by Mudgee mud on Mon, 01 May 2023 9:14 +0000
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.