Low oil pressure - possible lifter failure/defect?

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dodgedude

dodgedude

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I have a built 340 in my 68 Dart. 9.5 compression, hydraulic roller, W-2 heads, Norris stainless 1.6 rockers. I have only ran it stationary, have not drove it yet. Last night, I let it warm up to operating tempurature, and noticed that at 190*, the oil pressure was low at idle (10-15psi). This comes up immediately when given any throttle. Warm, 2000 RPM, 50psi or better. At idle, I also could hear some lifter/rocker noise, so I pulled the covers to adjust the valves. This is a hydraulic roller (COMP) with matching lifters. Everything went well, all seemed to be somewhat on the loose side, except for #6 exhaust, which I had to tighten the adjuster screw a good 1/8 inch deeper than all others to get the play out. I have not run the engine since I found this issue. (the pushrods are good, and yes, the same length, and was seated properly) The preload was adjusted 1/2 turn after play was removed (approx .025)

Could this lifter have collapsed? Or be defective? and if so, could this cause low oil pressure? My next step is to pull the intake to inspect the lifter, I guess. Has anyone else had this failure with so few minutes of running on an engine?

Thanks for your opinions.
 
Sorry, I'm not a "roller lifter" guy, buy you are gonna havta give people more than a couple of hours.....................
 
i always recommend high volume oil pump. performance builds usually have larger clearances, and some of the rocker sets have extra oiling "on purpose" (for instance it's stated in the documentation that comes with harland sharp rockers)

before the naysayers and HV pump haters come along however, here's my advice.

i'm not sure of your brand. but 1.) you should be using a brand new pump with any build dont take chances 2.) an HV pump is best unless you are using an external oiling system or dry sump system for high rpm racing engines. 3.) in your current position i would talk to the engine builder right away. you could have a broken part on that rocker set. sometimes the lock nuts or rockers themselves or whatever can get small cracks... or maybe a bad roller lifter set. call your guy. asap. i think you are wise not running it, if you run it stuff could break quickly. you could have wiped a lobe.
 
Was the engine broke-in before your last run at 190 degrees? What weight oil is in it? Manual oil press. gauge?
 
The car has not been driven, as the cam is a roller, it does not require a break in proccedure. 10/40 Valvoline with zinc additives. Melling High volumn pump. Everything is new. Ran to operating temp to verify cooling fan operation. Prior runs were only for 5-10 minutes, pressure maintained 30lbs at 850 RPM. Yes, manual guage, however I have not tried a different guage.

I had to use a smaller oil filter for header clearance issues, off os a 97 Ram magnum application. Could this be presenting issues?

Bottom end was assembled at a reputable machine shop, top end added by myself. Rockers/heads had been run on previous race engine of mine with no issues.

Oil pump was taken apart and inspected, primed, and then engine was primed with drill and priming tool before dropping in car.

Mostly concerned with lifter at this point, seems to be colapsed, but I don't know if this could cause the issue of low pressure.

I plan to check with a different manual guage, then pull intake to inspect lifter (after I call COMP) and then pull pan and check clearances, etc.

Thanks
 
I don't think a lifter is your problem, unless it has fallen out of the bore.

What is the oil pressure cold at idle?

Is this a high pressure and or high volume pump, or a standard pump? If it is a standard pump, 10 PSI at a 500 RPM idle is twice what it needs.

If you have a standard pump and oil pressure is 50 PSI or better at 2K RPM, then it is fine. If it is a high pressure or high volume, or both, then I would be worried.

Remember, roller valve trains can be noisy, regardless of being mechanical or hydraulic.

Nevermind. I see where you say it's high volume. It still my be ok. High volume doesn't always mean high pressure. How much ultimate oil pressure does the engine have as RPM increases? If it hits 60 PSI or better, I don't think the oiling system has a problem. Although, I think a high volume would have more hot at idle, but I am not sure since I normally don't run a high volume on anything.
 

Are all the oil galley plugs in place?
10-15psi at idle hot with a HV pump is way low, should be 35+ easy
Roller valvetrains tend to make some noise due to the aggressive lobes, but yours may be due to low oil pressure at idle.
I find most hydraulic rollers like 3/4-1 full turn of preload.
 
Have you pulled the intake to look? In my opinion preload should be initially set before the intake is on. "X # if turns" is kind of vague and I like to verify by measuring. Then you can jot down the number of turns for your engine and be done.
1/8" is a big change. I'd pull it and look before you mess more with it. I do think the pressure is low for an HV pump. I don't use them and I generally have 15-20psi at hot at idle and 40+ at 2500. But if your shop set the clearances wide that could be it. Regardless - I'd want to see that lifter in person.
 
Preload was set prior to intake installation. Reset due to noisy valvetrain. Turns is fine for setting preload, if you know your threads per inch, (3/8-24), then 1 turn would equal .04166666 inches. So 3/4 turn would result in a .03125 preload. This is what I relied upon.

After forcing the plunger gently down on the suspect filter, then releasing pressure and cranking the engine, but not starting, I found the lifter to respond and was able to set "normal" preload last night. (may have been stuck, and the plunger not coming all the way back up) As far as the oil pressure, I originally bought a pump from the local Carquest Store, was told they were supplied by melling and it was supposed to be "high volumn". But with all of the manufacturer changes that go on with the retail stores, who knows if this was actually a high volumn pump or not, or who the manufacturer was, as it is privately labeled for CQ. It has an easy 30psi cold at idle, and falls as it warms up, but stays above 10psi. It will build to 50 plus when RPM is brought up, warm. I guess that I am inexperienced in hydraulic roller valve train, and was concerned with the noise. It is no noisier than a mechanical set up, so this may be normal???

Thanks for all of the input, I may pull the pan and check things out, just for peace of mind, but I will replace the filter with a WIX filter and see if that shows anything first.
 
Depending on the lifter the preload could be anywhere from .020-.050+. I normally will set it around .030 but it might need more. You might try going another .030 and see if they stay noisey.
 
If it is a Melling HV pump, it will have HV cast into it after the part number.
 
Update: Found the issue, the lifters are coming up too far in the lifter bores and exposing the oil ring on the lifters causing MAJOR bleed off. The picture below is the worst, but most are exposing this groove. These are COMP retrofit lifters, and I didn't even order the largest lift cam!! I am calling COMP tomorrow to see what we can do to fix this problem...hopefully, or I will be running a standard camshaft, instead of this roller. I was really happy with the performance of this cam, but 5 lbs of oil pressure at idle was not going to work. Beware of this issue if you are planning a hydraulic roller. My understanding is that in the machining process of the block, there could be different chamfering of the lifter bores, resulting in what you see here.
 
Correct on the varying heights of the tappet bores. But - I think there are lifters that will work for you (probably not Comps) but I tend to run flat tappets or use the later roller blocks and factory lifters on my stuff. You might want to look into the Howard's lifters. Pulling the intake and dropping new ones in is cheaper and easier than a full cam swap and break in...
 
I have researched the hughs lifters and yes, they will work, as the oil ring sits about .100 further down on the lifter. It's just disappointing that COMP didn't have this information included in their original part info as something to look out for. Now I have to try to get COMP to warranty their lifters, as the are truely not a "retrofit" drop in design. This will also require another set of push rods, as the hughs lifters are overall a different height. At least they are taller, and I may be able to have Smith Brothers shorten the ones that I currently have. Just when you think things are done and ready to enjoy and drive, this crap happens.
 
Look at it like this. At least you found the problem. It's not some unobtanium alien problem that no one can put their finger on. You found solid evidence to what caused your problem and know what the solution is.
 
RustyRatRod said:
Look at it like this. At least you found the problem. It's not some unobtanium alien problem that no one can put their finger on. You found solid evidence to what caused your problem and know what the solution is.
Click to expand...


x2. Unless this is your commuter to work - it's a little more time without it to get things together well. Nice work in finding it.
 
I absolutely agree. I am happy that I did discover the issue and no longer have to wonder why I have low oil pressure. I know the solution. I have spoken with COMP and it sounds as if they are willing to work with me in a warranty situation. I am forwarding pictures to them.

I also pulled the engine and verified the bottom end. It is in perfect shape, clearance at .002 on rods and mains.

So just out a little time, and a few gaskets. Could have been a hell of a lot worse.

I thank everyone for their help and comments.
 
And by the way, I went ahead and became a GOLD member. This site has been a huge help. Thanks everyone!!
 
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