Technical End float / End play on 479CC Rebuild?

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Technical End float / End play on 479CC Rebuild?

ChiapC

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Hey all.... I'm working on re-assembling my 500N engine. I've got the crank in with new bearings and everything fits nice and tight. Except the end float / end play. I'm used to VW's where there are shims. I don't believe those exist here. I've put the crank in, timing chain cover on, with the appropriate pulley's on. The issue is if the crank is pushed towards the back of the engine (front of the car) the pulley comes into contact with the timing cover. There is a spacer that goes on the front of the crank, which is in place. It pushed it out a bit, but it still comes into contact with the timing chain cover.

If I pull the crank/pulley towards the rear of the car, it moves enough to where it clears the timing cover and will rotate freely. I don't want to put it all together as is knowing if the crank slides to the back, my timing cover will be shattered.

Any thoughts/suggestions?
Thank you!
 
Despite what is printed in the 'Factory' w/shop manual, end-float (measured at the timing-gear end) should be about 3th. The pulley pulls up against the sealing washer (the one with the expanding ring) and the shaped washer (which goes on with the female shamfer on the crank 'hole' TOWARDS the crank) that goes between the sealing washer and the shoulder on the crank. There are no spacers or end-float shims on the 110/126 engines, just the inner surface of the timing-chain end bearing (which is 'end-float-shim' shaped). I hope this helps you---if you get really stuck, feel free to contact me direct on [email protected]
 
I appreciate it! I may pull it apart (again) and properly lay it out, photograph it and be in touch with you Tom! I’ll post it all here, as it seems this may be a regular question, in case it helps anybody else out! Thank you!
 
Sorry, forgot to mention, are you aware that the 'sealing washer' (the one with the expanding ring) goes on with the FLAT side towards the pulley and the SHAPED side towards the crank. (a) there is a very slight shoulder on the shaped side and, (b) if you put it in the wrong way you run the risk of very little (or even none!) oil pressure. The torque for the crank-nut is 149 NEWTON-METERS.
 
I believe I have that right already. I’ll have to double check. I’ve been away from the engine for a few weeks waiting on parts!
 
I appreciate it! I may pull it apart (again) and properly lay it out, photograph it and be in touch with you Tom! I’ll post it all here, as it seems this may be a regular question, in case it helps anybody else out! Thank you!

Hi ChiapC, please see the attached pic. To be clear, assemble everything on the crankshaft as per a manual and torque the hollow bolt to the recommended level. Then measure between the FRONT of the rear bearing (at the timing case end) (ignor the part about the flywheel end) and the crankshaft face adjacent to it. For what it's worth my engine man says the lower limit is right and the upper limit excessive !!!! If you need anymore information Tom @ the hobbler is where the pic came from - he is a guru !!
:worship::worship::worship::worship:
Ian.
 

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For reference, here is my current setup, or at least what I’m asking Tom about!
 

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Morning Chase. I have received your e-mail and later today I will send you a picture of the relevent diagram for the 479cc engine from the 'Factory' work-shop manual. Comparing the diagramin in the manual, with the pictures that you have sent me, you would seem to have too many washers! The diagram shows just the 2 washers to the left of the sprocket, then the sprocket, then the pulley, then the tab-washer and finally the large nut. As I am sure that you are aware, the sprocket goes on with the timing markrowards the rear of the engine (so that you can see it when you time the camshaft). The trick when checking the end-float is to build it all up, without the timing case, and with the nut done up fairly tight, but not neccesarily torqued. As you mentioned in your e-mail, the washers are fitted with their 'down' faces (in the picture) TOWARDS the crankshaft.
 
In your pictures, it is the washer between the 'sealing' washer and the sprocket that I can't find a home for. And apologies, I forgot to mention the 'oil-dispersal' washer that goes between the pulley and the tab-washer. At the risk of asking a (OK I admit it) very silly question---have you got the bearings in the correct ends. The bearing with the 2 'chain-grooves' goes on the timing-chain end of the engine (the rear).
 
Well... in an effort to problem solve.... I pulled of the new crank bearing and associated pieces and bolted in the original bearing. Wouldn't you know... the end play drastically reduced. At least cut in half. There is very minor play now. Maybe 30 thou. That's without bolting on the pulley. So I think that was the issue. That I was using a 499cc front bearing that was sold as to work with my engine, but apparently it's all different.


I wish Peter (BigVTwin996) would have told me there are so many differences between these engines! :) (He probably said that in every other e-mail between us!)


So the height of the old parts would also allow clearance for my pulley to clear the timing cover as well. So multiple problems fixed with the original parts. I think they're all good enough to reuse..... Though I will at least give it a little effort to find the original stuff. Though I'm not crossing my fingers!!
 
...........................
I wish Peter (BigVTwin996) would have told me there are so many differences between these engines! :) (He probably said that in every other e-mail between us!) ........................../QUOTE]

Have I ever mentioned that N's may look like later 500s but very little is actually the same..... they are almost Prototypi's for later cars....

Ohh and never throw original parts away....
 
Here’s the setup that looks like it will work, which is the original setup for reference. I’ll try to get better pictures of individual pieces....

Don’t mind the mess of grey permatex, as I had to clean the timing cover surface again!
 

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Just to show how different a 'N' is from later models, I was looking at your latest picture Chase and thinking "there is something wrong here". The reason? On all the later models, looking at the rear crankbearing 'in-situ' the retaining bolts at "4-o-clock" and "2-o-clock" are countersunk, with 2 grooves on the bearing housing for the chain. I checked an engine in the workshop and then double-checked my w/shop manual (500N and 500D), The 500N rear bearing is held in place by 6 hex-head screws, NOT as per later models, 4 x hex-head screws and 2 countersunk screws (originally 'Philips' type, now cap-head) and does NOT have 'chain-grooves'. Just goes to show---always double-check!
 
On all the later models, looking at the rear crankbearing 'in-situ' the retaining bolts at "4-o-clock" and "2-o-clock" are countersunk, with 2 grooves on the bearing housing for the chain. !

Wouldn't that be the front, crankshaft bearing?

I think that the fact that the end-float issue has been sorted by using the original main bearing shells shows that it's likely that end-float was always intended to be adjusted by the thickness of one or both of the flange-faces of the white-metal of the bearings. I suggest that these might originally have been cast slightly oversize and then after measuring the tolerance they would be machined down to give the correct clearance. Alternatively, as with pistons and cylinders, after manufacture they might have been batched to give the engine assemblers a range of sizes so they could choose one appropriate to each engine.

There's not much point in specifying or measuring a clearance unless there is some way to remedy an incorrect tolerance. Ultimately, the best answer to this query would be for an explanation of how this is actually done. :confused::confused::confused:
 
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No Peter, it IS the rear crankshaft bearing---the one at the timing-chain end of the engine. I have carefully read through the relevent section in my 500/500D w/shop manual and it gives no advice/instruction of how to adjust/rectify end-float of the crankshaft. In fact the drawing in the w/shop manual (the 'factory' version) shows the correct way to ascertain the bearing to crankshaft shoulder clearance at the timing-chain end of the crankshaft, but DESCRIBES it to be done at the flywheel end! I have on occasion had to 'flat-down' (very carefully on an absolutely flat surface with well lubricated 1200 wet 'n dry) the 'thrust bearing' end of the rear bearing to give clearance---I had one new bearing give only 2 thou clearance---I normally aim for 5-10thou end float.
I agree completely with your thought that at the factory, bearings with differing 'thrust bearing thickness' might have been available to obtain the optimum clearance. Nowdays though, you have to take what you get and hope that you obtain a sensible end-float clearance.
 
A lesson I keep reminding myself about " always compare and measure what you are putting in with what you have taken out"


It appears this also applies to minor things like brake shoes as I am currently facing...…..


I have also started to take pic's of the strip downs as I do them. As my aging brain and infrequent time to spend on these project these days proves the pic's are great reference.
 
Nowdays though, you have to take what you get and hope that you obtain a sensible end-float clearance.

...some people might do that and I'm sure that the amount of or lack of end-float will make no difference in most cases. But nowadays, I like to attempt to get things within specification as far as is possible. The only practical solution if the end-float was too great would be to try another bearing or bearing pair until it was right...it could get very expensive.:eek::D

No Peter, it IS the rear crankshaft bearing---the one at the timing-chain end of the engine.

...I disagree. The manual that this seems to come from makes the mistake of showing the timing-chain end bearing as being where the float is measured whilst describing it being done at the flywheel end....:eek:...quite a significant error isn't it?

We have become familiar with calling the cylinder at the rear of the car "No. 1" and on engines in general, the timing chain/belt end is usually the front of the engine. All of the specialist suppliers refer to the bearing with the slot to clear the chain as being the "front bearing".

You can call it what you wish but if we are trying to advise each other it probably helps to conform with the common nomenclature on such basic details as this.:confused:
 
Fair comment Peter---having checked on the web-site of a couple of the main suppliers, I have to agree with your observation as to which bearing is described as 'front' and which is described as 'rear'. I will be honest and say that it is a detail I had never really looked at---I will amend my descriptions accordingly.
 
Interesting conversations here! In my very lay person’s opinion, the front is the timing chain end.

For the record, my replacement front bearing did come with the grooves cut out for the timing chain and the recessed screw cavities. I had to specially order the screws after the fact, as my original bearing had the original FIAT bolts still.

Turns out, I won’t be using MOST of the parts associated that I purchased. Possibly including a timing chain, which may be another issue in itself. I also had to order a new cam sprocket, as mine was pretty worn, per my engine builder friend. I found an original new one, so I’ve got that going for me.

I bought my parts through FD Ricambi, who was adamant that there have never been any issues fitting these parts to a 479 engine. Now I need to send proof back. They are substantially different. See the attached pics!
 

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