shortblock teardown questions
05-21-2011, 11:03 PM
#1
Member
Thread Starter
Join Date: Apr 2008
Location: Minnesnowta
Posts: 360
Likes: 0
Received 0 Likes
on
0 Posts
Car: 1987 Camaro Z28
Engine: 355ci, XE262 , 650dp
Transmission: T-5, RAM clutch
Axle/Gears: 3.23 limited slip
shortblock teardown questions
so i finally got around to tearing down my old 305 thats been sitting on an engine stand for almost two years now, and ive got a couple of questions...
1) whats a good way of seperating the connecting rods from the pistons?
2) is the plate held in with two torx bolts (see pic) holding the cam in? the cam wont pull out. ive never encountered that before.
3) i posted a few pics of the bearings. i dont know if this motor had 70,000 miles or a 170,000 miles (cant tell with these odometers). How bad do they look? i know some of the rod bearings are in pretty rough shape, but the mains dont look that bad to me.
i find this interesting because before this motor was pulled, it had an internal antifreeze leak (i never noticed any white smoke). back when i was using the car as a daily driver, i would add a gallon of 50/50 every other week. this went on for roughly 6 months.
anyway, i keep reading about how "antifreeze in the oil will destroy your bearings" but in my opinion the shortblock still had life left in it after all of that even. i know that water and oil are not miscible, meaning they will not mix. so how would the "water" be pumped threw the oil passages constantly? I noticed the antifreeze collected heavily at the bottom of the pan. but i also noticed at the bottom side of the valve covers, so it had to get there somehow
1) whats a good way of seperating the connecting rods from the pistons?
2) is the plate held in with two torx bolts (see pic) holding the cam in? the cam wont pull out. ive never encountered that before.
3) i posted a few pics of the bearings. i dont know if this motor had 70,000 miles or a 170,000 miles (cant tell with these odometers). How bad do they look? i know some of the rod bearings are in pretty rough shape, but the mains dont look that bad to me.
i find this interesting because before this motor was pulled, it had an internal antifreeze leak (i never noticed any white smoke). back when i was using the car as a daily driver, i would add a gallon of 50/50 every other week. this went on for roughly 6 months.
anyway, i keep reading about how "antifreeze in the oil will destroy your bearings" but in my opinion the shortblock still had life left in it after all of that even. i know that water and oil are not miscible, meaning they will not mix. so how would the "water" be pumped threw the oil passages constantly? I noticed the antifreeze collected heavily at the bottom of the pan. but i also noticed at the bottom side of the valve covers, so it had to get there somehow
05-22-2011, 07:28 AM
#2
Supreme Member
iTrader: (1)
Join Date: Sep 2005
Posts: 26,156
Received 1,695 Likes
on
1,288 Posts
Car: Yes
Engine: Usually
Transmission: Sometimes
Axle/Gears: Behind me somewhere
Re: shortblock teardown questions
1. Take them to the machine shop. Disassembling them often destroys the pistons. But since it's a 305 and you won't be spending your money on that anyway, you can experiment all you want before throwing it all in the trash (except for the cam retainer and hardware, the lifter spider and hardware, the lifters themselves, and the figure-8s) and getting a 87-96 TBI truck 350 short block to replace it with, which will cost EXACTLY THE SAME in the end but will give you 15% more motor.
2. Yes that is the cam retainer plate.
3. Looks like the metal the mains are made out of is different from the rods, and resisted the attack of the destructive fluid somewhat better. Doesn't matter too much, since they and the entire rest of the short block are headed to the scrap heap.
Yes antifreeze DESTROYS oil. Yes it settles out of the oil when the engine is not running. No it does not stay that way, in the violent and highly dynamic environment in the oil pab with the crank whipping around at however many 1000 RPM and the oil pump sucking the contents of the pan FROM THE BOTTOM. Miscible or no, it turns the oil into some kind of a powdery sludge that doesn't lubricate, and is an acid besides. The entire crankcase, including the oil pan, the lifter valley, and the 2 rocker galleries, is interconnected by multiple holes and passages; anything that gets into it at any place is transported by the constantly circulating oil to every other place.
2. Yes that is the cam retainer plate.
3. Looks like the metal the mains are made out of is different from the rods, and resisted the attack of the destructive fluid somewhat better. Doesn't matter too much, since they and the entire rest of the short block are headed to the scrap heap.
Yes antifreeze DESTROYS oil. Yes it settles out of the oil when the engine is not running. No it does not stay that way, in the violent and highly dynamic environment in the oil pab with the crank whipping around at however many 1000 RPM and the oil pump sucking the contents of the pan FROM THE BOTTOM. Miscible or no, it turns the oil into some kind of a powdery sludge that doesn't lubricate, and is an acid besides. The entire crankcase, including the oil pan, the lifter valley, and the 2 rocker galleries, is interconnected by multiple holes and passages; anything that gets into it at any place is transported by the constantly circulating oil to every other place.
Thread
Thread Starter
Forum
Replies
Last Post