Main end bearing?

spetz · Post by **spetz** » Tue Mar 21, 2006 2:00 am

Reading the UK FTO site, it seems a lot of FTO owners are having main end bearing problems

is this a common problem of these engines?

And what is the cause? Running low on oil?

Post by **Bennoz** » Tue Mar 21, 2006 12:26 pm

I've been speaking to a few of them, most of the motors have had solid workouts (ie driven hard.) Hostile Performances went the other day. It does happen, can happen to any motor. Good maitenance will help you avoid it. Mind you, out of the 4000 odd cars they have over there - only 4 of them spun big ends....

spetz · Post by **spetz** » Tue Mar 21, 2006 12:53 pm

It seems a lot of FTO's are having that problem.

A friends Version R needs a new engine because of that

And I am getting a new engine rebuilt as the mechanic said the main end bearing is on it's way out.

Now, I don't understand why the engine needs a rebuild if the main end bearing is gone? To my knowledge it is the bearing that holds the crank in position? So why can't the sump etc be taken out from under the car and the bearing replaced?

Post by **Bennoz** » Tue Mar 21, 2006 1:21 pm

There are 4 main bearings that hold the crank in place in a FTO. Each on of them has a bearing (not a roller bearing, a finely toleranced bearing shell that isnt much more than a bit of lead lined brass)

On order to remove the crank all 4 of these main caps must be removed. BUT - not before everything else that the crank is attached to:
Clutch - gearbox must be removed first
Harmonic balance and - with all asscociated belts
Lower cross member must come out to get at the sump
All the pistons (big ends) rods that are attached to the crank (6)
etc etc etc the list is huge, I cant think of any more right now.
Crank is the heart of the motor, it cant really just be 'popped' out from under the car.

Once the damamged bearing is found - chances are it will have damaged the crank journal. The crank will need to be machined (again, extremely fine tolerances down to thousands of an inch) and a new bearing will need to be fitted. And seeing as bearing shells come in sets - its often wise to do the lot in one go, especially if any stray metal fragments have passed through the oil galleries onto other journals - conrods as well (big ends)

mrx · Post by **mrx** » Tue Mar 21, 2006 6:15 pm

Unconfirmed, but I think that this is what has happened to me - twice.

Does worry me to hear that it is happening to other cars on a growing basis.

Storm · Post by **Storm** » Tue Mar 21, 2006 10:38 pm

As stated above, only a small percentage of cars have shown this across here in the UK and these are ten and eleven year old cars. Even the Japanese cant make things completely bulletproof

Nacho · Post by **Nacho** » Wed Mar 22, 2006 12:18 am

So you saying it's better off to get a new engine all together?

Would this problem happen more under boosted conditions?

Storm · Post by **Storm** » Wed Mar 22, 2006 10:02 pm

Nacho wrote:So you saying it's better off to get a new engine all together?

Would this problem happen more under boosted conditions?

More boosted = more pressure on bearings etc so yes, you will be more likely to run into problems.

A new engine would be nice but I dont reckon theres that many around. Getting the bottom end rebuilt or engine reconned would certainly give you longevity if it was done properly.

Arashi

mrx · Post by **mrx** » Wed Mar 22, 2006 10:35 pm

Actualy, from what I understand it, revs cause more strain than boost, which makes sense on a bearing I suppose...

One possible drawback of our free-revving engines.