The M1 single plane operating range is the “sweet spot” but it works fine on the street.
Why is it all torn down now; major changes or just little stuff?
RammerJammer75 shows how well the bypass hose will work in his second picture. Nice picture.
Just for reference, I will attach a picture of an M1 dual plane for Magnum heads and with Magnum bypass hose and thermostat.
View attachment 1715625159
Sorry a lil late to the party. Story of my life day late, dollar short. I'm building a 360 mag motor for a 3/4 ton truck, and it will be carbureted.
I've been bitten by EQ in the past so I ain't interested in another set of their heads. I had a set of stock heads I took to a machine shop years ago with an LA intake gasket and asked them to drill them out, not realizing that the LA intake bolts weren't quite truly perpendicular to the head's intake face, ( they're like 7* closer to straight up from there) and I'm tired of chasing the thread about the jig that was being passed around here that mysteriously disappeared from the face of the earth....
I have a set of good stock magnum uncracked heads (one NOS) and went looking for an intake that would let me directly bolt a carb to a set of stock, as manufactured magnum heads.
I wasn't looking at the time but got offered one "just like"Jaharabi posted, for a impossible to pass up price, in another thread here, that I'm participating in/ that I took the guy up on... I should have it the end of this week or so.
All that said I didn't know that MP made 2 different types of carbureted dual plane intake for the magnum. The story on the one I have coming is that it was originally a part of a MP 300hp crate motor assembly.
Was that the difference between the 2 versions pictured above? Did the one with the 78-older big thermostat only come on those engines originally , not to be offered for sale seperate from one of those engines? What was the deal with the offset thermostat version? Running wise I don't see much difference between the 2 versions besides thermostat location and size. Which will not matter in and of itself on running characteristics. We're there differences in running characteristics between these?
There is another thread about intake manifold choices running currently in either the SB section or the magnum swap section of the forum right now...
For my purpose I don't think I will notice any difference in how this engine will run at least between the 2 MP M1 dual plane versions.
For those that love the air gap, I see a problem with that design. When the engine is warm, fine. But on a cold engine during warm up or if running in cooler weather I can see the airflow around the plenum as a negative. Look at all the small blocks (LA) when the exhaust crossover would be plugged up, how those engines ran great stone cold on the choke, then ran great warmed up but when "1/2 warm" they'd die and you'd have to 2 foot them at a stoplight until they finished warming up, because the exhaust heat passage was plugged up solid.
In pix of the M1 with the centered thermostat it appears there's a part of the intake cast in there appears to be a cast in tunnel from the previously unused rear coolant ports in the head to heat the intake to help alleviate these issues...
Maybe I've been hanging out on the/6 forums too much where there's much talk about this situation among the guys that run dual dutra manifolds or headers instead of a stock exhaust manifold.... They have to put some kind of a "water box" fed by the heater hoses under their intakes to eliminate/prevent that problem on those.
And Jaharabi. you're only about 100 miles away.... Had I known you had an intake like you showed id have tried to get it from ya.....
(For what shipping is costing from California for the one I have coming, I could have driven out your way and back.... And maybe seen some of your other "junk" I (used to anyway, when you posted more haha) see you posting about on here ....
