LD32 Engine build

jonbills

Membership Secretary
Site Administrator
But how thick are the cylinder walls of the other 4 cylinders?

Is it really worth that extra few ccs?
stock bore is 84.5 which gives 2.8 L, so 3.2 L is more than a few extra ccs!
The 4 are serviceable and as Mark says, if I need a rebore later, they can have liners too. or I'll get the other block out of the shed :)
 

johnymd

Club Member
Firstly. I’m no expert but if 2 off the bore broke through, would the other 4 be very close? I’ve seen people mention that 4mm is the minimum wall thickness for safety so have the bores been ultrasonic tested? Also, would you not fit 6 liners rather than just 2?

I’m interested as I also have a ld28 block sitting in the workshop and having someone else do the r&d for you is great on the bank balance :)
 

jonbills

Membership Secretary
Site Administrator
Firstly. I’m no expert but if 2 off the bore broke through, would the other 4 be very close? I’ve seen people mention that 4mm is the minimum wall thickness for safety so have the bores been ultrasonic tested? Also, would you not fit 6 liners rather than just 2?

I’m interested as I also have a ld28 block sitting in the workshop and having someone else do the r&d for you is great on the bank balance :)

Yes. they measured the 4 bores ultrasonically and they're happy they're good for my use. I don't know the number they measured, but I think they will have been conservative - it's more money for them if I have liners. I don't think it's 4 mm needed - pretty sure most of the liners are only 2 or 3 mm. The bore spacing is only 96 mm I think, so max possible with 89.5 bore would be 3.5mm wall thickness. We'll see!
 

Turn & Burn

Club Member
I agree with Rob and John, for the cost of a 4 more liners it’s insurance. The liners are made from a stronger material than the cast steel block so will support a thinner wall, and definitely have no inclusions or corrosion pits that u/sonic testing has not spotted. The u/sonic testing only proves the areas you’ve tested. I wish I’d linered mine tbh. Could have gone 90mm too! I have a couple of thin points but they’re low down where I think the side loads and cylinders pressures will be lower.
 

jonbills

Membership Secretary
Site Administrator
Nah, its a long block. They said there's enough material in the back 4 so I'll keep as much integrity from the original casting as poss.
 

jonbills

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Site Administrator
The RB flywheel arrived and Phil machined this adapter to match the 80mm crank boss and 81mm flywheel flange.
who knows what the adapter was originally? [emoji848]
 

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Mark N

Club Member
That adapter looks like the thing that made me buy a second flywheel, thinking I had been sent the wrong one initially.
It wasn't until much later, when I was ready to pull the rear main seal, that I realized my (schoolboy) error.
Luckily, I have enough projects that it won't go to waste.
 

jonbills

Membership Secretary
Site Administrator
That adapter looks like the thing that made me buy a second flywheel, thinking I had been sent the wrong one initially.
It wasn't until much later, when I was ready to pull the rear main seal, that I realized my (schoolboy) error.
Luckily, I have enough projects that it won't go to waste.
Yep, that'll be it [emoji16]
 

jonbills

Membership Secretary
Site Administrator
Not quite, they don't balance the rods and pistons on it, just the crank, flywheel and clutch.
One of the benefits of buying modern forged rods and pistons is that their weights are matched anyway.
 
Not quite, they don't balance the rods and pistons on it, just the crank, flywheel and clutch.
One of the benefits of buying modern forged rods and pistons is that their weights are matched anyway.

i'm interested to see how you finish your kameari pistons, are you going to wet and dry the machined edges etc as they suggest?
 

jonbills

Membership Secretary
Site Administrator
i'm interested to see how you finish your kameari pistons, are you going to wet and dry the machined edges etc as they suggest?
Absolutely, the machined edges are quite sharp and would probably cause pre-ignition /detonation if not smoothed off.
 
If you have to wet and dry the edges of the pistons then how can the weights be matched?

I've not weighed mine to see how accurate they are. where the valve reliefs are the material is that thing that after 'processing' they'l need to be checked for weight.
 
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