SB 302 Harmonic balancer B or C key

289 - 351 cid Small Block Performance
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Kingspeedy2
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SB 302 Harmonic balancer B or C key

Post by Kingspeedy2 »

whats the business with different types of Harmonic ballancers ?
Some are B key and some are C key all i could find is

"C" Key top dead center is at the 10 O'clock position.
"B" Key top dead center is at the 11 O'clock position.

what are they talking about? the key way of the crank is at either 10 degrees when the #1 piston throw is at TDC for a C key and at 11 degrees for a B key?
my SCAT crank looks like the key is at 11 oclock when the throw is at TDC of course the engine is new disassembled right now

does that mean on externally balanced Damper the weight is shifted in relationship to the key differently for the B and C key so you could end up with a real bad vibration issue ?

why do they have to screw around with this Stuff >LOL

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poboyjo65
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Re: SB 302 Harmonic balancer B or C key

Post by poboyjo65 »

My GUESS is where the timing pointers should be. different ford cars & trucks had the timing pointers at different positions on the balancers, 10 & 11 o clock are the pointers positions. which ever one you need for your car is what I presume they mean. aftermarket balancers have multiple sets of timing marks for any application. where are you reading this from?
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65clevorcyclone
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Re: SB 302 Harmonic balancer B or C key

Post by 65clevorcyclone »

From my experience, the keyway location is always at TDC, if it wasnt, how would you line up the timing chain to the cam and crank correctly. I would agree that the different location are for where the 0/TDC mark is on the balancer for different timing pointer locations. Remember, 221/260/289 had cast in pointers on the timing covers on drivers side, early 302 had a bolt on pointer on the drivers side, then the 5.0/302/351 had bolt on pointers on the passengers side.

Comechero65
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Re: SB 302 Harmonic balancer B or C key

Post by Comechero65 »

I agree that the the B and C keys must relate to the location of two of the three timing mark locations but not the actual keyway. AFAIK the keyway is always the same location on the crank no matter what SBF engine. Generally two unbalances of 28 oz and 50 oz but keyway still in same location.
Some aftermarket dampeners come with all 3 timing marks and some have removable weights for the correct unbalance.
Ron
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CALIFORNIA CALIENTE
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Re: SB 302 Harmonic balancer B or C key

Post by CALIFORNIA CALIENTE »

I have NEVER seen this! I have built many 289,302,347,352,351 and 418 inch SBFs,with stock cranks and aftermarket crankshafts,and with stock and aftermarket balancers!Some have been 28,50 or Neutral Balanced,keyway and key is always straight up pointed at camshaft O with cylinder #1 at TDC!!Built many 429 and 460 FORDS,same thing!! ROY.
Real Racecars have 3 pedals
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Kingspeedy2
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Re: SB 302 Harmonic balancer B or C key

Post by Kingspeedy2 »

The B and C key issue came up when looking for a timing pointer to purchase at Summit racing
Because my pride got in the way .i bought a bare, fully machined block .i have put many engines together but never a Ford .as i Enjoy engine work and putting it together myself so there is no one to blame . and there are few things i find more rewarding than listening to an engine you have built whether ts a Briggs and Stratton or a 20 cylinder diesel come to life for the first time..plus i am a Quality control inspector with a machinist background...so i am a bit .picky so my wife says..
anyway .i have been piecing the parts together and dont want to assemble the engine until my chassis is closer to being ready..its humid on the wetcoast and one day its sunmy and next its rainy i can better monitor corrosion when the parts are tucked in to my dresser drawers rather than a garage with fluxuating temperatures..
Next time i am putting in a SBC

Kingspeedy2
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Re: SB 302 Harmonic balancer B or C key

Post by Kingspeedy2 »

Your explanation makes sense about it being a timing pointer factor
I am using the Ford performance racing timing cover
And looks like its standard practice to grind off the cast in holder for the crankshaft position sensor and the timing pointer straddles that and utlizes 1 bolt hole either side of where the sensor onde was.
I better wait and see once the balancer is installed

Thanks all

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poboyjo65
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Re: SB 302 Harmonic balancer B or C key

Post by poboyjo65 »

PLEASE dont put a sbc in a ford or mercury!! just reading it is like fingernails on a chalkboard,sickening! & goes against the balance of nature! not to mention you car will be hated by both chevy & ford guys so its resale value goes thru the floor.

the timing pointer will need to be on the side opposite the waterpump inlet, so if you use a 10 or 11 o clock pointer you need a driver side inlet, or you wont be able to see it, if it will even mount up. of course you can always use timing tape & put a pointer where ever you want it, but tape seems kinda temporary . it's best to use the timing cover, water pump, balancer, & pointer from the same year engine, alternater & ps brackets & all pulleys from that same engine will save lots of headaches too.
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Comechero65
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Re: SB 302 Harmonic balancer B or C key

Post by Comechero65 »

It would appear you are the most familiar with gm engines then fords. So if you are going to build a ford engine then you should learn more about the intricacies of fords. There are many on this forum as well as other forums who are knowlegable on fords and quite capible of schooling you on the details needed.
Detail what engine and parts you have and someone can advise what is needed for a complete workable package. There have been different generations of ford engines, you just need to know how each one differs.
I agree putting a SBC in a fords not considered the ideal thing to do. Also doing so on some forums is not allowed discusuion will get you banned.
Ron
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65clevorcyclone
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Re: SB 302 Harmonic balancer B or C key

Post by 65clevorcyclone »

I saw a GM guy put a SBF together. He hammered the thrust bearing into the rear journal lol

Kingspeedy2
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Re: SB 302 Harmonic balancer B or C key

Post by Kingspeedy2 »

Okay Okay,LOL ,,don't worry I was joking about putting in a SBC, Especially since this car is a bucket list item for me and if its not going to be done right its not going to be done at all.It is however going to be restomod...I am a big CLASSIC 66 ERA BATMOBILE fan so my vision for this car will be what a retro Bruce Wayne would drive when out with the ladies and not driving the Batmobile...No turbine afterburner (sorry) but hopefully it will be classy .
The engine will be black witth red highlights
I have a black march performance serpentine drive KIT with black alternator, air conditioning compressor and ps pump on order so, it will utilize a CR water pump with drivers side outlet.
And yes I spend a lot of time in airports and away working so I have a shelf load of books to read up on the Fords..body work.welding.transmissions.fasteners ,wiring,metal fabrication ..Its like my Mistress,(dont tell my wife) as I dream about working on it and cant wait to get my hands on her when I come home after 2 weeks ...Actually I am a bit obsessed ...Thank you all for your help

redhotcomet
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Re: SB 302 Harmonic balancer B or C key

Post by redhotcomet »

That would make sense that it would refer to timing pointer position. I've often wondered about that, but I've never seen it discussed. I'll have to check my balancer now. I replaced it awhile back and when I compared the new to the old it looked like the old one had spun about 10 degrees. Maybe it didn't spin and they were made for different pointer locations. Interesting!
1964 Caliente hardtop, 302/T5/8.8"

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redhotcomet
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Re: SB 302 Harmonic balancer B or C key

Post by redhotcomet »

I went out and checked mine. Can't find my old balancer I must have junked it. Pulled my number one plug and put in my piston stop tool. Sure enough, timing pointer is off by about 20 degrees. The explains why it likes to idle and runs best at 0 degrees initial, and rattles if I give it more! Guess I need to pick up some timing tape!
1964 Caliente hardtop, 302/T5/8.8"

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redhotcomet
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Re: SB 302 Harmonic balancer B or C key

Post by redhotcomet »

Here is a diagram of timing pointer locations.

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I'm guessing I have a B timing pointer with a C balancer, which is I'm seeing a difference of 20+ degrees.
1964 Caliente hardtop, 302/T5/8.8"

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