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JaniH 09-22-2025 01:25 PM

Lucas oils?
 
No one speaks about Lucas oils anymore, does anyone Have experience of The marine 20w50 or 20w50 racing? Rhode Have crazy ammount of zinc compared to others, over 3000ppm.

SB 09-22-2025 02:03 PM

+50hp :)

Joking…..

Sure it’s all good.

Seriously…What ever makes you sleep st night. :thumbs

ICDEDPPL 09-22-2025 02:05 PM

3000ppm?!
 
  • Additive “over-treat” — too much ZDDP can cause film flaking and spalling, actually increasing wear.
  • Can increase deposit formation on pistons and rings.
  • Raises ash content, which can lead to fouled plugs and pre-ignition in high-RPM engines.

  • 1,200–1,600 ppm is the sweet spot for most high-performance flat tappet and marine big blocks.
  • 2,000+ ppm only makes sense for short-life racing oil (where engines are torn down frequently).
  • 3,000 ppm is overkill unless it’s a specialized drag/nitro engine oil designed for very short runs.
Seems like a better choice :
Lucas Synthetic SAE 20W-50 motor oil (non-“Racing” / standard synthetic) has around 1,265 ppm zinc.

JaniH 09-22-2025 02:11 PM


Originally Posted by SB (Post 4935184)
+50hp :)

Joking…..

Sure it’s all good.

Seriously…What ever makes you sleep st night. :thumbs

Night Be so thick that IT robs 50hp. 🧐

JaniH 09-22-2025 02:18 PM


Originally Posted by ICDEDPPL (Post 4935185)
  • Additive “over-treat” — too much ZDDP can cause film flaking and spalling, actually increasing wear.
  • Can increase deposit formation on pistons and rings.
  • Raises ash content, which can lead to fouled plugs and pre-ignition in high-RPM engines.

  • 1,200–1,600 ppm is the sweet spot for most high-performance flat tappet and marine big blocks.
  • 2,000+ ppm only makes sense for short-life racing oil (where engines are torn down frequently).
  • 3,000 ppm is overkill unless it’s a specialized drag/nitro engine oil designed for very short runs.
Seems like a better choice :
Lucas Synthetic SAE 20W-50 motor oil (non-“Racing” / standard synthetic) has around 1,265 ppm zinc.

I am toi affraid of those high zing levels. Now i Have to decide between kendal gt1 20w50 vs valvoline vr1 20w50. I Would really want to try Mobil 15w50 synthetic, But we dont Have that here in Finland.

Tartilla 09-22-2025 03:07 PM


Originally Posted by ICDEDPPL (Post 4935185)
  • Additive “over-treat” — too much ZDDP can cause film flaking and spalling, actually increasing wear.
  • Can increase deposit formation on pistons and rings.
  • Raises ash content, which can lead to fouled plugs and pre-ignition in high-RPM engines.

  • 1,200–1,600 ppm is the sweet spot for most high-performance flat tappet and marine big blocks.
  • 2,000+ ppm only makes sense for short-life racing oil (where engines are torn down frequently).
  • 3,000 ppm is overkill unless it’s a specialized drag/nitro engine oil designed for very short runs.
Seems like a better choice :
Lucas Synthetic SAE 20W-50 motor oil (non-“Racing” / standard synthetic) has around 1,265 ppm zinc.

Dan, well said.

The largest issue for ZDDP (zinc) is the high levels of calcium (detergent) 3000ppm or higher. It washes away the zinc that is in the oil, trying to do its job. As Dan mentionend. 1200-1600 ppm zinc is optimal, and way better with a lowered calcium level to around 1000ppm.

800-900ppm zinc is a maintenace level zinc for already broken in FT cams. But it's also not enough for high pressure contact areas. Perf Marine BBC, almost every contact point is high pressure.

SP rated oils often have the reduced calcium, for direct injection engines. But you need an analysis info source to be confident your oil is doing what what you need.

Too much zinc...think thick paint...it will crack and chip off. Too brittle to flex. Same with concrete and metals.

Proper zinc levels will create more friction as it protects. Part of the process.

Tartilla 09-22-2025 03:13 PM


Originally Posted by JaniH (Post 4935186)
Night Be so thick that IT robs 50hp. 🧐

Many dyno tests for different oil viscosities. Once oil is at temp (210f-220f) there is minimal hp difference from 'thin to thick' oils. If anything, thinner oils will reduce HP.

Perf Marine engines are a different animal. Often sitting at 85% max for very long periods of time.

Not all engines are the same for windage and oil management. A properly setup BBC will have minimal oil entrainment in the crank.

Tartilla 09-22-2025 03:29 PM

https://bobistheoilguy.com/forums/th...7-1-5k.383225/

VR-1 20w50 1500mile oil analysis for a 2020 Harley.

Mentioned that the VR-1 conventional 20w50 was quiet on the top end, vs the synthetic was noisy...just like the Mobil 1.

Generally, using what you have available is the best COA...provided it meets your needs.

Kendall doesn't mention their curret SAE rating on their website. most info I've found for it is 10yrs or older. So no recent SAE package ratings...but have a look anyway.

Brad Christy 09-23-2025 05:44 AM


Originally Posted by JaniH (Post 4935187)
I am toi affraid of those high zing levels. Now i Have to decide between kendal gt1 20w50 vs valvoline vr1 20w50. I Would really want to try Mobil 15w50 synthetic, But we dont Have that here in Finland.

JaniH,

AmsOil?

Thanks. Brad.

JaniH 09-23-2025 08:32 AM


Originally Posted by Brad Christy (Post 4935230)
JaniH,

AmsOil?

Thanks. Brad.

That looks interesting! I like synthetic oil heat resistance If there IS Any difference compared to quality mineral oil.

ICDEDPPL 09-23-2025 09:41 AM


Originally Posted by JaniH (Post 4935187)
I am toi affraid of those high zing levels. Now i Have to decide between kendal gt1 20w50 vs valvoline vr1 20w50. I Would really want to try Mobil 15w50 synthetic, But we dont Have that here in Finland.

Eddie Young uses GTX in all his engines..
https://shop.advanceautoparts.com/p/...hoCjuoQAvD_BwE

maybe thats available in the land of the Fins?

For Amsoil I use COMPETITION DIESEL DOMINATOR 20W-50
https://www.amsoil.com/p/amsoil-domi...gxMzY0OTQ2NjYw

For film strength.
Zinc ≈ 1,200–1,400 ppm; Phosphorus ≈ 1,000–1,200 ppm.

.

For a marine engine with forced induction (turbo or supercharger), especially under heavy loads, here are the specific ways COMPETITION DIESEL DOMINATOR 20W-50 helps — and things you benefit from over a more “standard” oil.
Benefit How DOMINATOR’s Spec Helps / What It Does

Higher film thickness / load-bearing capacity
The oil is formulated to deliver “50% more film thickness” compared to the 3.5 cP HTHS limit of SAE 15W-40. This means during high cylinder pressures (as you get with turbo boost, high torque, etc.), the oil maintains a thicker protective layer between bearing surfaces, pistons, rings, etc., reducing metal-to-metal contact and wear

Better resistance to fuel dilution
In boosted diesels (especially marine), you often get more incomplete combustion, blowby, or fuel entering the crankcase or ring area. That dilutes the oil (thinning it) and reduces protection. With a more robust synthetic base and stronger viscosity maintenance (both at operating temp and under shear), this oil holds its viscosity better even as dilution occurs.

Strong high temperature / turbo charger protection
Turbos get very hot, especially in marine settings where cooling is harder and airflow can be more restricted; oils near the turbo see high heat and need oxidation resistance and deposit control. DOMINATOR’s synthetic formulation with high oxidation inhibitor content helps prevent breakdown, coking, and deposit build-up, helping prolong turbo life.

High HTHS viscosity
With ~5.5 cP HTHS at 150°C, the oil resists thinning under high shear / high temperature better than lower viscosity oils. That helps preserve oil film under load / rpm / boost.

Good cold tolerance (to an extent)
The pour point (-37°C) and the cold cranking simulator numbers indicate it will behave better on cold startups than many heavy non-synthetics. For marine, depending on water temperature or ambient, that helps reduce wear during startup. But note: “20W” means it won’t flow quite as freely as a 15W or lower at very low temps

High TBN & Ash / Detergent / Dispersant capacity
TBN of ~10.1 gives buffer against acidification (from combustion, sulfur, etc.), helping prevent corrosion, soot / ash acidity damage. Good when running hard. The ash content is ~1.0 wt% – trade-off: more ash means more potential for deposits in some applications, but in competition / boosted context that's acceptable.

This oil is very well suited for a boosted marine diesel engine, particularly one used in hard duty / high load / high RPM / turbo conditions. It gives you:
  • Strong protection under high pressure and heat
  • Resistance to breakdown and deposit formation (especially in turbo area)
  • Better handling of fuel dilution and shear stress
  • Good buffer against acid and wear



My other favorite is Driven MR-50 15w50
I put in a distributer incorrectly and didn`t engage the oil pump.
idles for 10 minutes and I got on plane at 2000 rpm before I saw the warning light didn`t turn off.
Thought the engine would be toast but nothing in the oil filter at all. Ran it rest of the season without any issues.
That`s impressive.

JaniH 09-23-2025 09:47 AM

Have used The comma xflow 15w40 mineral For the brake in My new build, and all The Time with My Old engine with The same short block, bearings, melling select 10774/60psi spring, cold Idle 60psi, hot Idle always over 40psi, from fast Cruise to wot 60psi. On The new build i replaced The GM roller lifters For Johnsson 2126bbr with axle oiling, and seems that those bleed some pressure when The oil IS warm, approx 10psi. I also changed merc 8qt oil Pan For 8qt milodon full sump kick Out Pan with all The goodies. IT IS also possible that i Have too much oil in The pan, and that robs pressure.

Tartilla 09-24-2025 02:59 AM

You mean with too much oil...you're getting the oil entrained into the crank and starving the pump pickup a bit, resulting in 10psi reduced pressure?

If the lifters are bleeding off, the end of the lifter gallery will have even less oil pressure.

Grooves are often cut into the lifter bores for FT cams. It does add to the oil management issue, getting into the crank, just like your new Johnsons will.


JaniH 09-24-2025 03:07 AM


Originally Posted by Tartilla (Post 4935291)
You mean with too much oil...you're getting the oil entrained into the crank and starving the pump pickup a bit, resulting in 10psi reduced pressure?

If the lifters are bleeding off, the end of the lifter gallery will have even less oil pressure.

Grooves are often cut into the lifter bores for FT cams. It does add to the oil management issue, getting into the crank, just like your new Johnsons will.

My gen6 block IS priority main oiled, If that helps. Mk4 IS difference.

Markus 09-24-2025 06:16 AM

Since you are in Europe, take a look at Ravenol. Good stuff.

Ato24.de has great prices, and I am sure they can ship to Finland. (They ship to Sweden).


JaniH 09-24-2025 12:15 PM


Originally Posted by Markus (Post 4935296)
Since you are in Europe, take a look at Ravenol. Good stuff.

Ato24.de has great prices, and I am sure they can ship to Finland. (They ship to Sweden).

I assume you Have big block right? What ravenol you Have Been using?

Markus 09-24-2025 12:43 PM

No big block for me. I am one of those sophisticated outboard cat people.

If you want a load of zinc, I think the Break-in oil is the one to get. You will find specs on the Ravenol website, so you can pick based on what you think your engine needs.

I think my redneck friend with a Pro Charger on a 540 was considering this one:

https://www.ravenol.de/en/product/mo...rfs-sae-15w-50

He got a good deal on some Amsoil, so ended up going with that. More redneck, too.

JaniH 09-24-2025 01:40 PM


Originally Posted by Markus (Post 4935319)
No big block for me. I am one of those sophisticated outboard cat people.

If you want a load of zinc, I think the Break-in oil is the one to get. You will find specs on the Ravenol website, so you can pick based on what you think your engine needs.

I think my redneck friend with a Pro Charger on a 540 was considering this one:

https://www.ravenol.de/en/product/mo...rfs-sae-15w-50

He got a good deal on some Amsoil, so ended up going with that. More redneck, too.

Very interesting products indeed. What i really like they spec different oil for gasoline and Diesel marine engines.

Tartilla 09-24-2025 03:48 PM


Originally Posted by JaniH (Post 4935292)
My gen6 block IS priority main oiled, If that helps. Mk4 IS difference.

Of course Priority Main feed...but the same concept on the main priority feed gallery. The end feed port tonthe last bearing will have reduced oil pressure compared to the 1st in line.

Same factor with your bleeding lifters. Less pressure at the end...meaning less than the gauge indicated.

No big deal...it's always been this way. The recomended pressures account for that. The bleeding lifters are the 'new' factor. It drops 10psi across the board. Confirm your pressures/volume is GTG and carry on. Oil flow will also cool the lifters and rollers.

Tartilla 09-24-2025 03:50 PM

Lucas makes a Hot Rod oil. It's likely destructive with the ultra high level of Zinc...almost touching 3000ppm.

It's had a bad rap for frothing.

Their additive is just a thickener, and displaces additives.

They feel like more of a marketing company vs a perf lubcricant Co.

I wouldn't run it it was free.

https://pqia.org/lucas-hot-rod-classic-sae-10w-40-motor-oil/

Markus 09-25-2025 09:11 AM


Originally Posted by JaniH (Post 4935321)
Very interesting products indeed. What i really like they spec different oil for gasoline and Diesel marine engines.

It is good stuff. 100% PAO and/or ester base stocks unless otherwise stated, and top notch additive packages.

The products are expensive in the US, but for those of us who are in Europe, they are very reasonably priced compared to alternatives.

I run Ravenol in my car, and will run it in the boats once I run out of my stash of Itasca/Quakerstate/Pennzoil 100% synthetic 2-stroke oil.

JaniH 09-25-2025 02:11 PM

I found kendal gt-1 20w50 from local store, and But them in. Also cut The oil filter and nothing there to worry about. Testing tomorrow.

hpmaniac 04-23-2026 03:59 PM

30 years ago i was at a gm parts event and warren Johnson was there, The big block chevy god, I Talked to him for a good 30 minutes picking his brain, i had so many questions my brain was in overload mode haha, we talked about oil and at the time they were having wrist pin issues, they had always broke engines in with conventional oil, they started using synthetic redline oil on break in and all the wrist pin issues went away. But we are talking 500ci engine turning 10-10500 rpm!

SB 04-23-2026 05:03 PM

That must have been cool !!! ^^^^
Wrist pin oiling issues typical of pretty high vacuum dry sump systems. Modern DLC coatings used by many peeps on wrist pins. Anyway…just talking out loud.


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