Cracked pre-combustion chamber

[miked]

mga paps,

PCC of my engine have cracks in #2,3 and 4...but i will not replace them.

i have the protruding valve 4d56. #1 exhaust is flush with the cyl head surface, the rest are protruding. i think it must be the valve seat insert that is worn.

intake valve in #4 have leaks when i filled all of the intake and exhaust ports with gasoline. again, i reckon that it is the valve seat. yet, i will not still replace the valve seats..another

the reason for not replacing them is that i don't have the much needed budget for the top overhaul at the moment....just the HG.

with fingers crossed, i hope they will still last up to its first overhaul.

cyl head surface is within warpage limit so far. but block is greater by 0.027 mm near the intake and exhaust ports (parallel to longitudinal axis of the engine)...i hope the HG will take care of the excess.

i've seen the PCC cracks last year when i replaced the HG....i'm changing again the HG today.

am i on the right path? probably not on some issues i think.

[reym]

Cracked pre combustion chamber can lead to head destruction.

protruding valve may lead to collision with the piston with just minor flexing of the timing belt.

You are on the right path if the plan is to destroy your engine.

You may find an abandoned cylinder head in wreck yards if you want cheap parts.

[miked]

fyi, there are two types of 4d56. early models (up to 1993) have valves protruding from the surface....late models (1994 and up) have recessed valves...

[speedyfix]

just get a surplus head and start with that. it's a better solution than working with a busted one.