Author Topic: Anyone with S&S rocker box on a FXR?  (Read 745 times)

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Offline 1340evo

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Anyone with S&S rocker box on a FXR?
« on: August 24, 2020, 11:54:07 PM »
Been trying to find a vibration I have around the 3-3.5K RPM mark and trying to think why my bike has been assembles as it has.

Basically the mounts have been set lower to drop the motor I assume to get clearance on the rocker boxes.

Although I'm sure this will still work, its not how its designed to be fitted so want to eradicate other areas before potentially pulling the engine to check there.

Has anyone seen this done before? And has anyone got S&S rockers on a 1989 FXR so I can see the clearance.

To put it back to std, I think the rear head will hit the frame?

« Last Edit: August 24, 2020, 11:58:44 PM by 1340evo »

Offline Deye76

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Re: Anyone with S&S rocker box on a FXR?
« Reply #1 on: August 25, 2020, 06:28:52 AM »
Can't find any information that requires motor mount alteration. This from several web sites.
"Taller engines may require engine removal for installation in FXST models."
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #2 on: August 25, 2020, 06:50:12 AM »
I think they are S&S but someone did say Zodiac before. But maybe they are for Evo (except FXR) ?

as I think the tops will be in contact.
This is the only reason I can think you'd do this... unless its something FXR custom builders do to make the motor lower??

Offline turboprop

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Re: Anyone with S&S rocker box on a FXR?
« Reply #3 on: August 25, 2020, 06:56:02 AM »
Been trying to find a vibration I have around the 3-3.5K RPM mark and trying to think why my bike has been assembles as it has.

Basically the mounts have been set lower to drop the motor I assume to get clearance on the rocker boxes.

Although I'm sure this will still work, its not how its designed to be fitted so want to eradicate other areas before potentially pulling the engine to check there.

Has anyone seen this done before? And has anyone got S&S rockers on a 1989 FXR so I can see the clearance.

To put it back to std, I think the rear head will hit the frame?



Your post is not really clear enough as S&S makes two different the of rocker boxes for Evo engines. Cast and billet.

Also, the year of the FXR frame is irrelevant to this discussion. The FXR frames, all models, all years, have the same physical dimensions as it pertains to surrounding the engine and drive train.

I have 124" engines in two of my FXRs. One is an Evo 124 with billet S&S boxes, the other is a twin cam with cast S&S boxes. Neither of them have clearance issues between the rear rocker box and frame.

I have run those rubber mounts n the high and low orientation. Thelow position will provide a little bit more clearance. Neither position has an advantage in handling or anything else.

I suspect the source of the vibration that you are feeling is from something else. Simply flipping over the rubbers is not it. 
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #4 on: August 25, 2020, 08:36:38 AM »
That's great information Turboprop. I'd didn't think it would change anything as they should work the same both ways, but was going to rotate 180 deg and see. But if you've run them both ways, I guess I don't need to bother.

Obviously the location caps that bolt over them are inverted as well to get the pin in the correct position, but would think either way the rubber of the mount will sit on the cut-out in the frame? or should I put these on the right way up to list the block off of the frame? What do these rubbers look like in cross section??

Just out of interest, why did you run them in the low position?... was it to get more clearance?

and what did you do with your font mount. Did you run that under the the mount like mine is?

Thanks
« Last Edit: August 25, 2020, 08:52:56 AM by 1340evo »

Offline turboprop

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Re: Anyone with S&S rocker box on a FXR?
« Reply #5 on: August 25, 2020, 11:24:08 AM »
That's great information Turboprop. I'd didn't think it would change anything as they should work the same both ways, but was going to rotate 180 deg and see. But if you've run them both ways, I guess I don't need to bother.

Obviously the location caps that bolt over them are inverted as well to get the pin in the correct position, but would think either way the rubber of the mount will sit on the cut-out in the frame? or should I put these on the right way up to list the block off of the frame? What do these rubbers look like in cross section??

Just out of interest, why did you run them in the low position?... was it to get more clearance?

and what did you do with your font mount. Did you run that under the the mount like mine is?

Thanks

I flipped them around to raise the rear of the frame slightly.

To flip them around, the end caps have to be moved around. I forget but I think had to be swapped from side to side. I dont really remember but its one of the things that the square peg will only fit in the square hole. What needs to be done will be clear when you do it.

Rotating them around to the lower position will result in some additional clearance, but I dont see why the additional clearance is needed. It certainly is not because of the S&S rocker boxes (cast or billet type). Unless the engine is super tall, there is plenty of clearance.

If this bike is indeed experiencing vibrations as you describe, and it is as a result of the engine making contact with the frame, there are other issues with this chassis that need to be addressed.

I would look very closely at the front engine mount, the exhaust, mid controls, oil tank, front and top stabilizer links (and their associated hardware). Keep digging.
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Online Hossamania

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Re: Anyone with S&S rocker box on a FXR?
« Reply #6 on: August 25, 2020, 01:21:43 PM »
My rubber horn mount is broken, causing a small vibration, found that by chance yesterday. One I hadn't thought of in all the years of looking and reading about chasing vibes.
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #7 on: August 25, 2020, 01:51:08 PM »
Well, a good couple of hours in the garage tonight, and both slots are now top front. And guess what, it still all fits LOL. TBH its to front that's within 1/4" of the frame but may be the front mount has been adjusted?. anyway, front mount is now on top as it should be.

but once you look at how these things work, it all pivots around the rear engine mount so it can't come forward and hit.

It's not changed much TBH. I though the angle of the exhaust might change relivant to the bike but its not, and maybe the bike would the higher / lower, but its not. All you are doing is moving the pivot point. Its the shocks that determine the height.

One thing I did see is the rear mount had been hitting the frame and had marked it say 2mm deep! Now they are the other way everything is clear and I can get a cardboard piece all the way around them.

Will torque up the rear shaft tomorrow (does anyone know what to) and run the engine to settle onto the front mount than nip this up.

Does anyone know the height of a front mount as this one looks to of been filed??   :chop:
« Last Edit: August 25, 2020, 01:55:32 PM by 1340evo »

Offline jsachs1

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Re: Anyone with S&S rocker box on a FXR?
« Reply #8 on: August 25, 2020, 02:49:59 PM »
I've installed Ultima 127" engines in FXR's, and for that matter FLHR's without doing any chassis mods. Only difference was in order to remove the rear rocker box assy. you needed to drop the front motor mount plate. :wink: Ultima 127" = 1/4" taller than stock.
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #9 on: August 26, 2020, 12:03:56 AM »
I think you could easy get 1/4" more in even in the 'up' position. The higher it goes, the more the frame opens up until you hit the top.
The engines do look to bounce around a lot on the mounts but in real terms they probably don't move much.

One thing I need to check is that the swing arm moves easy. I was sat on it last nigh (and my shocks are stiff) but it didn't appear to move much? I need to torque up that cross bolt and I've seen 40-45 LB/F as a figure to use.

Let's hope its solved the problem.. If not it could be engine out time??..  :)

Offline JW113

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Re: Anyone with S&S rocker box on a FXR?
« Reply #10 on: August 26, 2020, 12:18:34 PM »
Just to ask the obvious stupid question....

Did you do the rubber mallet test yet? Being, use rubber mallet and walk around the bike tapping on everything, so see if it rattles or not.

I have found many problems that way. Once I heard a rattle coming from the rear (I thought) of the bike. Thought for sure it was the rear fender, or the license plate frame, or the chain guard. I removed all of that, same rattle. The rubber mallet found the problem: front fender.

-JW
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #11 on: August 26, 2020, 01:40:27 PM »
Well, took it for a run tonight. Is it fixed... Well, NO ! Just the same as it was  :crook:

It does it maybe a bit lower RPM than I thought (what do FXR's red line at?) maybe even as low as 2 to 2.5K. Does it in all gears up and down the box. when accelerating or at constant speed or slowing down.
It also does it in neutral if you rev it?

I did buy a new clutch and did the spline shaft conversion a few years ago and I think I swaped out the primery chain then to see if it improved it, but no.

I'm wondering if the last guy who built the engine didn't balance the new pistons or something, although maybe he just fitted new rings after a slight hone? when it get's past the vibration area it revs nice and smooth up the the red line.

I have solid mounted forward controls. it kind of starts in them and moves back to the seat as RPM increases. I've taken a video of it in my garage in neutral as I rev it. I'll see if I can post it tomorrow.

Unlike a lot of rubber mount engines, it does not bounce around a lot? could it be my mounts are too stiff or too new???

I may take the baffles out of my pipes tomorrow as see if that helps.. could it just be the re-verb??

try this.... https://www.youtube.com/watch?v=NDexwht9CEs
« Last Edit: August 26, 2020, 02:11:25 PM by 1340evo »

Offline turboprop

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Re: Anyone with S&S rocker box on a FXR?
« Reply #12 on: August 26, 2020, 06:43:11 PM »
Well, took it for a run tonight. Is it fixed... Well, NO ! Just the same as it was  :crook:

It does it maybe a bit lower RPM than I thought (what do FXR's red line at?) maybe even as low as 2 to 2.5K. Does it in all gears up and down the box. when accelerating or at constant speed or slowing down.
It also does it in neutral if you rev it?

I did buy a new clutch and did the spline shaft conversion a few years ago and I think I swaped out the primery chain then to see if it improved it, but no.

I'm wondering if the last guy who built the engine didn't balance the new pistons or something, although maybe he just fitted new rings after a slight hone? when it get's past the vibration area it revs nice and smooth up the the red line.

I have solid mounted forward controls. it kind of starts in them and moves back to the seat as RPM increases. I've taken a video of it in my garage in neutral as I rev it. I'll see if I can post it tomorrow.

Unlike a lot of rubber mount engines, it does not bounce around a lot? could it be my mounts are too stiff or too new???

I may take the baffles out of my pipes tomorrow as see if that helps.. could it just be the re-verb??

try this.... https://www.youtube.com/watch?v=NDexwht9CEs

Serious question, is this your first harley?

Here are a few replies to some of the stuff in this post:

1. The RPM redline is not model specific, ie FXR. All evo engines have the same mechanical redline. I think the factory stated redline for the Evo engine 5,500 rpm -ish. Not uncommon for some to twist them a bit higher. An ignition module other than what came from the factory is required to rev them higher.

2. The last guy that rebuilt the engine probably didnt rebalance and true the flywheels. Evo engines were pretty good from the factory, Not like the horrors of the early TC cranks. If the engine builder used the same style of pistons as the factory used, then he probably didnt balance and true. Without paper it didnt happen.

3. Rubber mounted harley engines of all types will shake around at idle. Its normal. It should settle down almost as soon as the engine is above the high idle rpm range.

4. Depending on their source, new rubber mounts may require a few miles to soften up.

5. Exhaust reverb is not the source of any vibration you may be experiencing on that bike.

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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #13 on: August 27, 2020, 12:00:02 AM »
Hi Turboprop

in reply, I've had a few HD in the past. My Shovel was very smooth in comparison and I've had 10+ Sportsters.

1   its got the std ECU so will be 5.5K then.. so I'd say the issue is 1800-2000 maybe?

2   Yes, nothing on the engine at all I don't think. I'll look through the papers tonight and see if I can find anything. thinking it was hone and new rings

3   Thing is, its quite smoother at idle. Not sure the video shows it right TBH. come off idle and its okay until you hit the lets say '2K' area and then it has the rough spot. Go beyond this and its smooth a silk!

4   2600 miles since re-build so maybe a bit stiff. I have (by drilling holes in it) made a weaker front mount to try, but again, nothing changed.

5   I'm sure you are correct and this does feel front low down with it starting in the pegs. Think it's in the crank myself. Can I live with it?.. well I have done so far but is around the 65-70 MPH area in 5th which is annoying.

Q   if it is crank imbalance, would it show at a given RPM as I'm seeing? I'd think the answer would be yes, but not sure on HD.

Q   Whats the cost of addressing this? I'd remove the engine and strip it all down.

It is in the area where the VOSE should kick in so will test that.

Any more thoughts?.. thanks for your replies so far!  :teeth:

Just reading this.. wow.. this is me!! https://www.hdforums.com/forum/evo-classic-models/1072715-evo-engine-vibration-ugh-again.html


This is interesting.. any info ? http://store.balancemasters.com/osCommerce/images/SILVER_EAGLE.gif
« Last Edit: August 27, 2020, 01:59:05 AM by 1340evo »

Offline turboprop

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Re: Anyone with S&S rocker box on a FXR?
« Reply #14 on: August 27, 2020, 03:49:44 AM »
Here in the US a shop will charge about $250 to balance and true a shovel/evo style crank shaft. This does not include the cost of rebuilding anything, just balance and truing.
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #15 on: August 27, 2020, 03:56:54 AM »
Did you see the link to Balancemaster.. has anyone any experience of this??

Offline turboprop

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Re: Anyone with S&S rocker box on a FXR?
« Reply #16 on: August 27, 2020, 06:45:56 AM »
Did you see the link to Balancemaster.. has anyone any experience of this??

Search this forum. Lots of existing discussions about Balancemaster.
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Offline JW113

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Re: Anyone with S&S rocker box on a FXR?
« Reply #17 on: August 27, 2020, 08:33:44 AM »
Cold hard fact: It is IMPOSSIBLE to "balance" a 45 degree V-Twin. What is done is to manage the "out of balance" to the point where it is the most tolerable to the rider. From what I have found, any of those bolt on "magic" balance pills are plain old snake oil. Don't waste your money.

I think I confused your issue with a rattle, instead of engine vibration, since you were talking about the rocker boxes hitting the frame.

Rubber mount V-twins are typically pretty damn smooth except at idle. Just the opposite for rigid mounts. So if you are having really bad vibes around the 2400 mark, then something is indeed suspicious. However, for a run of the mill V-twin with 60 degree balance factor, that is about where the imbalance will be the worst. If you are feeling vibes at that speed, then it sounds like the isolation system of the FXR is not working as it should.

When is the last time you replaced all three engine mounts? I believe FXRs are prone to getting the two rear cleeve blocks to corrode and seize. Perhaps one way to tackle this is to replace them all and start from a known good point?

I recently had a '92 Evo rigid mount sent off to be balanced. What I got back was pretty impressive, and for a rigid mount, amazingly smooth. Except at 2600 RPM. In any gear, I can tell when the motor is passing through 2600 RPM as the vibs increase, and then fade away. At 3000-3500, it's amazingly smooth. This I believe has to do with how the flywheels are balanced, and what the balance factor used is.

They way they balance these things, depending on balance factor, it vectors the out of balance direction to the front/back, or up/down, or somewhere in between. For any given bike, there will be some "sweet spot" that the out of balance can be tuned to minimize rider felt vibration. Rubber mounts tend to be fairly immune to that, but in your case, evidently not.

It sounds like your top end involved just swapping pistons. If it were cast for case, likely not much difference. If cast for forged, then the pistons are likely heavier, and could have thrown the balance factor off a bit. But that should not have really made much difference if the rubber isolation system is working.

Personally, if it were me, I'd start with the engine mounts and heim links. I mean, the bike what, 30 years old? That stuff doesn't last forever.

-JW
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Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #18 on: August 27, 2020, 08:52:32 AM »
Hi JW

the whole system is new 2500 miles since. Its like a new bike with all rubbers replaced and everything painted etc So its not in the mounts.

I'd put the RPM range lower than I guessed before, maybe around the 2K mark.

Tickover and above its great, 2K the forward controls are bad, 2.5-5.5k its very nice with nothing at all to worry about

If I give it a bit in first and get above this area then its great, but if I don't, obviously the higher the gear, the longer the vibration lasts.

I did measure the side of the flywheel through the timing hole a few nights ago and got 0.40mm TIR which I think is a bit too much. I'm thinking its this as like I say, in the vibration zone it can literally make your eyes go funny for a second or two. All that said, I can push my leg against the air filter and it don't feel that bad there at all??? 

This guy has had the exact same problem... If he was in the UK I'd be sure I'd bought his bike https://www.hdforums.com/forum/evo-classic-models/1072715-evo-engine-vibration-ugh-again.html

Offline JW113

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Re: Anyone with S&S rocker box on a FXR?
« Reply #19 on: August 27, 2020, 09:59:07 AM »
OK, good to know. So now the question: What you doing lugging it around at 2K???

 :hyst:

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline ecir50

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Re: Anyone with S&S rocker box on a FXR?
« Reply #20 on: August 27, 2020, 11:01:54 AM »

Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #21 on: August 27, 2020, 02:24:42 PM »
Thats a good read, and nothing much I could not do in my shop. Maybe this is the winter I get stuck in and sort this mother !

will save a copy of that for future referance... Many thanks!

Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #22 on: August 28, 2020, 02:55:05 AM »
OK, good to know. So now the question: What you doing lugging it around at 2K???

 :hyst:

-JW

It's the pipes, they are a tad loud so I tend to keep it down a bit in places, but you are right, on the open road you can keep it up above the issue for sure. As said above, I do tend to ride around the issue and as long as it's not going to cause damage, I'll keep doing this until it comes in bits...
My Shovel must of been a good one as I could plod about on that all day with no vibes at all :)

Offline JW113

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Re: Anyone with S&S rocker box on a FXR?
« Reply #23 on: August 28, 2020, 07:48:11 PM »
My understanding of FXRs is: FXR = Freakin' Xtreme Rpms

The rubber mounted drive train accommodates reving the living Be-Jezus out of the motor, thus giving the perception they are more powerful than rigid mounted bike. The 80s/90s Softails, they were just not a whole lot of fun to hang on to North of 4500RPM. In fact, 3500 or less was more like it.

RE your Shovelhead, mine is also very sweet and smooth from idle up to about 320RPM. North of that, well...... I tend to keep it south of 3300 RPM. How about you?

-JW
2004 FLHRS   1977 FLH Shovelhead  1992 FLSTC
1945 Indian Chief   1978 XL Bobber

Offline 1340evo

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Re: Anyone with S&S rocker box on a FXR?
« Reply #24 on: August 29, 2020, 12:51:08 AM »
its a long time ago and ive had lots of beer since  :wink: so can't quite remember at the top end on the shovel... all i know is two up we toured UK and Ireland and it would sit on the motorway at 80mph no problem... cant remember it being anything like this?