Topic: Inertia Ring

[az_zoner]

I just finished this up a few days ago, an inertia ring for my flywheel. It came out at about 9.1 lbs. The thickness of the outer plate is a little thinner than the ones you can buy but I have it so a portion of it sits down inside the cast area on the back. This makes it so you don't have to grind on the engine block to get it to not rub. I also ran the clearance holes on the plate pretty tight to the bolt diameter and one it was installed it was a super tight fit. Probably overkill but I didn't want to worry about the balancing.

I originally heard about this on Pirate 4X4 but all the info that I have found seems to be several years old. Sometimes up to ten years old. I don't know if anyone ever had anything bad to say about them but it made sense so sense I have a new motor going into my jeep I thought I'd give it a try. 

I'm starting to assembly my engine this weekend and hope to get it in the jeep next weekend. I'll update with details in a few weeks.

Craig

[Jeffy]

So you have someone make it or did you make it?  I like how it requires no grinding.  I learned about the Inertia Ring from 4WD & SU Magazine when they did a feature on Jason Bunch's Rockstar YJ.  I actually tracked down the supplier for Tri-County Gear but they wouldn't sell directly.  I gave all the info to Paul Nasvik who bought one soon after.  I believe that's the one you probably read about.  It's an old review on 4x4wire.com.

[az_zoner]

I'm a mech enginer and I designed it. I work at a shop that has cnc and manual, mills and lathes. I hit up a few of the more experienced guys to machine it for me. Cost me two sets of movie tickets! In a few weeks once I have it in and running and feel comfortable with how it is performing I'll pass on drawings and/or solid models if anyone wants to machine one for themselfs. The only issue I would think is that I used a NAPA auto parts flywheel to pull dimensions off of so other brands may have a different casting for the ribs on the inside.

Craig

[sharpxmen]

very nicely made

unfortunately will take away some of your HP but will make it run smoother at low rpm and keep it from cutting out

Since you have access to all that equipment would be a good idea to balance the whole assembly (or at least check it, it's probably ok but you never know, it's a big chunk of steel).

[jfrabat]

I actually tracked down the supplier for Tri-County Gear but they wouldn't sell directly.  

I bought one from them directly a few (5?) years ago...

[Jeffy]

I bought one from them directly a few (5?) years ago...

Directly from Tri-County Gear or their supplier?

[jfrabat]

Directly from Tri-County Gear or their supplier?

TGC directly...  I remember I even talked to them on the phone.

[aw12345]

They have them in stock at their sales counter, atleast the last time I was there

[Jeffy]

TGC directly...  I remember I even talked to them on the phone.

They are only the reseller not the maker.  As far as I know TCG is the only one to sell them since they had it specially made for Rockstar.

[Wheezer]

I am very interested in this. My '95 YJ just turned 200K so I think a new engine is in my not too distant future. I figured, like many of you, that since a new engine is going in I should look into this. My biggest concern is building momentum when driving down hill. Out here in California we have some pretty big hills and I fear it will "run away" descending these long hills. One of the roads we use often to get into the Sequoia National Forest is called 9 Mile Canyon Road, it descends nearly 6000ft in those nine miles with some pretty hairy corners thrown in for a thrill. I use engine braking as much as possible to preserve the brakes would an inertia ring cause the engine to not brake as well? I would definitely be interested in reading all that I can before I throw in with this mod. Az_zoner, that is the sweetest ring I've seen, and I've been looking at these for awhile. If you decide to go into production please let us know. I used to ride Observed Trials motorcycles and we all weighted our flywheels with tremendous results, but I rode in Florida, no great long hills there. Thanks for the input and advice.

Wheezer

[sharpxmen]

I use engine braking as much as possible to preserve the brakes would an inertia ring cause the engine to not brake as well?

i doubt you'll notice any difference in that, if it was 100lb in weight maybe

[az_zoner]

I'm running a little behind in my rebuild but hope to fire it up this weekend. And then a test run the following weekend. I do have a few pics on how well it clears the engine block and will post them up later.




Craig

[az_zoner]

Here are a few pics prior to putting the engine back in. One of the things I didn't like about the ring you could buy is that they recommended that you grind away areas on the engine block so it wouldn't rub. I made this one so there was plenty of clearance.

So I'm getting close. I tried to fire it up tonight and I don't have spark, so I got a few more bugs to work out before I can give a performance review. 


Craig

[az_zoner]

I finally got my engine running the way it is suppose to. I took the first test drive and my first impressions are that it has no notable problem with acceleration. But this is a newly rebuilt engine with the 4.0 throttle body mod vs my old engine with 165k miles. To hard to tell. I can definitely feel a bit of roll on, less engine braking. But not a big deal to me. But the feel of torque is the most noticeable. I put the front wheels against the curb and in 2 wheel drive I was able let the clutch out without giving it any gas. Just 800 rpm idle.  So my hope is that when 4 wheeling I will be using/feathering the clutch less.

So overall I'm liking it! I have clean up work under the hood to do and an airaid system to put on this weekend but will hit some easier trails next weekend. I'll report back on how it performs off road.

Craig

[RNandKT]

Did you run a stock clutch? I have heard many others on pirate who did this and said the stock clutch wasn't up to the task of the heavier flywheel. Any issues with yours?