Changing oil soon
Race Director
Joined: May 2006
Posts: 18,734
Likes: 2,582
Only if the oil you pick has sufficient zinc/phosphorus levels for older engines. Did you read the sticky on the top of this forum?
"List of Flat Tappet Oils"
"List of Flat Tappet Oils"
Last edited by MelWff; Feb 17, 2017 at 04:37 PM.
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
You might find that you developed leaks or the ones you have worsen....molecularly smaller synthetic some say will tend to seep/leak more...dunno. I use dyno oil so no personal experience. I hear WalMart has good deals on Mobil 1. 
Drifting
Joined: Aug 2009
Posts: 1,346
Likes: 160
From: new iberia la
There are several synthetics that are suitable for old flat tappet engines.. pick one .Synthetics are far superior in lubrication and heat resistance .. and if your engine doesn t leak now, it won t leak with synthetics..
Melting Slicks
Joined: Jun 2011
Posts: 3,116
Likes: 598
The choices were based on ZZDP content of the oil for the L48 350.
http://www.amsoil.com/shop/by-produc...tic-motor-oil/
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
https://www.corvetteforum.com/forums...eal-leaks.html
Read ALL the posts, not just the first few.....then decide if the words "may leak" are applicable.
more education
http://www.chevytalk.org/fusionbb/sh...hp?tid/266605/
Last edited by jimvette999; Feb 18, 2017 at 03:57 PM.
Melting Slicks
Joined: Dec 2009
Posts: 3,233
Likes: 657
From: Thunder Bay
Take it from me - switching to synthetic CAN cause the engine to start leaking. I have done it on several occasions, and only had one engine do it, but it can happen. Switching back to conventional oil did solve the problem.
Melting Slicks
Joined: May 2002
Posts: 2,431
Likes: 52
From: Florida
I tried the Mobil 1 15x50 but latter switched to amsoil Z-rod products. The engine ran so quiet compared to the mobil 1 oil which on startup I think to too thick for colder climates.
The choices were based on ZZDP content of the oil for the L48 350.
http://www.amsoil.com/shop/by-produc...tic-motor-oil/
The choices were based on ZZDP content of the oil for the L48 350.
http://www.amsoil.com/shop/by-produc...tic-motor-oil/
https://www.corvetteforum.com/forums...eal-leaks.html
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Team Owner
Joined: May 2001
Posts: 87,367
Likes: 1,593
From: Western NY
Burning Brakes
Joined: Oct 2001
Posts: 925
Likes: 200
From: TX
Clean
I run amsoil zrod 10w30 in everything from the 69 Vette to the 2004 Vette (recommended by lg motorsports) to the 79 280zx to my Cub Cadet lawn tractor.
When I changed to amsoil in the 69 I used their oil flush treatment. Absolutely no problems.
Good stuff
VS
I run amsoil zrod 10w30 in everything from the 69 Vette to the 2004 Vette (recommended by lg motorsports) to the 79 280zx to my Cub Cadet lawn tractor.
When I changed to amsoil in the 69 I used their oil flush treatment. Absolutely no problems.
Good stuff
VS
Safety Car
Joined: Sep 2005
Posts: 4,226
Likes: 643
From: Orange County Ca
I run Mobil 1 in my '08 and my '69, with no oil related problem. Older stories of engine leaks, ruined cams, etc. seem to be just that, stories. Synthetic oil is generally better in all categories.
Racer
Joined: Oct 2019
Posts: 485
Likes: 181
From: San Diego
Just go to this site. In just a few minutes all of your concerns will be addressed. Very cut and dry.
https://bobistheoilguy.com/forums/
https://bobistheoilguy.com/forums/
Le Mans Master
Joined: Jun 2019
Posts: 5,479
Likes: 2,190
From: Loveland
In the olden days, 1960's, cars were designed for a specific oil. Engines and the new oils are different today. Old engines like old style oils and do very well with them. I am not sure why but a 10W-30 dyno oil is different than 10W-30 synthetic.
Try the Lucas hot rod oil. Amazon even has it.
Try the Lucas hot rod oil. Amazon even has it.
Burning Brakes
Joined: Sep 2016
Posts: 956
Likes: 443
From: Dutchess county New York
I use Shell Rotella T4 10W-30. It says 'diesel engine oil' which means it likely has the Shaving Cream Atom, Vitamin X and the other vitamins your engine needs. I found that if I go to Tractor Supply and they don't have it sitting there I order from their kiosk they wave the shipping charges to my home.
Funny how we fuss over these old cars and a simple oil change. I've lost track of how many fleet vehicles I had over the years that got beaten like rented mules for high miles and suffered no-name oil and filters at wherever the fleet managers sent us and never had an engine failure of any sort. Same for tires, some were better than others but they were all black and round and that was all that mattered.
Safety Car
Joined: Oct 2007
Posts: 4,222
Likes: 1,078
From: South Florida
I took a 200,000 miles 2002 5.3L engine swap started out using conventional oil just to get it going.
Put in synthetic after 2000 miles and it started leaking immediately from the rear main seal.
One of Synthetics huge advantage is uniform smaller oil molecules, they fit easier into tight spaces which is GREAT for your bearings and piston ring/cyl wall imperfections, substantial increase protection from wear.
But it may start leaking if the seals are old like mine were, 20~ years old original seals.
IMO if it starts leaking when you put in synthetic, you needed new seals anyways.
Put in synthetic after 2000 miles and it started leaking immediately from the rear main seal.
One of Synthetics huge advantage is uniform smaller oil molecules, they fit easier into tight spaces which is GREAT for your bearings and piston ring/cyl wall imperfections, substantial increase protection from wear.
But it may start leaking if the seals are old like mine were, 20~ years old original seals.
IMO if it starts leaking when you put in synthetic, you needed new seals anyways.
Le Mans Master
Joined: Jun 2019
Posts: 7,657
Likes: 2,469
From: Indiana
I think the only place non synthetic is recommended is the differential and then add 2 gm posi additives.
i run on my 79 all synthetic including manual super t10 transmission which i find superior to the other 3 i tried.
leaks? 😂 fix them as they leak..
also i run gm power steering fluid..
i run on my 79 all synthetic including manual super t10 transmission which i find superior to the other 3 i tried.
leaks? 😂 fix them as they leak..
also i run gm power steering fluid..
