MOTOR SWAP
Thread Starter
|
New User
Joined: Jun 2015
Posts: 23
Likes: 0
From: Hillsboro
Roger Carter, everything I have looked up for the flywheel it says I need a 157T manual flywheel for a 289. Do you know if my regular clutch and pressure plate will work with that? Or should I just purchase a new clutch and pressure plate? I also found and bought a 157T Bellhousing Separator Plate. I might be saying this part wrong, the shaft that comes out of the transmission would it be the same or do you think I would need to change that? I'm having a hard time finding anything about that on the internet. I appreciate all your help.
Laughing Gas
Joined: Sep 2003
Posts: 968
Likes: 5
From: Corbett, Oregon
I doubt that any of the information you found dealt with installing a 289 in an old truck and keeping the original 3 speed transmission.
When you start mixing and matching pieces on a small block clutch / bell housing assembly you run the risk of ending up with a non functioning system. It is real easy to buy what you think you need and when everything is put together you find nothing works. Expensive too.
Your best bet is to locate a flywheel that has the same diameter and tooth count as the one off your original 6, only with the balance for a 289. Try to locate one from a '68 to '80 truck that had a factory installed 302 or engine. Then you can use all the remaining pieces from your original installation.
Stay away from a 5.0 that is 1981 or newer. Ford changed the balance specs and those flywheels wont work.
The 157 tooth flywheel was typically used in the smaller cars, Mustang, Falcon, etc. because of the smaller transmission tunnel in these cars. I doubt the clutch/pressure plate from your truck would fit. The trucks usually used an 11" or a 12" diameter clutch. The 157 tooth flywheel is too small to accept the larger clutch. It typically would have a 10" or 10.4" diameter unit.
The clutch and pressure plate you need will be determined by which flywheel you end up with
As I said earlier, there is a strong possibility there is a difference in the input shaft lengths between cars and trucks. Using all car components may cause additional problems if there is an input shaft difference. There might be a different input shaft that would interchange, but I don't know.
I try to keep things simple and have found simple is usually the least expensive, in the long run. Don't try to make it more complicated than it needs to be.
The simplest approach for you is to find a flywheel that is the same physical size as the one in your truck but balanced for a 289 /302. That allows you to use all of your original parts and not to worry about their fitment.
If you have trouble locating the proper flywheel, a well equipped auto machine shop should have the capabilities of rebalancing your 6 cylinder flywheel to match 289 balance specifications.
When you start mixing and matching pieces on a small block clutch / bell housing assembly you run the risk of ending up with a non functioning system. It is real easy to buy what you think you need and when everything is put together you find nothing works. Expensive too.
Your best bet is to locate a flywheel that has the same diameter and tooth count as the one off your original 6, only with the balance for a 289. Try to locate one from a '68 to '80 truck that had a factory installed 302 or engine. Then you can use all the remaining pieces from your original installation.
Stay away from a 5.0 that is 1981 or newer. Ford changed the balance specs and those flywheels wont work.
The 157 tooth flywheel was typically used in the smaller cars, Mustang, Falcon, etc. because of the smaller transmission tunnel in these cars. I doubt the clutch/pressure plate from your truck would fit. The trucks usually used an 11" or a 12" diameter clutch. The 157 tooth flywheel is too small to accept the larger clutch. It typically would have a 10" or 10.4" diameter unit.
The clutch and pressure plate you need will be determined by which flywheel you end up with
As I said earlier, there is a strong possibility there is a difference in the input shaft lengths between cars and trucks. Using all car components may cause additional problems if there is an input shaft difference. There might be a different input shaft that would interchange, but I don't know.
I try to keep things simple and have found simple is usually the least expensive, in the long run. Don't try to make it more complicated than it needs to be.
The simplest approach for you is to find a flywheel that is the same physical size as the one in your truck but balanced for a 289 /302. That allows you to use all of your original parts and not to worry about their fitment.
If you have trouble locating the proper flywheel, a well equipped auto machine shop should have the capabilities of rebalancing your 6 cylinder flywheel to match 289 balance specifications.
Logistics Pro
Joined: May 2015
Posts: 4,469
Likes: 965
From: Tri Cities, TN
Flywheel unbalance
Don't know exactly why they changed the unbalance other than differences in firing order and piston and rod weights. But pre 1981, 289's an 302's were 28.2 oz. inches of unbalance and 1981 and later were 50 oz.- in. of unbalance.
Laughing Gas
Joined: Sep 2003
Posts: 968
Likes: 5
From: Corbett, Oregon
The change of imbalance. from 28.2 oz" to 50 oz" was a move to make for a lighter crankshaft, which can help fuel economy. Pretty sure it took place during the 1981 model year.
A small weight farther (edge of flywheel) from the center of a spinning object (crank) can have the same overall effect as a heavier weight closed to the center. This can reduce the overall weight of the object.
Ford reduced the size of the counterweights on the '81 and newer 5.0 crankshafts and added more weight to the flywheel/flexplates to compensate.
Small block Fords are typically externally balanced, that is they require weight added outside the engine, to the flywheel and harmonic dampner, to keep the rotating assembly balanced.
The 240/300" six cylinder engines are internally balanced. They do not require the additional weights added outside the engine to be balanced.
If you bolted the six cylinder flywheel to a 289 (and it will bolt on) you might not notice anything at idle, or low speeds, but at higher engine speeds the engine would feel like it was trying to shake itself apart. Think of a tire that is out of balance. You typically don't notice a problem driving around town, but you sure do at freeway speeds.
A small weight farther (edge of flywheel) from the center of a spinning object (crank) can have the same overall effect as a heavier weight closed to the center. This can reduce the overall weight of the object.
Ford reduced the size of the counterweights on the '81 and newer 5.0 crankshafts and added more weight to the flywheel/flexplates to compensate.
Small block Fords are typically externally balanced, that is they require weight added outside the engine, to the flywheel and harmonic dampner, to keep the rotating assembly balanced.
The 240/300" six cylinder engines are internally balanced. They do not require the additional weights added outside the engine to be balanced.
If you bolted the six cylinder flywheel to a 289 (and it will bolt on) you might not notice anything at idle, or low speeds, but at higher engine speeds the engine would feel like it was trying to shake itself apart. Think of a tire that is out of balance. You typically don't notice a problem driving around town, but you sure do at freeway speeds.
Thread
Thread Starter
Forum
Replies
Last Post
Apollo2112
1973 - 1979 F-100 & Larger F-Series Trucks
3
Jul 27, 2009 12:14 PM
