Which rings will save this?

[rebelrouser]

Hi, this is my first post so bear with me.
I built an engine for an old Vette using a 1972 4 bolt main truck block. It was a standard bore virgin block. I am out in the boonies so only one machine shop close and I had them punch it .030 over. I got it back, checked all bores with a good bore gauge and they were all spot on. I used Icon forged pistons with 1/16 inch rings. The pistons came with Hastings plasma moly ductile iron rings. Not knowing any better I slathered all (rings pistons & cylinders), in Valvoline VR1 high zinc oil and assembled. I used a scat forged 327 crank & rods, a mild (300HP) cam, edelbrock carb and performer manifold. I primed engine, filled carb, static set timing and lit it off. Fired right up, bumped to 1800 for cam break in and immediately oil smoke started. That didn't alarm me at first, but when it hadn't cleared in 15 minutes I new something was wrong. At 25 minutes I had idled it, set timing, mixed idle and shut it off. I pulled the intake and it had sucked the gaskets and flooded most cylinders with oil. I have since dumped the aluminum intake, which checked at .003" narrow at the bottom and replaced it with a 1965 square bore chevy iron manifold off of a 65 327. That one checked at .003" positive. Bolted that all up, fired it up and it seemed good, untill it got fully warmed up. Then the oil smoke came back. I had already dumped the oil with the break in additive and filled with VR1 20/50. I went out and drove it like I stole it. Just a lot of reasonably hard pulls and coast downs. At 200 miles it still smokes bad. Mainly after deceleration, or taking off from a stop, or any time you jump on it there is some. In 40 miles it will burn an 1/8 off the stick. So I tore it down again, intake seated no leaks. Valve guides are new, sealed and look good. Exhaust full of oil. I tore the motor completely down and it appears that the shop did not use a torque plate. I want to clean this up, and get some rings in it that will work. finding another shop, re-boring and getting new pistons is not workable for me now. I have three ring options. Plain old phosphate coated cast iron, plasma moly iron and plasma moly ductile iron. I am not sure if these rings didn't seat because of too much oil, or the distortions in the bore keep them from working. What might work? I have a new 240 flex hone and a new 320 flex hone, and all of the rings are available to me. Here are some pictures of the bore.IMG_20230318_130121776_HDR.jpgIMG_20230318_130045700_HDR.jpgIMG_20230318_130238251.jpgIMG_20230318_130245350.jpg

As Mentioned lot of ways to get oil sucked into an engine. Not being critical, but a cylinder leak down test might have been a diagnostic tool that would have saved you from taking the short block apart. I have had several guys bring in engines to run on my dyno that smoked like a stove, and all of them were either the intake leaking sucking in oil or PCV valve with lack of baffles in the valve covers. One guy had a 409 and where the old draft tube was at the back of the block they had installed a PCV valve, it smoked really bad. I don't see any issues from your pictures to cause a lot of oil smoke. Lightly hone it put back together. Once it is together leak it before starting, it will tell you if the cylinders are sealed up. Leak it again after it has run a while it should be better.

[benrep]

Ben,

I think you need to stop for a minute and think this out before you make things worse.

Millions and millions of engines have been honed without torque plates. It simply is not an issue.

Are you absolutely certain the rings were installed correctly ? I have seen more than one instance of them not correct and cause exactly the same problem. Post a picture of one of the pistons with the rings on it so we can see the ring faces.

Which part number piston ?

I would not touch the cylinders at this time. If you do end up doing anything just use a 320 or so grit dingle hone for a few strokes but I am not sure if I would even do that. Actually if you dont find another cause I would take it back to the machine shop and have them hone it a few strokes with a real hone.

How about some pictures of the intake gaskets to see how they are sealing ?

I just got in from the shop and I think you are correct. I just pulled the heads apart that were supposed to be perfect and found most of the intakes and some of the exhaust guides were knurled. A few guides were replaced. The knurled ones are definitely looser than the new ones. Those intake valves have evidence of lots of oil flow. The intake gasket was completely sealed and stuck to heads and intake. No oil there. The rings are all installed correctly, all dots up. They do look good, a little shine on the bottom of the second ring as there should be. I didn't think valve guides could loose that much oil, enough for wet exhaust ports and pipes. The intake valves do have good seals mounted on a machined surface, but the stems were very oily. The engine makes 18 inches of vacuum at idle. if the rings were letting oil by would it end up on the uphill side of the intake valves? I have very little overlap, 112* lobe separation.

[Tuner]

Are the steel cup umbrellas under the retainers over the springs installed and are the "square" O-rings properly installed inside the retainers?

[HQM383]

I have seen before where flat tappet lifters were not metering the oil through the pushrods correctly leading to flooding the top end with oil. Metering plate missing from memory. Oil was easily pulled through the submerged guides. New set of quality lifters fixed it. Maybe take a peek inside the lifters of the worst cylinders?

[jeff swisher]

I built 2 302 Fords both 1982 year both got the same cam and same pistons and rings and the heads were reused off the first build.
First build was Honed with TQ plates and second one was not.
The first one was broke in with mobil 1 synthetic this was in the year 2000.
Used 1 quart of oil from OKC to Phoenix.
I changed oil there and never used another drop.
E251K rings Those are wide rings.

2nd one did not get TQ plates and it used 1 quart every 3000 miles it was a 6 quart system and most of the driving time it was at 3000 rpm or higher.
Those 302 engines are thin.
I had 1 heads rebuilt at a shop and the reason was it needed new guides.
I got home and pulled valves to do some final porting and found 1 guide with more clearance than I thought was right.
I was young then and trusted people.

I called the shop and told them and they said everything was fine and run it.

I ran it and 2 weeks later that intake guide was shot and that cylinder cranked 60 PSI and all the others were 245.

Just saying that because unless you checked them yourself.

Now on the seals I do not like the Oring deal from GM on older heads I like viton valve seals that fit over the guide.
But the GM O ring with oil shedders Umbrellas did work when all clearances were good.

[bentvalves]

can you feel that hone finish with your fingernail?

[nxtruck]

I had a similar issue with a 355 sbc that I built about 6 years ago. Had the local and reputable machine shop bore and hone the block .030” over, machine the crank, rebuild the rods, and rebuild the 993-casting heads. Put it all together with a mild elgin cam (A Comp Cam 268h copy), broke the cam in with Comp Cams 10w30 break-in oil, and started driving it. After a few hundred miles, I could tell something wasn’t right. It was coating the plugs with oil and the tailpipes showed signs of oilyness. I found that the machine shop had stuck umbrella seals on it instead of the viton seals I had asked them to use. I also suspected the guides may be a touch loose. So, I pulled the heads, took them back to the shop, and we looked everything over. After finding the guides were loose and the wrong seals, they agreed to make things right. And they did. They installed bronze guides, set the clearances at .0012-.0015, and installed the viton seals. I reinstalled the heads and the oil consumption stopped. No more oily plugs or signs of oil in the exhaust. I would make sure that your guide clearances are within spec and, like Jeff said, use a viton seal. Like everyone else said, I don’t see an issue with the finish on your cylinders and a baffled valve cover is a must when using a pcv valve. Good luck with your project!

[Tuner]

can you feel that hone finish with your fingernail?

If an old penny (actual copper-not copper plated zinc- pre`79-`80?) can be rubbed on the cylinder wall without removing any copper, it’s smooth enough to be relatively safe but not necessarily smooth as would be ideal. It is my opinion that the plateau surface above the cross-hatch should be as smooth as possible and that isn’t smooth enough.

With a spring loaded three-legged trapezoid type “glaze breaker” hone put duct tape sticky side out over the stones (do a good job of securing the tape behind the stones) and use 400 wet-or-dry paper to polish the cylinders. Put the paper in the cylinder first and let the hone expand into it so the paper sticks to the duct tape. If the cylinder is large, a sheet of paper may have to be cut in half and the haves offset to get full coverage on all three stones. The two pieces have to be overlapped the right direction so they don’t act like a sprag. One way they trail and turn easily and the other they wedge up and jam. Use a ¼ or 3/8 drill motor and trickle water from a hose while you polish. WD 40 is OK but it’s messier and you have to wash with water in the end anyway. A trickle of water flushes the trash away and the paper doesn’t load up as quick. Stroke up and down to generally follow the existing cross-hatch scratches. If you have the patience for it, follow the 400 with 600 and 1000 paper. Naturally, you have to be careful not to tear the paper or let the stones touch the wall and scratch it. I don’t think the walls can be made smooth enough.

400 paper will polish the walls and achieve the “plateau finish” that has been the subject of a lot of mumble over the years and won’t remove enough material to eliminate the crosshatch marks of the stone hone job so there will still be enough oil to keep the “don’t make it too smooth” crowd happy. The surface of the moly ring is full of microscopic fractures that are where the oil molecules hang out, so the wall doesn’t have to be rough.

This is the exact process that Glidden and the every other Pro Stock engine builder I know are using with the ultra tiny, super thin rings with PVD-Moly face. Most stop with the 600 grit paper. Most hard core SS/ and Stocker racers have done this for as long as I can remember. We abandon it for a long time but came back to it when it proved to be better in testing. Its funny how things come full circle. The penny trick I have not heard of. I will try that.

[Tuner]

Now on the seals I do not like the Oring deal from GM on older heads I like viton valve seals that fit over the guide.
But the GM O ring with oil shedders Umbrellas did work when all clearances were good.

My thought was if they are not there it makes a bad situation worse.

[stealth]

Head gasket issue??

This looks suspicious ....

pic1234.PNG

[superpursuit]

I just got in from the shop and I think you are correct. I just pulled the heads apart that were supposed to be perfect and found most of the intakes and some of the exhaust guides were knurled. A few guides were replaced. The knurled ones are definitely looser than the new ones. Those intake valves have evidence of lots of oil flow. The intake gasket was completely sealed and stuck to heads and intake. No oil there. The rings are all installed correctly, all dots up. They do look good, a little shine on the bottom of the second ring as there should be. I didn't think valve guides could loose that much oil, enough for wet exhaust ports and pipes. The intake valves do have good seals mounted on a machined surface, but the stems were very oily. The engine makes 18 inches of vacuum at idle. if the rings were letting oil by would it end up on the uphill side of the intake valves? I have very little overlap, 112* lobe separation.
[/quote]

Knurling the valve guides creates a spiral, like a thread, for the oil to travel down into the cylinder. If they are in fact knurled then this is more than likely your problem. It will give you all the symptoms of a worn out valve guide regardless of the actual clearance.(Oil in cylinder, smoking on deceleration, etc.)


Hope this helps you.
Allan.

[mag2555]

Plus knurling reduces the support that you want the stem to have from the lenght of the guide by nearly 60%.

[rgalajda]

“Valve guides are new, sealed and look good.
 I pulled the intake and it had sucked the gaskets and flooded most cylinders with oil.
I have since dumped the aluminum intake, which checked at .003" narrow at the bottom and replaced it with a 1965 square bore chevy iron manifold off of a 65 327. That one checked at .003" positive.”



How does “Valve guides are new, sealed and look good.” turn into knurled valve guides.
Have the valve stems been checked for wear?

 “I got it back, checked all bores with a good bore gauge and they were all spot on”
How does one own a bore gauge but not check the cylinder head guides ?

What does .003” narrow at the bottom of the intake mean? How did you measure that?

[modok]

If using moly rings I recommend honing that engine with a torque plate.
What rings would "SAVE" it? I would say do a glaze break and go with plain cast iron rings for quick seating.

BUT, is it even the rings? the heads sound suspicious from what you said.

[jed]

All of the items discussed above are concerns to look out for but what really concerns me is the cylinder wall finish. Don’t think I’ve ever seen a finish quite like this. I’m going to call it a herring bone finish. I think what ever else you find and correct you will have to rehone the cylinders. I also think it will take possibly .0005 to clean up the cylinder. Remember that’s only .00025 a side. JMO