I have 2 gallons of STP in the basement that has zinc in it and was wondering if I should be putting a little in with each oil change in my flat tappet motors,I had this stuff for over 20 years and will it still be good. My moms old boyfriend used it in his big rig and I got it when he sold the truck and forgot all about it.
The Red label that was designed for 4 cyl had the highest zinc level of all stp. The old blue can stuff is pre EPA change of the formula. So use it.
I was at Rural King getting oil last night and finally reading the bottles and there is a diesel oil made by Lucas for pre 07 diesel motors that might be worth looking into,I usually used Rotella but its now made for low emission motors so I looked at the Rural King brand diesel oil and it had more of those specification letter and numbers so I am going to try it and add some of that STP I have. I had four gallons of that stuff and used two for the tired motors I was keeping alive and now wish I would have saved it but that was back when the oil was good and had no idea on what was in the future.
i asked a friend of mine this question yesterday. he worked in the research and development lab for S.T.P. when it was owned by First Brands. he told me that the amount of zinc in the oil treatment would not be enough to compensate for oil without it. the oil treatment has some good stuff in it but really is just a "thickener" to raise the viscosity. it won't hurt to add it. best thing to do is to buy oils that have already the right viscosity and have the proper additives blended into it. some oils are already "saturated" with additives so adding anything won't help.
Oh, for the the days of stacked cans between gas pumps. Aim just right slamming the spout in so ya don't crumple the can. Pour 30 weight in and you're set! Thanks to all who keep the info flowing.
I remember when it was considered good assembly lube, when assembling a new motor. 50% STP and 50% 50 wt oil. I've never been a fan of it for regular use though. When you would tear an engine down there was all his gray sludge in the corners of the block. However, I did keep a 389 Pontiac alive with 3 pounds of oil pressure by dumping lots of STP into it. Don
I was hoping to use it to compensate some for the lack of zinc in todays oil,there was a little discusion about this topic at the local cruise in last week and I thought once a motor was broken in the need for the high zinc was gone but one thought it was needed always but my flat tappet motors that were broken in long before it was reduced seem to be holding up with todays oils. I was hoping using that STP would help a little and I could use it up.
Why would anyone want to use STP? Whats its purpose? I wouldn't use it. Motor oil manufacturers have staffs of chemists who determine what additives are to be added to their products. Adding Snake Oil messes up the chemical balance. If it were me I'd pour that STP into a waste oil container. Gary
^^^ Because the OP wants to insure he has plenty of zinc in the oil to protect the lifters. Rislone makes a zinc rich additive that can be found at most auto parts stores. https://www.zoro.com/rislone-engine...gclid=CMSviYuW0swCFZdZhgodC1wAIA&gclsrc=aw.ds
How long have you been running your flat tappet cam? If a flat tappet cam is going to flatten it will usually happen when it is new. As for STP let me offer a story and maybe you can make a decision as to whether you want to use it or not. Back in the '70s I built two lower ends for a man named Granatelli. When I was still fitting things he showed up at the shop where I was working and carried in a couple of cases of STP and put them on my bench. I looked at him and said, "You are not going to put that shit in these motors are you?" He smiled and said, " Nope, I don't run this in anything I own, but it is good assembly lube." OK a rabbit trail there back to the question at hand, how long have you been running your flat tappet cam? Have you flattened it yet?
Don, from my conversation with the chemist, he said that the ground up "rubber" used to increase the viscosity would do that in any "hot spots" on an engine. he assured me it can't hurt. S.T.P. was one of the few patented oil treatments. it was not snake oil and it contained lots of good stuff. the lab did lots of testing and research and they debunked a lot of claims from other additives.
I'll take my chances using Valvoline VR-1 which is formulated with 1300 PPM of zinc and 1200 PPM of phosphorous. By adding STP to your existing motor oil you have no idea of the amount of zinc or phosphorous in your concoction. I've got too much invested in my engines to take a chance on being a backyard chemist. Its a crap shoot I'm not willing to take. Just remember too much zinc is just as detrimental as not enough. Gary
Always used to get a laugh out of the cars at the Indy 500 in the hay day of Andy Granatelli. The decals on the cars were for sponsorship money and the STP was used as an additive for the transmission lube. Nobody used it in the engines due to the fact that it would clog the oil passages of an Offy or four cam indy Ford engine.
I will look into the Rislone additive before the next oil changes,I just have too many vehicles to have to buy that expensive oil for them and would like to keep the cost down a little so I can afford to keep them. I am seriously thinking about roller lifters when I change the cams from now on so I will not have to deal with this any more.
Jeff, FYI, you can buy VR-1 conventional oil for less then $5 a quart at Autozone. On sale it's $3.99 a quart. Still don't understand why you would add Rislone . Don't you trust Valvolines staff of engineer's and chemist's to add the necessary amount of zinc and phosphorous to protect your engines? Gary
STP original formula was invented for the world war 2 German air force. Planes would come back with oil tanks shot up and the stp coated the parts and the engines lived. As a spoil of war the formula was retrieved by a subject of England. He renamed it Vigorlube then as a partnership a col of the U S Forces by the Name of T M Nesbit brought the formula back to the U S and marketed it under the Vigorlube name. A few years later STP was introduced to the main U S market. ....................................As for the engine assembly lube Vigorlube had a product called 50/50 . the original STP was a lot thicker in the late 50s to around 1970 or so . then it was made to pour faster..
Keep it simple. Last time I checked, Chevron Delo 400 had 1380 p.p.m. zinc. Available in single & multi-weights.
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