Landracing Forum
Tech Information => Technical Discussion => Topic started by: old chevy truck on January 14, 2011, 02:01:03 PM
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I am planning a new engine for El Mirage and Bonneville. I need advise regarding a dry sump vs wet sump in terms of engine life and durability. Some have advised me against using a wet sump citing problems such as elevated oil temperatures and oil starvation etc. resulting in engine failure. I would like to try a dry sump system but it will entail significant reengineering of the steering, exhaust and chassis. Is there a wet sump system that will get us to the 5 without leaving parts on the course.
A second thought, as a newbie I am frequently amazed at the brilliant discussion that takes place on this forum - e.g. the recent posts regarding wings on comp coupes and altereds. There are a lot of really smart people out there cleverly disguised as hot rod builder. Hats off to all! Thanks, OCT
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What engine?
What chassis?
What class?
How much money do you have?
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Probably a Chevy pick up of some sort judging by the guys nick.
DW
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Call the folks at Peterson Fluids and see what they have to say for your engine.
They have a new pump which is supposed to be a major improvement over conventional dry sump pumps.
They also can supply you with all the other pieces parts like aeration tanks, lines and fittings.
They supply some big name race teams so they know what it takes to keep an engine alive.
http://www.petersonfluidsys.com/pumps.html
Larry
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My car is a monza running a sbc (Dart) in altered class. The H body cars (vega, monza, skyhawk, starfire) are very narrow in the engine compartment and have a cross member, and drag link clearances which restrict the size of the oil pan sump. The pan volume can be enlarged if the headers are routed up and out the fender in front of the front wheel (like the Cohn Jucewik monza). An oil cooler and multiple filter may add addition oil capacity. I guess my question is - can a wet sump system be made adequate to allow 200 mph (7000 rpm) passes to the 5 or is it too risky ? Thanks for your thoughts, oldchevytruck
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A wet sump is absolutely ok as long as the capacity is not too small. All you need to remember is the oil needs to be in the pan, it's no good to you if it's all up in the top of the engine.
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I think the most important things using a wet sump are oil drain back and sump depth/volume. You need to keep the oil away from the spinning crank and rods and have enough oil above the pump inlet to prevent pump cavitation. This means good oil drain back, a good scraper in the pan and as deep as you can make it. If you have restricted depth in the area of the pump inlet then a dry sump is the best solution. A good dry sump can make more hps than a wet sump and provides some good opportunities for oil filtration and cooling over a wet sump both of which equal extended engine life.
Rex
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OCT, You're gunna get the guys that say you cant live without a dry sump. There's miles of wet sumps screaming there nuts off all over the world for a lot longer than we can at the salt & doing it well. I've run marathon boats in the past that ran 8000 plus for 1 1/2 hrs on 7qts of oil with a closed cooling system & pulling 2 skiers. Like I said, the oil has to be where the pump can get it even on a dry sump. A remote filter is alot simpler to service & if you use a
system 1 or an oberg type you will have a better chance of catching a problem early & while you're out there, hang a cooler on it if you need to. Windage tray & crank scraper on either system are a given. It takes more hp to drive 5 oil pumps than 1. Rule of thumb for a dry sump is 3 to 1, 1 feed to 3 scavenge & that's an absolute minimum. On either system you need to stop the crank from tossing the oil up into the engine, thats the hp killer & in a bad scenario, an engine killer. Run a 30lb idiot light on the thing so it will alert you to a prob early, it doesn't matter if it's on at idle but if you're in the 3 with ya foot down the intake manifold you'll be glad it's there.
I had a friend come out with a new lakester a while back, C/GL SBC wet sump bla bla bla. Made a pass, scattered the eng & blamed the wet sump POS. Came back the next yr, new wiz-bang dry sump ($$$), made a pass, scattered the eng again. Convinced him to open it up & eye-ball it & it turned out he was putting 4 rods in backwards, he's been running a wet sump ever since..
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geez I don't remember ever running a SBC :?
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Many thanks to Hot Rod, Rex And Kiwi. I appreciate your advise. A wet sump will save me a lot of work. I'll do what is required to keep the oil in the pan, the pick up in the oil, and all the parts in the block. As I said earlier, there are many very smart people who contribute to this site. Thanks, OCT
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My car is a monza running a sbc (Dart) in altered class. The H body cars (vega, monza, skyhawk, starfire) are very narrow in the engine compartment and have a cross member, and drag link clearances which restrict the size of the oil pan sump. The pan volume can be enlarged if the headers are routed up and out the fender in front of the front wheel (like the Cohn Jucewik monza). An oil cooler and multiple filter may add addition oil capacity. I guess my question is - can a wet sump system be made adequate to allow 200 mph (7000 rpm) passes to the 5 or is it too risky ? Thanks for your thoughts, oldchevytruck
We ran wet sumps on our small blocks until 2009. We had 10 quart oil pans and we never blew up our 350s.... we did disintegrate the 297 inchers though.... but we, in the end, determined that it had to be other than an oil pan issue as the engine was not revving higher than the 350s revved (8000 rpm at shift points and in the traps) when the smaller engines blew up.
Make sure the pan is baffled and screened (for de-aeration purposes).... to the best of my recollection (since we are NOT running a stock Chassis in our Vega).... a stock Monza chassis can hold a full length pan if you rebuild the "removable" cross member, restrict your steering and plug the tie rod end grease ports.... or use tie rods with the grease ports positioned differently.
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I have had a problem with the oil pressure going away before the 4 mile with a wet sump. May not be the best way, but I overfilled it 2 qts and was able to get to the 5 with enough oil pressure to make it live. Made scrap metal out of one with a dry sump. Rod bearing! It had a cross drilled crank and I will never run one of those again at 8000 rpm. My results are not the last word, not the first thing I have done wrong not the last.
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Yes, thanks for this thread! I got lots of the same info in the chat one night from Tone but since I like reading it is good to read the same reply from many folks! :cheers:
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I ran WET for quite a while in the 70's thru the 85 season.
issue is volume in the pan and the removal of air.
frohing drainback was the cause.
the best way to get the drainback flow is to directly plumb a hose out of the head / valvespring area down to the side of the pan. have a baffelplate covering the inlet inside the pan or else oil will flow UP /back into the head.
easily spun them back then in the 8200 - 8800 rpm range....and set records.
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I ran WET for quite a while in the 70's thru the 85 season.
issue is volume in the pan and the removal of air.
frohing drainback was the cause.
the best way to get the drainback flow is to directly plumb a hose out of the head / valvespring area down to the side of the pan. have a baffelplate covering the inlet inside the pan or else oil will flow UP /back into the head.
easily spun them back then in the 8200 - 8800 rpm range....and set records.
Can you describe your baffle?