Valve Seat Issues?

[flh canuck]

Wonder if this issue applies to both oil cooled and liquid cooled heads and what production dates?

[Ancient]

Yep, that's ugly. 

[harleytuner]

The video looked seriously bogus .

Having met Tom on two occasions at the Ohio Mile, talking Twin Cams and Sportsters (he was racing a Sportster there), he's a super knowledgeable guy, very pleasant, and also listens to you. I believe he wouldn't put something in public view if he had not seen this as an issue. Not to mention his reputation as being a straight up shop owner.

Tom is a straight up dude.  I can't seeing him making a bogus video. 

[PoorUB]

Well, I do like the whole M8 thing and was considering one for a while. Problem is, the quality issues just keep coming. Issues that should not be there in the first place and if any are there, they should be looked after, not specs provided to justify the problem rather then resolve the issues. That burns my ass to no end.  My V rod may very well be the last HD I own. If they could get the M8 to the reliability state of the Revolution drive train MoCo could have the world by the ass. With the current mind set of the company it looks they are heading the other direction. Who in their right gear head mind could accept loose valve seats and be told 13% leak down is acceptable for the cost of these things? Not me.
Ron

I was seriously hoping the M8 would be something new and great when news of it first came out. As far as I am concerned it is just a variation of a Twin Cam with new issues to deal with. I think they would have been better off to move out the cylinder studs on the TC and slap larger bore cylinders on it and keep running it that deal with the mes mess they started.

I rode imports all my life and finally bought my first HD in 2005, on my third one and growing tired of it all. For the money these bikes cost the technology and quality is lacking.

A BMW or even the new 2018 Gold Wing looks interesting.

[Tattoo]

The video looked seriously bogus .

I have been doing business with T-Man Performance for many years and TR and his crew are pretty straight up.

[CarlosGGodfrog]

Unless the replacement seats have a larger OD, how does a CNC machine make a hole smaller to get a tighter press fit ? Back in the fifties, weren't screw-in seats available for cars ?

[Don D]

Use a larger seat
TR is straight up.

[CarlosGGodfrog]

Ok, that makes sense.

[gonenorth]

  Maybe they can pressurize the primary with some of the blow-by so the trans lube will stay in the trans.

Makes me laugh when people state Harley quality is going down...they use to make some real junk.  Harley has always had an absurd amount of difficulty with design changes compared to Japanese bikes.  The M8 will be fine once sorted.

[Don D]

A detail not often discussed HD uses different vendors for castings and even within a single vendor there are different alloys. The numbers on the heads like 332, 332M, and 242 t5, all designate the alloy and heat or process treatment.  A poorly heat treated head could have a seat in at the proper press fit and still drop later. Once it is moving no telling what the original fit was.

[Ancient]

Question Don, or anyone else that might know, does the moco just buy in blank castings and machine and assemble themselves, or do they buy them in completely assembled and ready for install?

[Don D]

I don't know for sure but I would guess the part comes from the vendor completed and ready to install even if they have to subcontract some of the parts like the main casting. Typically in automotive the casting and all the component parts have individual numbers, many of which are not published and used on the build of materials internally to comprise the whole assembly which is the finished part number available to the public. Then all the individual parts such as springs valves and the other repair parts are also cataloged.

[TorQuePimp]

  would be far more valid for those of us that know

to provide interference fit numbers

If you are replacing them all....welding or cutting them out pretty easy to measure one and see

by the looks of it the press fit is less than .006 the three ive removed

[tmwmoose]

A detail not often discussed HD uses different vendors for castings and even within a single vendor there are different alloys. The numbers on the heads like 332, 332M, and 242 t5, all designate the alloy and heat or process treatment.  A poorly heat treated head could have a seat in at the proper press fit and still drop later. Once it is moving no telling what the original fit was.

That reminds me of a laugh years ago when I would attend factory school. When ever the factory would discuss a problem going on and what they found to fix it always started off with .."Well the VENDOR that made the gear that's failing blah blah blah told us blah blah ."

[rbabos]

  would be far more valid for those of us that know

to provide interference fit numbers

If you are replacing them all....welding or cutting them out pretty easy to measure one and see

by the looks of it the press fit is less than .006 the three ive removed

.006 is pretty tight.
Ron

[Moparnut72]

With.006 interference fit I don't see how you could get the guides in no matter how much heat and liquid nitrogen or dry ice is used.
kk

[Don D]

.006 is a little light on a seat
Guides a new story.

[rbabos]

.006 is a little light on a seat
Guides a new story.

What would you feel as a save interference with seats being so close to each other and available aluminum mass before they crack? Just curious.
Ron

[Moparnut72]

Yeah, you are right. I was thinking guides.    On the radials I worked on if the seats were bad the cylinder was then junk.
kk

[Don D]

Ron
.007 with a seat that size all things considered especially considering the heat some of these motors are subjected to.

[rbabos]

Ron
.007 with a seat that size all things considered especially considering the heat some of these motors are subjected to.

Thanks.
Ron

[jsachs1]

Ron
.007 with a seat that size all things considered especially considering the heat some of these motors are subjected to.

[prodrag1320]

Yeah, you are right. I was thinking guides.    On the radials I worked on if the seats were bad the cylinder was then junk.
kk

ive got a set of S&S heads a local shop installed a .008 guide in a STD hole,needless to say,it cracked all the way thru the head.we install seats @ .008 & guides @ .002.heat/freeze on both to install.a properly installed seat should never move or come out

[Don D]

Ok but then the alloy and heat treat (or lack of) needs to be factored.

[badcooky]

ive got a set of S&S heads a local shop installed a .008 guide in a STD hole,needless to say,it cracked all the way thru the head.we install seats @ .008 & guides @ .002.heat/freeze on both to install.a properly installed seat should never move or come out
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