Hi guys. I need to know if this 2001-2008 Eaton M112 Jaguar is a good match for my 49 Flathead. I only need it for street driving; I don't want to boost much. I have Navarro cylinder heads, 88 camshafts, and Ross pistons. I want to modify it with two Stromberg 97 carburetors as pictured. thanks
The M112 has a displacement of 112 ci, max rpm of 12,000. You didn't state engine displacement or max rpm, so I'll make generic assumptions. If you run a 2:1 pulley the blower will push 224 ci per engine revolution. A 255 will consume 127.5 ci per revolution. A 1.75 ratio. Assuming the carbs can keep up 14.7 psi x 1.75 = 25.8 psi, subtract atmosphere 14.7 gives 11 psi gauge boost. Looks about right on paper. The Eaton blowers have the intake at the back, so the carbs won't sit centered on top like on a Roots.
This may be the biggest hinderance to using it on a traditional flattie with carbs, and the most probable reason this thread may get deleted by the moderators.
Looking at the picture of the one with the carbs on top, they look almost identical other than the modifications done to move the inlet to the top and the plate on the back to eliminate the original intake port. I think I recall seeing a thread from years ago of the modifications done to get there.
I’ve seen people convert those Eaton blowers to carbs, how well do they hold up as they are designed for dry flow (no fuel) thru the blower. In the original application the injectors are at the intake ports.
I want to modify the carburetors from above, replace the closed rear bearings for gasoline, and close the rear intake. I want a city blower of approximately 5 psi. Is this a good combination? Thanks.
I'm not sure its really worth the effort, once you have done all the necessary modifications to make it work you might as well have just bought a 4/71. Plus it will still look like a modern piece and really detract from what sounds like a nice period looking flathead. Still, its your car and your money.
Its important to note the original poster is showing as in Spain, so those sources likely wont be any good to him.
Doing this conversion atm, I liked the challenge I'm using an NOS Eaton M90 blower off a T bird and using a custom 2x2 adaptor to mount 2 Stromberg WW carbs. Getting closer to finishing it as the pics are older. I''ve made a coupler to allow a gilmer drive rather than a ribbed pulley they come std with. You can run these blowers with fuel through them by using 2 sealed rear needle bearings that will prevent fuel from washing the bearing lube out of the bearings.. The conversion isnt difficult with a little machining and the available carb adaptor that can be sourced from https://www.oldtimespeed.com.au/ I'll bet money the M90 will be much more efficient and suck less HP than my 4-71
GM - Detroit Diesel powered vehicles and power equipment were sold in phenomenally large numbers, globally, since the inception of the brand in 1938. The 71 series platform was produced from 1938-1995. More importantly, it should be noted that the question about my sources was asked by someone in the same US state I reside in, and not the original poster. Local sources would only be known to those in their respective locality.
Thanks for the info, guys. I live in Spain (Europe), and it's difficult here, or there's a lot of money and taxes. Thanks
¿Cuál es un mejor candidato para un flathead, M90 o M112? Mi motor de cabeza plana es 8BA 239ci Con cabeza de Navarro Isky 88 Pistones Ross Racing Dos Stromberg 97 Pertronix Solo para uso en la calle.... Gracias
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