Mineral or synthetic?
Thread Starter
Heel & Toe
Joined: Mar 2016
Posts: 17
Likes: 0
Mineral or synthetic?
Hello everybody!
I write from Italy, I've just bought a 1969 Corvette with 427 L36 engine.
Before use it I want to change all the liquids so the question:is it better to use old oils and liquids or actual formulations?
F.e. for the engine I found good mineral oils 10-40 and 20-50 but the new syhthetic oils could be better or cause damage?
Maybe some additives are not compatible with old materials?
Similar thing about gear box and axle oil, brake fluid and antifreeze, old or new?
What do you think?
Thanks a lot.
Filippo
I write from Italy, I've just bought a 1969 Corvette with 427 L36 engine.
Before use it I want to change all the liquids so the question:is it better to use old oils and liquids or actual formulations?
F.e. for the engine I found good mineral oils 10-40 and 20-50 but the new syhthetic oils could be better or cause damage?
Maybe some additives are not compatible with old materials?
Similar thing about gear box and axle oil, brake fluid and antifreeze, old or new?
What do you think?
Thanks a lot.
Filippo
Had a 1976 L-82, 4-sp
Joined: Mar 2011
Posts: 5,338
Likes: 1,213
From: Some days your the dog and some days your the hydrant.
Royal Canadian Navy
Suggest you read the "sticky's" on engine oil. I would use synthetics as much as possible provided they're compatible. Example, use of synthetics in the differential will need friction modifiers for the clutches. Same for the manual transmission. I would use DOT 4 for brake fluid and not synthetic. Normal 50/50 mix for antifreeze.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
Synthetics. With the provision that it has 1000 PPM of zinc or better for the flat tappet cam.
Just because it's synthetic does not guarantee that it is appropriate for the engine.
If you have access to Mobil 1 0W40 where you are at it is a decent 1000 PPM true synthetic oil. Many other options as well that are flat tappet specific available over the internet.
Gear lube, either is fine. Again, synthetic probably better.
I agree with resdoggie on his recommendations.
Just because it's synthetic does not guarantee that it is appropriate for the engine.
If you have access to Mobil 1 0W40 where you are at it is a decent 1000 PPM true synthetic oil. Many other options as well that are flat tappet specific available over the internet.
Gear lube, either is fine. Again, synthetic probably better.
I agree with resdoggie on his recommendations.
Instructor
Joined: Nov 2013
Posts: 220
Likes: 17
From: Pasadena MD
Hello everybody!
I write from Italy, I've just bought a 1969 Corvette with 427 L36 engine.
Before use it I want to change all the liquids so the question:is it better to use old oils and liquids or actual formulations?
F.e. for the engine I found good mineral oils 10-40 and 20-50 but the new syhthetic oils could be better or cause damage?
Maybe some additives are not compatible with old materials?
Similar thing about gear box and axle oil, brake fluid and antifreeze, old or new?
What do you think?
Thanks a lot.
Filippo
I write from Italy, I've just bought a 1969 Corvette with 427 L36 engine.
Before use it I want to change all the liquids so the question:is it better to use old oils and liquids or actual formulations?
F.e. for the engine I found good mineral oils 10-40 and 20-50 but the new syhthetic oils could be better or cause damage?
Maybe some additives are not compatible with old materials?
Similar thing about gear box and axle oil, brake fluid and antifreeze, old or new?
What do you think?
Thanks a lot.
Filippo
Le Mans Master
Joined: Oct 2007
Posts: 7,459
Likes: 979
From: RI, Now Franklin/Nashville TN
Mobil 1 0W-40 European Formula (1,000 PPM ZDDP) and Walmart carries it in 5 Qt containers for $26.50 (you cannot beat the value here)..if your gaskets are in good shape, you will not have a problem with a true synthetic.
Last edited by jb78L-82; Mar 28, 2016 at 03:25 PM.
Pro
Joined: May 2013
Posts: 672
Likes: 31
From: Rapid City South Dakota
Synthetics are superior as far as motor oils and transmission fluids are concerned. I like Evans coolant, have used it for years. Who knows, it may save you from having to change a rusted out heater core and rotted carpet.....
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Thread Starter
Heel & Toe
Joined: Mar 2016
Posts: 17
Likes: 0
I'd like to use the car quite a lot, about 10.000 miles an year. In case of dino oil every 6000 miles as scheduled, but I'd like to use a semisynthetic if possible. I heard that a totally syhnthetic contains too much detergent and additives...
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I heard that a totally syhnthetic contains too much detergent and additives...
These things are necessary for reliable long running engines. If it were possible that your oil would come out clean after 5000 miles then you have a very poor detergent oil indeed. Dirty oil means it's doing it's job via the detergents.
What can happen is you have leaky crusty seals and they have been sealed by the contaminants in the oil taking up space in the leaky spots then you put in a good synthetic detergent oil and it cleans out those crevices after a bit and your seals start leaking. The molecule size of synthetic is consistent vs dino oil. If these molecules are smaller than the dino oil mix then it may leak.
If this happens you can get a seal conditioner to add to the oil which will attempt to soften and swell the seals so that they can seal again.
Oil to oil comparison though, synthetic is superior to dino oil.
Pro
Joined: May 2013
Posts: 672
Likes: 31
From: Rapid City South Dakota
I would skip the semisynthetics. Amsoil will go 1 year or 15000 miles and they have a quality filter that will do the same. It will be cheaper than changing dino oil twice per year.
Le Mans Master
Joined: Apr 2011
Posts: 6,284
Likes: 1,171
From: Hermosa
I run my Mobil 1 in my DD's for 10,000 miles with a filter change at 5,000 miles. Wix filters.
In the vette I don't run 10,000 miles in 5 years so change interval due to mileage is not an issue, just time.
Amsoil is a great oil, I just find it a bit pricey vs Mobil 1 and my 10,000 change intervals for my DD's.
In the vette I don't run 10,000 miles in 5 years so change interval due to mileage is not an issue, just time.
Amsoil is a great oil, I just find it a bit pricey vs Mobil 1 and my 10,000 change intervals for my DD's.
Le Mans Master
Joined: Oct 2007
Posts: 7,459
Likes: 979
From: RI, Now Franklin/Nashville TN
The main benefit of a synthetic is oil molecules exactly the same size for superior engine protection...to me the extended oil drain interval is a side benefit but by no means the primary benefit.
