LD32 Engine build

jonbills

Membership Secretary
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If you have to wet and dry the edges of the pistons then how can the weights be matched?
Having the exact same number of atoms would be hard; they'll be within a gramme or so.
Taking the edges off, I expect I'll be removing maybe 0.1g. And for comparison, the rods out of my old L24 varied between 735 and 743g. (actually one was 712, but it was a mismatched replacement).
 

AliK

Vehicle Dating Officer
Staff member
Club Member
Having the exact same number of atoms would be hard; they'll be within a gramme or so.
Taking the edges off, I expect I'll be removing maybe 0.1g. And for comparison, the rods out of my old L24 varied between 735 and 743g. (actually one was 712, but it was a mismatched replacement).

So here’s a challenge: weigh each one before and after, let’s see what the reality of it would be. It would be interesting to know.

The cylinder walls on Alan’s photo look mighty thin. I’m on the phone so can’t zoom in enough to read the widths + being the wrong side of 25, my eyes are getting worse! [emoji848]
 

jonbills

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So here’s a challenge: weigh each one before and after, let’s see what the reality of it would be. It would be interesting to know.

The cylinder walls on Alan’s photo look mighty thin. I’m on the phone so can’t zoom in enough to read the widths + being the wrong side of 25, my eyes are getting worse! [emoji848]
I'll try to remember when I get them back.
I can't read them, but I expect the calipers say 3.5mm.
 

Mark N

Club Member
Having the exact same number of atoms would be hard; they'll be within a gramme or so.
Taking the edges off, I expect I'll be removing maybe 0.1g. And for comparison, the rods out of my old L24 varied between 735 and 743g. (actually one was 712, but it was a mismatched replacement).

If I remember correctly, the Wiseco pistons I used in my RB had about a 0.2g variation straight of the box.
The Manley rods started with about 6g difference but the ends were all over the place.
It took quite a bit of work on the belt sander to match all the big ends and all the small ends.
I ended up with each assembly (piston, pin and rod) within 0.4g of each other, at which point I figured that was more than good enough for my application.
 

Albrecht

Well-Known Forum User
The cylinder walls on Alan’s photo look mighty thin. I’m on the phone so can’t zoom in enough to read the widths + being the wrong side of 25, my eyes are getting worse!

I can't read them, but I expect the calipers say 3.5mm.

I reckon 2.25mm

96 - (2 *(92.5/2)) = 3.5 was my calculation.
how does yours go Rob?

I tried to read the gauge.

The article mentions offset-boring some of the cylinders to mitigate differences in support for the liners in each 'hole'. There's differing amounts of metal left in each cylinder after boring, so they shuffled them about a little to suit. Therefore I'd expect different measurements for the gap between each bore. Not much left for the head gasket to sit on...!

I've seen this offset cylinder bore shuffling done on other types of engines too.
 

AliK

Vehicle Dating Officer
Staff member
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The article mentions offset-boring some of the cylinders to mitigate differences in support for the liners in each 'hole'. There's differing amounts of metal left in each cylinder after boring, so they shuffled them about a little to suit. Therefore I'd expect different measurements for the gap between each bore. Not much left for the head gasket to sit on...!

I've seen this offset cylinder bore shuffling done on other types of engines too.

So, coming from a point of utter ignorance on this topic: how does that work with the crank? Are they also using an offset crank of sorts?
 

Rob Gaskin

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So, coming from a point of utter ignorance on this topic: how does that work with the crank? Are they also using an offset crank of sorts?

I think the offset is across the block not down it. Might be wrong?
 

Albrecht

Well-Known Forum User
So, coming from a point of utter ignorance on this topic: how does that work with the crank? Are they also using an offset crank of sorts?

No. This is about shuffling bore centres along the centre line of the crankshaft, and the small differences are mitigated by the connecting rods finding their own centres on the crank pins. There's enough clearance between pistons and piston pins, and conrods and crank pins, to allow this.

What did the gauge read Alan?

Don't know. Can't see the scale!
 

AliK

Vehicle Dating Officer
Staff member
Club Member
No. This is about shuffling bore centres along the centre line of the crankshaft, and the small differences are mitigated by the connecting rods finding their own centres on the crank pins. There's enough clearance between pistons and piston pins, and conrods and crank pins, to allow this.

Thanks for that - makes sense.


Don't know. Can't see the scale!

Wrong side of 25 brah! [emoji12][emoji13]
 

jonbills

Membership Secretary
Site Administrator
The block's back from machining.
Turns out it was piston 2 and 6 that were linered not 1 and 2.

you can see through the core plug hole on #5 where it went through.

DSC_0197.jpg


DSC_0195.jpg

Next steps: make a crank case vent hole, make water holes on right side of block and figure out bolt holes for head to timing cover.
 

jonbills

Membership Secretary
Site Administrator
Diesel block & timing cover, petrol head gasket. Shows two of the things to sort.
DSC_0199.JPG
 

jonbills

Membership Secretary
Site Administrator
The block had a final pressure test today.
When hot, it has no leaks at 40psi.
when cold, theres a tiny leak between #1 liner and the block at the head face at 40psi. Not worried, running pressure is < 15psi, the gasket will seal it anyway and I'll put some ceramic sealant in for good measure.

DSC_0290.JPG
DSC_0292.JPG
 
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