What is thickness of a new 2.4 flywheel?

[caproader]

Guys,

My spec book says to go no thinner than 8.5mm on a 2.4 liter fly wheel. But it does not say how thick a new one is.

Therefore, when I measure my fly wheel, I have no clue as to what percentage has been used and therefore I have no idea if I am below 50% wear or above 75% or what. I would like to know if I can use what I got or do I need to throw this one away.

Can anybody help me with the new thickness of a 2.4 liter flywheel?

John
73 S with sporto and 2.7 MFI

[edmayo]

John, if no else pops up, I'll look it up tomorrow when I go to the shop.

[caproader]

Ed,

Thanks for looking out for me. I figure that if I measure my spare flywheel around the outer rim, I should get a close to new figure for original thickness.

But here is the larger problem I am addressing:

About half way through One Lap, just after Sebring, we started to get an engine vibration that got progressively worse as the week went on. Now that we are home, I am still trying to dial out the engine vibration. The engine has 9000 miles since a rebuild to 2.7 using EBS parts (including an lightened Al flywheel). A compression check was normal, an air flow check of the 6 stacks showed the same air flow through each stack, timing was normal. I changed the 2 transmission mountings. All six plugs look normal.

However, when I removed the MFI air filter cover, I notice a collection of aluminum shavings mixed with oil on top of the engine between the oil thermostat and the breather cover on top of the engine.

So now I am wondering if the aluminum shavings are coming from the flywheel eating itself up and spitting the shavings out through the hole at the engine transmission mating surface. If so, my plan is to take the engine down, inspect the light weight flywheel, and replace it with a steel OEM flywheel if necessary. Which is the round about way to getting to why I asked how to tell if my spare steel flywheel is still usable.

But the real question is: Why is the engine vibrating and what do the aluminium shavings tell me?

Thanks for any thoughts.

John

[edmayo]

John I wouldn't run that engine any more, I'll bet your flywheel has come loose and the shavings are from it wearing against the case.

[caproader]

Ed.

I was sort of thinking the same thing. Some times I hate it when people dis agree with me and some times I hate it even more when they agree with me.

Looks like I have to take everything out and apart. As George Patton once said: "I don't like to to have to take the same ground twice".

But all ranting aside, thanks for your advice. Pretty soon I will have to build a separate garage just to hold all the rounds of sarsparilla waitng for you here in Cincinnati.

John

[edmayo]

Well sorry to say I can find no spec for thickness of a new flywheel. My best guess would be that it may only be 1 or maybe 1.5mm thicker. Can't imagine that they would give you much more than that. As to the aluminum flywheel you may find that it is breaking up around the bolt holes, I think they copied the steel wheel without taking into account that it would need to be thicker for
the aluminum. I prefer to use steel wheels and just use the lighter aluminum pressure plates for weight reduction.

[caproader]

Ed,

Thanks. Autopsy on Saturday when my son and I take out the engine.

John

[caproader]

Here's the update:

After only 8000 miles a rivet separated on the outer circumference of the Sachs pressure plate, allowing the steel strap (now attached at only one end) to trash the aluminum flywheel and machine an 8 mm by 8 mm grove in the inner wall of the transmission bell housing.

John

[edmayo]

Wow, sorry to hear that John, that may only be slightly better than the flywheel breaking or coming loose. I've only seen a couple instances of those straps breaking, both times they were related to too harsh of a down shift, ie. not matching engine revs to transmission speed. Might be more problematic when using the lighter flywheel which will allow engine revs to drop quicker when downshifting if one isn't accustomed to double clutching.

[caproader]

Ed,

Here is a picture of the pressure plate that my son took. I agree with your thoughts on double clutching. Considering the 2nd gear synchro problem in 915 transmissions, it never hurts to always downshift.

So I am going to try and get the bell housing welded up, re-use an old pressure plate from a long ago parted out car (unless that might not be a good idea) and reassemble with a new clutch disk.

http://smg.photobucket.com/albums/v3...ndTarga007.jpg

Thanks again for your thoughts and advice.

John