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LD28 3.1 engine build


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Hi, I've been doing a load of searching, and there are probably about 1/2 dozen threads about building an engine on the LD28 block and crank and have got a lot of info from them.

I'm just embarking on building the engine. Aim is to use the 83mm crank and get the bore out to around 90mm with sleeves, which I think will get to about 3.1 liter. 

I'm looking to get some feedback on my plan, and possible answers to questions as I go along, or just bored silence :)

 

So - V57 block (rear sump), V07 crank and I've acquired 6 Isuzu 4ZE1 rods from Maxpeedingrods. They're 150mm long, 26.8 mm wide with 21mm little end and 52mm big end.

I'll be using my existing modified P90 head - chamber size is currently 39cc. 

 

Questions: 

1) by my calc, I'm looking for a piston with compression height around 35 to 36.  does that sound about right? Kameari have 35.5 CH forged pistons up to 89.5mm bore - anyone know any others?

2) with a 1mm undersize rod journal, can the crank be offset ground that 1mm and get me 84mm stroke? or doesn't it work like that?

3) Do I need to open up the water holes on the right side of the block to match the head water holes, or plug the head holes? I'm assuming the former, but read a thread maybe suggested the latter. 

4) The block doesn't have the water bypass to the pump hole, and it can't be made. I'm assuming this isn't a problem and I don't need to do anything to blank the head here. correct?

5) The replacement liners will need to be brazed in one way or another. Anyone got any details of what does and doesn't work here?

6) I'm planning to use the LD timing cover (modified to get rid of the mounting for the diesel pump). All the threads I read, people used the L20B timing cover - Is the only concern here the distributor? I'm running a distributor-less setup. I don't think L20B timing covers are so plentiful here in the UK. 

7) I don't like the idea of drilling my nice P90 head for M12 bolts, I'd like to keep it usable for my F54 block if possible, so I'd like to helicoil the block to M10 and just get longer M10 head bolts. Anything wrong with this plan?

 

That's all I've got for now - all feedback welcome. 

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  • 4 months later...

Update on this. 4 cylinders on the v57 block have been bored to 89.5 and are serviceable. front two got too thin and are being linered. 

The crank has been lightened to 17 kg and offset ground to 84.25 stroke and ia going for balancing with an XTD RB25 flywheel and clutch. 

Kameari 89.5 pistons coming next week, so its all moving along. 

 

Edited by jonbill
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I love that people are still doing this. 

 

Curious, when sleeving something that is already that thin, do you have to add material somewhere? I was under the impression with boring to that extent, cylinders unable to withstand would indicate a core shift and would need a new block as there wasn't much material holding the sleeves in once bored.

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11 hours ago, seattlejester said:

I love that people are still doing this. 

 

Curious, when sleeving something that is already that thin, do you have to add material somewhere? I was under the impression with boring to that extent, cylinders unable to withstand would indicate a core shift and would need a new block as there wasn't much material holding the sleeves in once bored.

Its a bit of a voyage of discovery. The firm doing the boring and liners seem confident the liners will be held ok top and bottom,  and they do a lot of them although not on this engine obvs. but I'll only really know if it works when I've run it. 

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  • 2 weeks later...

I kept the diesel intake too, it does look interesting (but it's not going on this engine!) 

I think the diesel may be a bit more common here; the gen 3 Patrol had it for quite a few years I think and sold in good numbers. (although wikipedia doesn't mention it). 

my blocks are v57 which seem thicker and reinforced compared to the v07 you got. my guess is that it has similar bore material as f54 petrol block, so probably safe to 88 or so. 

Edited by jonbill
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Posted (edited)
6 hours ago, AydinZ71 said:

Looking good :). Any particular reason for the valve reliefs in your pistons? What is your piston deck clearance looking like? Are you running high lift or a wild duration on your cam? What Static CR are you targeting?

 

 

yes, valve cut outs are to prevent piston valve contact. The cam has about 15mm valve lift and 300+ degrees duration. but also, thats how Kameari pistons come. 

the markings on the pistons are how much they're above the deck. about 0.4mm, so I'll use a 1.2mm gasket. 

Edited by jonbill
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Ah! Wonderful :) I mistakenly assumed they where custom pistons, hence my questions about your lift profile. Low volume and exchange rates mean Japanese A/M pistons here in the US are often more expensive than locally sourced custom forged units. Makes sense that they come standard from Kameari that way. Where did you source them from if you don’t mind me asking? 
 

You have a pretty wild profile! Should be loads of fun :) with 14mm of lift and a -0.4mm deck clearance, those pockets may very well be necessary. 
 

What kind of Valve springs did you opt for? If you have not yet looked into beehive springs, I highly recommend them! 
 

I just completed my head work, so I enjoy listening to what others are doing on the topic. Thanks for sharing! 
 

 

Edited by AydinZ71
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