Cylinder Head Intake Question

[Pan58]

During cleaning of my heads of my 1958 FLH found this:

Front Inlet:

Front Intake Nipple Side1.jpg

Front Intake Valve Side1.jpg

Rear Inlet:

Rear Intake Nipple Side1.jpg

Rear Intake Valve Side1.jpg

Front inlet is smooth and looks deeper, rear inlet is like raw, has a different shape and looks like smaller, not as deep as front. Is this normal? Or, the front is reworked and the rear not?

Thank you for your help.

[58flh]

58---On Flh heads the intake ports got smoothed by somone by hand.If you look at FLH heads & Fl heads you will see that there are many casting nerds left in Fl heads.FLH heads Have nerds removed & They were smoothed with a sanding-mop.-(not-sure about the MOP ROUTINE)-but the MOCOs accountants didnt want the guys on the line SPENDING TO MUCH TIME on ANYTHING for that matter!.Are Both of your heads FLH HEADS & are you sure?--I ask because the rear looks like it had many casting craps removed!-But the Front looks like somebody actually Did the job at home & Took the Time to get in the places where HD just did not do.Also on that rear head Maybe somebody has a better moniter them mine -Because I see what seems that the piece of the head might of been cracked-off during a guide install.I tried to ZOOM but it just turned grainy.Anyway the way your Front head looks Is how mine look.They were smoothed already-I just made a sanding mop & got into corners that they didnt.Maybe someone else can help you out on the rear head!---Respectfully---Richie

[Pan58]

No I'm not shure about the heads. The only thing I know from the pre-owner, that the rear head had a crack and was replaced years back (1989) with a used one. As I heard now, is a FL head.

Are the heads FLH and FL internally the same? That means, my I grind down all this casting nerds and casting craps and smooth out this inlet port, or are there some hidden oil passages behind? Especially around the valve guide?

[RUBONE]

The head castings, valve guides, valves, etc are all identical. Go gently on the porting. H-D quit doing it after a while as they found for normal use it had little if no benefit. It may allow a slightly higher top end when coupled with the H cam and stiff valve springs of the FLH over the FL, but in the real world it isn't much of much value. Often the thin area under the valve seat breaks away.

[58flh]

Rubone----Thanks for confirming!--58 Make a sanding mop & just smooth the intake & ex. tracts until smooth!-(By all means do not try & make anything BIGGER!!!!!!!!!)-Your bike will run like crap!.I dont know any other way to plainly put it!.Just smooth is GOOD. Its actually good in the combustion chamber!--It prevents any carbon from sticking to a casting glitch & then down the road it PRE-IGNITES the mixture.The olny things that I do on my heads for fast exhaust & fast-Fill--is I take the guides end that protrudes into the combustion chamber & Using the Attachment on the Apron of a lathe -I Taper the protruded ends.--Anything for some help there!--I have been doing it to many motors & Truthfully-I never tested it on a DYNO-Because I find it not practical to do--because IM not racing the clock!.They all run good!-I can olny guess that any Elimination of metal in this area-(& you do not want to shape the head!)- has to help.Maybe its just a habit left from my Drag-Racing days.----Respectfully---Richie