3L 2.8 sroker? Fit 5l pistons?

[Mudgee mud]

With minimal differences between the the 3L and the 5L
Similar to the old red 253v8 and red 308.
The 3l has the same piston stroke as the 5l.
But about 3mm across the pistons larger. That basically takes it up to a 3ltr.
I've heard the 5l has slightly larger valvess.
Can the 3L block be bored out 5L specs? And fit 5L pistons and rings.
The head will obviously be getting reconditioned. Fit 5L valves with head work....

[Rob_Wood]

Wouldn't it be easier to just get a 5L from a wrecker and reco it?

Boring out a diesel isn't likely to be as straight forward as boring petrol engine out back in the day.

[Mudgee mud]

True I guess. Just curious if that's the main difference between the two motors. Piston and bore width by 3mm.
That takes it CC up from 2.8 to a 3 litre. And slightly larger valves.
Is this main difference of the two?

[Rob_Wood]

If you're asking out of pure interest then I'm sorry, I don't know the answer.
If however you're looking to do the work, then you'll need to keep a few things in mind:
Piston wall thickness, newer block are not likely to have much meat in them like the old days.
Alloy blocks I feel would be a bad idea, just never had much faith in Alloy blocks from the beginning.
Valve sizes being different, might be an issue if you're putting a 3L head onto a 2.8 block. May not even line up properly. If you're looking to put larger valves into a 2.8 head then you'll have to consider wall thickness again.
The list probably goes on without thinking too much about it. I just feel it'd be easier to reco the engine you're wanting from a wreckers.

[Mudgee mud]

The crank shafts on these two motors are identical I believe, so are the connecting rods in length.
Thus, the distance from centres of the pistons stay the same. So the gap between the bores is increased by 1.5mm either side to make up the 3mm increase of piston width.
The same deal with the old Holden V8s. 253 and 308s! Their blocks externally where exactly the same. And same piston to piston centre measurements. These blocks were originally blue printed by GM to be a 350, but GMH decided to down size the motors cubic capacity.
There is no alloy heads involved at all with these series motors I believe.
Any head can be modified for larger valves generally.
Both heads line up perfectly, but some models had different water jackets.
I'm pretty certain Toyota took a cheap short cut to upgrade from a 3L/2.8 ltr series to the 5L / 3ltr series by just fitting wider pistons and valves.
Don't get confused with later 2.8s and 3ltr models.
If anyone else knows anything different between these two motor series , please post it.
Nearly every other part number I see is identical.
I have no doubts the 5L series could of had a slightly different shaped rocker cover, sump pan, oil pick design.
But all bolts up,the same.

[Rob_Wood]

Sounds like you're doing plenty of homework, best place to start. You seem to know Holden history, I know the Chev 350 block in my old HJ had 307 heads (we couldn't find any 350 heads at the time). I also know the Datsun L16, L18 & L20 engines were all built around the same block casting.
Whether Toyota have a similar history I'm afraid I don't know, sorry. Hopefully someone else can find the answers you seek.

[Mudgee mud]

Yes, I think Toyota have done same/ similar things over the years. Many car makers do such.
Holden would make a few mods to the engine, and paint the motor a different colour Red , then blue, then I black.
With upgrade changes like electronic ignition, pollution heads etc.
The black Holden motor was an old out dated motor from day one.
If one googles the P-76 Leyland block, they would be surprised how many car makers used its design, and long it went on to be used.
Holden and Ford panicked when Leyland tried to enter the Australian market! And actually banded together to bag Leyland out. In fear of losing sales.