synthetic oil for LT 5

[secondchance]

Originally Posted by HAWAIIZR-1

I used to use AMSOIL AMO 10W-40 as recommended by Marc, but just switched to AMSOIL ZROD 10W-30 after recommendation by AMSOIL and one of their reps. A case is on the way so I have not actually tried it yet. After seeing what Yun and others are using with Mobil 1 high mileage 10W-30 I may use that instead with it being so easy to get and no shipping to pay for. I just mailed off an oil sample (Blackstone Laboratories) to see how the AMSOIL AMO 10W-40 is doing after rebuild break in and what the phosphorus and zinc actually is.

As for oil filter, check out all of Marc's research and you can't go wrong: http://www.zr1specialist.com/HAT%20W...ers%202006.htm

I bought a case of Fram TG3985 for about $2 each when Rockauto.com had their closeout so I guess I have a lifetime supply and I see Marc has updated recommendation since.

Craig,

Mobil 1 high mileage 10-30 sells for less then $25 in a 5 qt jugs at the Walmart - not a bad price.

[HAWAIIZR-1]

Originally Posted by Dynomite

Craig.......I use AMSOIL 10W-40 as Marc suggests/suggested. But may switch to AMSOIL 10W-30 (where it is colder) if it is essentially the same except for weight. Let us know what Blackstone says



Cliff

I think when Marc did the analysis, the ZROD 10W-30 was not out yet and can't go wrong with either. I heard that too much ZDDP is bad for cats, but I don't run usually run them (only for the emissions testing I was trying to pass). I'm hoping I get a clean bill of health from the oil analysis and that all is okay.

[HAWAIIZR-1]

Originally Posted by secondchance

Craig,

Mobil 1 high mileage 10-30 sells for less then $25 in a 5 qt jugs at the Walmart - not a bad price.

Yun,
I like that Mobil 1 has a 10W-30 option; I did not realize it or noticed the update of recommendation. I thought it was only the 15W-50 that is too high in viscosity as Marc mentions. I like the thought of the price too as well as availability (when I return to the US). I even had to order my coolant by mail and was fortunate the Amazon.com would ship me 2 gallons of Zerex green stuff. The bases here sell Mobil 1 all day long, but not the high mileage oil. Thanks again for sharing this............

Craig

[GOLDCYLON]

Originally Posted by Dynomite

Craig.......I use AMSOIL 10W-40 as Marc suggests/suggested. But may switch to AMSOIL 10W-30 (where it is colder) if it is essentially the same except for weight. Let us know what Blackstone says



Cliff

This is what I use. GC

[hiperf406]

Originally Posted by HAWAIIZR-1

I used to use AMSOIL AMO 10W-40 as recommended by Marc, but just switched to AMSOIL ZROD 10W-30 after recommendation by AMSOIL and one of their reps. A case is on the way so I have not actually tried it yet. After seeing what Yun and others are using with Mobil 1 high mileage 10W-30 I may use that instead with it being so easy to get and no shipping to pay for. I just mailed off an oil sample (Blackstone Laboratories) to see how the AMSOIL AMO 10W-40 is doing after rebuild break in and what the phosphorus and zinc actually is.

As for oil filter, check out all of Marc's research and you can't go wrong: http://www.zr1specialist.com/HAT%20W...ers%202006.htm

I bought a case of Fram TG3985 for about $2 each when Rockauto.com had their closeout so I guess I have a lifetime supply and I see Marc has updated recommendation since.

Thats what I now use as recommended by Amsoil rep.

[LancePearson]

for an oil filter I went with the top two that Marc Haibeck talks about and bought my first two Napa 1324's for the car when I next do the first oil change on it that I do.

I've just used mobile 1 oil so far and put a small amount of the ZDDP additive I had on hand for my 76 in with it.

Early days for me with the lt5 though.

[Hib Halverson]

Originally Posted by Starman

I use a 50/50 blend of Red Line racing and street oil. Both are high in the EP additives, but this is not a cheap option.

Red Line is an outstanding product but be careful about using Red Line Race Oil, even 50/50 mixes, in street applications. Its level of detergents is insufficient. That's why it's branded as a racing oil.

If you're worried about ZDP, Red Line Engine Oils all have about 1200 ppm phosphorous, way more than enough for an OHC engine with flat tappet cams and direct acting bucket tappets.

[rkreigh]

with the relatively light spring pressures, direct acting buckets, and light valves, the LT5 doesn't need way high zinc

most of the cam failures are older style pushrod engines and solid cams, high spring pressures. the cams and buckets are tough as nails and a little zinc is enough

I'd worry more about killing the cats than I would hurting the cams/lifters with too much zinc. that's why the modern oils have been reformulated to cut back the zinc content

as hib points out, 1000-1100 should be plenty

[Hib Halverson]

The reason you don't need extra ZDP in the oil for an LT5 is not that the cams and lifters are extra tough. On the contrary, the cam lobes and lifter faces are no different from a material standpoint than what is used in other flat tappet valve trains.

What's vastly different are the loads at the lobe/lifter inteface point. On an OHC flat tappet engine, the loads are considerably less than are loads at the same interface in an OHV valve train. OHV engines run much higher valve spring pressure to control the mass of the pushrod valve gear along with the valve and tappet. That higher load is applied to the lobe/lifter interface. Since OHC engines don't require such high spring pressure and the load is not leveraged up by a rocker arm, OHC engines don't need near as much ZDP as do pushrod flat tappet valve trains.

"rkreigh" is spot on in his comments about too much ZDP causing chemical wear of the camshaft and lifters along with killing cats.

You run more than about 1600 ppm phosphorous for an extended period and you may suffer chemical wear of the cam/lifters and shorten cat life.

Keep that in mind when you buy any of these ZDP suppliments which if not used very carefully in precisely measured amounts can damage an engine.

If you are looking for more information on camshaft wear and engine oil, see: http://www.corvetteactioncenter.com/.../#.US_0to6uadU