Oil pump "rebuilding"
 

Well, I am real happy with the 258" engine I just completed, except for one thing. I opted to save $100 and went with a Speedway oil pump. While the pump provides adequate pressure, the new engine has substantially less oil pressure than the used engine (with used pump) I installed in my '51 this summer. That engine idles hot at 25 psi and runs (over 1500 rpm) hot at 55 psi. The rebuilt idles hot at 10 psi and runs hot at 40 psi. Since everything else is fine with the engine, I suspect the oil pump is not up to snuff.

I dug through my stash and found two original 8BA pumps that look to be serviceable. I checked the side clearance between the gears and the housing and one is .0015", while the other is .003". Since factory specifications call for a maximum of .005", I figure I am in good shape here. I used "Plasti-gage" to check the clearance between the ends of the gears and the bottom plate. The news here was not so good. One has .003" over the idler gear and .006" over the driven gear; the other has .005" over the idler gear and .006" over the driven gear. Since factory specs show a maximum clearance of .006," I suspect they may be usable as is. I am going to send them to "Flatjack" who graciously has offered to test them for me on a setup he has.

I am wondering if I should try to bring the end clearances down a bit before I send them. I have a "surface plate" (a 2" thick slab of perfectly flat granite) that I could use for this. I have used it before to flatten warped carburetor bodies by putting wet-or-dry sandpaper on it and rubbing the pieces back and forth. Even though the pump body is cast iron, I feel I should be able to remove a couple of thousandths quite easily. Is this feasible (or even worth the effort?).

Re: Oil pump "rebuilding"
 

Yes, sounds feasible. I saw a video where they recommend a circular or better still a figure 8 motion when flattening parts on a surface plate.

Mart.

Re: Oil pump "rebuilding"
 

You´re aiming to be 90 degree to the pumpshaft so might even be better to stick the body in the lathe and take a skim from the bottom that way.
Not easy to grind a high narrow part by hand.

Re: Oil pump "rebuilding"
 

What is wrong with 40 psi hot. Mine runs 30psi hot, think the spring might be weak because that is all it does cold or whatever. It idles at about 10. As long as you are getting oil through your motor you're ok and running a higher pressure just introduces more heat into the oil which is supposed to be removing heat.
Also if your pump puts out 55 psi cold how do you see it not being up to what it should be?

Re: Oil pump "rebuilding"
 

I've never uded sftermarket oil pumps, had bad luck with them. 10lbs at idle and 30 in cruise is all you need. I rin 10/30 oil

Re: Oil pump "rebuilding"
 

Frank and Ron - As I said in my original post "the pump provides adequate pressure". In my situation, I don't believe it is satisfactory. Remember, this is a FRESH engine; turned crank, new bearings of the proper undersize and all. Every 8BA I've ever had that was not completely shot had the kind of oil pressure I am experiencing in my '51 (25/55). I checked my '49-'51 factory manual, and surprisingly, I couldn't find any information about oil pressure at all. I consulted my old Motor manual that has a flathead section, and it says that the oil pressure for these engines should be 57 psi. From what I can see, any oil pump that only puts out 30 lbs has a problem. At this point, I simply don't trust the Speedway pump. I was at my shop today, and got one of the Ford pumps end play within specs (it takes about 20 minutes to remove .001 from the bottom of the pump with 220 grit wet-or-dry). I'll do the other one tomorrow, when the new relief springs hopefully show up, and send them off to be tested.

If they pass the test, I will be replacing the Speedway pump with the best one I get back. I am willing to bet that the pressure will be back up to my expectations.

I'd rather replace the oil pump with the engine on the test stand rather than in the car. If nothing else, it will be an interesting exercise.

Re: Oil pump "rebuilding"
 

Why waste power (and thus fuel) by churning the oil through a relief valve?? It just gets dumped right back into the pan only to be churned, and heated, some more! You just need enough oil in the bearing to maintain the hydrodynamic wedge, which does the actual lubricating.
O' Ron is right again!

Re: Oil pump "rebuilding"
 

Well that was an idea whose time has not come. I have spent the better part of the last two days rubbing my oil pump housing and bottom plate on 220 wet-or-dry and then on 80 grit emery cloth. I think I've taken almost .001 off so far. All I've ended up with are super smooth mating surfaces. This gives me another idea! I mic'ed the oil pump bottom gasket from the engine rebuilding kit and it is .007" thick. Since I want to reduce the end clearance by another .002" or .003", I'm thinking going to a .004 paper gasket to bring it withing spec. I know the factory had to have a good reason to go with .007, but with the finish I've now got on the mating surfaces, I think .004 will work just fine. Anybody out there have and reservations, opinions, or recommendations.

Re: Oil pump "rebuilding"
 

I take it that this is directed at me. In that case, let me be clear. I am going to replace an oil pump made in China that clearly does not perform up to factory specifications with a stock Ford oil pump after making sure that it meets stock Ford specifications.

Re: Oil pump "rebuilding"
 

I think we don't understand the oil pump system, The relieve valve is deaifned to protect the pumpand bearings from excess oil pressure. the 60 lb poind relief setting will start dumping excess oil through the relief port, this creats excessive heat in the oil (opening the valve) OIl is used to keep the bearings cool from the power loads placed on the oil in the bearing by flushing it out with cooler oil. By using a higher viscosity oil this delays the cooling process. Fortunately in most cases ths does little harm, But there is a reasion why the newer engines are using thinner oil.

Re: Oil pump "rebuilding"
 

After reading and re-reading the comments on this thread, I have come to the inescapable conclusion that the majority of you believe that the Ford engineers who originally designed the 8BA oiling system were wrong and set the relief pressure too high, and therefore I am making a mistake by trying to bring my system back to factory specifications. If that's not what you are saying please clarify it for me, because it sure sounds like it.

Re: Oil pump "rebuilding"
 

Thinner oil unto itself doesn't solve all evils. Other things to consider on "modern" engines - that enable the usage of thin oil:

1) Usage of roller lifters or followers (not flat tappet)
2) Very exact manufacturing tolerances and therefore tighter bearing clearances
3) Better metallurgy and heat treating for rotating assemblies (harder journal surfaces)
4) Structurally rigid designs - block webbing, 5 main bearings on a V8, etc.. This causes less crankshaft and camshaft "deflection" - which also enables tighter clearances
5) Vastly improved oiling systems -- "priority mains" on most, good oil galley designs, dry-sump oiling systems (on many), etc..
6) Good full-flow oiling systems and filters (keeping a lot of crap out of the oil)
7) Well designed crankcase ventilation systems (some with vacuum pumps, etc) - reduces oil contamination, moisture, etc..
8) Computer controlled everything -- effective fuel/spark management leads to less oil dilution and contamination . . . which also allows the usage of thinner oils.
9) Specifically formulated oils and additives.

The only reason I bring all of this up is to help us think about the fact that "modern" engines are very different from our good ole' flatheads - they are specifically designed for modern low-viscosity oils - and they last for hundreds of thousands of miles.

Re: Oil pump "rebuilding"
 

Re: Oil pump "rebuilding"
 

what bore and stroked said.

Re: Oil pump "rebuilding"
 

B & S, you have lots of experience building and running these engines. What type oil (diesel, gasoline, racing, synthetic, etc) and viscosity do you recommend for a fresh street flathead? I'm not trying to pin you down, but experience counts.

Re: Oil pump "rebuilding"
 

You didn't ask me, but I'll answer anyway. My local Dollar General usually has some known brands on sale. A couple of weeks ago, I bought some "Peak" (the antifreeze people) detergent 10-30 for $2.75 a quart. I think it's obsolete oil they are trying to get rid of. On the back of the container, it said : "Not to be used in vehicles newer than 1985". That sold me!:D

Re: Oil pump "rebuilding"
 

Hell, I'll share any of what I do - nothing secret or unique about any of it. LOL

It kind of depends on the bearing clearances and other factors of the specific engine. I'm super picky about how my cranks are ground, micro-polished, etc..

Special Crank Work: On my recent engine, I even had the 4 1/8" stroke Merc crank 'nitrided' to harden the journals (so I could see if it influences journal wear/life) - and also to experiment with thinner oils. (10w - 30w and 10w - 40w). Notice the funny 'grey' color of it when it came back:

Attachment 337775

I always specify my bearing clearances with a SET of bearings in my hand for both rods and mains. You'll get slightly different sizes - from different manufacturers - or even the same manufacturer (so I have to hand fit everything - to give the crank grinder the exact sizes I want). We don't have the luxury of .001 plus/minus shells like we do with our modern OHV race engines - so fitment demands that I have the bearings in advance.

Of course, I also run larger bearing clearances on my flatheads (more of a race style setup). On the mains I run .00275 on the front two and about .003 on the rear (extra on the rear - due to heat from the clutch). I run .00225 on the rods. I am a believer in "loose is fast" . . . prefer lots of oil through the bearings and especially when running "full floater" rod bearings (91A or 21A rods).

So - if it is a hot summer, I run 20W - 50W oil, in the winter I run 10W - 30W or 10W - 40W. I also run high quality Penn-Grade 1 oil (the 'green oil') - they make really nice oils that I prefer to use (Glockner). They have high ZDDP additives - which are good for our older engines (especially with flat tappet cams).

Note: This oil is not cheap and there are a LOT of good oils out there - so run what makes you happy. Me --> I decided awhile ago that I really don't worry about oil prices - as I don't change it that often anyway. :rolleyes:

Here are links to the various grades I use:

http://www.jegs.com/i/Glockner-Oil/4...-7120/10002/-1

http://www.jegs.com/i/Glockner-Oil/4...-7150/10002/-1

http://www.jegs.com/i/Glockner-Oil/4...-7144/10002/-1

http://www.jegs.com/i/Glockner-Oil/4...-7119/10002/-1

So there yah have it!

B&S

Re: Oil pump "rebuilding"
 

For those of you assembling flathead engines - here is a short video on how the crankshaft should rotate upon initial assembly. This is what I expect with correct clearances, journal prep, quality bearing fitment, etc . . .

Enjoy!

https://youtu.be/5_IkGWSIfl8

Re: Oil pump "rebuilding"
 

In case you missed it there was a post recently about the specs on the relief valve spring; here is a quote: Here is that information from a '48 manual:
Oil Pressure Regulator Relief Valve-Check relief valve spring tension and replace spring if tension is less than 78 ozs. or more than 87 ozs. when
compressed to length of 1.380".
That might have been your post; I didn't copy the author; in any case I am interested in your findings.

Re: Oil pump "rebuilding"
 

^^That info is useful to me. I lost the spring from one of my engines, I have a spring that physically fits, now I can test it to see if it will give the right spec.

i took the spring from a 60s English Ford oil pump.

Mart.