Zinc oil additive?? (Page 1/2)
86fierorestoproject AUG 06, 12:09 PM
Ok so we're rebuilding the fieros engine due to the cam lobe being eaten up, but I needed to ask, do I need to use zinc additives in the oil? I want this engine to last as long as possible.
PhatMax AUG 06, 02:22 PM
Just had my 2.8 rebuilt. They insisted on using a zinc additive like Lucas. If you have a cat on the car it may plug it up.
86fierorestoproject AUG 06, 08:52 PM

quote
Originally posted by PhatMax:

Just had my 2.8 rebuilt. They insisted on using a zinc additive like Lucas. If you have a cat on the car it may plug it up.



The cat was deleted awhile ago and the muffler is also going to be taken off, I'll probably use the Lucas additive as well I guess.
Patrick AUG 06, 08:58 PM

quote
Originally posted by 86fierorestoproject:

The cat was deleted awhile ago and the muffler is also going to be taken off...



That'll sound amazing... for about ten seconds.

fierofool AUG 06, 10:06 PM
I have been running Shell Rotela T4 10 w 30 in my Fieros for years. It has the zinc already in the oil at the right concentration.
theogre AUG 07, 01:12 AM
can kill a cat... also many additives can mess or kill O2 sensors, injectors, etc.
Many additives "bottles" are many for 15 to 20 gallons of gas minimum and mix w/ less can cause many problems.

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Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave

fierofool AUG 07, 09:11 AM
Zinc additives in the crankcase should have no effect on the injectors. It should only affect the o2 sensor and converter if it's burning a lot of oil. Lots of people on this and other forums have spoken of all kinds of additives in their fuel tank, like acetone, denatured alcohol, automatic transmission fluid, etc. Some people swear by fuel injector cleaner on a regular basis. Actually, almost all of today's fuels have detergents already in them that reduce the likelihood of clogged injectors.

Flat tappet cams need zinc as a lubricant. Our 2.5, 2.8, 3.1, and 3.4 engines are generally of that design. If used as an additive, as TheOgre pointed out, don't overdo it. Add the prescribed amount for the amount of oil.
Blacktree AUG 07, 11:52 AM
For flat-tappet lifters, the zinc additive is a good idea. Since you deleted the catalyst, there should be no side effects. Even with a catalyst, it should take a long time (i.e. a couple decades) for the zinc to affect the catalyst.

EDIT: Here's a question for you. Would you rather replace a bad catalyst, or rebuild an engine? If you forego the zinc to save the catalyst, you run the risk of destroying the camshaft and one or more lifters. And the debris from that can affect other parts of the engine. IMO, destroying the engine to save the catalyst is a false economy.

[This message has been edited by Blacktree (edited 08-07-2022).]

MarkS AUG 07, 02:45 PM
I've been very happy with this oil AND assembly lube for HFT engines like the 2.8 & the 400 in my current ride. No messing around with additives.

https://drivenracingoil.com...nal-hot-rod-oil.html

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1965 Tempest 400 CID
2018 Chevy Colorado Z71 3.6
2017 BMW X3 3.0 T
2015 BMW 535iX M Sport
2008 G6 GT "Street" Coupe 200K miles
2005 Buick 3.6 Rendezvous 225K miles

theogre AUG 07, 04:01 PM
Duh Ogre... think oil not gas....
But oil additive have similar problems. Many use way too much and even have right oil for a given car, believe API SF here but not digging thru charts, Zinc and Phosphorus in oil can wreck the cat and O2 but just take longer do to it.

You burn some oil no matter how good the engine is made. You just don't see the small amount but Cat and O2 hate this. Think bad for Fiero? Many current models have Multiple O2 sensors costing Way More Money to replace. (Worse if you have coolant problems and engine "burns" that.)

Is a big reason Why EPA and others worldwide force Engine Oil to have less of both every time get new specs. Currently API SN SN+ and SP. (I'm told API skipped SO because letters are old Standard Oil brand.)

------------------
Dr. Ian Malcolm: Yeah, but your scientists were so preoccupied with whether or not they could, they didn't stop to think if they should.
(Jurassic Park)

The Ogre's Fiero Cave