416 low oil pressure at idle

-

340kid

Well-Known Member
Joined
Mar 2, 2010
Messages
179
Reaction score
2
My sons 416's issues continue !
the hot idle oil pressure is only 10-12 pounds - this is with engine temp 180-190 and idle around 1000 rpm, using Valvoline VRI (NSL) 20/50 and Napa Gold (Wix) 1085 filter.
Initial startup the pressure is 40-50 but drops to 10-12 when hot ??

this is a new engine with less than 200 miles on it !

Spoke to engine builder - he didn't seem to be too concerned but i am.

Pulled distributor last night and confirmed the oil plug was inserted in valley, pretty positive oil shaft/distributor gear is the hardened tip pinned version.

What should i check next ?

any help or comments are greatly appreciated

340
 
the filter should be a 1086 but u have other problems than this. the old saying is 10 psi per every 1000 rpm but i like a little more . is it a melling pump?
 
Thought the short Gold Filter was #1068 ? I have one on my parts shelf. You guys got Lisdexia??
 

Attachments

  • phpNEaupTPM.jpg
    47.2 KB · Views: 858
#51085: $3.78 - "Super Shorty" Mopar oil filter, 3.79" tall (the 51068 is 4.338" tall, the 51515 and 51806 are 5.18" tall

Yes the other Napa filter is 1068

Wix site is same as napa except with a 5 prefix.
 
Motor has loose cam or main bearings. Possible poor machine work. Or lifter bores not sealed with incorrect lifters. Who ever assembled the motor is the liable person. Something is not correct and I wouldn't run it. Problem should have been caught on assembly.
 
Is it possable the plugs behind the cam plate were left out?
 
#51085: $3.78 - "Super Shorty" Mopar oil filter, 3.79" tall (the 51068 is 4.338" tall, the 51515 and 51806 are 5.18" tall

Yes the other Napa filter is 1068

Wix site is same as napa except with a 5 prefix.

Ok ok, I give. I just got knocked the Fck out by 5 dudes!! Lol

Learned me something tho!
 
I had a 340 that had a factory over size lifter in the block but some one had a standard size lifter in it had the same issue
 
Last time we assembled my 340, when we installed the oil pump dive, it broke the oil pump. I watched my dad install it, it wasn't like he pounded on it, just lightly tapped it in. Ended up with low oil pressure, pulled pan and found broken pump. Could also be the oil pump pressure spring. By chance do you have ARP main studs? One of the stud and nut on the rear cap will not allow the pump to sit flush, and you have to use a stock bolt.
 
Is the cup plug missing above the rear main cap, in the galley to make the oil go through the filter? You can check to see if it's in there by pulling the oil sender in the rear of the block and inserting a piece of welding rod down the hole. I checked 2 blocks in the garage and the rod went in 7.5" from the top. If it's not in there, you'll have low oil pressure, and it needs to go in from the bottom.
 
Before you start blaming it on parts, look at your oil.

You are running 20w/50 VRI.

Look at the viscosity index of that oil.

At 212 degrees F/ 100C it's at 20.5
At 104 defrees F/ 40C it's at 181.8

http://www.bobistheoilguy.com/forums/ubbthreads.php?ubb=showflat&Number=1496497

20w/50 is going to act like that. It's going to jump up in thickness/viscosity at low temp/ cold start and go down to around 10psi per 1000rpm at running temp, because it's engineered to protect parts under heavy use and this is consequential.

OilViscosityChart-Valvoline.gif


Listen to your engine builder. Every engine is different. If you were running 10w/30 or something lighter, you may have some concern on good seal on moving parts with tolerances, but the numbers you are seeing in oil pressure drop are normal for an eccentric viscosity index oil like that.
 
sounds like it was put together with loose clearances

If it's been consistent since built, this may just be the reality. I understand the nervousness, as i'd like more pressure also.

It sounds like you may have a decent relationship with the builder, so i'd just let him know, since he's ok with it, your sons gonna let'er rip and if a issue comes up.....it's coming right back to him for a full repair. That may get a different response from him, and if he's still cool with that......let it eat. :thumleft:

P.S. Like Dave eluded to, you may try a straight weight, 40 or so, and see if if it acts the same only a little higher pressure. That to me, would probably confirm the wider clearance theory.
 
Its been stated already , more than likely lifter bore issues. If not that then it is a bearing problem. I would not be comfortable with that oil pressure. You most definately will lost that engine--Mark my words. JRob
 
Before you start blaming it on parts, look at your oil.

.

I've never had oil pressure that low, ever, regardless of oil type.

Easy to find out, I guess. Put some 30W in the thing.
 
How are you reading the oil pressure? Are you using a mechanical gauge or a gauge with an electrical sender? If you mix gauges and senders you can get strange readings as well. For reference I am running a stock block LA 360 put together on the assembly line many moons ago. With 20w-50w I am reading 60-65 PSI cold and 25psi hot on two different gauges. I hope it is something simple.
 
#51085: $3.78 - "Super Shorty" Mopar oil filter, 3.79" tall (the 51068 is 4.338" tall, the 51515 and 51806 are 5.18" tall

Yes the other Napa filter is 1068

Wix site is same as napa except with a 5 prefix.

you are right on crackedback, originally had the 1068 on it, switched over to the 1085 witch is a little shorter, I have a 51515 on the shelf but I don't think it will fit, I had a tough time getting the 1068 off with the TTi's, things are so tight on this, the reason why I went to the 1085, we have TTI step headers with a canton billet oil filter adaptor plate.
 
Motor has loose cam or main bearings. Possible poor machine work. Or lifter bores not sealed with incorrect lifters. Who ever assembled the motor is the liable person. Something is not correct and I wouldn't run it. Problem should have been caught on assembly.


we are running a solid Lunati Voodoo # 60442 with their EDM lifters, I read somewhere today that edm's may cause lower pressures ???
 
Is it possable the plugs behind the cam plate were left out?

not sure, we used the MP timing chain tensioner and I had a conversation with the builder and he assured me all the plugs were installed
 
-
Back
Top