The Stovebolt Site Forums The Shop Area Engine Shop information on engine rebuild

http://www.aa1car.com/engine.htm
Found this sight this morning, was looking for reason oil pressure low or no oil top half 4.3 chevy I just rebuilt, looks like gotta pull base
check oil pump and pickup screen. might be of some help to someone.
jbennett
40 burb

can be different things,,,cam bearings,,crank bearings,,pump,,if no oil at top look at cam bearings...doc

Nope, complete rebuild, 30 on bore,rings pistons,
new cam and bearings, 30 on mains, 20 on rods, when I installed the new oil pump, forgot to measure screen to base just put it together level. donn't think it's rear cam bearing, line it up with one of the oil holes, has track around
bearing to feed galleys to lifters. starting cold puts out 75 psi drops to 55 as warms up, rev and jumps up to 75. no oil top half, read some place that cold start 4 qusrts in base one in the filter, start up and running ya got 1 quart in the left head, 1 quart in right head 1 quart in crank and cam and 1 quart in filter, that leave 1 quart in base. either way gonna pull base check pump and screen, if not that pull engine find cause. funny, when I primed first time ole cut off distributor got oil on top half. donn't make any noise just runs, runs nice, edelbrock intake and 4 barrel
jbennett
40 burb

Your oil pressure guage is it the factory gauge? Do you trust your guage?
Have you install a mechanical guage at the oil pressure port to test your guage?
What is you oil pressure? Cold? Hot? How many RPM's?
When you installed your pump did it have a gasket? Did you install a new gasket? Is that gasket directional and is it on upside down?
Wow,I sound like a drill instructor, but these are things I have seen in the last 35 years of being an auto tech.

thanks for reply, doc41 and toyvo, I started rebuild engines about 12 years old. 235 56 chevy two door. OK so this is what happened no oil in valve train, 4.3 chevy v6, 88 rat truck.
So I went to this for answer,http://www.aa1car.com/engine.htm worked out good for me got to thinking about what I had done. So today I pulled the base and pump and replaced oil pump and screen. a little wear on pump due crud that I did not get after cleaning block, total rebuild, I could see oil all over cam and lower half even timing lower sprocket and chain, got it all back together and primed by starter, no plugs no electrical hookup to distributor, still no oil to lifters.
OK, so I put the plugs back in and fired it up and still no oil to lifters, just a little hear and there, so I watched it and said what the heck and did a clack adjustment on the lifters.{loosen adjuster til clack is heard, tighten til clack stops}
as soon as the first one started to clack oil came up and started to run down, did all 12 and am now on happy wrench puller,notta more pretty than seeing oil go drip drip drip off the end of 12 lifters at idle, so engine runs good, no noise and smooth, getting oil top to bottom, knock wood.
Where I went wrong I can only think is I adjusted the lifters before I primed the engine.and the lifters never got a chance to pump up. Shoud have just snug the rockers and readjusted after startup. funny, all I had to do was back off on the rockers, well I got a another new oil pump and screen,engine runs smooth, donn't get muck better than that.
But maybe, somebody will put a 4.3 in a ole chevy and have no oil in the top half and run accross this.
jbennett
40 burb

Who woulda thunk it?

if it works use it,,maybe if the center plunger is to far into the bore it can,t oil,,,doc

Doc, it works, why I donn't know, got about 30 miles on it seems ok. bought the parts from new engine in houston. usally I git over haul parts from northern for modern stuff. was going to save 50 bucks.The lifters were just thrown in the box they shipped me . do not know where they were made. I know the rod bearing were from india and didn't fit.wrong size. had to go to local parts get 20 over. Ordered 20 over and got 5 over I measured them. see how long it lasts live an learn.
jbennett