Good, Good, Good, Good Vibrations...... NOT!

[JW113]

Well here it is, end of fall and staring at winter, and me with too much free time to think about stuff. I just love riding my '77 Electra Glide, but little think that has always bugged me, above 65mph the engine vibes start getting pretty bad. If I could just fix that one little thing.... Perfection!

A couple years ago when I found my Evo Softail cases had cracked, while I was fixing that I sent the flywheel assembly to Darkhorse for them to do their magic. What the heck, right? Worth a shot. What I got back simply amazed me. The "before" Softail was what I considered the typical rigid mount big twin, vibs somewhat acceptable below 60mph or so, but wind 'em up them up to 80-90+, not a whole lot of fun. In fact, was the reason I bought a Road King in '04 and gave away my '91 Softail. However, after getting the Darkhorse treatment, this bike is now smooth as satin at any speed you want to ride it. Amazing, I tell ya. Mirrors are clear and steady, none of that hand numbing vibration coming through the bars. Love it.

So, I called Darkhorse and asked if I sent them my Shovelhead flywheels, could I expect the same results as I did my Softail? The answer I got back was a question back to me: Why would you not expect it? OK then, I'm all in.

So I spent my Thanksgiving time off tearing the wheels out of my Shovelhead. And frankly, am very glad I did.

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First problem I found was a broken top motor mount. Hmm, excessive vibration, or something I did wrong, or maybe both?

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Then I noticed the carb support bracket was also broken, and the carb was hanging on by the compliance fittings. Yikes.

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And lastly, and I was kind of expecting this actually, one of the cam lobes didn't look real nice. Some of you may recall a post on HTT a while back advising to take heed if you and installed a set of <name withheld> aftermarket tappets and tappet blocks, which were reported to have gotten the tappet board angels wrong in any direct? Well, it appears I was victim of this. Guess we're going back to stock.

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So tomorrow, off the flywheels go to Wisconsin. In the mean time, I picked up a set of +.040" KB 8.5:1 Forged pistons, which are a little lighter than stock. Also have a nice used Andrews #2 cam I'll install. I have an S&S top motor mount on the way, and will fab up a much beefier carb mount, probably drill the rear rocker box and secure it across both boxes. On the fence about installing an Ultima single fire ignition set up, but what the heck, christmas is just around the corner so merry christmas to Johnny I think.

-JW

[Ohio HD]

Come on JW, just a small 4-1/2" stroke?     

[JW113]

Heh, heh. I have a set of 4-5/8 wheels that I considered for about this -><- long, but reality set in. And the reality is, it don't need it! It's a two wheeled tractor! The other reality is, I HAVE a hot rod (113") and I never ride it! Should put it out on the curb with the key in it and a "Take Me" sign.
 

-JW

[2017FLHTK]

JW113, are you gonna have the cases modified for a big bore kit while you have everything apart?

[JW113]

Nope, it's stock bore (+.040) and stroke for a 74" motor. Even with the broken stuff reported above, it was a fine running bike. The only complaint was high speed vibration. Boring/stroking will only make that more difficult to control, IMO. The short stroke 74 is a great running mill, it has all the power and more for they way I ride it, no reason that I can see to mess with it.

-JW

[david lee]

id like to see a pic of the flh they look better than the later stuff. dont see em anymore here in australia exept at my hd mech shop good luck with your fix jw

[JW113]

Question to the pro guys, if you don't mind. Now that I have the engine apart, I'm considering removing the cylinder studs in the case, bolting back together, and using a piece of 320 sand paper taped to a piece of thick glass to surface the case where the cylinder base gaskets seat. Even with Cometic steel/viton gaskets, they both weep a little.

What do you think? Good/bad idea?

thanks,
JW

[Ohio HD]

If you mean by Pro, I was once paid to rebuild motors....

If it were mine, I'd take it to someone who can mount the cases with the crank bore perfectly horizontal. Then run an indictor across the cylinder mount surface. Then if needed have them clean them up to be exactly 90° to the crank centers.

The problem with blocking sanding anything is you probably will make high and low spots unless you have a way to sand the entire surface with a ridged block. Even then, you might set the cylinder mount surface off and be further away from 90°.

just my 2 cents.

[kd]

I agree.  If you haven't already watched it, watch the video by Tom Reiser on decking cases and why it's done. The video is with an earlier TC case set but I'll bet it is absolutely relevant to your needs.  You will see how little of a vrience it takes to cause a seeping gasket.  Like Ohio said, you can introduce a variance or make the one you have worse by hand working it.

https://www.youtube.com/watch?v=sD0ON4Aa7KQ

[turboprop]

Question to the pro guys, if you don't mind. Now that I have the engine apart, I'm considering removing the cylinder studs in the case, bolting back together, and using a piece of 320 sand paper taped to a piece of thick glass to surface the case where the cylinder base gaskets seat. Even with Cometic steel/viton gaskets, they both weep a little.

What do you think? Good/bad idea?

thanks,
JW

Not the worse idea, and it has been done with success. I am prepared to do this with just about every FXR primary drive and trans case I touch. Like your trouble head, FXR are old and have had a lot of opportunity for 'experts' to make 'improvements'. I have a very large piece of 2" glass that sits in its own drawer in a Vidmar cabinet.

If you do this, use some 600 or 800 grit wet/dry paper for aluminum and cover the flange surfaces with machinist dye prior to lapping. Use a figure 8 pattern and ensure that no area of the flange goes off of the sand paper while lapping. Machine would be better but not always practical or needed.

Best of luck.

[JW113]

Well I went ahead with it. Turned out 'ok', but there was a spot on each spigot at the apex that was a bit deep, even after sanding quite a bit.

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I decided to call it good, Don't want to take it down any further. The front one is under .001" deep, the rear just over .001". Will put a dollop of Permatex #1 under the gasket on those two spots at assembly.

I used a digital level and checked as best I could if anything was obviously out of alignment. With the cam gear bay at a perfect 90.0deg, the cylinder decks are 0.0deg, and 22.5deg. So I don't think I got it wildly out of alignment, although this kind of measurement is crude of course. And it is an AMF era motor, so who knows how close it was before? Clearly the spigot surfaces were not very true to each other, should have taken a before pic I guess. Take my word for it, they were a mess.

-JW

[Buglet]

  That looks like it should make a better seal. Like you say it's probably better then it was when new.

[JW113]

OK I caved. I took a carpenter's square across the timing surface and the cylinder base surfaces. Was not thrilled with what I saw. So, the cases are at the shop awaiting to get squared up. I actually looked for a set of Ultima cases, figured what the heck, but evidently they are unobtainium right now. Another victim of the supply chain malstrom? I sent a message to Jireh inquiring when they expect more stock, but no response. And S&S is out of my budget range. Oh well...

-JW

[72fl]

Jw carpenter squares are not the most accurate, I would try a regular quality square and see what you come up with if possible. (Starrett comes to mind)
If you know of local Machine shops, they will have a Variety of Starrett Squares.

[JW113]

Well it's a bit moot at this point, the cases are already at the shop. I figure if nothing else, I'll sleep better knowing the pistons aren't going up and down at a little bit of an angle.
 

-JW

[Ohio HD]

JW, I'd caution to ask the shop to see that the cam chest gasket surface is at 90° to the crankshaft horizontal plane. The crank is the deciding factor as to what is within angular tolerance.

I know in theory the gasket surface should be at 90° to the crankshaft, but I'd want to verify before machining from the cylinder base pads on the case.

Just my 2 cents

[kd]

 

[turboprop]

JW, I'd caution to ask the shop to see that the cam chest gasket surface is at 90° to the crankshaft horizontal plane. The crank is the deciding factor as to what is within angular tolerance.

I know in theory the gasket surface should be at 90° to the crankshaft, but I'd want to verify before machining from the cylinder base pads on the case.

Just my 2 cents

The machine shop action for this it to have the bushings in the cam cover line honed with the case halves.

[kd]

   What does that have to do with confirming the cam plate mounting surface is at 90* to the crankshaft horizontal plane before indicating the deck surface for trueing?

[Ohio HD]

JW, I'd caution to ask the shop to see that the cam chest gasket surface is at 90° to the crankshaft horizontal plane. The crank is the deciding factor as to what is within angular tolerance.

I know in theory the gasket surface should be at 90° to the crankshaft, but I'd want to verify before machining from the cylinder base pads on the case.

Just my 2 cents

The machine shop action for this it to have the bushings in the cam cover line honed with the case halves.

I agree for a straight bushing to pinion shaft.

Decking the cases, I'd use the crank horizontal plane as the measure to assure that I was decking the cases correctly and parallel to the crank. 

[JW113]

Well, I have the motor all back together, all the component compatibility issues resolved, and fired the thing up on Monday. Just a couple short-ish runs in the garage to get it warm, then shut down. Yesterday I took it on a couple 2 mile spins around the neighborhood. And now, one more issue to figure out.

Both times yesterday it spewed a big pile of oil out the breather. After getting back the garage, it was dripping ever so slightly, probably the surge of oil from start up. So... wet sumping? I put a piece of plexiglass over the oil tank hole and fired it up, oil flowing quite well from the return, so the scavenge seems to be working OK.

Today I did some troubleshooting. I pulled the drain plug (no metal chips on it) from the crankcase, got about 8 oz out. Seems a little high, was expecting more like 3 or 4. I looked at the tappet filter, no debris. I pulled the check valve ball, no debris on that either. Cleaned the well with some industrial Q-tips, then gave the seat a few easy tap-tap-taps with an old check ball. I fired it up, let it run for a few minutes, no oil blow but I had drained the crankcase already so no surprise there.

Will let it sit overnight and see what happens tomorrow. Maybe looking an an issue in the cam chest. Damn.

-JW

[kd]

If you don't recall that happening before it's probably related to the rebuild.  Any change in parts of the oil pump  or venting?  Do you think realigning the cam cover bushing may be causing it to dump more oil and it's overwhelming the pump return? Is this the engine with the breather valve debacle? 

[Ohio HD]

Maybe a sheared keyway on the return side?

[JW113]

10-4, the very same. This now has a new set of S&S cases, S&S oil pump, stock nose cone that I align reamed to the S&S case (because the cam was binding up). When I checked the return flow, it was coming back into the tank like a fire hose, so the scavenge side is clearly working. I will pop the nose cone and make sure it's a pre-92 gasket came with the kit, but everything else in the kit was definitely Shovelhead. But the take home point to me is that it does this at start up, and not while it's running. So not sure how an internal leak would explain that.

-JW

[JW113]

Maybe a sheared keyway on the return side?

Am 100% the scavenge is working. Seen it first hand. And that would not explain wet sumping, would it? Also, the tank level has not gone down at all, so the oil is not all ending up in the motor then getting blown out, it's making it's way back to the tank.

Bummer.

-JW