I'm no expert by any means but I have rebuilt a lot of SBC's over the last 40 years or so. Most of them were quite some time ago though because, as most have said, crate motors are usually cheaper. That said, I have to ask a couple questions. What is your intended application? Do you want to go drag racing? Do you want to go street racing? Do you just want a good running somewhat strong cruiser? How many miles on your 307? have you done a compression test on it? A leak down test? Is it just a low oil pressure issue? How low is the oil pressure? Other than the oil pressure, does it run well? Does it have reasonable power? What is your budget? If you go crate motor or even just a used take out motor better add in extra $ in your budget for the always unforeseen stuff. We all want to have a bad ass motor but from my experience sometimes you spend a lot of money to get one then realize a milder build might have been a better way to go. Less costly, better driveabilty, better gas mileage, less money to spend on driveline components (trans, drive shaft, rearend, etc to handle the extra power). If you have the budget, go crate. But if not, maybe just look into dropping the pan on your motor and figuring out the oil pressure issue (depending on the above questions).
Thanks Engine runs smooth. the odd time the idle goes up and down on it's own. Totally a cruiser. Nothing fancy. I just placed Castrol 50 grade oil in it and it ran worse when it started up.I was running Shell Rotella 40 grade . I think I am better running it for the summer then taking it apart in the fall. I don't know how many miles are on it.
how much oil pressure is "low oil pressure"? and why run thick oil? If it is getting oil to the bearings, and it's not knocking, normal oil (5W30 or 10W40) should be fine. The Corvair I took on a trip last summer had less than 5 at hot idle, and a bit over 20 and hot cruise....still running fine, thousands of miles later. I only had the gauge on it for a little while, when I got the car running, it was too depressing so I removed it. The idiot light worked, I think it turned on around 2 or 3 psi, and it would come on at hot idle, unless I put the PG in neutral. You know, you could just keep driving it, and wait around for a good deal on an engine that someone is planning to remove from their car--so you can test drive it, before you buy. Or take your time to save up some $$$ to buy your dream crate motor, or build one.
This is probably totally off base but if you are having apparent timing and idle issues you could check the lower bushing on the distributer. Something else to consider if it is a 307 is that unless you have changed the cam shaft thee is a good chance that you have lost at least one lobe on the cam. That also makes them near impossible to time or set idle. All this is cheaper than replacing the engine. There is a less traditional often cheaper than a 350 bolt in option. A friend had a mid sized chevy with a 305 HO, they were a commonish engine and pretty spunky as motors from the era go.
SBC with 7 LBS OIL PRESSURE FOR EVERY 1000 RPM IT WILL LIVE Example: So if you cruise at 3000 rpm you need only 21 lbs oil pressure.
Crate motor......,,that’s what pro shops and TV shows do What is the oil pressure with normal oil Not the 50 weight stuff
This 307 timing set was running just fine, no real indication of an issue. Most of the nylon is gone, and the crank sprocket was cracked. Hell all that nylon chunks could be plugging up his oil pick up screen
sounds like a normal sbc with some miles on it I have seen new ones idle with 10 psi new and gm is ok with it if its not rattling I would run it I had a 390 like that, lots of miles low OP no rattles swapped in a new pump and got the idle pressure up from less than 5 to 10psi
Vicky I saw one in worse condition years ago, was running, but owner noticed oil leakage in front of engine, the chain had gotten sloppy enough to wear a hole in the front cover.
And at cruising speed? RMP and oil pressure? I would try regular weight oil and pump more of it with a high volume pump. That's going to cost you $50.00 and a couple hours. Stock bearing clearance wants a stock oil pump for stock oil pressure and flow. Tight bearing clearance wants a high pressure pump to get oil flow. Loose bearing clearance wants a high volume pump to get oil pressure. Some guys will build an engine with certain properties and goals in mind. Some want tight bearing clearance and some want 'em loose some stay with stock clearance. Use the corresponding oil pump. A used engine with a little bit of wear opens up that clearance beyond stock and more towards loose- use the same logic and run the high volume pump to get oil pressure. With all that said, I don't think the oil pressure is "too low" - it's down but not a major concern. I certainly wouldn't jump into the crapshoot gamble of a swap with a used engine swap over it. Only If I was really bored I'd try the HV pump
Happy Easter as well. The earlier year 350 4 bolt main 2 piece rear main seal engines are good. If looking for a reasonable 350 completely rebuilt ready to go I usually go to a site called Karls Chevrolet but type in crate engines after the name and look through all the crate engines. Many to choose from reasonable price and I believe free shipping. Good luck. Charlie
Wouldn't hurt to look at them, Now is the pan coming off to look at the bearings and while your in there change the oil pump? Or Is the pan coming off to change the pump and while you're in their check the bearings? Does it matter? With the pan off do you just look at bearings and not change the oil pump on an engine with low-ish oil pressure? With 6 psi at 800 Rpms and everything quite running good and the only problem is the oil pressure gauge's needle doesn't have a full erection - I'm guessing nothing is shot, it's just not NEW anymore. No sense changing an engine out if it needs an oil pump either
I took a 350 chevy block to my machinist for machine work. When he saw it in the back of my pickup he said. "That's a 1980 block..can't use it." I axed him how he could tell it's a 1980 and he pointed out some faint black marks in the lifter valley...said only 1980 350 blocks do this....were tiny cracks where coolant weeped into the oil..made it unusable. I'd say stay away from 1980 blocks. BTW, it came out off a buddy's parent's 1980 chevy van...
I get saving some cash and looking for a cheaper way but if the car is a keeper save for a crate and move on to the next project. I bought a 350 crate from Jegs on sale for $1250 with free shipping.
Recently went to my local machine shop and bought a freshly machined 4 bolt 350 block for $ 300 . A guy never picked it up and the machine shop just wanted to get his labor and parts back. Had new cam bearings and freeze plugs. Check around you might get lucky . A crank kit and they rest is cheap for a 350. A 2 bolt will do everything you need. We ran a 2 bolt is a limited late model and ran 26 races with it. The block in my avatar was a 2 bolt with main studs and an Eagle crank and rods ,turned it 8200 every pass.
I'll wait till the fall to take the oil pan off and check the bearings and oil pump. I will place back in the 40 grade oil. I saved it. just put in before the winter. Maybe the new electronic guage isn't correct. will try to find a test guage. What do all the people do with their used engines when they get a crate? Decore in the back garden ? lol thanks for all the helpfull comments.
Wait till fall????? If you screwed around all morning drinking coffe and watching cartoons before getting started, you'd still have enough time fuck off , time to drink lots of beer, cut the grass and still get it all done before dinner.
used engines? sell it on craigslist....like you've been shopping for. You won't get a lot of money for it. If you take out the gauge, and put in an idiot light instead, you'll probably be better off. The engine will be fine with oil pressure like that, for many many miles. A little bit of oil needs to get to the bearings, and somehow early engines with no pressure to the rod bearings lasted a very long time. Think about it.
oh, sorry, I didn't notice you're up in Canada. Your location on your profile requires a little bit of knowledge of geography to understand that...not something I'm very quick at. But the idea is that you run an ad in some local trading medium, like the same thing you would do to find a used 350 to buy.
In Canada it's Kijiji. I believe this service was rolled out in Canada but supposed to be introduced in the US shortly after. Has been around for like 10 years, don't you have it in the US? Later... I guess this answers my question https://www.nytimes.com/2015/05/18/...he-us-rules-online-classifieds-in-canada.html
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