HEMI Tech: Harmonic Balancers and related

Great subject and just as important as the rest of the components!

1) Harmonic Balancers...
- When should they be replaced?
- What's available?
- What other makes will work and what modifications to make them work?
- What should be used for what application?
- Where can you get them?

(this thread was started previously by another HAMBer, Kerry, will link to it below)

 

Here's the link to Kerry's thread:
http://www.jalopyjournal.com/forum/showthread.php?t=120937

Excellent start and great info here!

 

Here's a link to a discussion about removing the stock H-balancer mounting flange:
http://www.jalopyjournal.com/forum/showthread.php?t=129835

 

Just want to bump this with some info I got from Bob Walker (Hot Hemi Heads) this morning.

Talking with Bob about my 331 application, I'll be running a 354 crank in this motor and the target HP is around 400 HP or so. For my application, he recommended that their 340 Harmonic Balancer would be sufficient for the application.

Now, question for you guys. Anyone running one of these or have one they can get some measurements off of for me? Just need diameter and over thickness (length on crank) of the unit.

BUMP

 

The harmonic balancer that Bob Walker told you would work has the same dimensions as the 331/354 one. If I remember correctly(which siometimes I don't) the 340 has to have a new key way cut into it or will be off on the timing mark do to the location of the pointers on the 331 and the 340.

 

It think the one's that Bob sells are already modified and indexed. For $158 it better be!

So you think they're the same size then? I'll measure my stock 331 when I get home.

Here's the link to HHH's 340 "stock replacement" unit:
http://www.hothemiheads.com/harmonic_balancers/harmonic_balancers_stock.html

At a glance, it does appear to be the same dimensions.

 

Scooter I have a pic of mine using HH dampner and single grove pulley you get the ideal of the depth from the block out. I can't get to my car right now to get actual demensions. I also had a pic with a three groove pullies but had to go with one groove to clear my fan motor.

 

A thread by HemiRambler I ran across regarding 340 balancers:
http://www.jalopyjournal.com/forum/showthread.php?t=219802

Wow, this catagory is still weak on info. Must be do for the bump anyway.

 

Scooter here's the near finished product on mine. 340 Balancer that I re-cut the keyway on. As you can see in the pic - I remade a timing pointer (it used to be centered on those two bolts) and it's also on TDC #1 right now - lined up @ "270".
I'm either gonna put a timing tape on it or just time the motor off a different cylinder - haven't decided yet.

FWIW - this balancer sticks out about 1/2" more than my 392 Fluidamper does. I wonder if Bob from Hot Heads shortens his or if maybe mine is goofy???

 

Thank you for sharing that! Great info!

What's the timing cover I see there??

 

Rather than cutting a new keyway in my 340 balancer, I just set the #1 cylinder on TDC (check it at least twice to be sure) and made a new line on the balancer for TDC with a hacksaw. A lot easier than cutting a new keyway. I was going to put a timing tape on after I did that, but I never got around to it.

It does require a "stepped" key since the keyway in the 340 balancer is smaller, but I just had a machinist friend mill a little off of both sides of the stock Hemi key to fit the 318 balancer. If you are planning on running a blower though, I'd step up and have new keyways cut in the balancer for a dual key.

The one from Hot Heads is great, but you can save a few bucks by buying a regular old 318/340 balancer and having a stepped key made.

 

MORE good info! Thanks Bass!

 

This brings up a question: (270 Dodge) does the crank end and the 340 balancer end-up being flush at the front? Right now, mine is stuck with the crank about 1/4" or so shy of flush.

I hate to put any more stress on the bolt threads, but I may be just wimping out.

 

I'm not sure I fully understand the question - so ignore me if I'm in left field.

Sounds to me liek you are 1/4" away from being fully installed - and you don't want to crank on the bolt too much.

If I got it - read on:

First off it's quite possible that you are galling things due to the press fit being too tight - better to be safe than sorry - remove and inspect before things go "bad" . When assembling be sure to put some high pressure lube on the mating/sliding surfaces - this should allow it to press right on without any trouble so long as it's sized right.

Also they make a harmonic balancer installation tool - it's nothing more than a piece of threaded rod (basically it's a stud that screws into the snout of your crank) you then slip your dampener in place - there's a little thrust bearing (looks very similat to an Early Ford Kingpin bearing) and then a washer - install the nut and crank away - since you aren't moving the stud AND it's fully installed in the crank the risk to hurting the crank threads is virtually nill. Besides the press fit shouldn't be anything more than a snug fit - I'D VENTURE a guess that it's somewhere between .0005" and .001" - basically a light press for that size shaft (I have the real number wrote down for mine somewhere - I can look them up if you'd like)

If you're cranking the hell out of this - STOP! something ain't right - take it apart and check things over. Don't forget the LUBE Molypaste or a Dry Film lube ought to work just fine.

 

That's an old Cragar two piece timing cover. They're very SLICK in the sense that you can change the cam without dropping the pan.

 

COOL! I like it! You should post a picture of it so we (or at least myself) can drool a little.

 

Thank you for the comments/instruction!

I'm going to take your advice (remove it and check). I didn't measure everything, so I'm operating in the blind. I tried to do it all with the regular bolt, and a longer bolt, but have ordered a real tool to use next weekend. I searched the local tool stores and none of them had an installer.

The farther I go, the closer the slinger gets to the aluminum timing cover, so I need to measure it all first.

I used some anti-sieze on the shaft, which may be just clogging up and making it tighter.

 

Scooter, Here's a couple shots of the timing cover in question (2 piece Cragar)

There was a time when you could get 392 timing covers cheap - I used to try and grab them when I could - the one on the floor is actually NOS. The other shot shows the "split" line better.

It's amazing how many companies sold covers for these motors. I'd still be collecting them if the prices hadn't gotten INSANE.

 

sniff..sniff, I want one

Tha cover is nice!!!

 

Ok boys just recived my SFI Race Powerbond balancer for my 330 desoto and all i have to say is wow really nice product correct keyway and indexed and for $222.31 +free shipping i guess you can't beat it . so here's some pics nice and compact too..

 

How about what would fit the 276 Desoto?

 

All of the EarlyHemi crank snout are the same diameter and extension so all can use the late balancer. As previously stated the keys are smaller in the late LA-B-RB units so either rebroach the hub or use a stepped key. The timing marks on the late part will be in 'left field' so set and remark the balancer ring or use timing tape and/or a new pointer.
Also, when properly installed, the crank will not be flush with the face of the hub. This allows for tensioning of the bolt and prevents any possibility of the hub not being 'clamped' against the gear.
We have used both cast and forged style balancers on early engines. A modified cast style has been useful for balancing certain 'heavy' assemblies.
If you are uncomfortable using/reusing core parts, companies like Pioneer make replacement units and are available at most parts houses.

Keep in mind that there are two sheave bolt patterns; use a round file to elongate the offending hole and make the fix.
.

 

so heres my 318 balancer i picked up for $30, is there anyhting i have to do to make it fit my 276 desoto besides makeing the keyway wider

 

Nope.
Rebroach the existing keyway, rebroach a new keyway or use a stepped key.
Bolt on and go.

Now, with all said, you may find alignment issues with the sheaves but they should be minor, and then the bolt hole alignment correction.

.

 

alignment issues with the sheaves? bolt hole alignment correction?

your talking about the pulleys correct.

i was wondering if the thin disk thats pressed on, looks like a dust/dirt requires an rework. thanks.

 

Sheaves = pulley in generic terms. They are different in your Funk & Wagnalls.
The tin on the back side holds the felt dust cover. Although some folks do not use it, I find it to be a 'no horsepower lost' way to keep road garbage off of the lip seal. The felt is still packaged in o'haul gasket sets.

.

 

very good, thank you very much kind sir.

 

So what are you guys doing for timing pointers? I'm using a stock 354 front cover... and, for now, a stock crank hub with balancer. I dont believe any of my engines came with a timing pointer (should really go back into my ddep storage and check!).

May need to fire this thing up in a month or two...

 

Locate TDC and put new marks on the dampener OD to match the tab on the front cover, or bolt on a new tab in a new location if needed and mark the OD accordingly.

.

 

Stepped key.