New FE Blower Intakes

[hwoods]

how would that intake perform if you put a custom top plate on with (2) 4 barrel carbs or throttle bodies for Fuel Injection?

[GerryP]

Terrible.  Very short runners, massive but shallow plenum.

[Tommy-T]

I'm using a fully prepped truck crank and leaving the snout its original size.

I am planning on running a 6-71 around 12% over on a 390 crank, how worried should I be about shearing the crank snout off? I wont be running a conventional water pump so I will be running the belt closer to the engine than most guys with a conventional street set-up, I am hoping that will help keep me out of trouble, but has anyone actually had first-hand experience with a sheared off snout on a blown FE?

Yeah, sort of.
I sold my Mustang with an 8-71 blown 454. It had a 1U crankshaft and an Electromotive crank trigger ignition. The gentleman who bought it from me said he went to start it one morning and it popped hard out of the blower,then wouldn't start. He sent me a video of the lower blower pulley wiggling around while the motor was cranking.
Now realize this 50 year old crankshaft had been in my supercharged FE for 10 years, and I was not using a harmonic balancer. It was a clean break right behind #1 main. It did no damage to any other components and was rebuilt requiring a new crank and balance.
I felt so bad about it that I bought him a new 3.98 stroke Eagle crank, the only aftermarket choice that had factory rod and main journals. It's been up and running for a while now, it'll be interesting to see how the cast Eagle crank holds up.

[falcongeorge]

I'm using a fully prepped truck crank and leaving the snout its original size.

I am planning on running a 6-71 around 12% over on a 390 crank, how worried should I be about shearing the crank snout off? I wont be running a conventional water pump so I will be running the belt closer to the engine than most guys with a conventional street set-up, I am hoping that will help keep me out of trouble, but has anyone actually had first-hand experience with a sheared off snout on a blown FE?

Yeah, sort of.
I sold my Mustang with an 8-71 blown 454. It had a 1U crankshaft and an Electromotive crank trigger ignition. The gentleman who bought it from me said he went to start it one morning and it popped hard out of the blower,then wouldn't start. He sent me a video of the lower blower pulley wiggling around while the motor was cranking.
Now realize this 50 year old crankshaft had been in my supercharged FE for 10 years, and I was not using a harmonic balancer. It was a clean break right behind #1 main. It did no damage to any other components and was rebuilt requiring a new crank and balance.
I felt so bad about it that I bought him a new 3.98 stroke Eagle crank, the only aftermarket choice that had factory rod and main journals. It's been up and running for a while now, it'll be interesting to see how the cast Eagle crank holds up.

Well, whats VERY interesting about this, is that it broke BEHIND the #1 main. Legend has it that the long, skinny FE snout is supposed to shear off the end of the crank in a high-boost blown application. This story would indicate that the snout itself is not the weak point. I think a lot of the various stories that go around, about LOTS of things, not just FE cranks, are based more on the way things LOOK, rather than any empirical evidence.

[GerryP]

...various stories that go around, about LOTS of things, not just FE cranks, are based more on the way things LOOK, rather than any empirical evidence.

Unless you can afford professional engineers for failure analysis, it's always going to be that way.  Truth is most "mysterious" materials failures are related to harmonics.  Very few of us are skilled enough to forensically identify the root cause.   Was it the dampener, the timing chain, the camshaft, a axial balance issue or about two dozen other things?  Who knows.

[falcongeorge]

...various stories that go around, about LOTS of things, not just FE cranks, are based more on the way things LOOK, rather than any empirical evidence.

Unless you can afford professional engineers for failure analysis, it's always going to be that way.  Truth is most "mysterious" materials failures are related to harmonics.  Very few of us are skilled enough to forensically identify the root cause.   Was it the dampener, the timing chain, the camshaft, a axial balance issue or about two dozen other things?  Who knows.

https://www.speed-talk.com/forum/viewtopic.php?t=49163&sid=52dbd1148c473c53a53196902fdc244d#p653646

[falcongeorge]

Has anyone put a blower case on one of these yet? Mine just showed up a couple of hours ago, I dropped my blower on, it looks like the bolt pattern that the case bolts down to is back to front. I have to check with a buddy of mine that builds 6-71s, I think I can swap the rotors end for end in the case when I rebuild it, but otherwise I gotta plug the bolt holes in the manifold and re-drill the pattern!

EDIT: Its all good, I just talked to my guy, when you rebuild a original 6-71 (like mine) you are SUPPOSED to reverse the rotors. WHeeew! Big sigh of relief, I can sleep tonight!

[fastback 427]

Just for shits and giggles ordered one of these on black Friday. 330$ free shipping.  Showed up today, looks very nice but a couple of very small imperfections as previously reported. I mean cant they take the time and earn that 330 bucks!

[Falcon67]

Sweet.  If the budget wasn't so tight this year I might have bought the 351W intake, just because.      I did buy the 1" and 2" "Super Sucker" knock off spacers.  Just for fun.

[Barry_R]

Probably broke behind the main because that's the weak spot - the place with the smallest overlap cross section.  The snout load just gave it enough wobble to accentuate the loads there.  I have seen a couple other cast cranks break in that same area on higher power or drag race applications.  Forensic work might show some bearing wear or deformation in that front shell, but most guys would just replace the bearings without even bothering to check since the crank was getting swapped out.