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Eaton M90
https://slantsix.org/forum/viewtopic.php?f=30&t=63490
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Author:  Dart270 [ Wed Apr 24, 2019 4:31 am ]
Post subject:  Re: Eaton M90

Go for it. Ideas plus hard work with your hands is often rewarding and promotes learning!

Lou

Author:  Tim Keith [ Wed Apr 24, 2019 12:51 pm ]
Post subject:  Re: Eaton M90

I think it might work well. Plan B might be to cast the intake flanges in iron with the injector bung included. I've always wanted to build a small foundry furnace. These cast iron intake flanges wouldn't be large castings. The square steel tubes for the six runners could be braised to the cast iron. I'm concerned that the square tubes might be too fat for sufficient clearance with the exhaust manifold - the iron casting would extend a thinner section a bit further away from the cylinder head.

I don't know how a machinist might cut a square step inside the intake flange to secure the rectangular inner alloy tube. The old fashioned shapers can perforn that operation so I'm sure it can be done. I'd like to deconstruct the project so that low cost intake manifolds might be produced. There isn't much of a market for $500 intake manifolds. But, if we can build this using readily available materials - other than the cast iron flanges, then we could make this type of manifold a more popular item. I'm sure the EBay 1/2-inch thick steel flanges could have a welded steel "bung" tube section attached that might be produced on a small milling machine that I could afford to purchase. It doesn't need to be a casting.

The much talked of custom head would be cool and spendy - visions of *relatively* cheap torque dances in my head! As Aretha Franklin sang : Drop the pedal and go, go, go!

Tim

Author:  slantzilla [ Wed Apr 24, 2019 3:42 pm ]
Post subject:  Re: Eaton M90

There used to be a guy on E-bay who sold steel intake flanges. I had some of his header flanges, they weren't too bad.

Author:  Tim Keith [ Wed Apr 24, 2019 4:04 pm ]
Post subject:  Re: Eaton M90

slantzilla wrote:
There used to be a guy on E-bay who sold steel intake flanges. I had some of his header flanges, they weren't too bad.

He still produces those flanges. I'm ordering a set tonight. This motor would be used in a shortbed D150. I don't know realistically how much power the M90 might produce with a budget long block, but I'd be pleased with 150+ hp and gobs of torque. It'll will have Dutra Duals. Others can build the race motors. I want the truck to feel more like it has a stock 318.

Author:  slantzilla [ Wed Apr 24, 2019 6:31 pm ]
Post subject:  Re: Eaton M90

That seems to be a very reasonable goal. I think an Eaton with make 5 or 6 psi.

Author:  kesteb [ Wed Apr 24, 2019 8:14 pm ]
Post subject:  Re: Eaton M90

The M90 is rated at 11psi at 11,000 or so rpm, anything more and you pump hot air. The lower pulley from a Ford 3.8 v6, with the stock upper M90 pulley, will do that at 4800 rpm. Well within the \6 range.

Current thought is that with a modern efi setup, the plenum size should be around 150% of engine size. With dutras this means the intake runners have the be at least 7". This gets the plenum past the dutra flanges. With the eBay flanges, 1 5/8" steel tube works great and give a slight increase is runner volume.

Been there, done this 2 times now, starting the third time now.

Author:  Tim Keith [ Wed Apr 24, 2019 8:22 pm ]
Post subject:  Re: Eaton M90

I ordered the flange set. I don't intend to make as much power as it can. I'd like to set a modest baseline and improve later. I don't understand the engine management side of things so I need to keep it simple as I learn. I work in IT, but EFI is a different kind of tech than I'm used to working with. I have trouble setting an alarm clock :)

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