• Welcome to ClassicBroncos! - You are currently viewing the forums as a GUEST. To take advantage of all the site features, please take a moment to register. It's fast, simple and absolutely free. So please join our community today!
    If you have problems registering or can't log into your account, please contact Admin.

Engine Identification Help

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Ok so we know its a 302 Block

But the front balancer is a 50oz and recently when I replaced the clutch I found it had a 28oz flywheel. I installed a 50oz matching the balancer and that's what a 86 5.0 calls for.

The engine used a 86 Bell Housing and 11" clutch, both the flywheel that was on it and the one I put on were 164 tooth. It also accepted the 86 pilot bearing and it did have a one piece rear main.

This engine runs good before and after and doesnt leak so I don't want to tear it down just to find out the specs but I also want to make sure I don't knock a bearing out of the bottom end.

I've heard there is a tool to measure stroke length through the spark plug hole. However Google searches haven't turned up anything. I've also considered pulling a push rod and measuring it that way.

I see two or three paths forward.

1) Assume the engine was balanced properly by the PO have the original flywheel resurfaced and reinstall it.

2) Measure the stroke and make sure it is a standard 302 and assume i have fixed some mistake that could have been made during a motor swap.

3) Pull the Oil Pan and check see if there is a part number on the crank shaft.

Ideally would like to not involve an engine shop as for the cost of engine work I could drive this one till it goes then replace with another take out 302

Any advice?
 

B RON CO

Contributor
Bronco Guru
Joined
Jun 29, 2016
Messages
2,325
Hi, remove the starter and look for a casting #. Good luck
 

JSBX

Contributor
Sr. Member
Joined
Mar 10, 2010
Messages
578
As B RON Co said. There is a number on the block right above the starter area. I cleaned the area with degreaser and used my phone to take a picture of the numbers. You can use those numbers to find out what the engine came out of.
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
I guess what I'm asking is does anyone know what the tool is to measure crank stroke? I'm already pretty sure it is a post 82 block
 

Broncobowsher

Contributor
Total hack
Joined
Jun 4, 2002
Messages
33,361
Why measure the stroke? Do you expect anything beyond stock?

1-piece rear main seal = 1983 or newer.
50 oz-in was used before that, 1981 or 82 depending on the source. So the engine is a 50 oz-in engine.
Neither the flywheel nor bellhousing car what year the engine is. The balance in the flywheel will care, but will bolt to either balance crankshaft. The pilot bearing also has no date. From 1962 to 2001 there was no difference to where the pilot bearing goes into the crank, just different bores depending on what transmission is mated.
How do you know the old flywheel was 28 oz-in?
How do you measure crankshaft stroke by removing a camshaft pushrod? That would be a neat trick I would like to see.
 

jamesroney

Contributor
Sr. Member
Joined
Sep 11, 2007
Messages
817
Loc.
Fremont, CA
1. Pull the pan, measure the stroke with a ruler.
2. Look at the crank for a LOT of Mallory metal in the crank. If you can’t find a crap-ton of metal added to the counterweight...then something is wrong with your assumptions.
3. Look at the crank for a Ford stamped part number. That will tell you what the crankshaft was. Then go back to step 2.
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Why measure the stroke? Do you expect anything beyond stock?

How do you know the old flywheel was 28 oz-in?
How do you measure crankshaft stroke by removing a camshaft pushrod? That would be a neat trick I would like to see.

The Bronco was originally Marks Crawler "1WILD69" who at one time had a 347
https://classicbroncos.com/forums/showthread.php?p=1424119#post1424119\post7

When he sold it though he just said it was a 5.0 Mustang Engine
https://classicbroncos.com/forums/showthread.php?t=242609

I'm told a 347 uses a 28oz flywheel and I'm wondering if he possibly just reused that flywheel when he took out the 347 for the standard 5.0.
Which would mean I installed the correct 50oz flywheel when I changed the clutch, as that also matches the balancer.

Measuring the push rod would just be an indicator for if any work had been done to the engine, I should have clarified that sorry
 
Last edited:

Broncobowsher

Contributor
Total hack
Joined
Jun 4, 2002
Messages
33,361
347 is an aftermarket package that can be had in 3 different balances.
The 50 oz-in is popular with the mustang people as it reuses as much of the old parts as possible
The 28 oz-in is another option, common in older Fords since you can reuse the old parts as well.
And a 0-balance, or neutral balance also exists. All the balancing is done inside the engine so no external counterweights are needed. This is a more correct way to build an engine, but getting flywheels and dampers is more difficult as they are not your old leftover parts.

Weight can be added/removed to change the balance of the different parts. Just costs money to have a balance shop do it. Just because it is an old flywheel, doesn't mean it is still the original 28 oz-in balance.
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Again, I don't care what this engine is as long as its got the right flywheel and balancer. I've seen a few things out there about using a coat hanger down the sparkplug hole, marking it and measuring the distance between it to get a rough idea of the stroke. Can anyone comment who has done that?
 
Last edited:
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Here are my flywheel pictures:

If you compare the two mine has two large holes drilled into it in about the 5 o'clock position compared to the pattern of the other two. This would leave me to believe it could have been modified. Though the weight size it's self matches the 28oz size flywheel one.

screenshot_20201123-113216_gallery-jpg.331387


screenshot_20201121-091949_chrome-jpg.331388
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Called my local Machine Shop thats done some work for me in the past. Their suggestion was pretty simple. I'm going to bring them another off the shelf LUK 50z flywheel and they are going to spin it up along side the flywheel I took off to see if they have the same imbalance or not.

As long as they match I'm good and it would save me breaking down the drivetrain. If they do not match I'll have to decided where to go from there.
 

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,831
is the Harmonic balencer stock ford and does it have a 3 bolt pulley pattern or a 4 bolt pulley pattern?
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
is the Harmonic balencer stock ford and does it have a 3 bolt pulley pattern or a 4 bolt pulley pattern?


4 bolt and not stock ford but its shaped just just the stock ford 50oz. My thought is its probably just a Chinese tool copy
 
Last edited:

Rustytruck

Bronco Guru
Joined
Feb 24, 2002
Messages
10,831
well then it could be anything the manufacturer wanted. rules out stock ford 3 bolt being 28oz.
 
OP
OP
Desertfox1023

Desertfox1023

Newbie
Joined
Jun 15, 2020
Messages
23
Well lesson learned.

The machine shop checked out both flywheels and spun them on the balancer. They were within 3 grams of each other. He said the 28 OZ flywheel had a few extra balance holes in it and had been rebalanced to match the 50 OZ. At least I know I'm not going to toast my motor.
 

DirtDonk

Contributor
Bronco Guru
Joined
Nov 3, 2003
Messages
43,572
Glad it's sorted. Thanks for the update.
Sorry you went through all that though. If the engine had been running, you'd know instantly if either end was turning an improper part. A 28oz flywheel on a 50oz engine, or the other way around, is going to idle a bit rough and then shake the crap out of you at anything over 1000rpm, and then just gets worse from there.

Never experienced one with the wrong damper, but it would likely be a similar, if less severe experience.
If your engine shakes, everything is suspect.

Paul
 

sprdv1

Contributor
REBEL
Joined
Mar 8, 2007
Messages
79,661
Well lesson learned.

The machine shop checked out both flywheels and spun them on the balancer. They were within 3 grams of each other. He said the 28 OZ flywheel had a few extra balance holes in it and had been rebalanced to match the 50 OZ. At least I know I'm not going to toast my motor.

Always a plus not jacking it up ;)
 
Top