low oil pressure

[Racer X]

2 hours ago, Wally said:

so as far as i know the method to check bearing clearance is to measure diameter of rod and subtract inside bearing diameter.. Thus the difference being the clearance. If so, yes, that does scare me to attempt. If there is a way to remove one conrod cap and measure the clearance gap i feel safe to do that...but i dont think that possible. I may drive up to the engine rebuild shop and ask the man to pull up his notes from my rebuild and see what he has written down. Of course this wont let me see shell condition

 

Since rebuild, I have put maybe 100 miles on engine. Only oil change since then is one i am doing now. 

Yes, the best way is to remove everything, and measure, and figure the difference. 
 

But as mentioned, plastigauge is what you would use in this case. Remove one bearing cap, wipe the journal and bearing shell with a clean, lint free cloth (I cannot overemphasize the importance of cleanliness), lay a line of plastigauge on per the instructions, replace the bearing cap (with the bearing shell), install and torque the fasteners, remove the cap and check the plastigauge against the standard printed on the paper sleeve the plastigauge came in (I cut a length of the sleeve a little narrower than the journal so I’m not trying to lay 6” of paper sleeve on it). 

After making a note of the reading, clean the plastigauge with a bit of denatured or isopropyl alcohol, and after ensuring the journal and bearing shell are clean, apply some assembly lube and reinstall, torquing fasteners to spec.

Do not rotate the crank during this process, as doing so will smear the plastigauge and skew the results.

You will need to rotate the crank for each rod journal, to the bottom of the stroke (precision isn’t a concern, you are only moving the journal to a position where it is easier to access).

 

As I mentioned, now is the time to do this. All main bearings, and rod bearings can be checked, just only do one at a time. Work methodically, and remember, cleanliness is crucial. I’m confident that if you know how to handle tools, and feel ok using a torque wrench, you can do it.

 

Thanks for the information about the time on the engine.

 I have to ask, why haven’t you engaged the builder about this? If I paid someone else to rebuild an engine, and it only had 100 miles on it, I would look to them to resolve it.

 

 

Edited January 31, 2023 by Racer X

[Wally]

 

36 minutes ago, Racer X said:

 I have to ask, why haven’t you engaged the builder about this? If I paid someone else to rebuild an engine, and it only had 100 miles on it, I would look to them to resolve it.

up until a little while ago didnt really know there was an issue. at first i thought it simply a malfunctioning gauge as the engine sounds great. Then i took the gauge out and swapped it and still nothing. Also wasnt really sure what to ask him just yet. thought i'd get as much info as i could before i go to him and sound like an idiot complaining.

[Racer X]

12 hours ago, Wally said:

 

up until a little while ago didnt really know there was an issue. at first i thought it simply a malfunctioning gauge as the engine sounds great. Then i took the gauge out and swapped it and still nothing. Also wasnt really sure what to ask him just yet. thought i'd get as much info as i could before i go to him and sound like an idiot complaining.

It would have been a good idea to talk with the guy before going to all the fuss you’ve gone through at this point. 
 

You would simply relate the concern and allow them to respond.

 I suspect the rebuild cost a few bucks, and you work hard for that money. You have every right to expect a quality product, eh?

Should you decide to talk with the guy, don’t tell him all that you have done so far, as that would cloud the issue. Simply let them know that you have a concern about low oil pressure, and let them decide how they will address it.

 

[Wally]

i am watching lot of how to's on measure spacing with plastigauge. Just watched another video.

can anyone confirm this is how they measure using the paper instrument? A micrometer?

Also,

1) what are the torque specs on conrod bolts you use?

On internet i found between 33-40 for 9mm

and 20-24 for 8mm. How would i know which to use?

i checked the preset torque range from front to back

and they ranged from 30 to 37 ft lbs. 

i took a micrometer diameter of the bolt, like in image below. It was around 7.6ish mm.

Would appreciate insight as this will let me know the torque i need to put them back at

2) what should be appropriate bearing clearance?

 

After sleeping on it...i think i am gonna try to do this. never opened my torque wrench so might as well. Just need to run to oreilly's for the plastigauge. 

Edited January 31, 2023 by Wally

[Wally]

here is image of bearing from #6 closest to cab 

[Patcon]

Plastigage?

[Wally]

update from today. Since i have 8mm bolts lot of questions. With torque being too high in 30ftlbs instead of low 20's....i would think extra pressure would mean higher oil pressure...to an extent. 

so i am worried setting things at 24ft lbs will decrease oil pressure more. I guess we will see. I plastigaged #6, here is an image. Not sure you can tell but right at .0015... or 15/1000ths of an inch.

Still trying to find out what the range should be for this. Will post results of other 5 bearings when i get to them.

 

[jonbill]

less torque on the bolts won't mean more clearance and less oil pressure. 

but you might need new bolts - they may have stretched at that excess torque. 

[Wally]

final results

[Racer X]

18 hours ago, Wally said:

i am watching lot of how to's on measure spacing with plastigauge. Just watched another video.

can anyone confirm this is how they measure using the paper instrument? A micrometer?

Also,

1) what are the torque specs on conrod bolts you use?

All the torque specifications needed are either in the factory service manual, or, if using the 9mm rod bolts, the Frank Honsowetz book How To Hotrod Your L Series Engine.

18 hours ago, Wally said:

On internet i found between 33-40 for 9mm

and 20-24 for 8mm. How would i know which to use?

Use the factory service manual, or the book by Mr. Honsowetz.

18 hours ago, Wally said:

i checked the preset torque range from front to back

and they ranged from 30 to 37 ft lbs. 

I’m not sure what you mean here.

Did you use a torque wrench like this?

 

A beam type, or a dial type are the only types of torque wrench that will allow you to see the force required to move a fastener, i. e. how tight it was. Once the fastener is moved, it will no longer be at the proper torque.

Using a click type torque wrench cannot do this with any degree of accuracy.

 

 

18 hours ago, Wally said:

i took a micrometer diameter of the bolt, like in image below. It was around 7.6ish mm.

You need to measure the shank of the bolt, not the end of the threads sticking out of the nut.

18 hours ago, Wally said:

Would appreciate insight as this will let me know the torque i need to put them back at

2) what should be appropriate bearing clearance?

Again, the factory service manual will have everything you need to know, including proper bearing clearance.

18 hours ago, Wally said:

 

After sleeping on it...i think i am gonna try to do this. never opened my torque wrench so might as well.
 

I’m a little confused Wally.

You mentioned you checked the torque on the fasteners, but now say you haven’t opened your torque wrench.

Also, as an aside, having never opened your torque wrench, how did you tighten the lug nuts on your wheels? Sorry for getting off topic, but lug nuts should always be torqued to specification.

 

 

[Racer X]

1 hour ago, Wally said:

update from today. Since i have 8mm bolts lot of questions. With torque being too high in 30ftlbs instead of low 20's....i would think extra pressure would mean higher oil pressure...to an extent. 

so i am worried setting things at 24ft lbs will decrease oil pressure more. I guess we will see. I plastigaged #6, here is an image. Not sure you can tell but right at .0015... or 15/1000ths of an inch.

Still trying to find out what the range should be for this. Will post results of other 5 bearings when i get to them.

 

How tight the fasteners are will make zero difference in the clearance, provided they are torqued correctly (severely under torqued may cause a larger clearance, but there will be other, more serious consequences, such as the bottom end coming apart, not a good thing).

So far it looks good. The bearing shells show no wear. How do the journals look?

Also, you can run your fingernail across the journal and bearing shell, to ensure there are no cuts or grooves.

 

Next, what do the main bearing journals and bearings look like?

 

[Wally]

14 minutes ago, Racer X said:

Using a click type torque wrench cannot do this with any degree of accuracy.

You mentioned you checked the torque on the fasteners, but now say you haven’t opened your torque wrench.

long story short...my good torque that i used in past got broken. I did buy a click style one that was new. I have a digital one ordered..waiting on it. leaving off oil pan until it comes in so double check all tightenings and see if current torque wrench is off