If your memory is better than mine, you'll remember about this time last April I did a test fit of the 351 in the CVX 18.
At that time I found a bad engine coupler, which I replaced and some teeth on the flywheel that looked like they belonged to a NHL goalie.
I can't believe it took a year to address the flywheel issue but 'yall know how life and other projects happen.
So....back to the flywheel.
Recently I've been watching a craigslist ad for a flywheel off of a 351 Volvo Penta but hesitated to act because it was a mid '90's unit and my engine is mid '70's. What's the difference you ask? Ford small blocks are externally balanced and Ford changed the 302 engine's imbalance from 28 ounces to 50 ounces some time in the '80's. You can't use a 28oz. flywheel/damper on a 50oz. engine and vice versa. I wasn't sure exactly when this was done or if the 351 also was affected.
I didn't know the tooth count for the VP wheel but mine is 157 with a diameter of 12 1/4 in.
I reached out to Jason in search of some answers.
Thanks Jason, you're input is appreciated.
Searching through some of the Ford sites I found the very same question.
The answer is that 351's were unchanged through their production and retain a 28oz. imbalance.
In the meantime I saw new flywheels priced around $200 and up........mostly up.
With that in mind I searched for ring gears and found prices all the way up to an unbelievable $140, of course that was for an OEM Mercruiser unit.
On Saturday I stopped at the local NAPA store and found they had a ring gear that fit, it was at another store so it would be Tuesday before I could get it.......my price $23.53!
Arriving home after the trip to NAPA I broke out the hammer to remove the old ring gear. After making sure the lip / shoulder was facing up I proceeded with a few exploratory taps. Once I saw the paint separated from the gear I went into full
hammer on mode.
A couple good wacks an the ring gear gave way.
A little work with a Scotch Brite pad removed the small amount surface rust.
A good cleaning was all I could do until the new gear arrived on Tuesday.
What do you do with the old gear?
How 'bout an automotive Darwin Award for those who insist on engaging the starter while the motor is running.
Tuesday arrived and so did the ring gear. I picked it up after work and proceeded home for the install.
A quick recap of the specs
Ford 351w Flywheel
157 teeth
12.25in. outside dia.
Ring Gear
NAPA Part # BK6003030
157 teeth
12.025 inside dia.
So....how do you get a 12.025 inside dia. gear to fit on a bigger (12 1/4 in.) Flywheel?
BAKE IT !!
That's right...get out the Easy Bake Oven and scorch it!
Heating the gear expands it enough to easily slip over the flywheel. As it cools it contracts and becomes a tight fit.
Science lesson is over, now back to the practical.
After preheating the oven we'll bake the ring gear for 30 min. at 500 degrees.
Hint: Prior to baking clean the gear with brake clean, acetone,etc. to remove any residual oil from the
manufacturing process. You don't want the smell of burnt oil in your kitchen.
Hint #2: You may want to send your wife on an errand before you do this.
As added insurance I put the flywheel in the refrigerator before I left for work Tuesday morning. My thought was that the added cooling / contraction would insure a generous slip fit. In the end I don't think this was needed.
Here I'm removing the gear.....Remember not to use your fingers!
The gear falls loosely onto the 'wheel.
A few taps to make sure the gear is firmly seated against the lip.
I let it cool over night ....... And we're Done!
Before and After
