F-427 and RPM

[fetorino]

i have an f- 427 to sell if they love them so much!! i have a rpm now . previously had port matched sidewinder, and holley street dominator . i strongly believe the sidewinder was the strongest runner and the lightest of the lot by a good margin.

My dyno data doesn't back that up.  The Sidewinder did reasonably well in my testing in the 400-500 HP range, but it wasn't as good as a Performer RPM or the single plane intakes.  The Performer RPM made 504 peak HP on my 390 stroker engine, the Holley Street Dominator made 499, and the Sidewinder made 496.  Also, the Sidewinder weighs 25 pounds, the Performer RPM weighs 27 pounds, and the Holley Street Dominator weighs 25 pounds.  The lightest FE wedge intake I've ever measured is the 4V tunnel port intake, which weighs 18 pounds.

I may have been there that day.

[comet2]

hey,jay icant argue your dyno numbers all i have is an assometer when it warms up i have to change intake gaskets,so i can compare weights of the two again.the only reason i switched is because some butcher ported it and it developed a leak at a pushrod hole and started to run like an evenrude. also some of the sidewinders were cast in magnesium .

[jayb]

Wow, I didn't know they ever cast the sidewinders in magnesium!  That would be cool, and light...

[comet2]

yup, i saw one for sale at columbus swap meet 15 years ago . it looked like it was dredged from the bottom of lake erie horrible looking,pitted blackened the guy wanted 800 i thought he was on crack ! extremely light piece for sure!!! magnesium is 2/3 the mass of aluminum apply that math to what you said earlier. 25lbsx.66=16.5 lbs!!!!! maybe you had one!! this theory may seriously flawed my spelling also mag has to be passivated after it is in a molten state which creates a protective film as mag is highly reactive .thow water on molten mag makes hydrogen explosion!!! 

[machoneman]

Yes, Ford did do some mag intakes and here's a pic.

http://www.mustangandfords.com/techarticles/engine/mdmp_1210_ford_427_fe_build_big_blocks_on_the_dyno_real_iron_part_2/photo_09.html

Looking horrible is about par for 40+ year old mag parts since unless the parts were carefully wrapped in storage to prevent oxidation, old mag parts today would look just as described. Today though anyone lucky enough to score that intake has lots of trick metal coatings that would prevent said surface oxidation. IIRC, the very rare mag intakes were made for the GT-40 Mark II FE racecars (not NASCAR, where minimum weights way back then were almost 2 tons!).  Rare beasts indeed!   

[hotrodfeguy]

I also didnt know they had the SW in MAG thats cool. 

[fe66comet]

I would not use a magnesium intake as it is flammable. You already would have fuel and air all you need is a backfire and poof intake is a fireball. If you have ever seen magnesium burn it does it quite violently and fast.

[BH107]

I would not use a magnesium intake as it is flammable. You already would have fuel and air all you need is a backfire and poof intake is a fireball. If you have ever seen magnesium burn it does it quite violently and fast.

It takes alot of heat to ignite magnesium, and a backfire wouldn't do it. It would take a fairly significant engine fire to get it going. But if you are that scared of mag, never ride in an old Volkswagen as the engine block was magnesium.

[hotrodfeguy]

Just keep your foot in it then LOL
But back on track though any intake choice would be better than the F-427

[Qikbbstang]

I was in a junk-yard and found some Navy airplane magnesium wheels that were crushed/ruined. I picked up a couple football sized pieces and figured I'd have a ball reminiscent of high-school when a friends dad owned a machine shop that contracted for Grumen in the height of the Nam War. He'd smuggle home boxes of Magnesium shavings. Anyway I found magnesium chunks will spark like hell when you wail it down the street at night but as far as igniting it was a real dud just sparked and glowed nothing exciting.

[plovett]

In WWII during the night air war over Germany, pilots could see the fires on the ground from the British bombers and from the German night fighters which had been shot down.   They could tell if the fire was a British plan or German by the color of the fire.   Red-orange was British.   White-ish fire was a German plane.   The German planes burned white from all the magnesium in them.     That's what I've read anyway.   Call me Cliff.   

paulie

[Qikbbstang]

into the ports of either manifold and it's monsterous caverns that end up looking like funnels that feed to the manifold flange. Jays book shows this with a whopping 4650 and 4700 cc intake volumes.  You study inside a Perf RPM and the runners look to be the same H & W right up to the plenum area

[comet2]

hey guys if a particular intake costs 400 bucks and makes 10-15 more hp than a 75 dollar intake that can be improved with portmatch according to jays own words. which intake is the real POS !!!!  you will probably see more difference with weather conditions or fuel quality! i do have an RPM on a POS 390 with POS c7 heads because when you live in shebbyville thats all you can get!!!! BUT i have had a lot of fun with it for 20 years. and it still is running strong! knock on wood! what i am trying to say is if hot rod magazine mentions a slight improvement over an current part the current part is doomed and banished into oblivion!! then the shebbie boys find out and now their 305s are better and faster!! 
changing my previous mentioned intakes never made earth shattering differences so why pick on f-427 woudnt it be an improvement over a stock 2v for 75-100 bucks?

[ScotiaFE]

hey guys if a particular intake costs 400 bucks and makes 10-15 more hp than a 75 dollar intake that can be improved with portmatch according to jays own words. which intake is the real POS !!!!  you will probably see more difference with weather conditions or fuel quality! i do have an RPM on a POS 390 with POS c7 heads because when you live in shebbyville thats all you can get!!!! BUT i have had a lot of fun with it for 20 years. and it still is running strong! knock on wood! what i am trying to say is if hot rod magazine mentions a slight improvement over an current part the current part is doomed and banished into oblivion!! then the shebbie boys find out and now their 305s are better and faster!! 
changing my previous mentioned intakes never made earth shattering differences so why pick on f-427 woudnt it be an improvement over a stock 2v for 75-100 bucks?

I've never thought the 390 was POS. C7 heads will hold there own when tuned up.
It was the intake and logs that really sucked.
If you have a F 427 that you want to part with for 75 bucks I`m buying!

I think the F-427 has a great looking traditional appeal.
The RPM although works great is really not a great looking intake.
The Ed and Holley spider type have a great look.
Let`s face it, A great look is worth 50 HP.

[jayb]

Yes, let's not get too down on the F427.  There are better intakes out there, but with a port match the F427 is at least respectable, especially on ~400 horsepower engines.