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| | | Forums66 Topics128,083 Posts1,056,080 Members48,434 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
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on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Nov 2004 Posts: 266 Custom Title | | Custom Title Joined: Nov 2004 Posts: 266 | Hey guys. I've put about 700 miles on my rebuilt and mildly hot rodded '54 235 now. I just wanted to check that my oil pressure is ok. It runs at 35 psi all the time so I'm guessing that's where the relief valve is set. It hardly drops from there, if at all, at hot idle. This isn't surprising since all the clearances are tight, but personally, I'd like to see more at speed, maybe 45-ish. Or am I good where it is? If it should be increased, how exactly do I do that? Last, I just stumbled across Tom Langdon's write-up about preventing air leakage into the oil pump. How concerned should I really be about this? Thanks!
49 Chevy 3600 65 Chevy K10 48 International KB-1 Service Truck 55 Willys CJ5 - Chevy 331 powered 26 Model T Roadster Rat Rod 70 Tucker Sno-Cat 442-A 96 Dodge 3500 Cummins dually flatbed x-cab 4x4 06 Jeep Wrangler LJ rock crawler If you can't fix it with a hammer, it's an electrical problem | | | | | Joined: Mar 2014 Posts: 4,489 Moderator, Electrical Bay | | Moderator, Electrical Bay Joined: Mar 2014 Posts: 4,489 | It is up to you, but it sounds fine to me. I wouldn't be concerned at all.
~ Jon 1952 1/2 ton with 1959 235 | T5 with 3.07 rear end
| | | | | Joined: Jan 2020 Posts: 620 'Bolter | | 'Bolter Joined: Jan 2020 Posts: 620 | I have had both 216's and 235's and I have always referred to these old and rebuilt engines as slush bucket oil pressure. 35 Lbs. is a great o/p. I'm sure anyone would love that kind of o/p. Maybe the other Stovebolt folks can add to this. 45 lbs. is a dream to most of us. Doc.
Currently making 1954 3100 better than new and Genetics
| | | | | Joined: Mar 2010 Posts: 1,660 Curmudgeon | | Curmudgeon Joined: Mar 2010 Posts: 1,660 | I would buy an add-on oil pressure gauge and run a new oil line to verify. I recall a similar situation where sludge or trash was in the old line and gauge which caused a consistent reading.
"Adding CFM to a truck will only help at engine speeds you don't want to use." "I found there was nothing to gain beyond 400 CFM." | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | R&R the relief valve spring will do that if the pump output, bearing condition, and oil viscosity are all good, but it's not needed. You already have the largest factory pump. | | | | | Joined: Dec 2017 Posts: 1,652 'Bolter | | 'Bolter Joined: Dec 2017 Posts: 1,652 | Tom’s article was about keeping air out of the pump to prevent hydraulic lifters from ticking. Some hydraulic cam motors develop a tick you can never seem to get rid of. Air in the lifters via the oil pump is one of a number of possibilities for causing that. If you are running mechanical lifters this is not a concern. If running hydraulic lifters, this is only a concern if you have a lifter tapping, the tapping bothers you, and you can’t adjust it out.
Pressure, I think you want to double check that pressure with another mechanical gauge just to be certain, as recommended above. A steady oil pressure is just not a feature of these motors, lol. But hey, stranger things can happen I suppose!
Last edited by Dragsix; 06/15/2021 1:21 AM.
Mike
| | | | | Joined: Feb 2004 Posts: 29,795 Kettle Custodian (pot stirrer) | | Kettle Custodian (pot stirrer) Joined: Feb 2004 Posts: 29,795 | Any oil pressure at all indicates that the pump is producing more oil volume than the engine needs. Extra pressure just wastes horsepower that could be used to drive the vehicle. If you're that concerned about it, put a couple of flat washers behind the roll pin that secures the pressure relief spring into the pump housing. Just don't do like one of my competitors on the dirt track did- - - -he shimmed the spring so tight that the relief valve couldn't move, and the first time he revved the engine up the oil filter burst. Jerry
"It is better to be silent and be thought a fool than to speak and eliminate all doubt!" - Abraham Lincoln Cringe and wail in fear, Eloi- - - - -we Morlocks are on the hunt! There is nothing noble in being superior to your fellow man; true nobility is being superior to your former self. - Ernest Hemingway Love your enemies and drive 'em nuts!
| | | | | Joined: Dec 2018 Posts: 2,450 'Bolter | | 'Bolter Joined: Dec 2018 Posts: 2,450 | Southtowns27 You are doing great with oil pressure. If you increase it it'll wanna "wash" your bearings that is oil flow is too high-not necessary. Had a noise in my 235 oil pressure would hit it and shut it up,installed -.002 new bearings is quiet keeps 30 lb. gauge pegged ! | | | | | Joined: Dec 2008 Posts: 1,922 'Bolter | | 'Bolter Joined: Dec 2008 Posts: 1,922 | The local oil pressure at the journal/bearing interface is a function of the pump (gauge, relief spring, "nominal") pressure multiplied by the wiping speed of the 2 surfaces. The stovebolt's 2.3125" rod journal has 115.6% of the local pressure of a 2.000" (Gen-3 L6) journal at the same RPM. | | | | | Joined: Nov 2004 Posts: 266 Custom Title | | Custom Title Joined: Nov 2004 Posts: 266 | Thanks, guys. I'll leave her be...
49 Chevy 3600 65 Chevy K10 48 International KB-1 Service Truck 55 Willys CJ5 - Chevy 331 powered 26 Model T Roadster Rat Rod 70 Tucker Sno-Cat 442-A 96 Dodge 3500 Cummins dually flatbed x-cab 4x4 06 Jeep Wrangler LJ rock crawler If you can't fix it with a hammer, it's an electrical problem | | |
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