Need engine help!! At my wits end

[Nick88]

What's up guys. Recently I built the motor in my 1986 crewcab from a 350 to a 383 stroker. The engine has an issue though that it burns a ton of oil. Originally it had a comp cam flat tappet that wiped out on break in, I believe that's when the problems started. I have tried everything to stop the oil usage. It has blow by and drinks probably almost a quart of oil from idling for an hour. It puts out constant blue smoke at idle and when revved makes a grey blue cloud. It is FAR worse without a pcv valve. Without the pcv it puts out noticeable blowby from the breather and let's out a ton of smoke at idle. I checked compression, every cylinder cold is 170-180. I checked the intake gasket, the ports line up and everything is the right angle and sealed. Truck makes 40-50 psi of oil pressure hot at idle and probably 60-70 starting on a 60 degree day. What could possibly be wrong with this motor? Cylinder 3 and 4 barely have any oil on the plug, cylinder 8 has a bunch, i also believe cylinder 8 is the one that the cam lobe wiped out. The motor makes no weird noises and idles good but buttchugs oil. Please anyone help with this, what could cause the engine to have these symptoms, im stumped. Thanks.

 

[Ricko1966]

What's up guys. Recently I built the motor in my 1986 crewcab from a 350 to a 383 stroker. The engine has an issue though that it burns a ton of oil. Originally it had a comp cam flat tappet that wiped out on break in, I believe that's when the problems started. I have tried everything to stop the oil usage. It has blow by and drinks probably almost a quart of oil from idling for an hour. It puts out constant blue smoke at idle and when revved makes a grey blue cloud. It is FAR worse without a pcv valve. Without the pcv it puts out noticeable blowby from the breather and let's out a ton of smoke at idle. I checked compression, every cylinder cold is 170-180. I checked the intake gasket, the ports line up and everything is the right angle and sealed. Truck makes 40-50 psi of oil pressure hot at idle and probably 60-70 starting on a 60 degree day. What could possibly be wrong with this motor? Cylinder 3 and 4 barely have any oil on the plug, cylinder 8 has a bunch, i also believe cylinder 8 is the one that the cam lobe wiped out. The motor makes no weird noises and idles good but buttchugs oil. Please anyone help with this, what could cause the engine to have these symptoms, im stumped. Thanks.

Revive your old thread so we can see all that's happened. So we don't all ask the same questions again. And we don't make all the same suggestions again.

 

[Nick88]

Revive your old thread so we can see all that's happened. So we don't all ask the same questions again. And we don't make all the same suggestions again.

That old thread was mainly for the intake gasket I believe, but that's fixed now and it's still having the same problem, that's why I figured I would make a new one to try to gain more traction. Apologies.

 

[Ricko1966]

All this is pertinent information.

https://www.gmsquarebody.com/threads/new-engine-troubles-need-help.47122/

 

[77Dmax]

Get a boroscope. Put it down the intake and look at all 8 intake valves, if its pulling through the valvetrain it'll be obvious- the valves will have build up and be oil soaked.

Also scope the cylinders, specifically #8 for a cracked piston. Usually with a cracked piston the engine will huff oil smoke like crazy out the fill cap.

I've also seen an HV/HP oil pump provide way too much oil to the top end and submerge the valves in oil. That caused massive oil smoke.

 

[Ricko1966]

I'm still wondering if the rings are on upside-down or the wrong width,spreaders overlapped etc.

 

[xm20k]

Like I suggested in the first thread it could have glazed the cylinders and not seated the rings. If that is the case it needs a re hone and new rings.

 

[Nick88]

Get a boroscope. Put it down the intake and look at all 8 intake valves, if its pulling through the valvetrain it'll be obvious- the valves will have build up and be oil soaked.

Also scope the cylinders, specifically #8 for a cracked piston. Usually with a cracked piston the engine will huff oil smoke like crazy out the fill cap.

I've also seen an HV/HP oil pump provide way too much oil to the top end and submerge the valves in oil. That caused massive oil smoke.

I'll have to do that. The oil pump is just a stock one, puts out like 40-50 hot at idle and maybe 50-60 hot when revved, nothing crazy.

 

[Nick88]

I'm still wondering if the rings are on upside-down or the wrong width,spreaders overlapped etc.

I made sure that the rings were all clocked and the right way before installing, they were whatever rings came in the rotating assembly kit.

 

[xm20k]

I'll have to do that. The oil pump is just a stock one, puts out like 40-50 hot at idle and maybe 50-60 hot when revved, nothing crazy.

While your in there look at the cylinder walls and see if it still has crosshatch or if it's polished smooth.

 

[Nick88]

Like I suggested in the first thread it could have glazed the cylinders and not seated the rings. If that is the case it needs a re hone and new rings.

I'll have to get a horoscope and check. Would the compression be so high with the rings not seated fully? Also it seems only 1 of the cylinders is the problem, the rest of the plugs don't look too oily, would it be possible for only 1 cylinders rings not to seat and to cause this many problems?

 

[Nick88]

Borescope ordered and coming overnight. Any other suggestions to what could be causing this?

 

[1976dully]

You said that the rings were clocked. Hopefully that doesn't mean you lined up the split in the rings with each other.....

 

[Ricko1966]

Borescope ordered and coming overnight. Any other suggestions to what could be causing this?

Only 1 cylinder,now even more suspicious that one oil ring spreader got overlapped. And clocked is the least important part of installing rings,they walk on their own,you'll tear 100k original motors apart with the gaps lined up that had no issues. Your biggest issues are not placing the bevels or notches up or down depending on if it's 1st or second ring,another biggie is getting on oil ring spreader overlapped.

 

[Ricko1966]

Like I suggested in the first thread it could have glazed the cylinders and not seated the rings. If that is the case it needs a re hone and new rings.

And this is very possible I think we even suggested this months ago when he was talking about how much gas he was pouring through it,and only being run in the driveway no load on the rings