Flat tappet cam life

[clayfoushee]

Originally Posted by jmarsey

I run the Crane solid rollers and have had excellent results with the Rotella T 10w-30, Castrol Tection Extra 15w-40 and frequent oil change. My friend runs the Rotella 15w-40 in his FE solid flat tappet and swears by it as well.

I've been using Shell Rotella 15w-40 as well, but I am told the formula changed recently, and it now has a significantly lower zinc content. So, I'm searching for the best solution now.

Although I know synthetics are far superior for sheer strength, I have concerns about the slippery stuff in a 5-year old FE. It does tend to find ways to leak better too.

[zrayr]

Originally Posted by clayfoushee

I've been using Shell Rotella 15w-40 as well, but I am told the formula changed recently, and it now has a significantly lower zinc content. So, I'm searching for the best solution now.

Although I know synthetics are far superior for sheer strength, I have concerns about the slippery stuff in a 5-year old FE. It does tend to find ways to leak better too.

Blame for leaks belongs first to poor workmanship and poor seals/gaskets. I've got over 17,000 miles on a Hi-Po 289 engine using Mobil 1 15W-50 with zero leaks.

Z. Ray

[clayfoushee]

Originally Posted by zrayr

Blame for leaks belongs first to poor workmanship and poor seals/gaskets. I've got over 17,000 miles on a Hi-Po 289 engine using Mobil 1 15W-50 with zero leaks.

Z. Ray

Right. But FE's are a bit more notorious for leaks because of certain aspects of the design. It's not just poor worksmanship.

Right now, I'm fine with conventional oils, and I haven't tried synthetic, but it does sometimes cause leaks that weren't seen with conventional oils. Given my usage, I think I'll leave well enough alone.

[4pipes]

Originally Posted by clayfoushee

I've been using Shell Rotella 15w-40 as well, but I am told the formula changed recently, and it now has a significantly lower zinc content. So, I'm searching for the best solution now.

Although I know synthetics are far superior for sheer strength, I have concerns about the slippery stuff in a 5-year old FE. It does tend to find ways to leak better too.

I'm thinking of switching from Kendall GT-1 20W50 to the new formulation of Mobil 1 15w50 that has higher levels of ZDDP.
http://www.mobil1.com/USA-English/Mo...t_Engines.aspx
http://www.mobil.com/USA-English/Lub...il1_15W-50.asp

[clayfoushee]

Originally Posted by 4pipes

I'm thinking of switching from Kendall GT-1 20W50 to the new formulation of Mobil 1 15w50 that has higher levels of ZDDP.
http://www.mobil1.com/USA-English/Mo...t_Engines.aspx
http://www.mobil.com/USA-English/Lub...il1_15W-50.asp

Dave, I previously used Valvoline Racing 20w-50, and my oil pressures were 80 psi and above cold AND at RPMs above 3K warm, and only down to about 50 psi at warm idle. I switched to Rotella 15w-40, and they dropped about 10 psi on each end, which I felt more comfortable with, particularly at cold start-up.

Thanks Rick, it was your previous excellent research on solid flat tappets cams that motivated my change last year.

[rdorman]

I will be interested to see what the new formulation of the 5W-40 synthetic will contain zinc wise. 1600PPM currently is a lot of zinc!

I just recently discovered that the synthetic Rotella T is not a true sythetic but rather a 'highly refined' version of crude or mineral oil. The process results in a oil that has the properties of a synthetic and is considered a synthetic in the U.S. (due some legal action by Mobil and others). Classified a Group III synthetic.

Here is a brief description of the three types of synthetic oils base:

- Polyalphaolefin (PAO) = API (American Petroleum Institute) Group IV base oil
- Synthetic esters, etc = API Group V base oils (non-PAO synthetics, including diesters, polyolesters, alklylated napthlenes, alkyklated benzenes, etc.)
- Hydrocracked/Hydroisomerized = API Group III base oils. Chevron, Mobil, and other petrochemical companies developed processes involving catalytic conversion of feed stocks under pressure in the presence of hydrogen into high quality mineral lubricating oil. In 2005 production of GTL (Gas-to-liquid) Group III base stocks began. The best of these perform much like polyalphaolefin. Group III base stocks are considered synthetic motor oil in North America

[rdorman]

More information on Group III synthetics:

http://www.chevron.com/products/prod...npra_paper.pdf

An excert:

In addition to the synthetic moniker, customers are also concerned with performance. Modern Group III base oils perform at a level that is significantly higher than “conventional” base oils, both Group I and Group II, and substantially match existing levels of performance in finished lube applications already established by their traditional synthetic counterparts.

[4pipes]

Originally Posted by clayfoushee

Dave, I previously used Valvoline Racing 20w-50, and my oil pressures were 80 psi and above cold AND at RPMs above 3K warm, and only down to about 50 psi at warm idle. I switched to Rotella 15w-40, and they dropped about 10 psi on each end, which I felt more comfortable with, particularly at cold start-up.

Thanks Rick, it was your previous excellent research on solid flat tappets cams that motivated my change last year.

Clay, I'm a work in progress! Now I'm researching Brad Penn 20W50. This is the old green oil that Kendall used to make (they bought the refinery). This is the oil that so many engine builders used to recommend, including mine.

[rdorman]

The Brad Penn 20W-50 is a good Group III oils with 1200+ ppm of zinc and will work nicely for a flat tappet motor. I went the rotella route because you can get it at any truck stop or walmart in the country. With the recent reformulation of oils I don't know if the Brad Penn oil has changed, you may want to verify.

[Ant]

I am curious as to how often it is necessary to change valve springs to try and avoid catastrophic failures? With sprint race events of 7000rpm over 15mile races x3 per event and some much easier road miles. So not sustained high rpms!!

My camshaft is flat tappet with 180Ibs seated pressure!