ANOTHER 302 engine harmonic balancer question

[C_Man69EB]

Friends, I searched high and low, and can't quite reach the confidence I need to avoid asking the question here, in these terms.

I have a 71 Stroppe with a rebuilt 302. I did not build or purchase the motor, it came with the project, but its clearly professionally rebuilt or reman, new, never fired. Block is a D4DE-6015-BA casting, So a 74 casting era 302. It has a flat tappet cam. All internal components appear stock, but I have not disassembled the long block. I see no indication that its internally balanced, so my expectation is a pre-1981, 28 oz imbalance application on a stock motor.

The harmonic balancer that came with the truck needs to be replaced due to age. (but I cannot confirm its original or correct model for the engine) shows a part number D2TE-6316 C1A or Dorman 594-271. This crosses for a 68-69 Bronco, among other applications. It fits a 3 bolt pulley, which my truck had on it when i got it.

This balancer was on the truck motor with the pulley setup and drive accessories installed in a stock manner. However, like I said, I don't believe its the OEM balancer.. so I am looking for peace of mind that its acceptable to install on the motor.

As a non-critical side note, my truck did NOT have power steering originally, but a 1976 based system was installed when I got it. (and will continue to run it) So its assumed the crank pull at least is not original to the truck.

SO...

Question # 1: From the info I have stated, and the photos, do you agree this motor is "likely" an OEM build externally balanced motor requiring a 28 oz imbalance balancer and flexplate?

Question # 2: Is a factory 71 balancer a 3 or 4 hole? All the online sources indicate a 4 hole balancer and pulley. (curious, but may not change it, since it works)

Bottom line, if the 3 hole balancer is acceptable to the engine, I wont change a thing, because the configuration "works" on the accessory drive.

Thank you so much for your help.


Cullen

 

[Jdgephar]

Crank, balancer, and flex plate must match for balancing. I can see the weight on the flex plate, so it's externally balanced. Most likely 28oz.

3 or 4 bolt doesn't matter, as long as it matches the 28 oz balance. There are different thicknesses though, so try to find something that matches the old balancer thickness so your pulleys line up. There are spacers you can get if it's too "skinny".

 

[Jdgephar]

I bought one that can use 3 or 4 bolt pulleys
https://www.amazon.com/Assault-Racing-Products-8030228-Harmonic/dp/B072R7NX5X/ref=sr_1_11?keywords=ford+302+harmonic+balancer&qid=1553708101&s=gateway&sr=8-11

 

[Timmy390]

http://www.damperdudes.net/
Get the old one rebuilt

Tim

 

[Timmy390]

As to the balance......What letter and or number is stamped on the fist counter weight of the crank? M2 ?

What's the part number off the flexplate?

Tim

 

[DirtDonk]

As to your questions regarding the images specifically:

1. Image 1 the hole does NOT indicate an internal or external balance just by itself. All crankshafts might have some material removed (or a plug added) to aid in balancing no matter what type.

2 & 3. The right side (passenger) alternator bracket and tensioner arm are correct for this vintage as long as it did not have a Thermactor (air/smog) pump. Yours is period correct for just the alternator.
The left side power steering bracket is fine as long as it works and you want to keep it. Not sure how it interfaces with the original timing pointer for setting your ignition though. And that's one of the things with the dampers themselves. Where are the timing marks supposed to be? Ford had different versions.

Your water pump is Bronco correct as well. Passenger side inlet.
And in a perfect world your water pump pulley would be dual-sheeve (groove) as well. The power steering belt would run across the three pulleys as well.
If the current setup works fine, you can keep it. But it would be more proper to have the dual groove water pump pulley too.

Can you take a pic of your timing pointer? I can't see it in the images, but on a normal '71 it would be bolted to the timing cover at about the 2 o'clock position.
The problem with a lot of replacement dampers in years past was that the aftermarket never seemed to grasp that Ford used different timing locations on different engines. So you might order a damper for a Bronco and get one from a Mustang instead because they were all 28oz back then and in some cases the same size and offset. But the timing marks were on the wrong side!
Made for some very strange tune-up calamities.

They're better now, and some dampers even come with multiple timing mark locations to fit with multiple pointer locations.
I thought that the originals were 3-bolt, but maybe someone else can confirm that. It's been a long time since I paid attention to that and many new dampers come with multiple patterns to work with the different applications and years of pulleys.

Paul

 

[C_Man69EB]

http://www.damperdudes.net/
Get the old one rebuilt

Tim

Hey Tim, I am aware that some people rebuild them.. a brand new oem balancer like the one I have (which according to what everyone on this post is saying, I expect to work, but Im going to confirm timing location) is about 70 bucks... I would fine it hard to believe I could ship it, rebuild it and then have it shipped back more economically and or faster...especially when the one I have is probably not original to the truck.

But... its a GREAT suggestion and must be considered. Thank you for thinking of it.

 

[C_Man69EB]

As to the balance......What letter and or number is stamped on the fist counter weight of the crank? M2 ?

What's the part number off the flexplate?

Tim

Darn it, I put the motor back together, and the transmission back in...without confirming these things. current pic attached. UGH. If I can reach a comfort without digging this back up, I plan to leave it all together. I think I'm getting comfortable with leaving it there, and going back like it was when i got it (but it hasn't ran since I got it either, so, I could be in for a suprise if Im wrong...)

 

[C_Man69EB]

Crank, balancer, and flex plate must match for balancing. I can see the weight on the flex plate, so it's externally balanced. Most likely 28oz.

3 or 4 bolt doesn't matter, as long as it matches the 28 oz balance. There are different thicknesses though, so try to find something that matches the old balancer thickness so your pulleys line up. There are spacers you can get if it's too "skinny".

Excellent... this is what i was hoping to hear for my "comfort".

 

[Timmy390]

Better yet, 1 or 2 piece rear main? 99.999% of all 2 piece are 28oz. 81-82 was the changeover to both 1 piece and 50oz so there are a few oddballs out there with 2 and 50oz so I've read....

Tim

 

[Timmy390]

Hey Tim, I am aware that some people rebuild them.. a brand new oem balancer like the one I have (which according to what everyone on this post is saying, I expect to work, but Im going to confirm timing location) is about 70 bucks... I would fine it hard to believe I could ship it, rebuild it and then have it shipped back more economically and or faster...especially when the one I have is probably not original to the truck.

But... its a GREAT suggestion and must be considered. Thank you for thinking of it.

I've got to send them one and it's not cheap anymore. They used to do them much cheaper. The one I need is for my 390FE and it's $139 plus $50 core.....FE must stand for Fricken Expensive......LOL

Tim

 

[C_Man69EB]

As to your questions regarding the images specifically:

1. Image 1 the hole does NOT indicate an internal or external balance just by itself. All crankshafts might have some material removed (or a plug added) to aid in balancing no matter what type.

$$$ Thank you Paul, I was hoping you would chime in, 95% of the real challenge questions on this forum have your wisdom contributing. I darn near emailed you directly... LOL. Ok... crankshaft construction methodology confirmed.

2 & 3. The right side (passenger) alternator bracket and tensioner arm are correct for this vintage as long as it did not have a Thermactor (air/smog) pump. Yours is period correct for just the alternator.
The left side power steering bracket is fine as long as it works and you want to keep it. Not sure how it interfaces with the original timing pointer for setting your ignition though. And that's one of the things with the dampers themselves. Where are the timing marks supposed to be? Ford had different versions.

$$$ the timing pointer is/was indeed at the 2 oclock position. I am at work but I dug into my archives and found the pic below showing the timing pointer installed before I took it apart.

Your water pump is Bronco correct as well. Passenger side inlet.
And in a perfect world your water pump pulley would be dual-sheeve (groove) as well. The power steering belt would run across the three pulleys as well.
If the current setup works fine, you can keep it. But it would be more proper to have the dual groove water pump pulley too.

$$$ this is a very good point. I nearly asked the group for someone to show me a complete survivor/correct or original accessory drive setup with power steering, just so I could check. I cannot confirm it "works" because I did not buy the truck running. I think I will look for the double groove pulley for the added stability on the power steering drive.

Can you take a pic of your timing pointer? I can't see it in the images, but on a normal '71 it would be bolted to the timing cover at about the 2 o'clock position.
The problem with a lot of replacement dampers in years past was that the aftermarket never seemed to grasp that Ford used different timing locations on different engines. So you might order a damper for a Bronco and get one from a Mustang instead because they were all 28oz back then and in some cases the same size and offset. But the timing marks were on the wrong side!
Made for some very strange tune-up calamities.

$$$ I bet so!!! I have a hard enough time getting them tuned in when everything is where its supposed to be!

They're better now, and some dampers even come with multiple timing mark locations to fit with multiple pointer locations.
I thought that the originals were 3-bolt, but maybe someone else can confirm that. It's been a long time since I paid attention to that and many new dampers come with multiple patterns to work with the different applications and years of pulleys.

$$$ Thank you. You have answered my questions.

My next steps, Im going to source a 3 groove pulley, mock up the entire setup, and then pull the trigger on the balancer which will give me a chance to keep the setup I have or change balancers and crank pulleys and offsets. I'd prefer not to mess with too much spacers if I can avoid it. Im trying to do a "restoration" on this since its a baja, with only a few minor period mods like tires, small lift, WH urethane bushings, carb, headers but make it look pretty close to OE.

 

[DirtDonk]

Cool, thanks.
Standard pointer for your year. While the engine is in it's state you can verify TDC of compression on #1 cylinder and make sure the marks on your new damper match up.
You can rotate the engine by hand (when you get the damper, or at least the bolt back together) and watch the valves open and close. Watch for the marks to come up when both valves are fully closed and there's your TDC.
Then you can make sure the marks on your new damper line up, or move the pointer to match.

Or better still, apply some "timing tape" to the ring of the damper and never worry about accurate timing again. If you've seen it you'll now what I mean. Good stuff.

Without the damper in place, I can't remember if the crankshaft's keyway is at 12 o'clock or not. But someone will know and if so you can use that as your initial guide just to make sure it's on the compression stroke. But you'll need the damper to do the final lining up of marks.

Have fun!

Paul

 

[Skytrooper15]

Check this one out,second one from the top
https://www.partsgeek.com/ss/?i=1&ssq=crankshaft+harmonic+balancer+for+1972+ford+bronco&x=16&y=7

 

[Broncobowsher]

Everything you have pointed out tells me this is a regular 28 oz-in engine. Order up that damper and call it good.

Now for finding one with the right timing marks...

 

[C_Man69EB]

Cool, thanks.
Standard pointer for your year. While the engine is in it's state you can verify TDC of compression on #1 cylinder and make sure the marks on your new damper match up.
You can rotate the engine by hand (when you get the damper, or at least the bolt back together) and watch the valves open and close. Watch for the marks to come up when both valves are fully closed and there's your TDC.
Then you can make sure the marks on your new damper line up, or move the pointer to match.

Or better still, apply some "timing tape" to the ring of the damper and never worry about accurate timing again. If you've seen it you'll now what I mean. Good stuff.

Without the damper in place, I can't remember if the crankshaft's keyway is at 12 o'clock or not. But someone will know and if so you can use that as your initial guide just to make sure it's on the compression stroke. But you'll need the damper to do the final lining up of marks.

Have fun!

Paul

All understood, thanks Paul

 

[C_Man69EB]

Check this one out,second one from the top
https://www.partsgeek.com/ss/?i=1&ssq=crankshaft+harmonic+balancer+for+1972+ford+bronco&x=16&y=7

this one? yes, this looks like what everyone tells me the factory correct balancer should be. Which is partially why I started the thread, I wanted to reconcile this balancer vs the one that was installed when I got the truck.

I partially think that the thinner balancer was used because it worked with the double groove crank pulley so they could add the power steering pump, and keep the pulley offset in tight...who knows.

 

[jamesroney]

this one? yes, this looks like what everyone tells me the factory correct balancer should be. Which is partially why I started the thread, I wanted to reconcile this balancer vs the one that was installed when I got the truck.

I partially think that the thinner balancer was used because it worked with the double groove crank pulley so they could add the power steering pump, and keep the pulley offset in tight...who knows.

I don't know who "everyone" is, so I'll chime in. Dorman 594-023 is a 4 bolt, 28.2 in-Oz damper, and it is not correct for ANY Early Bronco. There is a ton of confusion about the 4 bolt damper, because it became standard equipment on all 1970-74 passenger cars and light trucks with the Driver's side inlet water pump. The U-series Bronco, (and the E series Econoline BTW) did NOT convert to the Driver's side inlet, and retained the 3 bolt damper thru 1977.

The 3 bolt damper from 1963-66, (hubless) and the 67-77 (with hub) share the same 3-bolt flange location. The thick vs. thin did not change the pulley location. It just changes the mass of the harmonic ring.

Additionally, you have the wrong water pump pulley. You know it's wrong, because when you order a power steering belt for a 74-77 Bronco, it won't fit. This is one area that is remarkably accurate in the parts books, and in the Ford MPC.

 

[C_Man69EB]

I don't know who "everyone" is, so I'll chime in. Dorman 594-023 is a 4 bolt, 28.2 in-Oz damper, and it is not correct for ANY Early Bronco. There is a ton of confusion about the 4 bolt damper, because it became standard equipment on all 1970-74 passenger cars and light trucks with the Driver's side inlet water pump. The U-series Bronco, (and the E series Econoline BTW) did NOT convert to the Driver's side inlet, and retained the 3 bolt damper thru 1977.

The 3 bolt damper from 1963-66, (hubless) and the 67-77 (with hub) share the same 3-bolt flange location. The thick vs. thin did not change the pulley location. It just changes the mass of the harmonic ring.

Additionally, you have the wrong water pump pulley. You know it's wrong, because when you order a power steering belt for a 74-77 Bronco, it won't fit. This is one area that is remarkably accurate in the parts books, and in the Ford MPC.

Thanks James, I learned several things here.

for a couple notes, when I said "everyone" I mean that autozone, oreillys, pepboys, and rockauto (not bronco vendors but mainstream parts retail) show that damper to fit a 71 bronco as the correct oem application. It was also suggested above by another member. What I'm hearing you say is that this is incorrect? I can't disagree, I dont really know one way or another.

Water pump pulley, yes, I agree its wrong for a 74-77 with power steering. My truck did not have power steering so I assumed it was right for that application...but yets, adding power steering makes it incorrect. I have already sourced and bought a double groove pulley for a factory PS EB in the last couple hours from BroncoNut.

Thanks for clearing up thickness questions, I didnt know that.

 

[matts460]

I just had to replace my balancer when I rebuilt my motor on my 77 bronco it had factory 3 bolt pulley 28oz balance 2m crank. I got the right one from Wild Horses $130 bucks, very nice, bolted straight on, had proper 3 bolt holes and proper timing marks for timing cover mounted timing pointer.