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5w-30 in a 1500...

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When I raced the 1500, I ran 20W-50. But for the street I used to run 10W-40 in it (here in NJ).

I run 10W-30 in my current, street MGB with no ill effects that I can see (driven gently and mostly in Summer only).

I guess you could <span style="text-decoration: underline">try</span> the 5W-30 and see if it reduces oil pressure.
(but why this question?......did you just bid on a pallet of 5W-30 on eBay? :jester: )
 
Must have found a 55 gallon drum that fell off the back of a truck. :wink:
 
They're selling this new biodegradable oil here in Austin. It only comes in 5w-30 flavor. I leave a lot of oil on the pavement these days, and I would feel a little better about it if it were biodegradable. Also, the marketing info makes the oil out to be superior to synthetic... and you can ALWAYS trust marketing materials. :wink:

https://www.getg.com/engineOil.php
 
Oh... and also wondering if lowering oil weight might give me some MPG gains.
 
The 5W oil is an MPG exercise for newer vehicles.
One, your engine most likely is not "new", or even a recent rebuild, especially if it leaks that badly.
Two, was the 1500 even designed for multi-grade oils?
Reason I say that, is my 1950 Ford, loaned it to my brother to take to college, and he broke 9 rings using 10-30.
Flatmotors were designed for single-weight oil, the squirt holes on the big ends of the rods designed to squirt further up the cylinders when hot and thinned out. I ONLY use 30wt in my Flatties now, went 300K on last one.
My Jag came with a sticker on the fill cap (still there) stating "Filled with Premium 20-40" or something like that. I use 20-50 now.
As much issues as most LBC's seem to have with hot, low oil pressure, I'd NOT be using 5w-30. 10w minimum, 30 minimum.
Go ahead and try it, be prepared for more oil leakage, and leass oil pressure, and possibly smoke out the tailpipe.
Dave
 
My motor is a recent rebuild, but I did break some rings, so I have it open right now while I repair them. I have always run 20-50.

What would be the drawback of running single weight 40 or 30 in my 1500 motor?
 
40 single is basically for clapped out motors. BTDT. Slows the smoke out the tailpipe, and tends to quiet noisy bearings.
Texas, you'd be okay most of the time, but in colder climates, getting a cold engine (and oil) to start on straight 40 can be difficult unless battery, cabling and starter are in good condition.
Makes a higher than normal draw.
BTDT, too. Even straight 30 up here makes getting the six volt positive ground vehicles started in freezing weather a trip.
 
Sorry to be thick... but by "clapped out" do you mean worn out? Are you recommending that I NOT use 40?
 
Don't use straight 40.
If the engine is reasonably tight, all it will do when cold is not give good oil to where it's needed.
 
By the way, my last tow van (a 2005 Ford 3.9 Freestar), ran <span style="font-weight: bold">0W-20</span> oil (which I ran to maintain warrantee).

And I towed out to Pittsburgh with that thing in the Summer at least 5 times (8 hour tow for me......A/C on the entire way). The funny thing is that 3.9 was an old-school pushrod engine designed in the 60s. When I traded it in, it ran perfect.

But back to your engine: BE SURE you have some sort of crankcase venting in that 1500. They build up pressure more than most engines and will push oil out the very weak rear seal.
I set mine up with a simple vacuum attachment from the intake to the valve cover (so that the crankcase had slight negative pressure) and it stopped leaking (before that, it was a mess).
After my fix, that engine ran could run a 4-Hour enduro at minimum 5000 rpm the entire time without losing a drop of oil.
 
I would not use 5-30 in one of these engines, like mentioned that oil grade is for modern engines, not yours. I understand you wanting to be green friendly but think of it this way, running 20/50 (which I recommend Valvoline VR1 20/50) is more green friendly than turning a rod bearing, and letting a rod get lose and stick a hole in the block and dumping a Valdez size oil slick on road :smile:
 
Nial, at the moment our 1500 only has a vent tube off the rocker cover. Are you saying all you did was plumb that into the intake manifold? No PCV? Was the air flow controlled by the tubing ID or an orifice or anything? That would be an easy switch for us to make.
 
Pressure is pressure, if I stick a ice pick in your tire, I don't need a dry vac to suck the air out of the tire, because it is pressure. You will find almost all racers not using any sort of PCV, because it never need to relieve crankcase pressures, racer most commony vent to catch tank with breather. All early cars were vented to atsmophere and only after the goverment stepped in was the PCV invented and then only for emmission on old tred engines, if your engine is healthy you're way better served venting to atsmophere, a vaccum on the crankcase thru the fuel induction can never be a good thing and often times cause problem with pulling oil into the carbs and into the engine, that why you don't see racers using it, Nial is the first racer I ever heard say he used vacuum on his crankcase. The 1500 has very ample breathing thru the block and head, unlike the A series engine. Because of the design of the 1500 block and head it breathes good, and has three nice size orfices to draw the pressure out of the block.
 
Before I would believe the sale crap on their web site (which was short on technical data), I would mosey over to Bob Is the Oil Guy (BITOG) and see what they think of this "green oil".
 
Morris, we have similar climates and I run 20/50 winter and straight 50 summer w/ Lucas both ways. As everyone knows, my motor is at less than optimal clearances with it's variable stroke crankshaft. While it'll spin slower when it's colder, I've never had any trouble cranking it when it was cold out down here. IIWM, I'd use 20/50 min on your motor in the summer. I ran 20/50 for years but am running straight weights now as I believe they don't drain back as quickly and tend to stick better when sitting preventing less chance of "dry" start ups.
 
dklawson said:
Nial, at the moment our 1500 only has a vent tube off the rocker cover. Are you saying all you did was plumb that into the intake manifold? No PCV? Was the air flow controlled by the tubing ID or an orifice or anything? That would be an easy switch for us to make.
Click to expand...

Doug:

No PCV. Just the setup you see pictured below. Vent is before throttle plate, so not pure vacuum. My 1500 ran a single carb so this was pretty easy. I experimented with different orifice diameters and ended up about 3/8" (I think). This was racing only, so all I needed to do was get it to work in the range that I ran it. Worked like a champ and all ended weeping of rear main seal. Engine was freshened about every 3 years (about 75 hours of racing).....but I'm gentle and tend to keep things under 5800.
I'm curious to see how my new 1275 will be in the regard.....I know the scroll seal can be a problem..

carb-vent-1500.jpg
 
I ran 10W-30 once, and my observation was the oil pressure came up quicker. Once the engine was warmed up the oil pressure was around 10 PSI at idle, so it seemed a little scary to me. The 5W isn't going to come into play unless the engine is cold, so you could certainly get away with it.
 
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