Home » Public Forums » GMCnet » [GMCnet] Olds Engine Lube System Information
| [GMCnet] Olds Engine Lube System Information [message #281472] |
Sat, 04 July 2015 20:41  |
 |
USAussie
Messages: 15912
Registered: July 2007
Location: Sydney, Australia
Karma:
|
Senior Member |
|
|
G'day,
As part of the research I'm doing into the oiling system I used a link that Chuck Boyd provided awhile back there is a plethora of
information about Olds engines here:
http://www.442.com/oldsfaq/oldsfaq.htm#Table of Contents
In this section:
http://www.442.com/oldsfaq/ofbld.htm#BLD Engine
Scroll down to:
Oiling
Olds oiling systems aren't as bad as most would think. My race engine builder Danny Lattimore, (who is the one that has a 10 sec
Olds in D/Stock class, 70 SX with a 455 in it), has been building these things as long as Joe Mondello has. He has never found half
of what Joe says to be true. If you want to listen to all Joe has to say you'd buy all His parts and have $5000-$10000 in an engine.
It's true all the neat things make an engine slightly more efficient but you can have yourself a great street engine for under
$3000.00. One that will go a very long time. If you put oil restrictors in the block at the bearings you're not really accomplishing
what you want. I would go with rotating the cam bearings slightly where it feeds oil to the lifter galleys and put a stock regular
oil pump in the engine with a 4 quart pan.
Make sure to run near the max limits on all your bearing clearances. We run .0031-.0033 on the mains and .0025-.0027 on the rods.
NEVER had a problem. Studs are not required for the bottom end either. Good bolts work just as well. On an engine rebuild the best
money spent is in the cylinder heads and the cam with impeccable assembly practices and you'll have one heck of an engine.
In the oiling picture, you can see that the oil comes from the oil filter back into the engine where it goes up one side of the
lifter gallery to the front of the block, intersects with the timing chain oiling feeds, main oiling feeds, and the lifter gallery
on the opposite side. The mains get fed from front to rear on an Olds engine, and the rods in turn. Every time we've had oiling
trouble or even questions about the system (before I got smart and had Dave Smith build us a quality oil pan and system), I would
check out the #7 & #8 rods and the next to the last main bearing since they're the last to get oil pressure and the first to lose
it. This is also a good way to judge the condition of an engine you're buying, I wouldn't buy a used engine to drop in and run
without looking at the bottom end. If they don't want to let me look at this, the price drops down to what I'd pay for a rebuildable
core.
[ Thanks to Ken Snyder, Jim Chermack for this information. ]
Oil Pumps
If you keep the revs below 5 grand your stock system will be fine. People are being misled here. Olds' have an oil volume problem,
not pressure. These are two different animals that often get confused. High pressure does nobody any good if there is not any oil to
pump. In an Olds motor the oil must be returned to the pan as quickly as possible or the pan may be sucked dry. 40 psi pressure warm
is more than enough. Too much pressure, say over 80 psi is hard on an engine too.
In my 85 Cutlass Salon I run a Toro 5 quart pan with a Diesel oil cooler filter adapter and a diesel radiator with a Fram 1 quart
filter PH 11. I have a total of 8 quarts with this lo buck stock system. I run a Melling HV pump that runs around 60 psi. This car
runs 12.80s all day at the track with no oiling problems. With short bursts to 5800 RPM the 8 quart system works great.
I did port the rear main oil flow passage off of the pump mount for better initial flow. I think this is very important. I also
polished the return valleys under the heads to the lifter area for faster oil return to the pan.
My 455 in my boat is subject to long bouts at 5500-5700 rpm. A 5 minute cruise at this RPM is not uncommon. I use a Dooley
Enterprises 14 quart pan on that motor. I also have a dual remote filter set up. It takes FOREVER to change the oil in that baby!
The pump is a high volume with a special pick up for the big pan. The rear main has been ported too. The engine internals on my boat
are the same as my '85 Salon.
The way to improve your pressure on the Melling, or any oil pump, is to assure that the gear to cover clearances are correct. Take
your oil pump to your machinist and have them check that the gears are the same length and that you have minimum clearance to the
cover. A gasket might not be needed.
A Fram HP25 will also give you more pressure at idle than an HP2. If you are going to do all that work to replace the rear seal you
might as well put on a larger capacity pan and you will not have a problem with sucking the pan dry. Use oil restricted push rods
and grind the oil return holes in the block and heads and you should have no problem. I have heard that main oil restrictors are
good and bad.
[ Thanks to Tony Waldner, Al Varhus for this information. ]
High Volume Pumps
HV oil pumps do pump more per/rpm than the standard volume oil pumps. You may have been told or heard that the oil pump's pressure
relief valve pops open at a set pressure, directing all the excess oil back into the oil pan before it goes up to the top of the
block.
I used to think that the protrusion jutting from the oil pump spewed oil back into the pan. However, recall that inside there is a
solid piston- the pressure relief piston. Oil cannot flow past it in any large volume. What happens when the pressure relief is
activated is that the excess oil pops the piston open, and is directed back to the pump's *intake area.* Not back to the oil pan.
Since the oil passages remain a constant diameter, you are pumping exactly the same amount of 55psi oil at 4000rpm using a HV pump
as you are using a standard pump; the pressure relief valve is just allowing more of the HV's output to go allowing more oil to
bypass back to the pump inlet. A subtle but important difference.
I suppose that in theory, the pressure relief might not be able to keep up with the extra output of the HV pump, but you would know
this when you saw the oil pressure climbing at high revs beyond what the pressure relief valve spring is rated at (if you don't know
what that is, you can figure it out once you run your engine much above idle, as a HV pump will "max out" rather quickly at a
certain psi and stay there no matter how much you rev your engine- for example, my 403's HV pump hits 55psi by about 2000rpm and
stays there, no matter what I rev it to). In that case, you would need some reserve oil, because the drain backs in the heads would
be the bottleneck for the extra oil going through the lifters (which are kind of "oil pumps" themselves).
Restrictors
As for the oil restrictors, they only restrict flow to the cam bearings (refer to a diagram of the Olds V-8 oiling system to confirm
this one), not to the lifters or the pushrods or the upper end of the engine. A reversible way of achieving the same thing is to
drill a smaller hole in your cam bearings, and install that hole facing the oil feed hole from the main journals. To restrict flow
to the upper-end of the engine, you need restricted pushrods.
On most Olds engines, they have a tendency to over-oil the top end. If you look at the oil flow picture in the service manual, the
restrictors (per Dave Smith) should be in the front center oil line and the oil lines going straight to the cam bearings on the next
three back. In this position, the only thing to get less oil is the cam bearings. Now on our solid lifter cammed 350's, we also add
a second restrictor to the front web, but it's on the side that does not supply the mains. These are the only lifters that get any
restriction from this system, the only way you could restrict all the lifters/pushrods would be to drill and tap each lifter oil
hole and install a restrictor in each one.
I'd forget the oil restrictors. I've heard of too many people having this kind of problem. Remember, Olds didn't put them in the
original W-31.
[ Thanks to Ken Snyder, Mick Gillespie for this information. ]
Extra Capacity Pan
Consider this: you can have a high-capacity oil pan in a couple days via mail-order for about $200, including the extended pickup.
How much have you already sunk into the motor? Is it worth the extra peace of mind to have a couple extra quarts of oil on hand to
feed your engine? Then again, unless you start running this engine at a constant 4000rpm, you really won't encounter this problem.
This is your call.
Diesel Oil Cooler
The diesel Olds V-8's have an extra quart of oil capacity because of the oil cooler they are equipped with. Not from an extra-deep
pan, as in the Toronado oiling system. The oil pan is the same, though the gasket is more sturdy.
The trick setup, using factory parts, would be the Toronado oil pan (along with the sturdier gasket) and the diesel oil filter mount
with the cooler adapter lines, for a total of a 7-quart capacity using factory parts.
High capacity oil pan.
High volume, high pressure pump.
Oil restrictors to keep oil at main bearings.
Oil cooler.
Oil Return from Heads
The oil goes up top. Here is how to get it back down to the pan faster. Complaining about leaking valve covers? This modification
solves that, and more importantly, helps oil return to the oil pump. Here goes:
I did this project when I had my mill (just torn down and still dirty) on the stand, so that is the only way I'm going to recommend
doing it. Full credit for the idea of an external oil return system goes to Joe Mondello, who told me he does this to race and
marine (i.e. heavily flogged) engines. By the way, the purpose of this whole thing is better oil return. The leak free valve covers
are a nice bonus.
First thing to do is get your die grinder out and enlarge the oil return hole (downward) that is located at the front of the lifter
valley. Blend the lower side of the hole downward so that any oil coming down from the front oil return holes does not pool in the
valley, but instead will drain immediately down through that round hole.
Next, use your die grinder to smooth out the entrance to the oil return holes located at either end of the cylinder heads. This is
especially important for the rear (towards the firewall) holes, since the natural tilt of the installed engine pools the oil to the
back of the head. Typically, these holes were simply drilled into the head perpendicular the head surface, so there is a lot of
improvement that can be made to the entrance of the hole. The end result should look like a funnel. BE VERY CAREFUL ABOUT GRINDING
TOO MUCH!!! You want to make a funnel, not a canyon. Just use a fairly fine burr in your grinder so that a nice satin finish
results.
Closely examine your oil return holes and you'll see that the large gallery drilled in from the valve spring area is intersected by
a small gallery that actually returns the oil to the valley. For the motor head with a good collection of burrs, a long shaft burr
with a small (¼") head can be used to do some limited smoothing out of the intersection of the galleries. By looking down the large
gallery, you can see that the oil must climb uphill to reach the entrance to the small gallery. Since oil can't climb, it pools in
the valve spring area until it reaches a high enough level to spill down the small gallery. With my engine on the stand and the
valve covers/intake manifold off, I poured oil over the valve springs to simulate the oil return process in a running engine. I had
oil all over the floor and none coming out the return hole into the valley. That explains why my valve covers would frequently leak.
They were literally holding about 3 ounces of oil each due to the poor oil return design of the Olds cylinder head. Six ounces
doesn't sound like much, but I want every ounce in the oil pan, not in the valve cover area.
Make sure you have each head on the correct side of the engine (I think they're interchangeable too, but I've always kept them on
the same sides; don't ask me why...) You will be installing 90 degree elbows on the back of each head. I did this four years ago,
and as I recall, I used ¼ NPT fittings. Once you read this, you can decide on the size of the plumbing for yourself. I drilled a
hole into the back of the cylinder head to intersect the large gallery that comes down from the valve spring area. Use a depth gauge
or similar tool to determine the correct spot to drill. There is a bulge in the casting that corresponds to the gallery, so this is
pretty easy to do. Ideally, the bottom portion your drilled hole will intersect the large gallery at its bottom. In this way, you
will get maximum drainage without drilling into unknown territory. Tap the hole for the appropriate thread size. Repeat this
operation on the other head.
Next, you'll have to decide where to drill the back of the block to install a tee fitting. Joe Mondello recommended using the
machined portion on the vertical part of the block(right below the area where the rear intake manifold seal would go) near the
distributor hole. The important thing here is to place the hole lower than the holes you drilled in the heads, so that gravity can
do its thing. You won't have a whole lot of difference in height between the block holes and the head holes, since the block hole
will have to be drilled high enough to allow you to screw in the tee fitting (that's an important thing to check BEFORE you
drill!!!). As I recall, my block hole is about ¾" lower than the head holes. Before you drill, make sure the distributor clearance
is accounted for.
Now, you simply connect the heads and the block using your choice of braided steel line or fuel line. Joe uses braided aircraft
hose. I used metal fuel line because I had just spent most of my available pennies on a RAM clutch and pressure plate. I should not
have used metal line because 1) the bending and precise lengths required really taxed my patience and 2) when I was smugly enjoying
the rather nice finished result, it dawned on me that I could no longer remove my distributor! Once the engine is reinstalled, space
is very tight, and there is no way you're going to get in there and disconnect metal lines. I could rotate the distributor for
timing changes, but removal was not possible. Off came the metal pipe and on went ½" heater hose with double clamps. Make sure you
keep the set up flowing downhill from heads to block, but tight enough to allow easy engine installation. Since the oil return is
not under pressure, braided line is total overkill. But guess what I'll be switching to next time the motor is out for PM? Yep, Mr.
Mondello's advice to me has never been wrong. I'll be installing braided line.
This has been a long posting, but it's worth it. Once you have the engine on the stand, this will be much easier to conceptualize.
When I repeated my oil pouring experiment, no oil went through the stock rear return holes in the head. Every bit went through my
newly installed return system. Complimented by some contouring with the die grinder to the rear of the valley beneath my newly
drilled hole, the oil now returns down the back of the valley, directly above the sump. The important thing about this project is to
carefully visualize and do lots of "mock-ups" before you drill anything. Also, clean everything thoroughly when you are done
(meaning garden hose clean). Now my valve covers never leak, so I've been able to switch to the extra-thick Mr. Gasket cork gaskets,
which gives me clearance for Mondello's SAR-455 adjustable roller tip rockers under stock valve covers. One more thing, this set up
is virtually invisible when installed, so even stock purists can take advantage of a race proven oil return system. I've had my hood
opened up for some pretty sharp Olds fans, and nobody has ever spotted it. However, it is difficult to service any leaks, so do it
right the first time or get your hoist ready.
Next time I have the engine out, I may reroute these lines down the side of the block and then directly into the oil pan. Should be
fairly easy and more accessible in case of leaks.
[ Thanks to Scott Mullen for this information ]
Plugging Oil Bypass Valve
I would only do this if the engine is in something you take care of and change the oil regularly, since it would suck to have the
oil filter plug up, causing zero oil pressure in the middle of nowhere. I had an accurate oil pressure gauge plus had the factory
idiot light still working so that in the event I did loose oil pressure, it would catch my attention instantly.
It's actually quite simple. On the aluminum filter adapter that bolts to the passenger side of the motor there is an internal
passage that has a spring loaded plate in it. When the filter clogs up the oil goes through this passage to maintain oil pressure.
As I remember (been a couple years since I did this) all I had to do was to pry out a steel insert that held the plate in, remove
the spring, then drill/tap the hole for pipe threads. Install a pipe plug and all your oil is forced to go through the filter.
[ Thanks to Mike Bloomer for this information. ]
Diesel Oil Pan
Diesels use the same pan as the gas 350. Extra oil is all in the cooler circuit. It does not drain back on shutdown.
[ Thanks to Frederick Nissen for this information. ]
Toronado Oil Pans
Although I personally do not consider the Toronado pan to be a performance part, it will give you an additional quart of oil
capacity over your small block pan. Which will help keep the temperature of the oil down. This makes it a good choice for lower rpm
applications such as towing, etc. However, for the most part, this additional quart of oil is kept in a second "sump" area in the
front of the pan. This second sump (with no drain back provision to the oil pump pickup) is required on Toronado's for clearance of
the drive axles. And this is what creates the problem with using a Toro pan in a performance application. This front sump places the
crankshaft's counterweights directly in the oil.
For one, this creates windage that reduces horsepower. At high rpm, this will also throw the extra quart of oil up the right side of
the block/crankcase. Although the Olds engineers did add a deflector to the side of the Toro pan to minimize this problem, the oil
is not in the pickup area of the pan where it is needed the most at high rpm. In addition, because the crank is spinning in the oil
sump, this will aerate the oil. Which creates a foamy and thereby poor lubricating oil condition.
The Toro pan has no rear sump baffle that was used on all other big block pans as a means of keeping the oil in the pickup area
under hard deceleration/braking. Instead, the Toro pan requires the use of a short baffle (or windage tray) that attaches to the
fourth main cap (and one of the oil pump bolts). By the by, this windage tray will also fit the other Olds pans and I recommend
using it.
The Toro pans also have another baffle attached to the number one main cap as a means of reducing windage caused by the timing chain
being in the front sump area. In my view, as a performance part, the only redeeming quality of a Toro pan is the bolt on baffles.
Not the pan itself.
Toro pans are larger in both depth and fore and aft dimensions of the sump. Depends on the body and exhaust configuration of the car
you are putting it in as to whether it will fit. On most it precludes a single exhaust as there is no place to put the crossover
pipe. The oil pump pickup tube is longer.
As for the dipstick difference's, they are the same length with full and add in the same locations. Between the Toro and non-Toro
oil pans, FULL is the same distance below the pan rails. Olds motors want to run the level just under the crank weights. I
investigated this extensively one time. Turns out there are a couple different standard tubes & sticks to match. All correct matches
have the same level at FULL. The Toro pan, being a bit narrower, has the ADD mark about 1/8" lower than others'. I think the 307
tube has a slight bend in it, if that makes a difference.
The Toro pan has a deeper sump; it holds five quarts (plus one in the filter for six total) while all other Olds pans (big block,
small block, and diesel) only hold four quarts (plus one in the filter). The Toro pan will fit an A-body chassis (can't speak to
G-bodies; I assume someone like Charlie will have the info). The oil pump is the same, but the pickup tube is longer for a Toro.
Toro pans will fit all 64-up (except 394, of course) Olds V8 blocks, big and small. The diesel pan is the same as all other small
block and only holds four quarts; its the additional volume in the oil cooler that gets the system up to six.
The later Toro 350 and 307 pans differ from RWD pans in appearance but not capacity. They look deeper and less wide. This is to
clear the final drive unit. The 403 powered Toro's used in '77 and '78 use the same 6 quart pan as the early 425 and 455 cars, but
they do not have the baffles that bolted to the main caps like the big motors did.
[ Thanks to Greg Rollin, Frederick Nissen, Joe Padavano, Tony Waldner, Bill Reilly, Chris Witt for this information. ]
Factory Oil Pans
There is a significant difference in big block and small block oil pans. There are 2 big blocks (Toro, and non-Toro) and the small
blocks are all the same. My Olds engineering documents show three distinctive pans. P/N's are 391440 (4 qts) for small block, 399270
(4 qts) for big block and 398438 (5 qts) for Toro. Pickup tubes are the same for both the 4 qt pans. The Toro has a different oil
pump pickup.
The 455 pans have slight bulges just ahead of the sump to clear the rotating crank/rods. Small blocks don't need the clearance hence
those pans have no reliefs. All the aftermarket pans have bulges so they fit either engine. Factory 455 pans fit small blocks but
the reverse is not true.
The main difference between the 65-72 small block pans and the big block ones is the baffle used on the big block pans. This baffle
is designed to keep the pump pickup submerged in oil under hard deceleration/braking. Now just why the Olds engineers felt this was
not necessary on the small blocks (even the W-31's), I couldn't say.
[ Thanks to Jim Chermack, John Pajak, Greg Rollin for this information. ]
Regards,
Rob M.
_______________________________________________
GMCnet mailing list
Unsubscribe or Change List Options:
http://temp.gmcnet.org/cgi-bin/mailman/listinfo/gmclist
Regards,
Rob M. (USAussie)
The Pedantic Mechanic
Sydney, Australia
'75 Avion - AUS - The Blue Streak TZE365V100428
'75 Avion - USA - Double Trouble TZE365V100426
|
|
|
|
Current Time: Tue Nov 19 05:02:38 CST 2024
Total time taken to generate the page: 0.04337 seconds
|
GMCforum
Search
Help
Register
Login
Home
