Smoke on acceleration - video
 

I’m going to do a compression check to see if it’s the rings. Once I got everything together, there was not really any smoke coming from the exhaust. However, when I blipped the throttle, smoke came from the exhaust; bluish hue. I figure the valve stems are probably ok.
And, since I’m going to have the trans out of the truck, it might be a good time to pull the motor if the rings are bad.

Just checking to see if my thinking is correct on the smoke @acceleration. What do you guys think?

Also, how do I determine what size rings I need for my pistons?


Trying to post link to video- hope this works:
https://youtu.be/sSD6IEEq-Is

Re: Smoke on acceleration - video
 

I watched the video, are you talking about the smoke coming from the breather? If you're getting noticeable increase in fumes/smoke from the breather as you rev. the engine, especially with no load, I'd say your due for an overhaul. Blue smoke from the exhaust means you're burning oil, but it could be from the valve guides too.
The size of rings that you need will be determined after teardown and depending on whether it needs machining.

Re: Smoke on acceleration - video
 

When I revved the motor, the smoke was more prominent from the leaking exhaust pipe and muffler.

Re: Smoke on acceleration - video
 

It’s time for an LS

Re: Smoke on acceleration - video
 

Needs rebuilding. That's blow-by coming out the breather cap- combustion gases leaking by the rings. The rings are shot.

Re: Smoke on acceleration - video
 

I could cure that smoky breather in two shakes.
So could you Steve if you look closely.

Re: Smoke on acceleration - video
 

How would you do that?

Re: Smoke on acceleration - video
 

Did compression check, all cylinders 155-165. Added oil to each and no increase in compression readings.
Maybe it’s just valve guides?

Re: Smoke on acceleration - video
 

:lol: Yeah, buddy!

Asshat- Put a PCV valve on that valve cover and connect the hose from it to the carb! That'll at least recycle the smoke. I thought you were getting smoke out the tailpipe. That accelerator pump or the circuit need a little help to get that stumble out when you speed the engine up.

Re: Smoke on acceleration - video
 

In the video you should be able to see the new PCV valve.

And, I am getting smoke out of the tailpipe.

Re: Smoke on acceleration - video
 

Might be new but it does nothing if it’s not hooked up!

Re: Smoke on acceleration - video
 

It's plain as day, it's right in the first part of the video. The hose from the manifold goes to the PCV valve.

Re: Smoke on acceleration - video
 

The only hose I see of the intake goes to the steering column but if it’s smoking from the exhaust it don’t matter

Re: Smoke on acceleration - video
 

New video.

https://youtu.be/7jyLDeL3MMk

Re: Smoke on acceleration - video
 

Any idea how many miles are on that engine?

Re: Smoke on acceleration - video
 

No idea. That is why I am pulling it.
Going to check the pistons and bearings.

Re: Smoke on acceleration - video
 

Debating on whether I should just re-ring the pistons and hone the cylinders or send this off to a shop and get everything re-done.

I am inSouth Orange County CA, so there's not any shops right around me. Everything is up towards Santa Ana and Orange. Anyone have a shop they used in this area?

What would you guys do if you were on a limited budget?

Re: Smoke on acceleration - video
 

This is what everybody is looking at I think...when the say the pcv not hooked up

Re: Smoke on acceleration - video
 

Yeah, that was in the first video I posted. However, I did pulg in the manifold vacuum hose to the PVC, and it still does smoke as seen in the latest video above.The motor is out of the truck, so at this point it doesn't really matter.

Re: Smoke on acceleration - video
 

I got ya..good luck with the rebuild...

Re: Smoke on acceleration - video
 

Your primary concern for how to approach either rebuilding it or just a ring job is to assess the cylinder walls. Is there a ridge near the top where the piston rings stop going up on the stroke? Do you have some inside calipers that can reach into the bore and measure for ridge thickness and taper?

I'd like to see a piston to look at the oil control rings. Even with good compression if the oil control rings are not wiping the cylinder properly, it's still going to smoke. Do you know anyone on the board knowledgeable enough to help you with that assessment? I'd look at it but I'm about 60 miles away, and I loathe driving the 405 after about 27 years of doing that.

Re: Smoke on acceleration - video
 

I may be able to borrow some inside calipers from work. It’s been about 30 years since I rebuilt a motor, so I am a bit rusty. When I get the block disassembled I can post some pics. I really don’t know anyone on the board that is near me. I’ll have to some checking around and see if there’s a machine shop nearby. The main problem is finding a shop/machinist I can trust.

Re: Smoke on acceleration - video
 

There is a slight ridge at the top of the cylinder bore, about 3/8” below the block surface.

Re: Smoke on acceleration - video
 

Pull the rings off one piston and check their fit and gap.
Use A feeler gauge To measure.
You might find none of the rings will stay in the bore to be measured though.
I’ve seen that on a 396 that burned a quart every 1oo miles.

Re: Smoke on acceleration - video
 

Calipers won't be accurate enough to measure past the cylinder ridge and on down into the bore...you'll need telescoping gauges and micrometers..or a true bore gauge...
And ditto to what geezer says...