ZDDP in oil

[cragginshred]

I am taking a poll in the oil preference. It has been strongly suggested to get one with plenty of ZDDP, in which case the Valvolene VR1 20/50 seems to be the popular choice. I have the a 95 SN with GT 40 and did opt for the 20/50, what are thoughts out there regarding getting one with the ZDDP and the weight?

[AirTool]

I'm not sure how this link will work....maybe it expires.

http://www.planetnautique.com/vb3/se...earchid=116638

[east tx skier]

I use the VR-1 20/50 in my 98.

[jmo]

The GT40 needs oil with Zinc in it, Excalibur or other chevy blocks don't.

[jmo]

I used to run 15w-40 castrol GTX (Diesel) in my GT40 given I run in early spring to late fall in New England.

[DanielC]

I run Valvoline VR-1, 40 W. but I warm the engine up before I push it.

[AirTool]

The GT40 needs oil with Zinc in it, Excalibur or other chevy blocks don't.

coincidently correct...more correct would be: engines with tappet (for lack of better words) lifters need ZDDP. engines with roller lifters/rockers don't.

[Nautiquehunter]

This is probably going open a can of worms. I use Mobile 1 full synthetic 15W50 in my 89 351W and my 08 350 according to Mobile the 15w50 has the higher levels of ZDDP needed for older flat tappet engines and is also excellent for newer roller lifters. I have been using Mobile 1 in my cars since 1977 when it was introduced and never had an issue .

[jmo]

coincidently correct...more correct would be: engines with tappet (for lack of better words) lifters need ZDDP. engines with roller lifters/rockers don't.

Yeaahhhh... I am aware of the fact that its the flat tappet motors which require the ZDDP, but given most people don't understand the difference and since its been discussed in many other threads I opted for brevity on my post in answering his question. He has the Ford GT40 block hence he needs an oil with ZDDP.

Were there earlier boats made by CC that had a Ford block that weren't flat tappet?

[cragginshred]

The folks at the Nautique parts place in SC were saying the 20/50 would be heavy but they also did not comment on the ZDDP factor, so I guess I am good as this is what I put in my GT 40. By the way how does the motor respond to a heavier oil?

[TRBenj]

20w50 is not too heavy, that is bad advice. I run it in all my Correct Crafts.

You need an oil with high levels of ZDDP (1200 ppm or greater) in any flat tappet cam engine. The rockers dont care what type of oil you use. All Ford Windsor marine engines fall into this category- even the latest GT40 MPEFI's used in 2002 were flat tappet engines, to my knowledge. Chevy engines prior to ~1996 were flat tappet as well. All Vortecs have roller cams and are more tolerant of newer oils.

Oils have changed drastically in the last 10 years. Ones that used to be good for these engines now have significantly reduced ZDDP levels. Many oils marketed towards diesels fall into this category- Rotella and GTX 15w40 come to mind. I believe any 50w oil is exempt from the reduced zinc levels in the newer specifications, so there are more choices available in that weight. A few good choices that I know of for flat tappet engines are:

Valvoline Racing VR1 20w50
Shell Rotella 30w and 40w
Mobil1 15w50

[jmo]

TRBENJ,

Am I reading this spec sheet correctly in that Castrol GTX 15w-40 Diesel (works for both cars and trucks) provides 1300ppm of ZDDP?

http://www.castrol.com/liveassets/bp...GTX_Diesel.pdf

Thanks

[AirTool]

Were there earlier boats made by CC that had a Ford block that weren't flat tappet?

No. I just didn't want anyone to walk away and apply that elsewhere in life. I have a 93 Chevrolet truck with a "chevy block" that needs ZDDP.

The conversion to rollers was (in a roundabout way) the result of the government requirements. Ford got out of the marine engine business before this evolution thus you don't see factory Ford marine engines with rollers....except in the case someone put out some high performance/rpm model that they converted to rollers.

[jmo]

No. I just didn't want anyone to walk away and apply that elsewhere in life. I have a 93 Chevrolet truck with a "chevy block" that needs ZDDP.

The conversion to rollers was (in a roundabout way) the result of the government requirements. Ford got out of the marine engine business before this evolution thus you don't see factory Ford marine engines with rollers....except in the case someone put out some high performance/rpm model that they converted to rollers.

That's a good point...

[core-rider]

FWIW, all 1994 and newer 351W block castings had the bosses provided for installing a roller cam. All that needs to be done for the conversion is to drill/tap the 2 bosses, replace the cam/lifters for roller versions, install the spider that holds the lifters in place, (reason for the 2 bolt bosses) and install shorter pushrods.

My 1993 Ford Lightning has the 351W in it now clocking over 125,000 miles and I have used Castrol 5W-30 or 10W-40 in it since 1998 when I bought it. Never a minutes trouble. Now I understand the RPM levels and loads put on marine engines are different from automotive engines, but I think some people over think the whole ZDDP thing a bit much. If it makes you sleep better though carry-on.