Boring the cylinders .. HOW LARGE ??

[Thumper460]

I saw an add for a "big Bore" kit for the r53 engine. WE have always been told the max over bore is .5mm !! Remember ? ANY gear head knows that 95% of the engine block out there can always take a deeper Bore than that. I like most , just blew it off.. why should I care, right ?

Well even though we only have a 1.6 Ltr 4 cylinder.. cubic inches ALL WAYS matters. So I took two r53 blocks to my Machine Shop for SONIC TESTING
to see what is true !! And I consulted two OLD guys that have been cheating the rules for eons. When the rules were always restrictive, and we just 'cheated' our way around those rules.. I call it American Ingenuity !! LOL

These are my results... these little blocks are a 'semi-siamese' block !! they are solid connected at the lower cylinder, and have a water passage on the top of the cylinder ( approx 2 inches) !! Freaking bullet proof !!

No.. How much metal can I remove on a cylinder wall thickness and still have a long strong engine life >?? Well on the standard Cylinder wall thickness of the two blocks I presented..
I can over bore to a 1.7 Ltr engine. If I get really testy, I can go as far as 1.75 Ltrs !!

Keep the stock Crankshaft.. and Rods,sonic test , bore it and rock !!

Thumper