The engines for American made cars in the early 1970's and 1980's made by GM had high amounts of ZDDP (Zinc dithiophosphate) in their oil content to help with the very high loads on their flat tappet lifters.  Do you add a ZDDP suppliment to your engine crank case oil to aid your American GM car engines run smoother?  Our engine oils in the US have been so regulated that they no longer contain sufficient amounts of ZDDP.  Back in the early 70's there was as much as 1500ppm of ZDDP in engine oils but now there is nearly 100ppm in regular motor oils, if that amount.  Most synthetic oils have zero levels of ZDDP!

Have any of you tried to add ZDDP to your cars engine crank cases as it does help a great deal.  I just wondered what you use as an oil suppliment.

And do any of you put a lead additive to your gasoline supplement for those GM cars prior to 1974 as that was the last year GM made cars for leaded gas and switched to unleaded in 1975 thus adding a catalytic converter.

Just wondering what you use?              

http://www.penriteoil.com.au/index.php

There are brands of oil available here that contain zinc.  I didn't use any oil additives in my Grand Ville (or any other Pontiac I've owned).

As far as the lead additive for gasoline, I've always thought that it was snake oil.  I had a '64 Bonneville for 10 years that I used daily and ran it on propane (lpg).  That car travelled 200,000 miles in the time I had it and I don't know how many miles it travelled before I got it.

When I finally pulled the engine, the heads were fine.  They were the original and correct 389 heads.  You could have serviced them and used them again.

A former GM engineer in cylinder head design, John Sawruk, visited Australia a couple of times.  He told me many years ago that removing lead from gasoline was not seen as a major factor in valve seat recession.  The main contributor to valve seat recession was the increasing lean air/fuel mixtures that the factory was forced to use to meet emissions.  This was also the reason that the HEI ignition was introduced, as those lean mixtures were hard to fire with a points ignition.  

Oh that's nice.  The Penrite has .0124 zinc content according to the material safety data sheet.  Our oil here is only at best .080 so we need the Zddp boost.  

Outstanding.  

Regarding the fuel additive the Lead additive was only for those cars prior to a catalytic converter.  I've never used it and my car still runs great.  But our octane levels here are 94.  We can get 100 octane levels for our cars here but they are at the local airports.  LOL

Brad Penn is available here. It has very high zinc levels, around 1500-1600 p.p.m. About $110-120 for 12 x 1 quart containers.

Brad Penn oil is the way to go thats all i use in my motor

No addatives needed,  Amsoil has plenty of zinc


http://www.highzincsyntheticoil.com/

This is the one I use   http://www.amsoil.com/storefront/rd50.aspx

Brad Penn and Amsoil.  Looks like good stuff.  We can't get it here with such high Zddp levels.  It kind of stinks really.  LOL

:mad: