Have an 8BA with "95% Oil Flow Modification. This is where the oil galley is tapped at top rear of block and a remote filter is installed. I have about 30 - 35 Lbs of oil pressure at start up. With engine warm and at idle, oil pressure is at zero. At cruising rpm oil pressure is about 15 Lbs. I have about 2000 miles on engine since rebuild with no issues. This is with a melling oil pump, not a high volume pump. Called H&H and they don't like this mod. I was told to restrict the oil flow to the filter to keep oil in engine longer and at higher pressure. I was also told a high volume pump was not necessary and that it would make no difference. Using Bred Penn 10-40 oil. Is this something I even need to worry about? Would switching to a straight weight oil make a difference? Any advice would be greatly appreciated!
I have this system on my 8BA. When I notice a slight drop in press at cruise, I know it is time to replace the filter. My set up uses a Car Quest R85348 filter. I use 15W40 diesel grade oil. I have about 75000 miles on the engine, runs 48 psi at cruise and about 25 psi at hot idle. Unless your filter is badly plugged, I think you have some internal problems. I would bypass the filter system and see if this makes any difference in oil pressure. If you want further info, e mail me at [email protected] I just re read your post. If you restrict the flow of oil to the filter, you will restrict the oil flow to the engine. Depending on the amount of restriction, there is a good chance of doing some real damage. I think the advice you received on restricting oil flow at the filter refers to the original by pass filtering system
Are you getting your pressure reading from the dash gauge? or a mech. gauge?. I know a lot of guys that have about 5 to 7 ish psi at idle fully hot. I was told to run Brad Penn 20-50
Thanks Rick - Appreciate the info on what your using for filter and oil. Can you tell me where your oil pressure tube is mounted on your engine? The oil you use isn't synthetic is it? What brand oil is it? I can't imagine internal problems with this rebuilt engine but who knows. It runs great with absolutely no issues other than the oil pressure. I'm going to start with a different filter and oil and see what happens. H&H suggestion on restricting the flow to the filter also sounds like a good idea to me and a fairly easy thing to do. I'll see what other replies I get and post after trying a few things.
Dan - thanks for the reply. Using an aftermarket gauge with the line running to the top of block where the oil inlet and outlet lines go with the 95% setup. The line is piped to the raised casting on the block. This would be on the drivers side of the grub screw that gets installed with the setup if I'm not mistaken. 20-50 oil should make a difference. Can you tell me what filter you run?
are you using a stock ford filter canister? they have the proper 060 restriction in the input side. you must have it or you will starve the bearings
rusty - you sound like your on the right track as h&h suggested the 060 restriction. by canister do you mean the filter itself or the filter mount piece?
The .060 restrictor is ONLY used on the stock Ford bypass system. DO NOT restrict the flow to the remote filter used on a 95% SYSTEM.
Went through this with a Club Member and a New rebuild Flathead. Both He and the Builder know there Shit. That motor came apart and got a Rod and Main Bearing check and all was dead on. Then a fresh pump added just because it was easy. Nothing added up, same issue your describing. Same filter system and at one point the filter got taken out of the system and bypassed. Noting changed. Decided must have Cam Bearings to loose. Went after them, found the problem. It wasn't the Bearings, it was the Camshaft. The cam bearing journals were .010 under. Who knows how that happened. It's something you don't normally measure when dealing with New Cams. Fresh shaft, bearing journals on it checked. Put back together and all is well running 35 lbs Cold and 30 lbs Hot all day long. Who would have thought? The Wizzard
The cam bearings are the first thing that are fed with the oil flow. Excessive clearance will cause a low pressure reading. However, if the builder can't feel the looseness when installing the cam, I wouldn't put much faith in his build. Also may need to check the plug for the oil gallery at the front of the engine.
It has always bothered me that a lot of people will accept oil pressure readings of 5-7 psi at hot idle as adequate. I have had probably ten flatheads in my life that I drove long enough to become fully attuned to them. Three were fresh rebuilds, the rest good used engines. Not a one of them had a hot idle oil pressure reading of less than 20 psi. For an old, excessively warn smoker, maybe, but for an engine in relatively good shape, no way. Admittedly, all but two of these engines were of the 8BA series, but since the oiling system was essentially unchanged over the years, I would think it would apply over the whole range.
I don't think I'll tell Earl Floyd he's loosing his touch. His track record is pretty steller, instead at 80+ years old We'll just cut him some slack and move on. The Wizzard
Well thank you guys so much for the input. Unfortunately, at least for now, i'm in no position to pull the engine to check clearances. Will running the engine with loose cam bearing clearance hurt anything? I really don't want to have to pull this thing apart. After reading about so many guys running flatties with low oil pressure and not having any problems I feel better about just running it. As I mentioned - 2000 miles now and no issues. I will mention again that the guy at H&H thought I should restrict the oil input to .060 - they said the 95% mod eliminates the restriction the stock oiling system would have. They may not know everything but who does. I'm no expert on the oiling system of a flathead engine but it makes sense that if the oil were restricted, leaving it in the engine longer and at a higher pressure that would be a good thing and raise my gauge reading. So I'm left with contradicting opinions on what to do restriction wise. At this point I think I will try a heavier oil and see if I can at least get a few psi at idle to make me feel better. At some point I may take the engine out and go through a check of clearances. Thanks again to all that gave their two cents! I appreciate it!
Brad Penn still makes a strait 30 weight oil with all the good stuff in it. I'd go there first even though it's around $15.oo a Qt. The Wizzard
Having had great success with the 95% system, my first thought would be the oil pump itself. Remove it & shim the relief or replace the pump with a known good Ford pump. As Flatjack has stated, do not restrict anything & with the way the block is now plumbed, you cannot bypass the system.
I would never run a straight weight oil on a newly rebuilt flathead, even a good runner. With today’s much improved oil and Being aware of the initial wear factor during startup of a cold engine scares me. Not to change the subject. https://www.physicsforums.com/threads/why-most-engine-wear-occurs-during-cold-start-up.929237/
H&H must have misunderstood your question. I'm sure they are smarter than that. I don't think you understand oiling systems. You need the flow because the oil actually cools the bearings. Flow is much more important than pressure. Pressure is caused by a restriction to flow which is related to bearing clearances.
Another thing I've never understood is how these systems can be called 95%. The rear bearing does not receive filtered oil. So I think it is about 67%.
Is it possible for you to access the screw that forces the flow to the filter? If so, remove it and plug the hole that the oil now goes in and you will be back to a stock oiling system.
I did see a motor with that set up and 8BA pump where the original relief valve in the front of the valve chamber was missed. Started with pressure, but went away rapidly as oil warmed up Is the fuel pump push rod and bush in there? Another loss point. Time for a careful inspection and a quiet think about where the pressure is being lost. Garpo
Years ago I saw a 100% flathead oiling tech somewhere, does anyone here remember it or able supply a link to it please. Vaguely remember it required drilling a 1/4" hole down through the fuel pump pushrod hole into the rear main bore and then plugging the original oil gallery hole adjacent. Any help would be gratefully appreciated.
this is the 95% modification, as has been said before do not use any restrictions in this system!!! I also use a 9/16 drill bit to open up the verticle line from pump to oil press sender here to increase volume to filter, then I mount sender on output of filter to monitor oil pressure through bearings so I will notice any loss of pressure, when filter starts to plug up if you leave it where shown here you will not notice loss of pressure or bearing wear ................ been using this system in every flathead I build without any problems if done right. I use Valvoline VR 40W but Im in a warm climate..........
You are correct, they are smart when it comes to flatheads and they didn't misunderstand the question. When I built my blower 8BA I called Mike on this same subject. I went with his recommendation, no 95% mod. In fact Mike talked me into running with no filter. Of course this isn't meant to be a daily but it will get it's share of punishment...and oil changes.
I take my blown 8BA F1 out for a drive every now and then. I have the 95% solution. I use only Mobil 1 oil. A half quart of Lucas oil stabilizer takes care of all low oil pressure problems at idle or any where else.
do you know can lucas be added to any oil? per a suggestion I was planning to try the brad penn 20-50 to see if it makes a diff. would also try adding the lucas to that if recommended. if trying that makes a difference that's an easy fix for sure. if not I will probably check the pump out. does anyone have a good resource for oil pump pictures? relief valve, where to shim etc. this whole flathead thing is new to me and I need to know what I'm looking at!
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