Upon reading "Snake Oil for your Shocks?" a long lost memory popped into my head. In 1978 I bought a new Datsun 810 (I liked your choice of a Datsun Z to illustrate the article) and with help from a more experienced friend, removed the struts from all four corners. While I trimmed the springs with a grinder, my friend unscrewed the gland nuts on the struts, drained the thin stinky oil and refilled them with motor oil, I forget what viscosity but probably 20W something. I was pleased with the result.
Dewey Foulk
In our lever shocks used in British cars (like my Sprite), 20W oil is a common substitute for the "special" oil sold by some vendors.
I've seen racers use 30W oil in lever shocks.
And even some who mix up a "witches brew" of 30W oil + STP (not sure if it's a good idea).
I haven't received my magazine yet, but FWIW, recent testing on our shock dyno showed a consistent 50% more more damping at very low damper velocities and around 5-7% more damping at higher velocities. I'll see if I can get the actual numbers next week. Those results were found by doubling the kinematic viscosity.
aeronca65t wrote:
In our lever shocks used in British cars (like my Sprite), 20W oil is a common substitute for the "special" oil sold by some vendors.
I've seen racers use 30W oil in lever shocks.
And even some who mix up a "witches brew" of 30W oil + STP (not sure if it's a good idea).
Yep, we even used differntial oil. I really is not much thicker than a heavy engine oil.
Back in the 70's a friend was road racing a '71 Capri with the 2.0L. Since this was a "Showroom" type class as far as car prep he replaced the shock oil in the front struts. He went with to heavy of an oil and blew out the seals. Later when I and some friends modified a Capri for autocross and didn't want to spring for some performance struts we changed the shock oil. We used motocycle fork oil, 10W if I remember and the results were everything we expected with out blowing the shaft seals.
aeronca65t wrote:
In our lever shocks used in British cars (like my Sprite), 20W oil is a common substitute for the "special" oil sold by some vendors.
I've seen racers use 30W oil in lever shocks.
And even some who mix up a "witches brew" of 30W oil + STP (not sure if it's a good idea).
I've also seen pure STP used, and, no it is not a good idea. It can cause too much stress on the shock. It's unnecessary, as well. Changing the valving in the shock will stiffen them up sufficiently. Peter Caldwell of nosimports.com has even invented a way to make the front shocks adjustable.
admc58
Reader
6/28/12 9:53 p.m.
jimbbski wrote:
Back in the 70's a friend was road racing a '71 Capri with the 2.0L. Since this was a "Showroom" type class as far as car prep he replaced the shock oil in the front struts. He went with to heavy of an oil and blew out the seals. Later when I and some friends modified a Capri for autocross and didn't want to spring for some performance struts we changed the shock oil. We used motocycle fork oil, 10W if I remember and the results were everything we expected with out blowing the shaft seals.
My first car was a 70 Capri...they were all 1600cc and really slow but had great balance and hang time over RR tracks, the 71 was the 2.0L and a vastly better driving car with enough power to be fun.
Kinematic Viscosity made my ears bleed. Please splain
