Ok, I have a 1977 Monte Carlo with a 305 5.0L 69k original miles engine knock in it. It only happens at times when started and after it runs for a bit. I checked oil levels and while I may sound stupid saying this, I wasn't sure if I should have checked when it was running, off, or running it then turning it off. Neither one of the readings were good so I used common sense. I have a problem with the oil, so I bought 4 new quarts of 10W-30 oil and lucas oil stabilizer which is apparently good for engine knocks and an oil filter. Tomorrow I am going to do an oil change with the lucas and hopefully that eliminates the knock, but I was hoping if someone could give me some better insight on whats going on. Am I right on the ball with what I am doing? Do you think I have a leak and that's why my oil levels are going haywire, am I just stupid for trying to read oil by any of the 3 methods I listed earlier or is the engine knock not related to the oil?

My second question is the following and before you guys tell me to upgrade to a 350 listen to this. My 305 has 69k original miles and gets pretty damn good mpg. Now I have heard that a fuel injected 350 would do really well, but I mean honestly I'm a 19 almost 20 year old college kid and I really feel with a new intake manifold, headers, carb, and crankshaft I'd be doing quite alright performance wise. What is everyone else's personal opinion on this?

 

First thing first. you SUPPOSED to check you oil when car is not running. On a level ground, if you had the engine running, wait about 5 minute before you check the oil.

You state that you engine has 69K original mile. How do you know this? Chevy V-8 don't use oil that much, Unless the engine has run hard. I have a 86' SS with original 305 H/O motor which was built in '85, but it uses less than quart a month. the motor currently has over 200k, and will be replaced by 350 I'm currently rebuilding. I also have 305 truck motor in my other SS as the original motor died a while ago. The truck motor smokes a lot. When step on the gas, I feel like James Bond, but still uses less than a quart a month.

Now for engine knocking. Is it mechanical knock? Could be lot of stuff, but when did knocking started? Did it always had it, or just recently? Could be the gas you use, could be timing, could be motor running hot, just to name a few. Changing oil helps, but won't eliminate knocking.

As for the MPG, why not use OD trans? Engine size matter too, but OD trans does the wonders. Does your car has TH-350 or 400? If it's TH-350, you need to change/slide the crossmember a bit, but pretty much a direct bolt-on. you can reuse the driveshaft and all. Just get a lock-up kit or something. If it's TH-400, I'm pretty sure you can use the crossmember, but need to get driveshaft. Either case, you need to do little research, but it's do-able.

Lastly, you mentioned of some upgrade, but don't waste your money and time on 305. Unless you have some kind of sentimental value in the motor, proper way to rebuilt or upgrade the 305 is swap it to 350. Due to it's bore size, it's hard to make 300hp from 305 (it's possible, but you will hate the motor), but 350 have no problem making 400hp and up with right mod and still be streetable.

 

The knocking started intermittently , but it has been happening a lot more frequent lately. It has the 350 trans. I did my last oil change if I am not mistaken towards the middle of May and added no oil since then, so I guess low oil could be a big thing. I did not even know they actually *use* oil. I guess you learn new things everyday. When you say move the crossmember, is there a tutorial or something I don't follow when you say move the crossmember, but maybe I could ask a friend or something. As for the engine it's a numbers matching engine which the previous owner told me at least. I just took his word for it it, he seemed like an honest man but I mean I guess it could be possible that it was lying. So you mean to tell me with new headers, intake manifold, carb, and a crankshaft it would make no difference for my 305 performance wise? I mean lets say the motor winds up being numbers matching if I were to hold to it to increase my cars value more the upgrades I listed before would do nothing for it such as increasing it's horsepower or efficiency?

 

I hate to say this, but it's not a popular hot-rod car. It's a smog-era big ol' Monte. If you or anybody have a sentimental value to this car, they will pay a big bucks for it, but most likely, it doesn't matter if it's number matched. Number match will be worth the effort IF you have a car that can go to, say Barrett-Jackson type of auto auction.

As for the knocking, is it mechanical knock?

And for the mods, yes. It will bump up your HP a little and make it efficient. Biggest problem with 305 are those small post and valves. Tiny bore mean you can't use big valve without modding the cylinder or the head, which is not cheap. If you DO mod the head or cylinder, it will lose compression. Lose compression, any gain that you made by mod will be lost. And the port is not capable of moving the air engine needs because of the small port.

If you going to spent that much money on 305 (Intake, carb, crank, headers), save your money and get a 350. Slap on a intake and headers and call it a day. You really don't need a carb until you get into cam and dual exhaust. Stock carb will do just fine. Besides, most of us don't make kind of HP to break stock crank unless you use power-adder like Nox or turbo. IF you do indeed manage to break a stock crank with your engine HP, you can always brag about it on the web, or to your friends.

 

The engine knock was cured, it just needed some Lucas and more oil. It was low. I took your advice, I found a GM 350 Crate motor with 20k on it for 300$ near me and I'm buying it for my birthday. It pushes 250 HP with no mods, so for me not to buy it would be pretty stupid. My question is though would the 350 trans be able to withstand the GM 350 crate motor? What do you think about that?

 

the 350 trans is what they 350 motors usually had behind them so you should be fine. be sure to check the block and head numbers to insure it really is a 350.

 

x2. Check the ID # on the block and head. I'm rebuilding a 350 right now because some fool decided to put 305 head on one side and 350 smog head on the other side, split the crank in half.

TH-350 should be more than enough for the crate 350.

 

You're so right, being that it's from craigslist and all he is saying is that it's "dirty" I need to carefully examine this motor.

 

Where in Rochester are you? I'll be up there this weekend picking up some patio stone. Don't have a lot of knowledge about the monte's or performance SBC parts, but can help you with IDing some parts and some maintenance items. Could also show you where there are a couple decent junk yards if you get adventurous.

 

Had you caught me about 2 months ago I would've been there I moved back to NYC. haha I was in Henrietta though.