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Aluminum manifolds 27027-55A

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64duo
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Aluminum manifolds 27027-55A

#1

Post by 64duo » Sun Jan 18, 2009 2:42 pm

Author: 64duo

I have 2 late panhead aluminum manifolds. 1 of which is NOS, yet they both exhibit similar crummy casting especially on the inside surfaces and on the lips. I know the lips are critical for a correct seal (cotten!), but even the inside is just plain lousy workmanship, very rough, ridges, casting sluff, etc. This has to have an impact on an already tough path to follow with the 90 degree bends for fuel & air to pass. I'm worried that this will create additional issues. Anyone else deal with this or have a solution? Thanks in advance Jonathan 64FLH

Image
Image

Post by mbskeam

go to the hardware store and get one of those sanding drums. and clean it up, but it don't have to be polished, some roughness is okay, as it will help the gas stay atomized.
just knock down the big casting flaws.
as for your lip, is it all the way through, kinda tuff to see in pic. looks like corrosion to me.

mbskeam

Post by cotten

I doubt you will detect any difference in performance; The ports limit the maximum flow, not the manifold.
And now you know what "NOS" stands for.

....Cotten

Post by panpal

The gas is sucked through the manifold, so a 90 degree bend does not affect the flow near as much as it would if it was pressurized into the ports in the heads.



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Re: Aluminum manifolds 27027-55A

#2

Post by 58flh » Tue Apr 24, 2012 12:36 pm

I never seen a clean intake oem or head-ports oem yet!--If they had to grind every slopy-crap in there --YOU THINK HDs ARE $$$ NOW?---add another $8,000 a bike--just my 2---Richie :shock:

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Re: Aluminum manifolds 27027-55A

#3

Post by UPSROD » Tue Apr 24, 2012 3:34 pm

Factory FLH heads have the intake ports smoothed out ( flowed ) when new.

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Re: Aluminum manifolds 27027-55A

#4

Post by Cotten » Tue Apr 24, 2012 10:58 pm

UPSRod!

I always took "flowed" to mean it was actually hooked up to a flow bench and measured.

This was unlikely for production machines,
but no doubt the castings were inspected and dressed before assembly.

But I honestly have never seen evidence in the fossil record of the supposed porting differences of later Pans.
My '65 Police Special tank-shift FL's ports look just like my those of my '65 FLH, for all practical purposes.

Perhaps the difference was only a couple more minutes on the "burr bench"? Or maybe just the select runs of castings!

Turbulence is not a bad thing for a workhorse motor.

....Cotten

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Re: Aluminum manifolds 27027-55A

#5

Post by UPSROD » Tue Apr 24, 2012 11:24 pm

Tom, My FLH heads are smooth inside, hand finished, blended etc. My FL heads are as cast, that is the only difference
I know of between FL and FLH heads except the part# in the parts book. This is also stated in Palmer's on page 182.

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Re: Aluminum manifolds 27027-55A

#6

Post by Cotten » Tue Apr 24, 2012 11:52 pm

UPSRod!

So you got a set where the burrmeister earned his keep.

Please consider that it may well have been the worst runs of castings that got the attention!

Clean them up and we will call them something special.

....Cotten

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Re: Aluminum manifolds 27027-55A

#7

Post by RUBONE » Wed Apr 25, 2012 1:22 am

Factory FLH heads have the intake ports smoothed out ( flowed ) when new.
Actually only the first few years, then they stopped doing it. There was also a problem with the polished intakes breaking around the unsupported portion of the seat and a chunk falling out. I have a factory set of those heads. They are even mentioned in the new model literature for '56.
Robbie

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