Hot Rod Forum banner
21 - 40 of 43 Posts

·
Registered
Joined
·
1,964 Posts
Compression rings and oil rings are two different functions. The most likely time you see both fail is in high wear engines where the cylinder walls are gone in taper and ovalness.

One thing not considered is wiped cam lobes. Which arrives at the question of one cylinder or many showing oil pull over?

Lots of problems with guide fit on aluminum head’s. Final fit should be with a reamer not an abrasive brush.

Bogie
Brodix recommended " wet hone" to finish thier guides a few years ago ...
 

·
Registered
Joined
·
1,964 Posts
Yeah, seal protector is like a piece of a plastic straw, just shrunk nearly closed on one end...like a condom for the valve tip. Soft clear plastic.
All of them I have came in with the sets of valve seals....but not all sets come with the protector and I don't have a clue why, so I save them in my toolbox so I always have one.
Valve gets installed in the head, seal protector over the tip after that, then the seal pushed on.

Prepping the valve stem/keeper groove sherp edges I do with a small hone stone....600 grit wrapped around a popsicle stick or piece of keystock woulsd also work.

Pushing the valve through a new seal in theory wouldn't hurt the seal since you need the upper edges of the seal surface to remain as manufactured....the main damage is pullng an unprepped valve out through the seal, that can knick the upper square edge of the seal lip and turn it into a tiny funnel at the seal-to-valve interface

No idea if the propane through the oil return hole would be a valid test.
I think I remember getting some extra protectors from Alex's parts ?
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #24 ·
Compression rings and oil rings are two different functions. The most likely time you see both fail is in high wear engines where the cylinder walls are gone in taper and ovalness.

One thing not considered is wiped cam lobes. Which arrives at the question of one cylinder or many showing oil pull over?

Lots of problems with guide fit on aluminum head’s. Final fit should be with a reamer not an abrasive brush.

Bogie
Hey Bogie! The block was bored and and torque plate honed. With only 2500 miles, I expect the bores to be in petty good shape. I checked the bore job for taper and clearance before assembly as well as "ovalness". All cylinders had .0015" - .0018" piston to wall clearance. KB Hypers. My ring seal is good as per my leakdown gauge. 1.5-2% leak in all cylinders.

It has a hydraulic roller cam. I just inspected all the valve train about a month ago. All good.
I measured all the guides when I assembled the bare heads. .3415" OD valve stems in .3433" ID guides. Very consistent .0018" clearance in the intake and exhaust guides. ( I keep good notes.) This problem is either valve seals or ring issues. I am quite sure.

Well, this AM I decided to go ahead and remove the heads to just see what is going on in there. I have head gaskets and intake gaskets in stock. At that point, if I don't like what I see, I'm only about an hour away from having the engine out of the car and on the stand.
 

·
Rod...from a Chrysler?
Joined
·
5,647 Posts
wrong thread.....carry on..........
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #26 ·
I'm not there yet, but if I decide I need to put new rings in it, what is the best plan for a deglaze/ hone job on a very low mile engine? Dingleberry or back to the machine shop or ??.
 

·
Registered
Joined
·
14,580 Posts
Moly rings line a fine and plateaued finish, I recommend against a dingle berry, as far as the shop they need to understand the different hone finish needs of cast iron compared to chrome compared to moly faced rings.

Especially where chrome is concerned the finish is coarse this is needed to break the hard ring surface to the wall. Done to a moly faced ring it tears them up. Moly likes a light finish, done to a chrome ring they will never stop burning oil.

As head’s go it is important to be sure the guides were super cleaned then lubricated. Grit left behind from honing the guides carves them up pretty fast when left over grit and hard chrome valve stems go to work on the guide. I use chemistry lab tube brushes and lots of clean solvent to scrub them followed by high pressure air dry, then I plug the bottom with a wood plug sufficient to slow or stop leakage then fill each guide with light oil and let ‘em soak for a couple, three days. Then drain and drip for another day before starting assembly.

I don’t like abrasive honing the guides beyond that needed to put oil retaining scratches in the guide. Non ridged hones are a random cutting device with no control over concentricity nor linearity of their cut. It’s easy to get out of round and tapers, waves and or bulges in the length. It takes experience to drive these tools without screwing up the results. Amateurs and low time pros are well advised to stay with the more expensive precision cutting tools than cheaping it out with dingle berries.


Bogie
 

·
Registered
Joined
·
1,964 Posts
I'm not there yet, but if I decide I need to put new rings in it, what is the best plan for a deglaze/ hone job on a very low mile engine? Dingleberry or back to the machine shop or ??.
Mine had close to 10k miles on it . 240 grit flex hone , just enough to get a good crosshatch Rings seated immediately . compression / leakdown is very consistent . AFA " cutting " the cylinder walls unevenly , the hone people say you'd have to ride the hone for days to remove a measurable amount of metal , ( slight exaggeration ) checking with a dial bore gauge , before & after honing. I could not detect where anything had been removed . I'll check the grit # tomorrow to be sure ...
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #29 ·
I got the heads off last night. I had the heads half way cleaned up before I realized I should have taken pictures to post. Every intake valve was coked up on the backside of the valve head. Pretty bad. Except #3 intake valve which looked like the day I installed the new heads, port and valve whistle clean. Not sure why that is except that was the only cylinder that the valve seal was good on?
I would say that bad valve stem seals is the culprit. Oil coming from the bottom end would not coke up the back side of the valves, would it?
I disassembled the heads and measured all the valve guide ID's. They show no wear at all since installation. Still at .0018" clearance.
I'm pretty well convinced that valve seals are the problem, not rings or guides. I think, unless some of you guys think different, I will just clean, install new seals, and reassemble the motor. And see what happens. It only costs a few gaskets and a few hours work if seals are not the problem.
 

·
Registered
Joined
·
14,580 Posts
That or the plugs are too cold a common problem with aluminum heads as thy pull heat really fast. It is likely that it is seals given that 7 out of 8 are showing coking of the valve backside. Probably from damage incurred upon valve assembly or enough lift to where the valve retainers are hitting the seal lip. Possibly the spring if they are not contained by the head. There needs to be a steel cup http://store.440source.com/images/2001065.jpg or spring locator http://contentinfo.autozone.com/znetcs/product-info/en/US/edm/5770/image/3/ between the head and spring. These are sized to the spring OD as well as guide OD.

It might be the intake gasket isn’t making a tight seal, this is a common problem with aftermarket parts like head’s and machine operations like block decking and or head milling with the intake going uncorrected for these material removal operations which result in dimensional position changes of the head’s that result in them sitting lower and closer together. An uncorrected intake sits high and cannot close the valley off to where an internal leak sucks oil from the valley past the intake gasket. Look carefully at the gasket and the lower port bosses for oil staining that will indicate leakage past the gasket.

Bogie
 

·
Race it, Don't rice it!
Joined
·
8,281 Posts
OIl on the backs of the valves indicates it's pulling oil from above the guides and your leak down numbers look pretty good so I'd look at the stem seals, rocker stud threads, or intake gaskets.
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #32 ·
That or the plugs are too cold a common problem with aluminum heads as thy pull heat really fast. It is likely that it is seals given that 7 out of 8 are showing coking of the valve backside. Probably from damage incurred upon valve assembly or enough lift to where the valve retainers are hitting the seal lip. Possibly the spring if they are not contained by the head. There needs to be a steel cup http://store.440source.com/images/2001065.jpg or spring locator http://contentinfo.autozone.com/znetcs/product-info/en/US/edm/5770/image/3/ between the head and spring. These are sized to the spring OD as well as guide OD.

It might be the intake gasket isn’t making a tight seal, this is a common problem with aftermarket parts like head’s and machine operations like block decking and or head milling with the intake going uncorrected for these material removal operations which result in dimensional position changes of the head’s that result in them sitting lower and closer together. An uncorrected intake sits high and cannot close the valley off to where an internal leak sucks oil from the valley past the intake gasket. Look carefully at the gasket and the lower port bosses for oil staining that will indicate leakage past the gasket.

Bogie
Yep. Easy enough to try the next hottest plug. I'm using NGK 5671A-7 currently.
There are locators and .075" shims under the springs.
The block has been decked .015". I checked the angle. It feeler gauges good. I have a bore scope and I looked down the manifold to check port alignment. Looked good. Earlier I suggested running a hose in the oil return hole in the head into the valley and the other end out the oil fill hole in the valve cover and hook it to a valved propane source or other flammable source. With the engine running, turn on the propane. If the engine speeds up, there is a leak? Wouldn't this be the same as spraying starting fluid around the manifold to find vacuum leaks? This problem gets brought up a lot. It would be good to have a diagnostic test for it.

I have the heads cleaned up and ready to assemble. Seals should be here tomorrow PM. I still have the decks and carboned up piston tops to clean. I have done this a lot of times and hated it every time. I keep the Shop Vac focused, but there is always crap that gets in the bore clearance. Any good tips for this operation?
 

·
Registered
Joined
·
1,964 Posts
I got the heads off last night. I had the heads half way cleaned up before I realized I should have taken pictures to post. Every intake valve was coked up on the backside of the valve head. Pretty bad. Except #3 intake valve which looked like the day I installed the new heads, port and valve whistle clean. Not sure why that is except that was the only cylinder that the valve seal was good on?
I would say that bad valve stem seals is the culprit. Oil coming from the bottom end would not coke up the back side of the valves, would it?
I disassembled the heads and measured all the valve guide ID's. They show no wear at all since installation. Still at .0018" clearance.
I'm pretty well convinced that valve seals are the problem, not rings or guides. I think, unless some of you guys think different, I will just clean, install new seals, and reassemble the motor. And see what happens. It only costs a few gaskets and a few hours work if seals are not the problem.
My intakes were horribly coked up , cleaned them & installed new seals when I went through it , boroscope shows reasonably clean since . one clean valve could mean that valve was being " washed " . I guessing but running rich / cold plugs , low speed operation , cam overlap all play a roll in buildup on the valves ...
 

·
More for Less Racer
Joined
·
20,453 Posts
I have the heads cleaned up and ready to assemble. Seals should be here tomorrow PM. I still have the decks and carboned up piston tops to clean. I have done this a lot of times and hated it every time. I keep the Shop Vac focused, but there is always crap that gets in the bore clearance. Any good tips for this operation?
Don't bother with cleaning th carbon off the piston tops....once running, the engine is just going to proceed to start carboning them back up, so why run the risk of getting carbon chunks into the ring lands or between piston and wall.
Just let them be, they will be fine.
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #35 ·
Don't bother with cleaning th carbon off the piston tops....once running, the engine is just going to proceed to start carboning them back up, so why run the risk of getting carbon chunks into the ring lands or between piston and wall.
Just let them be, they will be fine.
LOL. OK. I'll leave 'em be. That is the exact reason I would never make a flat rate mechanic. I am obsessed with not putting things together dirty.
 

·
'23 T-Bucket Pickup
Joined
·
1,850 Posts
Did you use #2 Permatex or equivalent on the intake bolts ? There are a couple of threaded holes for the intake bolts in the head that go in to an intake runner. Just a thought
 

·
'23 T-Bucket Pickup
Joined
·
1,850 Posts
Did you use #2 Permatex or equivalent on the intake bolts ? There are a couple of threaded holes for the intake bolts in the head that go in to an intake runner. Just a thought
Not the intake runner. My mistake. I’m thinking in the area under the valve cover. Some are blind holes and some go through. It’s been a couple of years since I last built an engine.
 

·
Registered
Joined
·
6 Posts
Hi there, Just wondering did you deglaze the bores, If not that could be the problem. You can still have reasonable compressions and/or leak down but use oil if they were not deglazed or honed. Additionally rings have a cupping with some brands and you can install them upside causing oil consumption. Did you check the rings to see if they were cupped?
Regards
Bill
 

·
Registered
Joined
·
198 Posts
I had a new 383 that used A LOT of oil. It turned out the intake gaskets were sucking oil from under the intake. Replaced gaskets and problem went away. Odd but true. Vortec heads.
 

·
Registered
Joined
·
1,167 Posts
Discussion Starter · #40 ·
Hi there, Just wondering did you deglaze the bores, If not that could be the problem. You can still have reasonable compressions and/or leak down but use oil if they were not deglazed or honed. Additionally rings have a cupping with some brands and you can install them upside causing oil consumption. Did you check the rings to see if they were cupped?
Regards
Bill
Block was bored and torque plate honed. Rings were installed as per directions on box. Dot up. It is possible that I made a mistake. Though really unlikely. I have installed a lot of rings. But still possible. If valve stem seals and new sealant on rocker arm studs don't fix it, that will be the next area for inspection. I'm hoping that is not the problem.:)

I had a new 383 that used A LOT of oil. It turned out the intake gaskets were sucking oil from under the intake. Replaced gaskets and problem went away. Odd but true. Vortec heads.
The block has been decked, which sometimes causes this problem. I have laid the manifold on and used feeler gauges to check for parallel surfaces at the head and manifold mating surfaces. According to the feeler gauge, the surfaces are parallel within a thousandth or two. This should not be the problem.
The 383 in my roadster (different engine) takes the thick Felpro 1266 intake gasket (.120" thick IIRC). A 1206 will not let the ports line up well and would definitely leak. On this engine the thin FelPro 1205 or the Edelbrock 7201 both will work.

I am setting the valves this AM and will finish up engine assembly today. My transmission should be done today or tomorrow, so I can get my Model T back on the road in the next couple of days. I'll let you guys know if my efforts have helped the oil consumption problem or not. If not I'm into engine removal and complete disassembly.:(
 
21 - 40 of 43 Posts
Top