What would be the Symptoms of over tight E-Shaft End flote?



Would it just distroy the Thrust bearings or would it give signs first such as Engine tightening up when warm etc?

basicly i'm having some problems with the Engine Tightening up, I remember it was as tight as it could be without going out side the Tollarances.



I have not tried to start it since but i towed it round the Block to get it started and the more Warm it got the Tighter the Engine became. Before i started i could easly turn the Engine over by Hand (with no plugs in) when it was warm i could'nt (even felt like the car was begining to Struggle Turning it as i let the Clutch up after it had been firing for a cupple of Minutes) It had been running the Day before but i was having problems making it Idle and managed to Flood it.



Now its Defo Tighter than it was but cold i can still turn it over by hand? But it has develped a Squeek from the Thrust bearing/Oil pump area (Behind the Front cover)



My first guees was i may have picked up the wrong Spacer when it was being Built up? or Maybe its so tight that i've fitted the Chamfered washer the wrong way up??



Does this sound the sort of thing it would do? and if so apart from the Thrust bearings,Washers and Spacer could it have damaged else where?



Its just like there is a lack of oil to the Thrust bearings and the Built up Vasaline was Lubing them until its got warm now there is Little Lube. It may be lack of Oil but i have Oil Presure and its being Pumped as there is Oilabout at places like the Filter and OMP.

These engines need to come apart again before any starting or running is done. The outcome of no end play is a failed needle race. Fractuered needles give off very fine pieces of Rockwell 70s bits that will go right through the bug screen on the oil pickup. Goodby oil pump. More runnung means loss of bearings and loss of control of end play, so the crank will begine to run on the ends of the stationary gears, and hose the rotors and gears.



During assembly, you clamp the mag base dial indicator to the front iron and build up the front stack. That is all of the stuff inside the front cover and outside the front cover that goes on the crank.



Torque up the front pully bolt. With the indicator on the front counterweight with the indicator shaft parallel with the crank centerline, and dial set at zero, lift the assembly gently with a lever under the pulley. Do not pry up under the counterweight. It is quite flexible and will instantly give a false indicator reading.



It should have between .0015" and .0025". It will run fine at .001" if you never ever scream the engine. It will run fine at .003" if you never ever use the engine hard. Looking for .002" to .0025" and you cannot hurt it, at least not the thrust bearings.



The thrust bearings need only an occasional drop of oil to survive. They get a stream of oil. Note the tiny hole in the crank just under the bearing set.



A very stiff clutch cover can lead to a short life of the rear most bearing. (All of the force on the clutch pedal appears on the rear bearing) Thus the larger bearings on later engines. Upgrade to the larger bearing if you need such a clutch. (you probably don't). Bearing life is shorter when shifting at very high revs.



Never pry on, or strike a flywheel to help remove the flywheel, nor on the front pulley to remove it. You are prying on the thrust bearings and plate. Discard any such parts if you even suspect that prying may have occured.





Lynn E. Hanover

Yup sounds like the wrong spacer. Check it before you crank it again or you are risking quite ba bit of extra work.

lynn's right, its gotta come apart again. btu you could loosen the front pulley bolt a little and see if it gets better or not

Lynn

I've seen a lot of motors as of late from the factory pushing the outer limits of end play. Most of them are in the 0.003 to 0.004 range. Most of the RX-8's and FD's are like that.

Double post:)

As soon as it happened i planned the Motor coming out again.



I'm hopeing the Bearing has'nt come apart (it still turns ok just squeeks and there is still some end play when its cold. (Did'nt check when it was warm becouse it was coming out anyway)



Cheers

"Do not pry up under the counterweight. It is quite flexible and will instantly give a false indicator reading. "



I think this may be where i went wrong, i did'nt swing off it but i noticed it would move some more if i applyed some presure, so i set it up with what i felt was enough presure on a Pry bar.



So in a Nut shell its too tight. So its better to have it more on the Slack side.



I will Pull the Motor then have another go.

There are some interesting points to think about here.



Plain bearings require a bit of running clearance for a full oil film to develope. So a rod bearing clearance might be .002" and a main bearing might be .003". Roller bearings can run with no clearance at all, and in most cases, with a preload. Tapered rollers require a preload to maintain locus. (like front wheel bearings)So oil requirements are minimal.



The amount of load that a roller can support is a function of its diameter. Note that the Mazda thrust bearing has very small rollers. Note also that in a radial application, a nontapered roller is always sliding one end or the other, because the outer end of the roller is traversing a larger diameter circle than the inner end. So, the outer end may be sliding a bit underspeed, or the inner end may be turning a bit faster than required.



So, it is not the ideal application for this bearing style, but if not preloaded, and is well oiled, it performs nicely.



If there were too little clearance, (so long as no preload exists) not much goes wrong, until the engine is screamed and the crank flexes a bit, and the bearings are run out of square on the thrust plate at very high pressure. Goodby bearings.



If there is too much clearance, not much goes wrong until you use the engine hard enough to cycle the rev limiter. You do run a rev limiter do you not? Anyway you can shake the engine hard and damage a bearing. More likely if you are running a crank trigger and two MSDs, one for the front housing and one for the rear. One trigger always cuts a few RPM before the other. Also, extra clearance allows a slightly higher load when the clutch is punched during a shift. Also very high spring pressures used in some clutch covers causes early failure of the rear thrust bearing. When you push in the clutch pedal, the throwout bearing pushes on the center of the clutch spring, and every ounce of that force appears in the rear thrust bearing.



The rotary has very poor low end torque. It also has poor high end torque. So why do you need a clutch cover with all of that spring pressure? For longer life from trans and rear end parts, a clutch that slips just a bit on upshifts is a good deal. It needs only enough pressure to hold on for your launch. That's all.



When racing with a dog ring box, road racing or drag racing with split dogs, you will be breaking things right and left, until you lighten up on the cover spring pressure. And then your rear thrust bearing will last a good long time.



Lynn E. Hanover

we scattered an engine with revlimiter(s). literally, peices came out. turns out with the stock gearing at thunderhill, theres about 50ish yards between top of 3rd and turn 1, and then its a lift, and get back on it, and then another 100+ yards to turn 3.



10-20 seconds @the 8500rpm limiter is bad

Well i pulled the Motor today, i have to say its not what i expected.



The washer that sits between the Two bearings has split into two pieces and the Thrust bearings have sort of jamed up on the damaged washer.



It was not what i was expecting? I have seen a Pic of it before when people have hit the Flywheel with a hammer to loosen it but i never did that?



I also checked all the parts closly when it was striped and cleaned and there was No cracks there then? this has happened within 15 minutes of Running an no more than 2000rpm.

It does sound as if the end-float was too tight to begin with and it roached the bearings. How tight was the front pulley torqued?



I've never had a problem with smacking a flywheel to remove it, but it never takes me more than one or two hits.

2 questions: how do you tell if the thrust bearings need replacing? what's the difference between regular and competition?

I didn't know there was a competition set.



Anyway, you can use the later (larger diameter) bearings by buying the latest stationary gear, or machining an older gear well just a bit wider.



The larger diameter moves the thrust load out a bit and closer to the bolt circle where the thrust plate is stiffer. The plate cones a bit when stiff clutch cover springs are used. The bigger bearings may be of a better design also, and or have more rollers. I cannot comment on that. I have never seen a set of them.



If the engine comes to you as new in a crate. The thrust bearings are probably fine. If it came from a junk yard. They need replaced. If you did not build this engine the last time it was out, they need replaced. In short, if you do not personally know the history of the engine, replace the whole shooting match.



The bearings and thrust plate are as hard as Chinese arithemtic. When the thrust plate cones a bit such as sitting on the flywheel in the junk yard, or from a miss adjusted clutch touching the driven plate, or sombody hitting the flywheel or automatic counterweight to get it off, or hitting the front pulley bolt to free it up, the plate cones a bit and the shock load appears only on the very ends of the rollers. They will not do that even once without some damage. The fragments that spall from the roller tips are microscopic, (means you cannot see them) and go right through the bug screen on the oil pickup tube and lodge in the oil pump elements. Some but not all, will end up in the oil filter. But there is no filter protecting the pump.



I keep the spacers, and a thrust plate now and then. The spacers seem to hold up to anything pretty well, and the thrust plates can be brazed to the bottom of oil cans to keep them upright.



Don't put an unknown thrust part on a nail or in a drawer. It will find its way into an engine some day and come back to bite you.



Lynn E. Hanover

as always, thanks for the response and advice, Lynn.



i got my new thrust bearings today and will assemble the front cover tonight. anyway, i just wanted to report to any interested parties that the bearing needles are notably longer in the competition bearings (by the way, they come from Mazda). i will try to remember to count the needles later and see if there is a difference in number, too.

Mazda Pn/ 0822-78-184, It has 42 needles.



Its an Ingersoll-Rand part, but those #s arent legible.