Proper way to disable the oil bypass - AGAIN

[Autoholic]

Jay, if you ran a remote oil filter and oil cooler setup (common on the 427 Cobra Semi-Comp), I'd imagine the pressure drop would be another 10-ish psi? Another part of the problem to think about. When looking at this though, you also need to look at your typical RPM's. If the engine rarely sees north of say 4500 RPM, chances are you aren't running a remote filter and cooler and you won't need high pressures. If you were building an FE to run 7000-8000 RPM's, this might be of far greater importance.

[KMcCullah]

You can shim the spring closed with a short piece of steel rod easy enough. Or if this block is on a stand, the offshoot to the bypass valve bore can be tapped and plugged.

I think the bypass was needed because the FoMoCo 427 pump made high pressure. Like 120lbs I've heard. And it didn't have a bypass built into it. Edit: I love to hear some history about this bypass valve.

My thought on this topic... I've had several bypass valves in automatic trannys get stuck open with a chunk of crap in them. And if the bypass in a side oiler block got stuck open it could starve the #5 main bearing, the #8 rod bearing and the #5 cam bearing. It seems like a lot of risk to me without much reward. I left the unfinished bypass bore in my Genesis block unfinished when I built my 504.

[IDOIT4SPEED]

So I just realized I pretty much wrote the long engineering version of what Scotia wrote.

Oh and remember, if you use a remote oil filter or an oil cooler, the oil goes from the pump to these first. You have any idea the kind of pumping losses that can be seen from this?

Here is a scan of an original advert for the 427 pump. Pretty sure this is a gerotor design as well.

not what I expected to see, friend has 62 406 center oiler with rear bypass. has gear on gear oil pump. thought 427 would take same pump?

[Autoholic]

If there was a design flaw with the gerotor pump, I doubt Melling would be using it and that this design is still widely used today. The gear on gear pumps were in trucks I think.

As for the bypass valve getting stuck open, the same could be said for the oil pump's bypass valve. The oil pump is more prone to being jammed as well, because it picks up from the pan. The relief valve in the block will have oil that has been filtered. I think the idea that it would jam is probably an unlikely situation. Your filter would have to implode or a part would have to break and in either case, you'll have bigger problems than a stuck relief valve.

[ScotiaFE]

Interesting as always.
Blair Patrick just sold a 427 SO block based engine on the forum here for a "cough" for a modest price.
That dyno print out showed 89.1 psi peak oil pressure at 6200 rpm and an average 83.7 psi.
Now if I was looking at those numbers I would be pretty happy with the oil flow.
It would be interesting to know how he got there, but using the plain old Melling M57-HV on my 428 I just don't see those
kind of numbers even at 6000 rpm.
I stop at 6000 rpm, mostly because I can't even drive the thing at that speed
so going higher is not going to help me.

[jgkurz]

I think the sideoiler system is an excellent oiling system.
I'm sure all the guys that think they know better than Ford think they are right also. 

Oiling systems sure are fun to argue about 

I'm not overly impressed with the sideoiler system.  It is not a true priority mains oiling system; it oils the mains and the cam bearings at the same time.  IMO it is only marginally better than the standard FE top oiler system.  The thing that makes it a little better is that the passages are larger and can flow more oil to feed larger bearing clearances.  The rear pressure relief valve would seem to be a benefit if you put a high pressure spring in the regular oil pump, so that the regulation is done at the end of the oiling system, but based on the tests I've done with oil pressure gauges at various spots in the engine, there isn't more than about a 15 psi drop off front to back, so as long as you have sufficient pressure up front I'm not sure that the rear valve is needed.  Although I have to say that when the sideoiler was designed, there weren't modern electronic ignitions, and Mike's point about spark scatter is a good one if you happen to be running points and a coil only.  With a modern electronic ignition distributor and CD ignition box like an MSD, I don't think you'd see the same problem.

The really good oiling system is the small block Ford oiling system.  That one is a true priority mains system.  That is also the oiling system that the Shelby block was designed with.

I looked at what Shelby did on their aluminum 427 block. It seems they redesigned the oiling system so the crank was indeed the first to be oiled. Their block doesn't include a bypass but they also improved the design so my previous logic that I could just disable the block bypass like Shelby did probably doesn't hold up.



http://www.shelbyengines.com/products/finished-block

[Autoholic]

Scotia, remember that bearing clearances play a huge factor in oil pressure. His engine might just be built to a tighter tolerance. Increasing your flow rate should allow you to reach operating pressure quicker but if you're already using a high volume pump, that doesn't help. Have you checked to make sure the relief valve isn't opening too soon?

[ScotiaFE]

Scotia, remember that bearing clearances play a huge factor in oil pressure. His engine might just be built to a tighter tolerance. Increasing your flow rate should allow you to reach operating pressure quicker but if you're already using a high volume pump, that doesn't help. Have you checked to make sure the relief valve isn't opening too soon?

Well I'm not in the same zone as Blair for building FE's, but I'm pretty confident that my 428 is working pretty good.
I actually have pretty much the same 482 that Blair sold, mine is based on a Genesis block,
but pretty much the same, Tunnel Wedge and BBM and such.
Someday I will actually assemble it.
I'm sure he has the bearing clearances just right so it must be boosted at the pump.
My 482.

[cjshaker]

I think there's way to much "overthinking" on this. There's no 'magic' in the sideoiler system. Back in the day, Ford was trying to get as much oil to the mains for endurance racing like Lemans and Nascar. That's what the sideoiler was designed for. They regulated at the block bypass valve to insure maximum oiling was available at the mains to help solve durability issues. It was the best solution, remaining in the confines of the FE block, without totally redesigning it.

Shim or eliminate the block bypass valve and it's no different than any other engines oiling system with a bypass valve at the pump. It's not an issue with other engines, and it wouldn't be an issue with the sideoiler. The centeroiler has no issues in anything other than endurance racing, as Ford found out. Early centeroiler 427's and 428's don't have oiling issues in drag racing (other than maybe flooding the head), so unless you're endurance racing, it's really a moot point. The engine will survive fine with or without it.

Personally, with a bypass at the pump, I don't see any need for the block having one. If you're running big clearances, I would prefer to leave it out or shim it, ensuring that the maximum available pressure is reaching the rear main.

[preaction]

IIRC the rear oil valve was put in place because the side oiler blocks were used for racing yes but they were also intended to be put in passenger car's and needed cold start up high oil pressure protection, you know for the people in north Dakota who could have bought a car with this engine.

[cjshaker]

IIRC the rear oil valve was put in place because the side oiler blocks were used for racing yes but they were also intended to be put in passenger car's and needed cold start up high oil pressure protection, you know for the people in north Dakota who could have bought a car with this engine.

That is what pump bypass' are for.

[Ranch]

The C9ZZ-6600-A oil pump was also a 22 gal/min- 70-80 lbs @ 4K
Doug at POP sez this spring is no longer available but sells a shim and new plug if you you'd like a little more than the M57HV
I don't see how any FE can have "Mains" priority oiling system unless you come in directly to them. The Side Oiler feeds are aimed more to the cam then the mains and I don't really see to much of a down side to a Center Oiler such as 406/427 with it's larger galleries.  Clearances to big for the street don't help, neither does worn rocker assemblies (biggest culprit)
 Naaa  I think Henry's boys didn't do too bad dam near 50 some yrs ago, ask Enzo.   .... JMO

[CaptCobrajet]

Interesting as always.
Blair Patrick just sold a 427 SO block based engine on the forum here for a "cough" for a modest price.
That dyno print out showed 89.1 psi peak oil pressure at 6200 rpm and an average 83.7 psi.
Now if I was looking at those numbers I would be pretty happy with the oil flow.
It would be interesting to know how he got there, but using the plain old Melling M57-HV on my 428 I just don't see those
kind of numbers even at 6000 rpm.
I stop at 6000 rpm, mostly because I can't even drive the thing at that speed
so going higher is not going to help me.

I always tap and plug the two "spit holes" in the crankcase, and eliminate the bypass.  The last thing you want to do is blow off oil to the rear of a front sump engine under hard acceleration.  That bypassed oil will never see the pickup until you let off the gas, or it blows up from no oil in the sump..........which killed many drag race 427's in the day.  The oval track apps may have seen some benefit, but I still can't see it.  The spit holes are in just a peachy place to wrap that oil right arount the crank and kill a little power also.

Rocker arm to shaft clearance, LIFTER BORE to lifter clearance, main bearing clearance, and to a lesser degree, rod bearing and cam bearing clearance all play a role in making the pressure more consistent.  If you have a severe bleed from one or more of these places, the idle oil pressure, and low rpm pressures will suffer.  I work on the pump a little also.  If it bypasses early, at least it is going to the front of the pan in the modern Melling pumps.  I use a few Titans also, but they bypass internal.  Not much gain there, but higher quality parts..........

[IDOIT4SPEED]

do you guys ever disassemble and check/clean your new pumps.

[Heo]

Yes since i got a "new" pump that
was scratched inside i always take
them apart
Fast and cheap insurance