*BREAKING* James Judd's Forged 1.9 Mk3 Ibiza HTA GT2868R Build *BREAKING*

[grahams81]

Right James, just had a look at the haynes manual and the standard 81mm pistons are actually 80.965mm so i wouldn't worry about your pistons.

The standard sizes i've got for the Main Journals are -
53.978 to 53.958mm
And the Big Ends Journals -
47.778 to 47.758mm
Endfloat on Crankshaft -
New Thrust Bearings 0.07 to 0.23mm wear limit 0.30mm

Bearing Running clearances -
Main Bearings 0.01mm - 0.04mm Wear limit 0.15mm
Big End Bearings 0.01mm - 0.05mm Wear limit 0.12mm

I hope this helps mate, ps let me know if you need to know the under / over sizes for the journals.
Cheers, Graham.

 

[James.Judd.1]

Thanks a lot Graham give me something to do this morning. I did check the thrust before I took it apart and it was 0.8mm which again I was happy with. I will be replacing all the bearings and seals anyway as it seems a little silly not to after going through all this hassle.

 

[James.Judd.1]

Love your attention to detail on all this work, nice one mate.

Just been catching up on this thread and read all your bad luck over the past few weeks - good to see it hasn't stopped you though. Onwards and upwards

These things never go as smoothly as you want but it's all part of the experience and at least now you know exactly what you're dealing with.

Interested to see how you find those cams too as I was always curious to try these. Keep it up

Thanks Robbie.

Yeah It has been a bit of a fiasco to say the least!
I enjoy every minute of it so its taking the sting away, and as you say atleast now I know exactly where I stand.

I was one of your old threads that got me looking for a set of the cams, It will be hard to tell if they make a difference as I will have no comparison with this build.. but atleast we will know if they work or not.
I am in the process of making a vernier cam pulley to dial in or out some timing if needed.

 

[James.Judd.1]

The cranks been ground, could you give me the undersized dimensions please Graham

 

[grahams81]

No problems mate here you go -

Mains 1st undersize 53.728 to 53.708
Mains 2nd undersize 53.478 to 53.458
Mains 3rd undersize 53.228 to 53.208

Big end 1st undersize 47.528 to 47.508
Big end 2nd undersize 47.278 to 47.258
Big end 3rd undersize 47.028 to 47.008

Cheers, graham.

 

[James.Judd.1]

I am getting a constant 53.72mm from 3 different axis and at 3 different positions of the main journals.
And a constant 47.53mm at the big end journals.

I assume its been done recently as there is zero signs of wear

 

[James.Judd.1]

Both had a 1st undersize then by the looks of this

 

[grahams81]

Dunno if your replacing bearings mate but be quite accurate with you measurments and order the correct size ones. I would check clearances with plastigauge to be sure on final assembly, to tight and you'll burn them out or they'll pick up, too slack and you'll have poor oil pressure and it'll knock.

Measure 100 times and order once..... Think thats the internet shoppers guide.

 

[James.Judd.1]

Yes I will be replacing all the bearings.
I agree, I will defiantly be using plastiguage on final assembly.
The crank was given the once over with a vernier caliper accurate to 0.03mm and I was getting very similar results (e.g. 53.71-73)
The final measurements were taken with a micrometer after making sure to remove any oil traces.

Measure 100 times and order once..... Think thats the internet shoppers guide.

I dont know about 100 times lol but I will be going over it a few more times.

Thanks for your help buddy.

 

[James.Judd.1]

After sticking the pistons in the airing cupboard for an hour to take the chill off I remeasured them all at 82.42mm in the center of the skirt 90deg from the wrist pin. But then I took a few more measurements at about 60deg and 120deg and they measure 82.33.

It would seem they are ever so slightly egged.

EDIT: I have measured the standard pistons and they seem to taper in a little at exactly the same place.

 

[grahams81]

Pistons are oval mate, that is normal. Not a lot of people know that !

 

[James.Judd.1]

Pistons are oval mate, that is normal. Not a lot of people know that !

Glad you said that.
I am a little worried about the 0.08-0.11 sidewall clearance now after warming up the pistons a little.
I also went and triple checked my bores and all my measurements are correct.

I may send wossner an email to see what they advise.

 

[chaazza]

Watching this closely mate looks real intense thoigh

 

[grahams81]

Be ok bud, 4thou clearance is normal 40 thou = 1mm so 4thou = 0.10mm so just over will be ok.

Dunno if you know but, on a side note your not suppose to measure bores when the engine block is in a engine stand. Apparently its better to put it flat on a bench.

 

[James.Judd.1]

Be ok bud, 4thou clearance is normal 40 thou = 1mm so 4thou = 0.10mm so just over will be ok.

Dunno if you know but, on a side note your not suppose to measure bores when the engine block is in a engine stand. Apparently its better to put it flat on a bench.

Its the just under that I'm worried about (0.08mm at the narrowest point) If the piston expands..

The block was measured sitting on a flat board on the floor.
I am also going to torque the head down and remeasure again just incase there is any warping.

 

[PhilW]

Pistons are oval mate, that is normal. Not a lot of people know that !

And also barrelled slightly.

Around 100µm ovality apparenty. Which is what your are seeing.

 

[DaNnY_LaD]

Pics!!!!!!

 

[James.Judd.1]

 

[Ape]

James, impressive stuff. If only I had a conservatory! The "Store" room in our place was changed into a second room / office.

 

[James.Judd.1]

Pics!!!!!!

^^^

Im still at work mate, pictures later.

James, impressive stuff. If only I had a conservatory! The "Store" room in our place was changed into a second room / office.

Thanks mate, yes is it pretty handy now winters setting in. I dont think there is a room left in the house that doesnt have some random Seat related item in it lol
I have a feeling Ill be finding bits that I forgot to refit for many years to come!