I am rebuilding a 1994 1.8, engine had 140k miles from what i was told by seller, the rest of its history is unknown.. I was told it was running fine.. I pulled the engine apart and it looked great on the inside, no problems, cylinders dont even need to be bored.. I was wondering if i should replace the oil and coolant pump.. or leave the old ones?

 

ps engine will be boosted

 

well while you've got it all apart, replace everything that you can afford to. Especially the oil and water pump.

 

yeah, it never hurts to have new parts in an engine. plus you'll probably be able to run more efficiently with stronger materials

 

Rehone the walls to get the crosshatches. This is a very important detail that seems to get overlooked now. Very important for the rings to be seal properly.

 

honeing was planned, not gonna forget about that... here is all that im doing.. tear down (done) hot tank head and block and check for cracks, check head surface, resurface if needed, hone cylinders, clean carbon from valves and piston tops (done) clean casting marks from head ports (50% done) replace all gaskets, valve seals, n stuff. lap valves to head.. thats about all i can think of...


anyone have any input on things i can do to the intake manifold to refreashen it?

 

Well it sounds like you are doing pretty much what I did with my rebuild (at least for the head) ... however from what Ive heard, its not a good idea to cheap out on getting your head resurfaced. It may or may not seal properly, but if it does not you are out a head gasket which is not worth the risk IMO. Are you going to put new main and rod bearings in as well? I think it would be a good idea to do so while you are at it if you arent already. Unless you dont mind pulling your engine and disassembling again in the near future you shouldnt cheap out because it is such a hassle otherwise.

 

yeah, forogt to add that, new bearings all around

 

fresh rods and pistons..?

 

yeah some weiscos and rods from m.net GB./

 

With all that you are planning get new valves and valve springs too. Valves, especially exhaust valves with that much mileage on them can't be trusted. Ditto the springs - replace 'em all.

 

geeeeez, you guys are talkin serious money now!!! no way im replaceing pistons and rods, they are in great condition, and as far as valves go... i think i will take my chances, unless i get a sweet deal on them.. springs, thats another story, i can see needing new valve springs

 

just because you can see the x hatch pattern doesn't mean the cylinder walls are true'd up. Get it honed now, so you don't have to do it twice. I also recommend new ARP connecting hardware, new bearings, and new mazda ductile iron rings (for longevity) because its not that expensive.