-L has jogged my memory. I have a box of old manuals I got from my Uncle Roy I had forgotten about. Turns out the earliest one is 1953, covering everything from 1935. The Le Mans model is listed in there too so looks like I found what I needed. The aluminum head is the same casting as the iron head, I have both here and they are identical as far as I can tell.
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Re: 1954 Nash Dual Jetfire Le Mans

Post by pdq67 »

I think that my F-I-L's Motor Manual is also a 1953 issue?

I also have it's second book that is about all the mechanical stuff that was worked on back then.

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