Hey guys, looking forward: I've read and talked to many people with many anecdotes about killing ls motors on track. That said I've heard really good things about them staying alive.
I have a baffled/trap door pan
I'm getting a crank scrapper
I'm going to run a 5 quart accusump
Is this sufficient? Who's got the real world experience? This engine will be relentlessly abused on track - essentially no street miles. Obviously it can and is done with frequency, just looking for some more experienced input! Thanks!
We built one for an endurance Miata that's won a few championships. Bone stock crate LS376/525 engine with an oil pan that has trapdoors. AFAIK it's been happy and healthy for years. Car runs aero and 275 Hoosiers so it's got a bit of lateral g going on.
Other than the cam spec, that's the same setup we've used on all our builds. It's the only pure track car but a lot of ours have seen significant track time and there have been no failures.
In reply to Keith Tanner :
That's what I want to hear. I have the moroso trap door pan that v8roadster sells. I figured it would be straight forward and then I started talking around in the padock and found an alarming number of people who exploded their various LS engines ... of course it's all just anecdotes, but it did make me a bit nervous...
In reply to accordionfolder :
I did all of that , scraper, baffles, trap door baffles, accusump, and a 22 quart oil pan.
As long as I used street tires I could get almost a season. When I went to Dunlop race tires. I'd start out with 120 PSI oil pressure. After one day of racing I'd be down to 30 PSI or less.
I'd drop the pan. Put new rod and main bearings in ( along with thrust bearings) After Sunday's feature I'd be at 15 psi or less
when I put a dry sump in I never replaced the bearings in over 30 years of racing. In fact those original bearings are still in it in the Packard museum. Fire it up and there will still be 80 PSI oil pressure.
Tell you what. Go look at any serious racer and you'll see a dry sump. You can buy good used ones for about 1/2 price of what they cost new. Pros replace them every 2 races. Low budget pros every season and serious amatures every few years.
But it's your engine, learn the hard way if you want.
In reply to AnthonyGS (Forum Supporter) :
But it's reverent because FrenchyD
A 22 quart oil pan is bigger than what's on my tow truck, ha!
The carnage I have seen looked like it was caused by valve-piston contact, not sure if valve float or timing chain failure caused by a harmonic. When chunks of pistons visit other combustion chambers to be social, and the cylinder walls get blown out by the naked connecting rod making a private mosh pit, it can be hard to determine what caused what.
AnthonyGS (Forum Supporter) said:
In reply to frenchyd :
Not an LS series engine.
Ok. Run your LS with race tires and a wet sump pan. See if the results are different. What do those other racers know?
accordionfolder said:
A 22 quart oil pan is bigger than what's on my tow truck, ha!
I think the standard pan is 16-18 quarts Because even on street tires Jaguars corner well enough to throw the oil around. The 22 quart pan came from the factory light weights. ( that had a dry sump system).
Pete. (l33t FS) said:
The carnage I have seen looked like it was caused by valve-piston contact, not sure if valve float or timing chain failure caused by a harmonic. When chunks of pistons visit other combustion chambers to be social, and the cylinder walls get blown out by the naked connecting rod making a private mosh pit, it can be hard to determine what caused what.
When I raced a Chevy ( wet sump) and things went bad cylinder walls always seemed to take a hit.
However of the 50 V12's I had only one popped a hole in the crankcase after he drove home from an oil change with the filter barely screwed on. Since it was die cast aluminum it would have made sense to just weld it up. Except there are so many around it's cheaper to start with a good engine.
In reply to frenchyd :
That's like saying: "my v6 Camry can't survive without a dry sump so you better put a dry sump in your BP-miata."
I'm looking for real world experience (i.e. Keith), not more apples to oranges anecdotes.
In reply to accordionfolder :
So you like rebuilding your engine? Good for you. I liked going to race after race after race, year after year after year, decade after decade and having the engine not need work.
Yes it had 5 oil filters and 3 air filters to check and clean. Just part of race prep.
Annually I'd do a leak down test to ensure I hadn't lost any power ( and it never did increase any leak down)
David Love got the same life from his 58 million dollar Ferrari. His too was dry sumped. I'm sure that just like me he occasionally went over the red line chasing someone or trying to keep from being passed.
The Factory even tried to quasi dry sump the Corvettes but since it didn't have the full system it didn't work as well.
It's your car. Do as you wish.
Are people frequently rebuilding engines in race cars running wet sump oil systems like Spec Racer Fords or Spec Miatas? So long as temperatures remain under control and the pickup tube is always submerged what would cause an engine to see excessive bearing wear after only a few days worth of racing?
In reply to MrFancypants :
BP engines don't have oil starving problems, period. Different engines have different requirements to avoid oil starving. It's why I want particular information on LS engines on track not just random anecdotes about v12 engines and SBC from the 70s....
In reply to frenchyd :
I'll keep that in mind when I build my jaguar v12. But since I've talked with a few other endurance racers running ls and Keith's opinion on it, I think I'll be ok for now.
accordionfolder said:
In reply to MrFancypants :
BP engines don't have oil starving problems, period. Different engines have different requirements to avoid oil starving. It's why I want particular information on LS engines on track not just random anecdotes about v12 engines and SBC from the 70s....
Yeah, that's the point I was trying to make with the question. Different engines have different needs.
In reply to MrFancypants :
Gotcha!
I'm fairly sure talking to a few people who do c5s on track that the baffled pan and a 1 quart overfill is what they swear by, but figured an accusump is cheap insurance.
I'm pretty sure Accusumps are common in Spec Miata as well, although I think that's only for the B-powered cars. My concern about accusumps is that it makes it a little difficult to determine just how much oil is actually in the system. I haven't run one on a car since 2003 or so.
Different engines definitely have very different oiling needs. If you have a baffled and trap doored pan that's well enough designed to keep G force and resulting oil slosh from starving the pickup, the question becomes one of how well the engine can return oil to the pan at high RPM with high G force. That's where a lot of the difference between engine designs comes in. If you end up with a bunch of oil trapped in the valve covers and not reaching the drain holes, you can run the pan dry (amongst other issues). But if the oil can get back to the pan fast enough without piling up somewhere on the way, you'll be fine.
MrFancypants said:
Are people frequently rebuilding engines in race cars running wet sump oil systems like Spec Racer Fords or Spec Miatas? So long as temperatures remain under control and the pickup tube is always submerged what would cause an engine to see excessive bearing wear after only a few days worth of racing?
Depends on if the pickup tube is submerged in solid oil or submerged in foam. The foam expands in the pickup tube, which causes a loss of real volume but since most engines are running with the pressure relief open at racing speed, this may not get picked up as a drop in oil pressure. The foam will also expand in the crankshaft on the way to the rod bearings.
In hard left turns the oil can be seen to be violently blasted up the oil return passages -- one of which would be to the left of the tappet. There is a delay that is approximately 5 seconds long (give or take) and the aerated oil in the shallow area of the sump and probably that oil which has drained down from heads makes its way to the sump. The highly aerated oil is drawn into the pickup tube and compressed by the pump. Typically oil can hold dissolved air at about 9% per bar pressure. The Porsche pump runs at many bars of pressure. When the oil emerges from the cam bearings (primarily) it releases air from the supersaturated oil like sodawater and this whitish-brown foam is clearly seen to be flung by the cam lobe onto the plexi-glas window. This is direct evidence of the high aeration of the oil in the wet-sumped 928 engine in competition use. This high level of aeration is what kills the 2/6 bearings. They just happen to be the first to get a good sustained dose of it in these situations. The Porsche 944 engine has a similar failure mode for the number 2 bearing since the bed plate oil passages are arranged similarly. The 944 engine was derived from the V8 block in the 928.
The nice thing that the dry sump gets you is the big deaeration tank, that also doesn't have a crankshaft spinning on its roof.
MrFancypants said:
Are people frequently rebuilding engines in race cars running wet sump oil systems like Spec Racer Fords or Spec Miatas? So long as temperatures remain under control and the pickup tube is always submerged what would cause an engine to see excessive bearing wear after only a few days worth of racing?
Formula Fords use a dry sump. Does spec racer Ford use the same engine?
frenchyd said:
MrFancypants said:
Are people frequently rebuilding engines in race cars running wet sump oil systems like Spec Racer Fords or Spec Miatas? So long as temperatures remain under control and the pickup tube is always submerged what would cause an engine to see excessive bearing wear after only a few days worth of racing?
Formula Fords use a dry sump. Does spec racer Ford use the same engine?
The FF you're familiar with uses the antique Kent engine - the fact that they're usually called "crossflows" says quite a bit about the era in which they were developed :) SRF uses either the CVH or a Sigma.
frenchyd said:
MrFancypants said:
Are people frequently rebuilding engines in race cars running wet sump oil systems like Spec Racer Fords or Spec Miatas? So long as temperatures remain under control and the pickup tube is always submerged what would cause an engine to see excessive bearing wear after only a few days worth of racing?
Formula Fords use a dry sump. Does spec racer Ford use the same engine?
The SRF has used three different engines, a 1.7 Renault (called Sports Renault, at the time), a 1.9 Ford, and now a modern 1.6 Ford (16v DOHC). I'm fairly certain that all of them are wet sump engines. I do not believe that any of these engines had durability issues and these cars run slicks.
The 1.9 Ford is not a Mazda engine, it's a Ford engine. The BP didn't come in a 1.9.
You might check Vorschlag's website. They have done a number of LS swaps into BMWs and IIRC at least one went boom due to oiling issues with track use.
The exact details on what they had done to it though, I don't recall. It's probably on their website somewhere.
