The Stovebolt Page Forums Home | FAQ | Forum | Swap Meet | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Helping out ...


EVENTS

Check in for status!

Jump over to the Events Forum, to post events -- new ones or the ones we have been enjoying for some time.
Look to see what's been cancelled or postponed.

Encourage one another!

Stovebolt Site Search
 
Old Truck Calendars
Months of truck photos!
Nothing like an old truck calendar

Stovebolt Calendars

Check for details!


Who's Online Now
7 members (reidy, 5WINDOWJOHN, Fox, festerhairball, Eureka Jim, Mike B, 1 invisible), 232 guests, and 3 robots.
Key: Admin, Global Mod, Mod
Forum Statistics
Forums50
Topics121,426
Posts973,547
Members43,932
Most Online1,229
Jan 21st, 2020
Image Posting Policy
Previous Thread
Next Thread
Print Thread
Page 1 of 2 1 2
216 oil Pressure Mystery
#1251264 Tue Jan 16 2018 11:35 PM
Joined: Mar 2002
Posts: 9,035
Master Gabster
I am pulling the 216 on my 1951 1 Ton to do a rebuild. When I put the truck on the road ten years and 40K miles ago, I did an in place rebuild. At the time I didn't have the space to pull the motor but now I do. Over the years I have replaced the main bearings and the cracked head. The motor has worn cylinders but runs well. One of the cylinders has been honed out some by a previous owner and so there is some piston slap in that cylinder. I plan to have the block bored and tanked. I will be putting aluminum pistons in it.

Now here is my mystery. Right from the start the oil pressure reading was nearly pegged when cold or at least well over half scale. After about twenty minutes of driving it will read 7 lbs on the highway and around zero at idle. I have replaced the oil pump and the oil distribution valve. The feed to the rockers has the proper restriction. When I replaced the main bearings I shimmed them so the clearance was at minimum and this made no difference in the pressure. The only thing that I haven't attended to is the camshaft bearings. So when I have it apart I will be looking to see if there is a cause of this low oil pressure.

As a contrast the oil pressure in my 1938 Master 216 has always been excellent. Even when the main bearings were really sloppy after I bought it, the oil pressure was excellent.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!
Re: 216 oil Pressure Mystery
truckernix #1251275 Wed Jan 17 2018 01:24 AM
Joined: Sep 2013
Posts: 1,062
M
Shop Shark
Truckernix said "I have replaced the oil pump" in reference to work performed on his 216 engine.

I'm still in the novice phase of building a 216 knowledge base. Which likely explains my curiosity with comment above. I've seen the rod dippers and squiters in the oil pan on my truck, I thought that was the source of the engines pressurized oil.


1951 3600 with Clark flatbed, T5, 4.10 rear
1970 340 Duster
1990 5.0 V8 Miata (1990 Mustang Gt Drivetrain)
1951 Farmall Super A



Re: 216 oil Pressure Mystery
truckernix #1251278 Wed Jan 17 2018 01:43 AM
Joined: Mar 2002
Posts: 9,035
Master Gabster
moparguy,
the 216 had an oil pump that fed oil directly to the main bearings and the camshaft bearings. There was also a feed to the "oil distributor valve" which opened after the pressure built up and it fed both those rod sprayers and the rocker arm.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!
Re: 216 oil Pressure Mystery
truckernix #1251281 Wed Jan 17 2018 01:51 AM
Joined: Aug 2012
Posts: 1,742
V
Shop Shark
The 48 216 in my 3100 gives around 14psi cold and drops to around 6 or 7psi warm. At idle it's around 6psi and at speed around 7psi. I run 15w40 oil.
I'm guessing your mains are less than 0.003" clearance? If so it's definitely possible the cam bearings are worn. Did the new oil pump make any difference? You might try testing the pressure with a another oil pressure gauge to verify the pressure.

moparguy, the 216 and early 235's have pressurized oil to the crankshaft main bearings, cam bearings, front timing gears, dipper nozells and the valve train. The dippers on the rods provide lube oil for the rod bearings and the subsequent oil mist lubes the cyl walls, pistons, cam lobes, dist shaft and all internal surfaces of the engine.
You might find this video interesting (once it gets past the opening lol).
Riding the film

Re: 216 oil Pressure Mystery
truckernix #1251282 Wed Jan 17 2018 02:01 AM
Joined: Sep 2001
Posts: 30,570
ace skiver
moparguy,

Your terminology is correct regarding the squirters being pressurized oil (the rod-dippers "accept/receive" the pressurized open-stream oil), but that is the "open pressure" part of the low-pressure lubrication in the 216 (and the same system in the early 235) engine lubrication system. Many people mistakenly call this a splash oil system - it is not.

The "source of the pressurized" oil is the oil pump.

If you have not already done so, read the Engine section of the Shop Manual. Here are some key pages:
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0605.htm
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0614.htm
http://chevy.oldcarmanualproject.com/shop/1948_51truck/51ctsm0615.htm





Tim
1954Advance-Design.com [1954advance-design.com]
1954 3106 Carryall Suburban [stovebolt.com] - part of the family for 49 years
1954 3104 5-window pickup w/Hydra-Matic [1954advance-design.com] - part of the family for 15 years
- If you have to stomp on your foot-pedal starter, either you, or your starter, or your engine, has a problem.
- The 216 and early 235 engines are not "splash oilers" - this is a splash oiler. [chevy.oldcarmanualproject.com]
Re: 216 oil Pressure Mystery
truckernix #1251286 Wed Jan 17 2018 02:16 AM
Joined: Mar 2002
Posts: 9,035
Master Gabster
Volfandt,
thanks for your response. Yes my mains were set for .001 to ,002. I was very careful because I was trying to get good results from a new rear main seal, and I did. I am thinking my cam bearings are probably quite worn and of course they will be replaced and maybe the cam if it is worn. I am wondering if there are any other places to look for the problem. I actually replaced the oil pump twice and it made no difference. I use the Rotella 15W40 and I understand it still has some good additives in it. I think I will parallel a new oil pressure gauge and see if they agree.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!
Re: 216 oil Pressure Mystery
truckernix #1251387 Wed Jan 17 2018 04:52 PM
Joined: Aug 2012
Posts: 1,742
V
Shop Shark
Correction, the 216 in my 3100 is a 49 not 48, must have been a combination brain and finger phart LOL.
Fred, In thinking more on your oil pressure situation, I'm being drawn to the R&R of the oil distributor. The TSM shows it broke down pretty good. When you've pulled the engine and disassembling it, pay attention to how it's assembled. IIRC it's primary job is to limit oil pressure to the top end until sufficient oil pressure is flowing to the mains. Did you replace this due to the pressure situation you're now experiencing?

One other thought, Are you running a by-pass filter? I am and have often thought about taking it out to see if I can gain alittle more oil pressure.

Good luck
Dave

Re: 216 oil Pressure Mystery
truckernix #1251412 Wed Jan 17 2018 08:33 PM
Joined: Mar 2002
Posts: 9,035
Master Gabster
Dave,
I replaced the oil distributor valve with a new one thinking it may be the problem, but no luck. I am running a by-pass filter but things didn't change when I added that.


1951 GMC 1 Ton Flatbed -- It is finally on the road and what a great time I have driving it!
1951 1 Ton Completed


My Chevy Master 4 Door is on the Road!
Re: 216 oil Pressure Mystery
truckernix #1251419 Wed Jan 17 2018 09:38 PM
Joined: Jan 2014
Posts: 1,374
J
Shop Shark
I think your parallel gauge idea is a good one. May just be getting a bad reading.


You've pretty much eliminated everything but the cam bearings. Good reasoning.

Re: 216 oil Pressure Mystery
truckernix #1251468 Thu Jan 18 2018 03:27 AM
Joined: Feb 2004
Posts: 21,240
H
Boltergeist
The oil distributor only comes into play when the oil pressure is below 15 PSI if it's working properly. Its function is to direct most or all of the oil flow to the lower end of the engine in hot idle and/or other low oil pressure situations. The rocker arms can survive a lot longer with little or no lubrication, compared to the rod, main, and cam bearings. When the oil pump is supplying sufficient pressure and volume to the rotating assembly, then a little oil can be bled off to keep the rockers lubed. I think the high volume pump modification I'm developing might be the answer to a lot of worn bearing problems on the low pressure engines, if I can ever get back to it!
Jerry


The murder victim was drowned in a bathtub full of Rice Krispies and milk.
The coroner blamed the crime on a cereal killer!

Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt!
Page 1 of 2 1 2

Moderated by  Woogeroo 

Link Copied to Clipboard
Home | FAQ | Forum | Swap Meet | Gallery | Tech Tips | Events | Features | Search | Hoo-Ya Shop
Powered by UBB.threads™ PHP Forum Software 7.7.4