Ironembraced

I recently installed a high lift cam & springs into my vette. I neglected to replace the stock LQ4 oil pump with an HV pump. I am now realizing that I really screwed myself.

Problem with replacing is, I have to pull off my steering rack and a bunch of other garbage just to get to the dang oil pump. It will have to be a well planned out project for me to be able to get it done in my garage. I won't have that kind of time and money at the moment. So it won't be getting that Melling HV pump right away.

I am debating running a ZDDP oil additive from now on, until I can get the pump swapped out with an HV. I'd feel alot safer with my valvetrain & internal bearings if I knew they were better protected with ZDDP. I know the phosphorus will kill a normal catylatic converter, but will it do the same with a high flow cat? Is there any other downside for heavy ZDDP use on a modern engine?

baxsom

iTrader: (6)

zddp is required in flat tappet motors where the flat bottom lifter rides directly on the lobe. in a roller cam it is not needed.

Ironembraced

That's correct..I was aware of that.

I am looking for more information about running it in a roller motor. I would love to know the advantages & disadvantages. I couldn't foresee any disadvantages besides destroying a cat. But maybe with hi-flow cats it would be okay to use ZDDP for awhile? I know it's not recommended by the manufacture...but I assume they also wouldnt recommend a customized valvetrain & a stock oil pump.

It has to make some sort of a difference in lubricating the contacting metal...they put high concentrations of it in break-in oil.

RPM WS6

iTrader: (3)

Unless you've converted to a flat tappet cam, I would not worry about adding ZDDP to your current setup. Current "SM"+ oils in the GF-3 and GF-4 energy ratings still have plenty of zinc for roller cams, aftermaket or not.

An additive such as this is not a substitute for a high volume oil pump. If you need more oil volume, ZDDP will not help with that (just like a high volume pump alone wouldn't help a flat tappet application in place of added zinc). They are mutually exclusive things and thus not interchangeable. Having said that, many people have run higher lift cams with stock oil pumps and no issues, so I don't think your situation is cause for alarm really.

Will ZDDP hurt your engine though?....No, not at all.

As for the cats, it's true that the zinc and phosphorus content was reduced in oil to prolong cat life. However, cats have been in place since 1975 and the zinc levels didn't first start to be reduced until around ~1995, and then further in 2001 and 2005. Stock cat or high flow cat won't matter, but either way it's not an instant death sentence, it's just that there is higher risk for contamination over the long term. Modern oils still have some zinc, so cats are still being exposed; and all cars with cats used much higher zinc content oils for over 20 years.

The oil spec change was made in an effort to further extend the life of emissions equippment. Frankly, if you have an aggressive aftermarket cam, you're already reducing cat service life by introducing excessive fuel due to increased valve overlap. I think this will wear the cat as quickly or quicker than an increase in zinc/phosphorus levels in your oil.

O2Form

Destroy a cat my azz, I bean putting ZDDP on every cat I see and they still aint hurtin!

PSST I don't believe the ZDDP story about it ruining cats.........ITS BS! the ONLY REASON ZDDP aint in motor oil is because they don't want the older cars and trucks around si they can sell NEW ****!

My old LS1 car used 1 qt of HIGH CONTENT ZDDP oil every 1500 miles for 200k and the cats were still fine........

Ironembraced

awesome...thanks both of you guys for the heads up. If anyone else has an opinion on ZDDP feel free to share it.

O2Form

Another thing, my jeep has over 200k on it using ZDDP oil and it still has the factory cat on it. Too much fuel and heat ruins cats not ZDDP.

chrisfrost

iTrader: (8)

Yes heat and nailin it all the time and head gasket leaks allowing coolant into the exhaust kill cats ,,,,,,as far as You're main question , unless You're engine has excessive wear and/or miles I don't see any need for a HV oil pump . There are situations where the pump stops working correctly and death occurs quickly so I would suggest using a mechanical oil pressure gauge and mounting it where it can be seen with a light that lights up if the pressure dips below a predetermined point or something similar or equally as effective .