Packard Forum Index » Modification Discussion

I did some reading on lightening flywheels and am looking at taking some meat off of the one I am going to put behind my 327.

The engine will probably never be much more than stock but I would like to take advantage of some of the cheap modifications that can be done. I have a background in machine work and the task does not intimidate me, just want a bit more knowledge before I dive in.

Obviously a person can take too much off and make it dangerous but I want to know if there will be any issues with things like idling. The flywheel is a monster and it looks like there is a lot of room to put it on the slim down program.

Other mods I plan to do are really based on the thought that I have convinced myself that they will be part of the cheap mods if I do it myself. Often these DIY projects end up costing more than just buying performance parts, but finding them and paying for them is not easy. Also, I like to fabricate and the reason for making some of these parts is truly just for looks.

Nothing ground breaking, but it look forward to each. I have a set of rebuilt Strombergs for the intake. Headers will be a must with the manifold. I have a 288 head to swap out and have already put electronic ignition and a new coil in.

I will wait on the engine mods because I want to get the engine in the car so I can drive it and see how it runs before I screw it up fooling around. That would at least give me a base line to start at in it's stock configuration. If I do all of these mods and the engineer runs great on the stand it may be a dog actually making the car go.


Sorry to get long winded off of the flywheel question.

It's always a tradeoff. A lighter flywheel will accelerate more rapidly. However, as a percentage of the total rotating/reciprocating mass of a Packard Eight, it will be a slight improvement.

When lightening, take off as much as is safe from the outer edge and taper toward the center. The mass from the ring gear to where the pressure plate bolts is your target area.

jack vines

Thanks Jack.

Every little bit adds up, not that my engine will ever be a model of performance, but I look forward to the easy mods.

I will trim some off before I get it resurfaced.

Well I shaved off 2-1/2lbs pretty easily. I found out the flywheel is not very straight when I put an indicator on it, has a high spot on the back.

I also left some meat to back up the starter gear that I had not planned on leaving. The starter gear is pressed on(as you experts know) and I was afraid to take all of the metal off behind it so I left a bit of a lip to help retain it. I was worried that the starter may gradually push the gear off over time impacting it during starts.

I will have it ground and balanced this week and get it put in.

I also welded some metal back onto the ball for throwout arm and turned it back to a ball, that was worn pretty bad.

Does anyone have any specs on the springs that are used for the throwout bearing?

Attach file:

---

  (111.17 KB)

I dealt with this topic a lot when I use to build engines. A lighter flywheel will not always make a car accelerate faster. When you are sitting in neutral and revving up your engine to impress your buddies at a show, yes it will tach up faster but in actual driving conditions you might actually make your car go slower.

As with anything in making an engine faster it is a balancing act. Putting in a .750 lift cam will make you sound like a hero but with stock heads and an intake you wont be going anywhere fast. Same with a flywheel. In a heavy car, which all Packards are you need the weight of the flywheel to keep the inertia going between shifts, a light flywheel in a heavy car will result in a bog as you shift into each gear. On the flip side a heavy flywheel in a light car will result in smokey burnouts in each gear, cool yes but not helping performance.

The rule of thumb we used in selecting the proper flywheel was 1 pound of flywheel for every 100 pounds of car, so 4,000 pound car 40 pound flywheel and so on. If anything with a low/ slow revving Packard L8 and heavy Packard car combo I would lean towards a heavier flywheel.

If you are set on reducing your rotating assembly weight go with lighter pistons rods or even lightening your crank.

Make sure you get the flywheel rebalanced after all the machining. A very small runout in the machining can have a big impact on the overall balance. The hot rod machine shops can balance components for you.

Thanks '84 and Fred,

I appreciate the input about flywheel weight, I actually was wincing while I was reading it because I was hoping I did not do a terrible thing. It is not going in a 4000 pound Packard but a 2700 pound hot rod, if you could call it a hot rod. I am just doing the modifications that I run across.

I have the flywheel at the machine shop being resurfaced and balanced.

If it is going in a light hotrod type car you probably did not hurt anything. at 2700 pounds you would even be fine with an aluminum flywheel, you know because aluminum Packard flywheels are everywhere . I must have missed the part where you explained the car it was going in best of luck to you and hope everything goes smoothly.