engine bolt tightening specs

[MilitaryPopo]

ok, the dumb beginner has another major question. i am putting back together the MP 350 ANI (260hp, chevrolet block, 1991), don't ask why i took it apart, guess i thought i might be able to see what was causing it to stall when put into reverse. and forgive my lack of knowledge on parts names. after placing the 2 'guide rods' that correspond with each cylinder back into place, the 2 'caps' that are screwed on top of them (one end of cap goes over rod and as a little hole through it to match the hole in the rod, the other end goes over a spring topped with a metal plate, the piece is held on by one bole going down between the 2). I can't find any information as to how tight to tighten these bolts down. i will also need specs on how tight to tighten down the intake manifold, carburetor, and the exhaust manifolds. i'd appreciate all input!

[JPC]

So- you removed your pushrods and rocker arms? -not quite sure what you're describing.

[MilitaryPopo]

yep, that sounds like them

[JPC]

The only fastener for which I'd particularly pay attention to torque would be the rocker arms, and even then it's pretty typical to assemble without torque spec. That said, it's usually being tightened by someone who's used to the "right amount".

From your description, it doesn't sound like you loosened any head bolts (hope not). It also sounds like you did not disassemble the carburetor, but only removed it.


All the other stuff can just 'go on' and it's more common (as an error) to over-tighten than to under-tighten. You might need some new gaskets.

From your description, the one item about which I'd be concerned is the gap between the end of the rocker arm and the top of the valve-stem. It's most likely that these are not adjustable rockers, and, in fact, that you have hydraulic lifters taking care of your clearance - so you don't have to worry. But if the rockers are adjustable, you will need to reset your clearances using a feeler guage, and this takes some practice/patience.

You can probably find a Haynes or other manual for the engine that will give you better information. And, probably, someone with more familiarity will hop in to refine my comments!

Regards,
JPC

[Corpus Skipper]

These are your valve rockers, and you have a hydraulic cam in this engine. The rockers have to be adjusted for the valves to work right. Roll the crankshaft until both valves are closed for one cylinder (the intake valve having just closed) You can tell which is which by starting from the front (water pump) end of the engine. The valves are in the same order on both banks, (Exhaust (E) Intake (I)) E I I E E I I E. Roll the pushrod between your fingers as you tighten the rocker nut until it just stops. Then tighten 1/2 turn. Turn the crankshaft and repeat for each cylinder. This is a rough setting that will allow the engine to start. Start the engine with the valve covers off (oil deflectors are highly recommended, available at auto parts stores, oil will squirt out of the holes you mentioned). Back the rocker nut off until the valve starts to tap, then tighten 1/2 turn while listening to the engine. If it sounds like it's missing a cylinder, the valve is too tight, so back the nut off a little. You will get a feel for where they "want" to be. Repeat for each valve and your set. You may hear many variations on this procedure, but this method has worked well for me. As for bolt torque, just tighten everything else evenly in a criss cross pattern. Head bolts, rods, main bearing caps, and the intake manifold are the only things that really need careful torqueing. Good luck.

[nevadamike]

Originally Posted by MilitaryPopo

ok, the dumb beginner has another major question. i am putting back together the MP 350 ANI (260hp, chevrolet block, 1991), don't ask why i took it apart, guess i thought i might be able to see what was causing it to stall when put into reverse. and forgive my lack of knowledge on parts names. after placing the 2 'guide rods' that correspond with each cylinder back into place, the 2 'caps' that are screwed on top of them (one end of cap goes over rod and as a little hole through it to match the hole in the rod, the other end goes over a spring topped with a metal plate, the piece is held on by one bole going down between the 2). I can't find any information as to how tight to tighten these bolts down. i will also need specs on how tight to tighten down the intake manifold, carburetor, and the exhaust manifolds. i'd appreciate all input!

Holy smokes!!! Quite an extensive overhaul.. What you describe are the push rods and rocker arm assemblies. The springs with plates are the valves and valve springs. One push rod--- exhaust, the other, intake. Please stop right there and go to your local parts store to purchase a munual on engine rebuild. You could do serious damage by tightening things out of sequence.
Way too much to go into here..... go buy a book. Mike.