Hamonic damper on '40 LaSalle engine?

[Andrew Pullin]

Hey folks. So, the machine shop is finally getting around to sending my assembly out for balancing. They said that I should include my harmonic damper/balancer/whatever other name you might know that part by. But did this engine even have one? It's the standard LaSalle 322 V8, although I've had it bored out to 346. I thought I remember there only being a rigidly attached front pulley, but I may have lost or never had said damper.

The other clue I have is that the Steele Rubber website only shows a rebuild part for the V16 engines.

So, is it just a rigidly attached pulley? If not, where might I be able to source parts / rebuilds /replacements for it?

[Brad Ipsen CLC #737]

You are right that the LaSalle did not have a "harmonic balancer" but it did have a solid hub on the front.  The Cadillac had one but it did not use rubber as on a modern car.  It uses a multilayer set of leaf springs.  The 38 to 40 V-16 did use rubber in the harmonic balancer.  If you are not going to go for the Cadillac balancer I would still send the LaSalle hub and pulley set with the crankshaft to the balance shop.  The other difference in terms of vibration control is the flywheel.  The LaSalle flywheel is a solid piece where as the Cadillac one has a flex plate that allows the crankshaft to flex a bit without trying to change the plane of the flywheel.  A spinning disc does not like the axis that it is spinning around moved.

[markl]

Brad,
I take it from your comments that you are basically recommending the use of the flexible (Cadillac) flywheel as well as the harmonic balancer.  I ran into the same issue as Andrew when working on my 37 LaSalle, and managed to locate a harmonic balancer (thank you Jim Beard) which I will use in the final engine assembly.  The flywheel for some reason seems to be a more rare part.  The existence of all the tank engines and spare parts for same is no help as these were all fitted to Hydramatics.  So I'd like to hear from anyone that has run the same engine w/ both the conventional rigid flywheel and the flexible flywheel.  Could you actually feel the difference?  Was the difference just in smoother running or did it just result in smoother clutch engagement?

Anyhow, Andrew; whichever way you go, you might want to look into the posts that deal w/ fitting a front seal to the timing chain case instead of just using the slinger set-up which came w/ the car.  That was certainly the case w/ my 37, and I think that comment applies to your 40 as well.  If you do intend to change over now, you will need to machine the back on the hub or the harmonic balancer, which ever the case may be, to a smaller diameter.  I was also warned to check the concentricity of the crank to the hole in the timing chain case which I believe also needs to be machined to a slightly larger diameter.  How exactly one would do this remains a bit of a mystery to me.  You will see in the posts on that topic, I suggested a low-tech method of inserting drill bit shanks as sort of a go no-go gauge.  Perhaps an inside spring Caliper could be used as well, but whatever the case, though a lipped seal has more tolerance than a bearing, I would imagine that it would still be important to get this w/in a few thou.

[buicksplus]

I have a 40 LaSalle and have driven it many thousands of miles.  It it completely stock with no harmonic damper or flex flywheel.  It runs very smoothly at all engine speeds, there is almost no vibration in this engine at all.  It is as smooth as my Buick straight 8 and much much smoother than my Chevy 216 six.

The harmonic damper is intended to damp out torsional vibrations in the crankshaft.  This issue is more important for longer engines (straight 8's or v16's especially) or for v-8's operating at relatively high RPM.  I don't think these torsional vibes are much of a problem for the stiff and fairly short cranks in the flatheads.  I imagine if it were a problem, Cadiallic would have built these engines with dampers, the technology was known then.

Installing a harmonic balancer is not a good idea.   If you could find one that fits the crank, front seal  and lines up with the pulleys (unlikely) a balancer is tuned for a particular engine and may cause more problems than it solves if installed on your engine.

Good luck!

[markl]

Bill,
I am heartened to hear that your LaSalle is as smooth as the Buick straight 8.  That was my recollection from when mine was last running, alas, 38 years ago.  I note that you said "...if it were a problem, Cadillac would have built them w/ dampers....".  Well the fact is, they did in the 346 version of the flathead.  The harmonic balancer that I purchased from Jim Beard's parts pile was no doubt intended for a 346 and was used in a Cadillac.  Since most folks that undertake a full blown rebuild of a 322 elect to bore it out to Cadillac Standard (3 1/2"), what I am now dealing w/ and I believe Andrew as well (correct?) is an engine that is essentially the the Cadillac 346.

So, I think there is no downside to adding the harmonic balancer that came on the engine in the larger displacement version.  The sheaves end up  the same distance from the front cover and will align w/ the generator and water pump, and I only suggest the front seal as it seem to be an improvement over the slinger arrangement that was used at least on the 37.

Finally, I was reminded by a CLC administrator to post my name and CLC# which I routinely do.  Sorry as I was writing my previous post at about 6 AM before my first cup of coffee kicked in!

Mark Lowery, CLC#25216

[J. Gomez]

So, is it just a rigidly attached pulley? If not, where might I be able to source parts / rebuilds /replacements for it?

Andrew,

Check with these folks, they may be able to get yours re-done or provide general info;

http://www.dalemfg.com/daley_001.htm
http://www.damperdoctor.com/

Good luck..!

[Andrew Pullin]

Hrm, well, at least I know I can go ahead with the engine work. I've never run this engine (it was a pile of junk when I bought it!), or any other Caddy flatheat, so I don't know what the harshness & vibration will be like. As other folks say, it seems somewhat doubtful that I'll be able to find a Cadillac damper or flywheel, so I guess my options are limited.

I've thought about adapting something cheap from Jegs, but, well, I'll see how "bad" it is first, then revisit that idea.

[The Tassie Devil(le)]

G'day Andrew,

If it doesn't need one, then there is no reason for installing one, unless you have drastically altered the internals which could start the onset of dangerous harmonics within the reciprocating mass.

I remember hearing the story of why Harmonic Balancers were fitted to the 427 FE Big Block Ford engine.   When the first engine testing was performed, there was just an flange on the engine to hold the pulley/s, and after spinning the engine at 7,000 Rpm for 7 hours straight, the crankshafts broke.   Installing a Harmonic Balancer stopped crankshafts breaking.

The 283 SBC has a hub, but the other Chev V8 engines use Harmonic Balancers of differing sizes.

Harmonics are cyclic vibrations that can, and will destroy anything unless controlled by an equal and opposite reaction.

With my Dragster engines, both BBF and BBC's, I ran a hub in place of the Harmonic Balancer as the engines were never running at any sustained revolutions that could induce harmonics.  Idle to 7,500 or 8,000 RPM for 9 seconds, and back to idle then turn off, harmonics didn't have a chance to start.

Bruce.

[buicksplus]

Friends:

I did not know that the 346 flathead had a harmonic damper.  FYI, my own 40 LaSalle is bored to 346.  I suppose if I had a damper off a 346, I would consider using it, it is probably compatible.