SBC Low Oil Pressure / Oil Drainback
ฝัง
- เผยแพร่เมื่อ 25 ธ.ค. 2024
- SBC oil pressure issues. The new engine has some issues, this is what generally occurs when you put together all used stuff. LOL.......If you didn't see the last video, the engine would fire up and run for a couple minutes with great oil pressure, then it would start to fall off a little and then would fall completely off to about 15psi. I would shut it off, wait a minute or two and fire it back up and then it would do the same, great oil pressure for a couple minutes then it would start to drop. I'm thinking we have a severely undersized drains in the lifter valley. This engine is normally run with dry sump equipment. Not having a dry sump with any scavanging from bottom now creates a situation where the oil is trying to drain back through the (4) small .500 inch holes. The same holes that the bottom crankcase area is trying to breath into the lifter valley through.
------------------------------------------------------------------------------------------------------------------------------------
www.TurboJohnRa...
The Drag Racer's Wife sub to her channel: / @thedragracerswife
Hang out with me live every Wednesday night for Tech Talk! Ask questions and share your setups. Join here: / @turbojohnracing
Thomas Racing Service: Jeff Thomas No Prep Struts
The Brake Man: www.tbmbrakes.com
Black Sheep Industries: blacksheepindu... Discount code: TurboJohn10
Tin Soldiers Race Cars: tinsoldierrace...
Check out the Jegs Pit Mat here: bit.ly/3Iq9Vc1
Forced Inductions: www.forcedindu...
Cam Specialist, turbo needs: www.GetFPP.com
Mod Series Shocks: qa1.net
Torque Converters: www.hughesperfo...
Turbo John always figures it out. He's a bad man. You don't see many guys that can do it all from bumper to bumper.
I pretty much can I’ve been wrenching in a shop at 13 years old auto shop 3 periods per day my senior year graduated automotive tech school certified brake lamp and emissions California certified in the early 90’s I’ve had my own shop in Spokane wa for the past 30 years. Cars are my life and I’ve been in every situation and scenario there is. John knows his shit obviously but we all look at thinks from different angles I’ve built over 100 engines but there’s always stuff to learn from no matter who they might be. Just trying to help I want to see this guy win I’m not down talking at all so don’t take it that way. I just wish I was there working on that car because it would be fixed by now. Lol
Same problem we had on Billy’s big block
Man, what did you do for the solution?
Call Bill John, get the solution.
I would try to figure out a way to drill at least 3 half of inch holes in the lifter valley to insure good ventilation for air and oil purposes. I know that you will figure it out for sure. God bless you and don’t worry he has your back. I will be praying for you to succeed.
Good luck John I hope you get it figured out
Can’t wait to see it back on the track
You are on the right track. You could do a external drain back. A lot of high end race motors have them.
Has to be the problem! Glad you got it figured out! I noticed the block didn't have the vent holes when you first showed it but figured it had another way to vent. Gaskets look like all the oil was in the valley!
Cant wait to see the outcome, thanks for the videos John.
If you have firewall room put a -10 or 12 fitting in the back of each head and run the hoses to the side of the pan. If you have blow by the air running up trying to get out the breather is holding the oil from draining back especially with only those 4 small holes for the air to come up and the oil to go down.
That’s what I think as well.
I would also check the oil pump pickup to pan clearance .It may be tighter than you want especially running without a pan gasket.
You need at least 3/8 of an inch pickup to pan floor. I have seen several engines starved because the pan floor is pushed in.
Could have sucked the pan up against the pickup screen on those spool-ups
It looks like you are on the right track T John! Best of luck! 🤩🤩
John for what its worth i think you are on the right track venting the crankcase better and your drain back mods should help alot. I bet just a vac pump with a good baffled catch can with a drain would be the ticket. Have you ever actually measured oil fill and drain? Then refill and run for a warm up then drain again to see what you are getting dilution per warmup. Im betting you will be amazed by how much fuel is really going into the oil. A vac pump and using your oil pan heater will vastly reduce your milking of oil. I love your hard working oops fixit and try again style. Done it a few times myself. Also on your thrust issues... Im betting you can adjust your pressure now that you have those dumps and surely a spot for a orifice.
Oooh, I thought you had standpipes in the aluminum block already! I would definitely do BOTH the front and back vents!! You could also just pour oil into the valley and see how much it holds before draining and how easily(or not) it runs into the pan
Yes, I’m gonna do that.
John, are you concerned about any additional bearing issues, besides that one rear main bearing?
That fuel pump port is for the drive pin that leads right into the accentric lobe on the cam to run a fuel pump.
Ran into this exact problem with one of these blocks in a sprint car.
We did vent from the fuel pump plate and the back of the block we also needed to run a vacuum pump. You may not need to run the vacuum pump though.
Mate, warned you about this a couple of months ago when you picked up the block. The high volume pump and no restrictors has made it worse
I have been building engines and racing sense the mid 70's. I never run a hi volume oil pump. I only run a hi pressure oil pump the hi volume pump will pump the pan dry .
High pressure high volume is what was recommended for my twin turbo mtr. I haven't had any problems like this but it's not an aluminum block either.
Those wet intake gaskets was one of the first things I noticed. I bet that valley has been pretty full of oil. Just my guess. We drilled extra holes in our dart block also. I really am going to lean to not being vented enough
No matter how many holes you drill you still have to overcome crankcase pressure.
@@dougoneill6603 true , but the more holes the more places for drain back.
On turbo 4 cyl we have welded cylinder head breathers shut and added vents to crank case. Any blow by on valve stems will force oil to drain down as there is no crank case vent coming up.
Hey buddy. We had similar issues/gremlins when we took our "working combo" out and switched to an aluminum block...
What was the fix for y’all?
John, there is another plug on the passenger side of the block down low in the center between cylinders, where does that open to on the inside, to crankcase or oil galley?
If open to the crankcase it would be better to use that hole than the fuel pump well that may fill up with oil. Just saying, to get the pressure out.
That fuel pump well also has an oil drain back hole in the bottom.
i liked the last phot of the small chamfer on the main bearing to direct some more oil to the thrust, was going to mention it, but you guys know... fingers crossed you got it with the screens out and extra venting
I run an electric scavenge pump to help evacuate oil out of heads back into sump.. works for me
Interesting
A lot of guys run stands in the lifter galley to keep oil from draining on to the rotating assembly, if too much oil is being pumped to the top end then oil drain back becomes much more critical
That valley has been so full of oil it was up to the bottom of the intake runners!!! Yes certainly filling up and not draining back fast enough if it was me I'd put that fitting from the pump plate to the pcv on the intake and that should give it enough suction pressure to let it drain back better
John the red colored sealer your using is loctite 515 or 518 ?
I have a dart shp run wet sump. Looking to add moroso vac pump the valley on mine has slots across above three cam, but dart recommended standard volume oil pump, while I'm currently running hv/hp pump and have fought oil consumption for years. Plan to put moroso standard volume pump and replacing valve seals and adding vac pump. If none of this helps rings will get done. Brodix suggest a cometic intake gasket with less overhang into the valley.
Great info, thanks john. AG
I would drill out the drain hole for the fuel pump a lot bigger and add the vent.
Yes
I had seen stand pipes but never the actual purpose...wet sump vents...making the connection now. What about the thrust seems that would still be a question.
Think the converter charge pressure is high
I believe you bout got it figured out
HELL YEA JOHN 💪
Yep I was thinking that block was designed to have a vacuum drawn on it… that’s why the oil was so frothy too.
That front block vent will be your most important one on the motor. I would avoid touching that back one. I could see oil blowing out of it. You might be able to use it as a equalization port to the valley
Good old yellow bulletin.
👍👍😎💪💯
Winter project.......go dry sump👍🏼
I was just thinking that a vacuum pump would solve the problem and right when I was thinking that you mentioned it But I understand you have to do what you have within your budget I use to run a 85 RX7 smog pump remove 3 veins out of the Rotor I don't remember the " of vacuum but it wasn't much It worked
I block of those holes as you have done on all Chev race engines. And open up the drainholes in the corners,, then put mesh on them to catch valve train junk. Wet sump or dry. The pan is vented through the valley holes. Though those reinforcing ribs across the valley are not ideal for drainage.
The breather from the pan to the top is a good idea,, or the left side of the pan to the rocker cover. That way the oil stays in the engine and not filling up the catch can. Then ofcourse breathe the rocker covers to the catch can.
May be worth breathing the valley as well.
Your on the right track, but it not oil drain back holes ! Your pistons rings have NEVER been sealed ,just look at your oil it is telling you ! All the compression and worse bust is going past the rings putting so much pressure in the pan the oil can NOT get back ! The best thing you should do is start it on GASOLINE and run it in to seal rings . I know your not going to so you had better take the big plug on back of block for your vent . Fuel pump hole is to small for the amount of pressure you have
Yep always break them in on Gas, learned that the hard way
No boost at idle
@@baby-sharkgto4902 he's referring to the pressure created by combustion. It IS present at idle.
Intake carb and distributor, fire it up and break it in on gas, I think the rings aren’t seated either. It milked the oil immediately.
Absolutely!! And with methanol, it takes a different cylinder hone. NOT A DRILL BALL HONE, NEEDS TO BE DONE ON A SUNNEN CV 616!! THE CADILLAC OF CYLINDER HONES. it can't be 600 finishing, Needs 420 stones and medium to Heavy pressure on the stones. Then a green scotch Brite in front of the stones for 2/3 strokes. This is if he is cranking on methanol. And by the way I don't rem if he put new rings in it or not?? ALWAYS NEW RINGS IN A FRESHLY HONE AND DEF NEW BORED AND HONE BLOCK.
Did you pull your oil filter apart and look for shavings or bearing material?
And YES the oil does start wicking into your intake runners especially under high RPM high boost levels ...You might see extra exhaust smoke at the top of your run ..
First thing I thought when I seen the intake gaskets was that valley was almost rite full by the looks
What are the return holes in the pan like? That was another problem back in the day. I know when we had this problem with 481x stuff back in the 90s we had to go dry sump but we were running all 1/4 mile You are on the right track you will get it
You will figure it out use your resources don't just throw money at it we all want to see you win again
Do the Fuel pump conversion AND the rear vent, add 12 an vacc. pump.
Hey John you should try and use a couple dabs of super glue to hold your gaskets in place and put a film of anti seize around your coolant passages. Alot less chance of silicone getting into anything! Also, much easier to clean up.
I think your on too something, makes sense cause it has good pressure for a little bit. I was thinking about it not being able to drain back with all the crankcase pressure from methanol too. May just have to put a couple vents going in to the side of the block, hopefully it’ll vent good enough through the fuel pump cavity.
Did this fix your issue? I have the exact same issue in my 406 as your caption and idk what to do
You should probably weld a T fitting on there so the oil that runs into the new vent galley has a way to drain back into the pan.
I think you might want to address the exhaust leaks on the headders while you are there. It looks like there's about a 1/4 inch of weld that needs to be finished
Way too much oil getting up top that isn't necessary! I'd try to figure out how to restrict the top end and keep the mains flooded. The design of the block keeps oil off the crank. So you'll have to work on the drain back ports so it flows better. Good Luck!
I am by no means an expert. But I was watching an SRC video last night with Billy the kids new aluminum engine over at Bob mcveigh's. And they were messing around with cutting a very slight Groove into the lifters. And when Bob cut a little bit deeper of a groove it was shooting a lot of oil up through the rocker arms more than it needed. That seems to me that it would flood the top of the motor out with oil and would not drain back fast enough. I think I had saw where you do something similar to your lifters. Just a thought man I hope you get it straightened out look forward to seeing you racing again
They don’t put holes in the block to keep the splash down on the crankshaft.
Why would you have low oil pressure at idle when there’s not as much needed to supply the pump? It would drop off at high RPM if anything
After 2 minutes of idle, rev the oil cannot get back in the pan!
@@TurboJohnRacing well if it’s moving that much oil up too with restrictors in then you have a lifter fit issue
@@TurboJohnRacing John if that were the case why would they even design it as a dry sump block?
@@TurboJohnRacing watch that Steve Morris video I sent the link in a comment. It’s your oil pump drive / cam pos sensor not down far enough. The oil galley leaks right past the distributor housing if it’s up just a big too high,
I think that hole is way to small. If you have 1800 hp and 5% leak down, that is airflow for 90 hp. Think of the size of the throttle blade on a 90 hp engine.
Did thou check the pump pick up tube for cracks?
I haven't heard you say that you have good oil pressure after you shut it down hot and wait for it to drain down then start it and see good pressure
You would have to take it all apart, but you can cutt out the front where the timing chain would be for case vintage.
Sorry if I ruffled any feathers, my other post got deleted. I thought I was helping by posting a nice cheap track event for cars to test 11/30 before the event on an unprepped surface...
I didn’t see it, TH-cam sometimes doesn’t post links or other pages. What was it?
11/30 Piedmont, Triad Street Scene runs street cars, no glue. Amateur crowd, family friendly event, $10 entry free to make runs. Gate at 5, track 6-10, can get tons of passes in...
Can you take the lifter plugs out and put breathers in their place? That’s an old small block Chevy trick
Those are main galley plugs. That tunnel in the middle is the main feed.
@@TurboJohnRacing got it …. Well that stinks!
Just my $.02 but it seems like if the engine was starving or oil, to think that only 1/2 of a 1 main bearing was affected seems like a stretch. Hope it works out well for you John.
I think I just got lucky with pulling the pan. Converter feed pressure may be way to high.
@@TurboJohnRacing I surely hope so, you've had way too much trouble this year. It's time to see you racing, instead of working. I know you feel the same. :)
I personally would of used that spot by the dipstick. Seems higher in the system and the cavity wouldn't fill with oil
Makes sense.
Why couldn’t you run more quarts of oil to compensate for the slow return from the valley?
We are gonna try that as well
If you listen he told you that because it is a turbo engine with no vent in the crankcase. It is not letting the oil back in the pan
@@Chromagen-Grumpy If you listen to me you’ll understand I post trying to help when I have something to offer; I don’t watch the entire video then hope I remember what I wanted to say at the end.
Thanks for the opportunity to educate the masses on not being a cyber bully. 👍
Take a larger piece of the screen you used and try and pour your motor oil through it. An average window screen blocks 1/2 of the air passing through it, imagine that with oil.
Thing about drilling holes is the metal shavings...gotta make sure nothing gets in there!!
Stick the drill bit tip in some tacky grease.
Chips will stick to the grease in the drill bit.
@@montenelson2917 Learn something new everyday!! 😎👍
Do the back one too the more the merrier.
Can you drill them back ones out a little bigger and use the vacuum cleaner as your drilling suck the metal back out🤔🤔🤔🤔🤔🤔🤔🤔🤔👍👍👍👍
Whatever you do please don’t drill holes in that block they knew what they were doing when they designed it. If the valley held that munch oil they would run a scavange up top,
In the book it says you are supposed to have a vacuum pump.
FIRST thing restrict the push rods. You only need a .040 hole in the top side of the push rod.
Having oil pressure issue. All plugs in block even hidden plug. bearing 2.5 to 3 thou. clock cam bearings/ Hei msd /stock pan with Melling hv pump.1/2`` off pan/20/50 oil wix filter only 30 psi when cold and 10 when hot. Does not increase much when at 2500prm. verified test gauges as well. Bad pump? Fresh rebuild 355. also new bypass for oil filter.
I think when you get it back together maybe start off with the correct amount of oil…. Having 2 or 3 extra quarts of oil may be making the situation worse especially with the longer stroke that you have now.
Well ain’t that some shit…. Just when I thought I knew everything 🤣🤣🤣
You need to pull some rod bearing caps and mains one at a time while the pan is off, don’t be lazy it will cost you more labor pulling the pan again.
I hope everyone understands that the engineer's for GM had this figured out back in the 1950's.
Maybe try an electric vac pump?
🤞🙏
It makes no sense that block being for only dry sump bro.. they would want more drain back holes for a dry sump. The holes aren’t there for a horse power gain nothing more. You have a bearing clearance issue I gurantee. You think all 7 qts are being held up in the valley on that engine? Really bro? With restricted as well?
Look at your intake gaskets. That whole valley has been full of oil.
I use Titon oil pumps and never have any pressure problems.
Not sound like an asshole but I raced late model dirt track years ago and we used those blocks and there designed for dry sump , why wouldn't you go the extra and mak it a dry sump set up ? I know it's a cost but you'll be better off in my opinion.
Vacuum pump
I would think if you have an oil drain problem you would have no pressure not just slowly falling off it would be sucking air
It’s almost funny to me that a race block made specifically for a wet sump would me made with a provision for a mechanical fuel pump 🤔
Bearings probably spin
Crankshaft bearings spin
Why don't drag racers use dry sumps and crankcase vacuum pumps like other racers? NASCAR has used them for years and they worked great>
Because a Nascar Engine bay does not already have the entire hot and cold side piping and turbos and blow off valves, etc. Of a Turbo system and upturned headers junkies up that engine bay already...hard to find all that room to continue to mount more system stuff a dry sump system takes in space. But, a vacuum pump may be necessary or a scavenge pump at least to keep the pan area evacced so the oil can easily drain back.
Just go dry sump bro !
Scrap that block and go back to an IRON block...... The weight savings is not worth all of this..JUST TURN UP THE BOOOST....GIVE IT ALL THE BOOST...lol
This is the last chance, lol
Ls
Hell yeah
Take oil pan off see if oil pump is broken 😡
He put a new pump on
@@Ada-zn3pw never had something new be bad out of the box?
I’ve got a badass vacuum pump for you! Messaged you on instagram!