bearings problem.

[RomanV]

Note that if you look on the table, block #2 + crank #1 = bearing #2!

Even though in the example below, they say that it should = bearing # 3.

It would appear that they perhaps revised the numbers in the table, without changing any of the surrounding writing.

[fivebob]

According to what's written in the manual (which is Gen II, but every other Toyota manual I've seen is the same) it should be "33344" the table makes no sense as it implies that for block 1,2 or 3 the bearing number remains the same. e.g. Block 1 + Crank 0 = 1, but so does Block 2 + Crank 0 and Block 3 + Crank 0. Coupled with the fact you have 5 marks available the table makes no sense, but the wording does.

What were the measurements of the crank & bearing shells, I've got the bearing specs and clearances so we can work backwards from there.

[RomanV]

I cant tell you that, as unfortunately I dont have a micrometer etc.

I took my engine to Lynn Rogers, and asked them to basically do any work/checking etc. that needed specialised tools etc.

When I asked about the mains bearings, they said that ordering from the numbers is the way to go, and you dont even need to measure them up.

So I can get this info, but not straight away unfortunately.
I'll have to find someone with a micrometer, or take it back to a workshop to be measured up I suppose.

Do you know where you got that picture from, with the numbers in it that dont make sense?

[vvega]

hmm in all honesty roman we would nee dto knwo what was teh bigger shell
it is posible that the 1 is a tigher fitting sheel thn athge 3's 4's your currently have

i cant see any block damage other than that you showed me and that was not significant

what concerns me is that with teh original bearing's in there
its still "pinching"

what we need are the written clearances for the mains
that will give us a idea if we are even on the right track

v

[RomanV]

This is the bearing sizes info out of the gen 3 manual.



EDIT: fixed now.

So the lower numbered bearings are smaller, which means more likely to fit my crank. Which fits in with the info in the 'suspect' table.... that's not to say that it is correct of course.

[fivebob]

You did read the crank numbers from the bottom up didn't you?

[RomanV]

This was one of my initial thoughts...

Apon checking the manual again, and then again just to be sure, I had them correct.

I swapped them over anyway, but it didnt improve the situation.

[fivebob]

Here's one for the 5VZ with the correct table, but I notice they read from the top down

[matt dunn]

Here's one for the 3MZ with the correct table, but I notice they read from the top down

Why is there only four makings shown when there are 5 bearings aren't there?

[fivebob]

The minimum clearance on all bearings except # 3 is 6 tenths. The difference between bearing the minimum size shell # 1 and a maximum size bearing shell #3 is only 4 tenths, so you should still have clearance, if only 2 tenths. Minimum clearance on #3 is 1 thou so you should have even more clearance there.

For those not familiar with the imperial system 1 tenth = 1 tenth of a thou = 1 ten thousandth of an inch.

Might be time to get the plastigauge out and see what the clearance is.

[fivebob]

Here's one for the 3MZ with the correct table, but I notice they read from the top down

Why is there only four makings shown when there are 5 bearings aren't there?

oops, read the document file name, not the title, it's a 5VZ, not 3MZ.

[RomanV]

Here's one for the 3MZ with the correct table, but I notice they read from the top down

Why is there only four makings shown when there are 5 bearings aren't there?

3MZ = V6 IIRC.


I plastigauged them last night, and the clearances were all about .1 of a mm. Which is larger than the allowed clearance. In saying this, it was about 1.30am at the time, after a long day of stressing over why everything is going pear shaped.

So the merits of my plastigauging is perhaps questionable.

But as Vvega said today, if the crank is 'pinching' on the sides of the bearings, then you'll still have clearance at the top where the plastigauge sits, as the crank isnt sitting all of the way down, it is resting on the sides.

I think I know 1 or 2 people that have an acutal gen 4 3sge manual, I will ask them to check the bearings table, and scan it if possible.

[matt dunn]

Maybe put it together minus one set of bearing shells each time to see if it's just one set that is stopping it from turning?

And i see now V6 = one less bearing journal.

And i also see the marking on the two diagrams are reversed from the number order on the crank.

Matt

[fivebob]

0.1mm is huge when talking about crank clearances, but if correct it points to a possible problem with the bearing caps. Have they been machined at any time?

You need to get an inside micrometer or possibly a bore gauge and check the the bearing tunnels are round, and that someone hasn't machined the block and not line bored it afterwards.

One other possibility is that you have the wrong caps on the bearings, I hope you marked them all before taking them apart.

[RomanV]

The big tolerance with the plastigauge sits well with vvegas theory...

Here is a hugely exaggerated pic of what I mean.



If the crank was resting on the sides of the bearings, because the bearings do not have a large enough inside diameter, there will still be clearance at the top where the plastigauge would be, even though it is tight.

[fivebob]

But that would only happen if there was something wrong with the bearing cap. There's not enough difference in the shell sizes to do that, certainly not between a #1 & #3 shell. Even the difference between a #5 & #1 shell (6 tenths) would only result in zero clearance on the sides, not an interference fit.

[RomanV]

Yeah, I see what you are saying.

Ive just been talking to Glenn AKA Mr. Celica RA45 on ICQ, and he just told me that:

well i got a block and we had to line bore that as it was out of wack

With reference to an Altezza block that he bought.

I wonder if there is a common problem with these late model blocks, or maybe just ones that have blown themselves up at some stage.

[fivebob]

Now that I think about it a side clearance issue could easily be related to a bearing or crank alignment problem.

Try putting plastigauge on both sides of the bearing as close to the part line as you can. If they don't read the same, then it's not likely to be a clearance issue.

[RomanV]

I think I know what you mean.

However, I think I will have to take it to a workshop or somewhere anyway. As I suppose this is all a bit silly, without getting the exact measurements etc. with a micrometer.

It could be something basic that has been overlooked, or...

I dont know.

I'll ring Lynn on tuesday, and then take it somewhere to be measured up after that, if he doesnt have any thoughts on the matter.
Lynn will no doubt be busy, and he's probably still sick of me pestering him from the last time he did some work for me.

[fivebob]

The difference between bearing the minimum size shell # 1 and a maximum size bearing shell #3 is only 4 tenths, so you should still have clearance, if only 2 tenths. Minimum clearance on #3 is 1 thou so you should have even more clearance there.

But that would only happen if there was something wrong with the bearing cap. There's not enough difference in the shell sizes to do that, certainly not between a #1 & #3 shell. Even the difference between a #5 & #1 shell (6 tenths) would only result in zero clearance on the sides, not an interference fit.

Doh, spot the mistake, the figures posted are bearing shell thickness not diameter, so differences need to be doubled.

Still not enough to cause the plastigauge readings you describe. At the most you would have 2 tenths interference fit, on average it would be zero, and minimum would be 2 tenths clearance.

Besides which I think it's academic as I believe you've got the correct shells.