At a crossroads - Do I open this can of worms? (V8 Location/Clutch Replacement) (1 Viewer)

[handcannon]

Use a stethoscope, or chunk of tube/garden hose with one end held to your ear, to see if you can pinpoint the location of what you are feeling. The nice thing about using a chunk of tubing/garden hose is that it will also help you locate the exact location of an exhaust leak.

Don

 

[RWBeringer4x4]

Use a stethoscope, or chunk of tube/garden hose with one end held to your ear, to see if you can pinpoint the location of what you are feeling. The nice thing about using a chunk of tubing/garden hose is that it will also help you locate the exact location of an exhaust leak.

Don

I already tried this, but I may give it another shot with a longer/wider piece of hose. I previously tried with some rubber fuel line and it really wasn't transmitting enough sound to pinpoint anything. I can hear a tap, through the valve cover, but I can't hear anything through the block, so my guess is it's in the head somewhere.

Then again, as CDaniel alluded to - I also have a ton of belts and pulleys in that area, so it could be something else transmitting through the valve cover as well. However, this IS a 283, which means there are no bolt holes in the heads, no mounting provisions in the area, everything mounts to the block.

 

[handcannon]

You might try momentarily removing the belts and running the motor to check for that noise. Doing this will help you determine if it is inside the motor, or something run by the belt. Be very careful to do this in as short of time as possible, as doing this will keep the water pump from circulating coolant, and you do not want to be dealing with issues down the road from overheating the motor.

Don

 

[RWBeringer4x4]

I wonder if I'm feeling the exhaust leak transmitted through the valve cover. I know there is a pretty significant leak right where the manifold meets the driver's side head. I believe it's leaking at cylinder 3 or 5. Feels like more of a mechanical "tap" but pressure does funny things.

 

[cult45]

Hey man, just read the whole thread. I know it's not what you want to hear, but I'd replace that donk while it's out. It's comp is merely acceptable, the leak-down test isn't great and now you've got a knock in the top end? Don't throw good money after bad. I reckon if you searched you could find a decent V8 of any description [283/307/327/350] and slot it in. I've just been through an F-to-V8 swap and it's a big job. Too big for a tired engine. My 2c.

 

[RWBeringer4x4]

Hey man, just read the whole thread. I know it's not what you want to hear, but I'd replace that donk while it's out. It's comp is merely acceptable, the leak-down test isn't great and now you've got a knock in the top end? Don't throw good money after bad. I reckon if you searched you could find a decent V8 of any description [283/307/327/350] and slot it in. I've just been through an F-to-V8 swap and it's a big job. Too big for a tired engine. My 2c.

Yeah, I don't entirely disagree with you. I go back and forth about it 2-3 times a day. The only motivating factors to preserving the 283 are: 1. just a cool, old engine (sentimental value??) and 2. Simply put, it's cheaper in the short term. I'm fully aware that, long term, that decision would be more expensive in terms of both labor and $$$, but I put so few miles on this truck that honestly, this tired 283 could potentially go another 10 years before it's dead.

The final decision will really come when I pull the engine and get the valve covers and oil pan off it and have a look. The "knock" I'm (not) hearing is odd. I can only feel it, there's no sound associated with it that I can hear over the engine, which is partially why I'm wondering if it's the exhaust leak.

 

[RWBeringer4x4]

Ok, well I spent some time actually driving the truck over a few days off around Christmas. Got to embrace these out-of-season 70 degree days!

A couple months ago I changed the oil to a high-zinc formula and added some seal expander/"gooifyer" to see if it might do anything. I also bolted on a new, properly tuned and jetted quadrajet. I can honestly say that, aside from the usual white vapor out the tailpipe at start-up, the engine now does not smoke, at all.

This leads me to believe that the smoke I was seeing previously was either:

1. Valve seals that the seal expander has gone to work on.
2. In reality black (not blue) smoke from an extremely rich condition generated by the previous carb.

In either case, aside from the mystery tap mentioned previously, I'm starting to think I owe this engine more credit than I'm giving it.

 

[RWBeringer4x4]

Ok guys, a few updates, a few more questions. Still haven't pulled the engine, because I still haven't painted the damn garage, and still haven't "Stethescoped" it to try and figure out the source of this, but I do get a slight "tap" at idle. I'm going to upload a couple of videos.

1. Yes, I have an exhaust leak, either at the donut or the manifold-to-head location on the driver's side.
2. The tap appears to come from the driver's side. It seems more pronounced when the engine is cold, just down off "high idle" but it is present event when the engine is warmed up. See below: It's kind of tough to hear but it's a very consistent "TAP TAP TAP TAP TAP" going on underneath the normal engine noises and the leaky exhaust. It's hard to catch on video.



And one from inside the cab, so I could step on the clutch and stop the input shaft bearing or throwout bearing from chugging:



Any thoughts? I'm thinking maybe a sticky lifter, but I've also heard the exhaust leaks can sound a lot like a sticky lifter...

 

[RWBeringer4x4]

Also -

My oil pressure seems oddly low, when hot, and at idle - about 9-10PSI. I've never verified to see if the gauge works properly, but it seems to respond properly to changes in pressure. With 10W-30, 2-3000 RPM, with the engine warm I get about 45PSI. At idle, it drops to about 9PSI. I've actually been told that's "low, but not too low" for a 283. Seems REALLY low, but I have no idea how many miles are on this engine either. Could just be a little "loose."

In this video, I hit the gas to show the gauge response, and run it up to about 3000 RPM (it tries to throw the fanbelt above that due to a misalaigned alternator)



LASTLY:

I currently don't have a PCV Valve connected to the engine, anywhere. So the engine "breathes" passively by blowing crank pressure out the breathers. I do get quite a bit of smoke from the breathers. I'm not sure what "normal" looks like since most vehicles run a PCV, but this seems like quite a bit of blow by to me. That said, the engine shows 140-155PSI compression all around. There is ABSOLUTELY ZERO smoke out the tailpipe

Thoughts?



Anyway, that's your video trip through the clustertruck for the weekend. Really interested in everyone's input.

At this point, all the unknowns in this engine have me really leaning toward just dropping in a 350. It's more expensive but I'm starting to think the peace of mind might be worth the extra money. It is fun to full around with this old smokey small block though!

 

[miller]

New motor one less cluster on the cluster Truck!

 

[pbgbottle]

That sounds just like my engine and I just drove it 4000 km. I'll have to record my engine sound for you. I don't hear much of a lifter but I heard a rattle (first vid ) that reminded me of a sound I used to have ,do you have the exhaust crossover flapper in there the flapper at the exhaust manifold where the exhaust pipe bolts to manifold. Mine rattle and ticked like crazy. Until I welded it open.

Your Engine sound just like any old 283 to me. Your engine idles and sounds nice.

 

[RWBeringer4x4]

That sounds just like my engine and I just drove it 4000 km. I'll have to record my engine sound for you. I don't hear much of a lifter but I heard a rattle (first vid ) that reminded me of a sound I used to have ,do you have the exhaust crossover flapper in there the flapper at the exhaust manifold where the exhaust pipe bolts to manifold. Mine rattle and ticked like crazy. Until I welded it open.

Your Engine sound just like any old 283 to me. Your engine idles and sounds nice.

Hey man, thanks for chiming in. Yeah - the engine runs surprisingly well. What are your thoughts on the blow by and oil pressure? I should just drop a PCV in it and see if the smoking goes away.

I don't have the flapper valve on the exhaust, I don't think. Last I looked it was just a manifold bolted straight to the exhaust through a leaking donut.

I guess I'm just gonna grab a stethoscope and start hunting. It may just be an exhaust leak but not knowing is driving me insane!

 

[RWBeringer4x4]

@SuperBuickGuy - check out the videos above - would love your opinion on this as well since I know you build a small block every week or two!

 

[shawnfj40]

That oil pressure is very low. I would start by verifying that your gage is accurate. 30psi on a warm motor is fairly normal 25 is livable 9 is not. if you have good compression and oil rings are good you might just need an oil pump and crank kit.

 

[RWBeringer4x4]

That oil pressure is very low. I would start by verifying that your gage is accurate. 30psi on a warm motor is fairly normal 25 is livable 9 is not. if you have good compression and oil rings are good you might just need an oil pump and crank kit.

Hey Shawn -

I generally agree with you - In my very limited experience with engines, I have read that my oil pressure to be at least 20psi - but if you dig around on various Chevy forums you find a number of guys getting 10ish PSI on fresh rebuilds. A lot of folks over there seem to think that if the clearances on the crank bearings are just a bit wide, 10psi isn't a huge issue, as long as pressure rises with RPM. In fact, the "oil pressure light" doesn't come on until 4-6 psi on most old Chevys.

I don't know how much I buy this as truth but the old "rule of thumb" was always 10psi per 1000 rpm. If that's the case, mine is still borderline, but "acceptable"

Definitely not saying you're wrong here - because even if mine is acceptable, it's borderline, just playing devil's advocate.

 

[Snowdogyyz]

Hey Shawn -

I generally agree with you - In my very limited experience with engines, I have read that my oil pressure to be at least 20psi - but if you dig around on various Chevy forums you find a number of guys getting 10ish PSI on fresh rebuilds. A lot of folks over there seem to think that if the clearances on the crank bearings are just a bit wide, 10psi isn't a huge issue, as long as pressure rises with RPM. In fact, the "oil pressure light" doesn't come on until 4-6 psi on most old Chevys.

I don't know how much I buy this as truth but the old "rule of thumb" was always 10psi per 1000 rpm. If that's the case, mine is still borderline, but "acceptable"

Definitely not saying you're wrong here - because even if mine is acceptable, it's borderline, just playing devil's advocate.

I'm running a 1975 SBC 400. My oil reading is between 18-20 at idle and 195 water temp. Brand new Dakota Digital gauges. Just to give you a comparison. Not sure if there should be differences between your 283 and my 400.

 

[RWBeringer4x4]

I'm running a 1975 SBC 400. My oil reading is between 18-20 at idle and 195 water temp. Brand new Dakota Digital gauges. Just to give you a comparison. Not sure if there should be differences between your 283 and my 400.

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Those Gauges are so pretty...DD really did a good job!

I need to verify the accuracy of the gauge before I go much further down the oil pressure road. It's a mechanical gauge that came with the truck - the sending unit leaks badly and I've never hooked up something different to confirm the accuracy.

Anyone have any thoughts on the smoke out the breathers? Is this level of smokiness "normal" and usually sucked up by the PCV or would this be considered excessive?

 

[pbgbottle]

I would run the pvc it will suck that smoke right up. You should have a pvc. Do you not want one? Just curious.

 

[awynne56]

Dd did such a good job on those gauges I just don't wanna fix something not broken. For what it's worth on my 350 oil pressure drops to 12-13 psi when in drive stopped.

 

[RWBeringer4x4]

I would run the pvc it will suck that smoke right up. You should have a pvc. Do you not want one? Just curious.

The engine originally had a PCV (one of the first that didn't use a road draft tube) but when I first bought it, it was malfunctioning and my father in laws hotrodder buddy took it out and slapped a breather in it. Said PCV's were junk. Funny thing is the same guy looked at my engine last weekend and said "you're getting a lot of blow-by, why aren't you running a PCV??"

Dd did such a good job on those gauges I just don't wanna fix something not broken. For what it's worth on my 350 oil pressure drops to 12-13 psi when in drive stopped.

Yeah - I also don't want to fix what isn't broken, hence the 7 page long thread trying to figure out if this 283 is shot haha!