Burlington crankshaft and float-a-motor mounts

[Dennis]

I was reading Burlington's website about recommendations and noticed they recommend not using float a motor mounts. Anybody have experience with a Burlington and would like to comment? I realize this is a suggestion and not required. Also I notice the kit made to install a 32 and up trans requires float a motor mounts, so it looks like you don't have a choice in that circumstance.

For George Miller, I read your thread about the upper insert modification for the rear main. Good information to have. Also do you use plastigage on a new crank with inserts?

[George Miller]

Yes I use plastigage on all cranks I install. as far as the Burlington crank I installed a few in our club, and had one in my 1928 Sport Coupe, which i no longer own. They all worked well with no excessive vibration. But none had float a motor.

[wensum]

Despite dire warnings, I have a Burlington crank in my modified motor and also Float-a-Motor mounts to reduce vibration. I cannot see the relevance of relating the mounts to the crankshaft? With quite a few miles done with the Burlington crank, no problems so far.

[Greynomad]

40,000 miles and no problems with float-a-motor mounts and Burlington crank in my tourer and I put a lot of load on them because I tow a trailer weighing about a tonne (2,200 pounds). I can't see a link between the crank and mounts either. Even with the Burlington, the solid mounts were harsh and noisy. I'm about to try one of those New Zealand made dampers. maybe with that, I could go back to solid mounts.

[Dennis]

So what did Ford have in the B models for mounts that bolted to the flywheel housing? Were they float a motor style or solid mount like a Model A?

[Beauford]

I have a burlington but a early '28 frame so the motor mounts to front X member. I have a little vibration at stand still. I bet if I used the yoke it would be perfect but I'm not messing with it.

[Ed H]

From what I have read and my little brain has put together, I think I will stay with the yoke Henry used. I will replace the springs and any other parts to make it factory again. Mine does not have the FAM, so no loss there.

[George Miller]

good move.

[plyfor]

Are the stock/ original mounts different for an AA fly housing vs. the A one ? With an F150 tranny, the AA housing is most often used, and we found it's difficult to get orig. mounts installed even with an older well made frame spreader-- which needs to clear the larger tranny housing set up. .

[CarlG]

I have the F150 tranny. I also have the frame spreader sold by most of the vendors. It takes a little ingenuity but it will work.

[Tom Wesenberg]

Are the stock/ original mounts different for an AA fly housing vs. the A one ? With an F150 tranny, the AA housing is most often used, and we found it's difficult to get orig. mounts installed even with an older well made frame spreader-- which needs to clear the larger tranny housing set up. .

My 1931 Parts Price List shows AA-5089-B for the right side, and AA--5090-B for the left side of the AA truck. I don't see a different number for the rubber spacer pad, so I'd guess that's the same. The rubber pads I bought from Snyder's were a perfect fit, while some people have bought pads that were too thick from other places.

[Dennis]

Tom, do you know what this dimension is supposed to be? Thickness of the pad? I was going to order new pads from Brattons as I have a list going there for some other items.

[dmdeaton]

Getting a better understanding of this. But never thought about the integral support of the solid flywheel housing bolted between the frame. Where does the stress come from that cracks the flywheel housings? Is it from the drive shaft jamming into the trans, or from the frame torqueing the housing on the solid mounts?

[Dennis]

Good question I'd like to read comments on. My 29 had original mounts, no FAMs, and the flywheel housing had no cracks. Maybe it lived on better roads in it's past life...

[Tom Wesenberg]

Tom, do you know what this dimension is supposed to be? Thickness of the pad? I was going to order new pads from Brattons as I have a list going there for some other items.

I don't know the thickness dimension.

[Tom Wesenberg]

I don't see what adding a Burlington crank would have to do with the rear mounts. Besides taking much of the load off the babbit, the counterweighted crank should add to the smoothness of an engine, both by adding weight and by removing some of the offset weight trying to bend the crank.

[Dennis]

Well tomorrow I think i'll give them a call and ask why they recommend no float a motor mounts. And I'll post back what they tell me.

[Dennis]

Ok I called Burlington Crankshaft this morning and spoke with Al. His reason for recommending using original Model A mounts are the same as what Brent Terry have stated in this thread. Something else he mentioned I don't recall ever having read before is that he has had people tell him they think the engine sound louder with float a motor mounts. Eventually I am going to change my crankshaft to a counterbalanced crankshaft without the welded and or bolted on counter weights and I'll start a new thread why i'm not too fond of counter weighted crankshafts.

[Tom Wesenberg]

"Eventually I am going to change my crankshaft to a counterbalanced crankshaft without the welded and or bolted on counter weights and I'll start a new thread why i'm not too fond of counter weighted crankshafts."

Now you have me confused. Why would you not like a counterweighted crankshaft, but install it?

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Do I really exist, or am I just a figment of my imagination?

[Dennis]

Tom, Sorry to confuse. I would buy a crankshaft like a Burlington or Scat. Not a crankshaft that has counterweights welded on.

[tbirdtbird]

hmmm, there are a lot of cranks out there with weights welded on and they seem to do just fine....looking forward to hearing your explanation

[Tom Wesenberg]

I bought a set of counterweights that press on, but need to find someone that can turn the crank to press them on.

[tbirdtbird]

Tom, do they press on, or shrink on like the BB weights

[Tom Wesenberg]

Yes, these came from Ohio and are like the BB weights. The crank cheeks need to be turned slightly, then the weights shrunk on.

[Dennis]

I'd trust those to stay better than the ones that don't go all the way around the crank. Where do you get those? Snyder?

[Dennis]

More story I heard today. Apparently someone in the past installed a new Scat crank and broke the front end of the crank off. And as the story goes on he had it wound up pretty tight spinning the rear tires and smoking them and then the crank snapped. Sure can't blame the crank for breaking. I'd break too if someone wound me up tight.

[Tom Wesenberg]

I'd trust those to stay better than the ones that don't go all the way around the crank. Where do you get those? Snyder?

Dan Price in Ohio. Maybe I need to take my crank and weights to him for installation.

[Dennis]

That would be a good idea. He should know better than anybody. And have him balance it while he's at it.

Good (best) idea Tom. Also those weights are progressive and require different OD dimensions ground on the four crank cheeks. They are not the same or common.

[tbirdtbird]

I have assisted someone shrinking BB weights back on, plus there were alignment split pins to locate. A royal pain, and of course the pins had to be just right. It took more heat than I would have expected. If Dan can do them, I'd for sure let him have at it

[CM2]

Properly welded counterweights are effective,its been done for years.

I still have an issue with the flywheel housing transferring driving force leading to cracks..it doesn't add up fully to me.A large percentage of the driving force is transmitted through the rear spring,basically two forces are applied,rotational and longitudinal. the same forces are transmitted to the engine mounts as well,though the longitudinal is greatly diminished the rotational is increased due to leverage.With the rotational force on the mounts greater the FAMs are superior by design.

Besides failing from lack of lubrication the rear spring shackles are under alot of load,perhaps thats why they are a high usage part.

[Denis4x4]

My welded counterweight crank is 25 years old and no issues with FAM installation. Engine is inserted and has a 39# flywheel.

[wensum]

Properly welded counterweights are effective,its been done for years.

I still have an issue with the flywheel housing transferring driving force leading to cracks..it doesn't add up fully to me.A large percentage of the driving force is transmitted through the rear spring,basically two forces are applied,rotational and longitudinal. the same forces are transmitted to the engine mounts as well,though the longitudinal is greatly diminished the rotational is increased due to leverage.With the rotational force on the mounts greater the FAMs are superior by design.

Besides failing from lack of lubrication the rear spring shackles are under alot of load,perhaps thats why they are a high usage part.

I had a crank with welded counterweights in a modified motor and despite careful balancing after regrinding, it was found to be cracked 5000 miles later. it's hard to pinpoint the cause of the cracking, but the welding has to be considered as a contributory factor? Otherwise, it was an 86 year old crank reground to 30 thou undersize, not excessive I would have thought?

[Dennis]

Where did it crack?

[CM2]

Id venture to say we all have cracked ford steel,in one form or another..that being said,metal fatigue,and the catastrophic failure that can occur from it is real.Hotrodders live by the grace of god,the things they do to 90 year old steel is beyond foolhardy..That crank could have failed for a number of different reasons,Dennis asked the right question.

[Dennis]

And then there is the wishbone connected to the bellhousing underneath. A lot of things going on that depend on those rear engine mounts to hold things in place. No wonder my front mount was off center in the past. Float a motor are coming out and going back with original mounts.

[George Miller]

good idea ,that is why they were made like they were to control forward and reward move meant. they also control side move meant of the torque tube. They also control side move meant of the wishbone to the front axle. They are very important.

[dmdeaton]

I keep beating this horse and reading this thread over and over. I am mocking up my chassis now. Currently I have the 5 speed transmission in place with FAM's on the housing. No torque tube, open driveshaft. I am really leaning towards swapping back to the solid mounts. If anything my thoughts are maybe running the front FAM's with solid rear mounts. It looks to me like the front FAM's would cradle the engine front better than the original single bolt mount. I am really not worried about vibration as much as keeping the strength. I have a peppy motor going in this thing. Thoughts?

[DaWizard]

Ok, since I don't remember everything that was put on this thread, and really don't feel like rereading it all over, I am going to stick my foot in here.

One serious thing you need to remember is because of the transverse spring, the rear end does NOT push the car forward! That spring flexes and the torque tube shoves the forces forward to the back of the transmission and the bell housing and the flywheel housing causing the car to move forward.

Now what you want to do is take away that thrust by running an open drive line, which might work but it is going to react differently not just because you have the FaM, but also you have somewhat softened that forward thrust. IF I was going to run an open drive line I would change the rear spring from the transverse to a pair of parallel springs which will take the forward thrust and move it to the rear of the car instead of the motor mounts. By doing this you can then run any motor mount you want without the risk of harm. Personally I think that the FaM does a decent job of isolating most of the vibrations but it does change the geometry of the forward thrust to drive the car.

My 2¢

[plyfor]

To go back to my question re: the orig. A mounts with the AA housing. Here's our situation. New snug fit FAM donuts,balanced crank / motor, lightened flywheel, V8 clutch, stock front mount, perfect crank hole alignment, F150 set up with solid torque tube and good clearance to cross brake shaft. Tried installing good set of orig. style mounts with new rubber pads, etc. All holes lined up but couldn't get the mounts to fit at the AA housing with the rubber pads. So could the rubber pads be sanded down slightly (or how much rubber thickness is needed) to allow the mounts to slip in without spreading the frame ? Will tightening all framepad bolts with spacer's etc. draw the frame rails inward slightly? Looking at a factory film, it appears the engine slid in without much persuasion with spreaders, etc.
Side note, the new FAM donuts are quite stiff and are restrained by the metal (Not aluminum) disks. I can't measure or feel any forward or side thrust movement but don't dispute it can occur. Couldn't the side plate spacers move some also? We have some original frame plates where the holes have been elongated around the spacers.
We were shy about 1/16 to 3/32" to get the orig. mounts to fit.

[DaWizard]

From the video files I have seen where they install the engine, the installer had a persuader for mount fitment, a little spreading won't hurt. Once you have everything tightened up there shouldn't be much spread.

[Dennis]

Recently helped install a rebuilt engine and used a commercially made spreader from the vendors. IMO a spreader is a must with original mounts.

[plyfor]

Thanks, Tom for the parts numbers. The aa.org web site also has no info. to compare the A or AA mounts lengths. Our spreader (SEE PHOTO) is decades old from AC&R in N. Ca., and we've installed a few stock rear mounts with the stock A tranny and even with cars all assembled. It's almost impossible however to get it to fit without taking all the modified brake/clutch pedal assemblies and a host of other parts off, etc.and to clear the larger F150 tranny and AA housing to spread the frame. The offset dimension isn't large enough. It seems the new rubber pads and spacers perhaps could be trimmed a bit, or get a different spreader. When I get to the shop, I'll take some measurements and see what we're actually dealing with.
Dm, if you have the 5 speed , what fly housing do you have?

Probably should have started another thread but here are some photos and dimensions. One photo compares the rubber pads from vendors, the 20+ year old thicker one has" made in USA" on it. The other photo is the stock A mount.We confirmed with the AA club that the AA rear mounts are taller but the same width (frame to flyhousing) than A mounts.We measured our in-car frame to housing which is 5 11/16, leaving approx. 2/16" for a pad each side. If the pads are 7/32 (Snyders, Brattons), the frame spreader would be needed given unevenness in metal profiles, etc.

[plyfor]

Am revisiting installing the original motor mounts to replace FAM's with our F150 tranny set up an AA fly housing. Without some custom fabrication we just can't get the spreader to clear without dismantling a lot of stuff and perhaps removing the F150 tranny which is 2x the size of a stock box. We do remove one cowl body bolt.

As an aside, the tranny does sit on a thin pad on the cross member, and there is no fore/aft movement of the driveline with the new FAM vendor's donuts which are very firm.

If we sand the stock rubber pads (bushings also?) slightly to get the +1/32" per side needed, will the frame be drawn in enough on tightening up the stock mounts or stress the flywheel housing?
Posting the photos again for reference.