z28cmr83

Sorry but there are just to many oil posts out there and none of them really answer my question.

I have a 305 with a 3.73 rear so it revvs higher than id like on the highway im going long distance (250 miles) of constant 2000-2800 RPM) also i have a valve/lifter tap. I am running Mobile1 10w30 fully synthetic, its all ive ever run in this car, and the tap has just come recently and it comes and goes as it pleases.

A friend of my told me to add lucas, i just read a post about it and i dont know if i want to risk it.

Is there any other synthetic out there that is thicker than 10w30 w/o going too thick (btw what is too thick), what weights does mobile one come in?

Ive read the battles between synth and dyno juice, but im the type of person who has to put the more expensive one in my car because it must be better, so i am deff looking for something synthetic.

Token

5w30.

8Mike9

Naw, 5w30 would be thinner than the 10w30 he has now.


Unsure on what Mobil has, may want to research the Mobil site and see what's out there.

Token

There's nothing wrong with either 5w30 or 10w30 for his application. I guess I'd suggest 5w30 in the cooler months, versus 10w30 in the summer time.

Lucas is garbage. You want your oil to flow freely, not gum up.

8Mike9

I'd almost agree...but he was asking if there were a thicker oil than the 10w30 he's running...5w30 is not the answer to his question.

Token

I read that way wrong. Sorry, frustrated at my own car lol

AJ_92RS

My guess is there's something else wrong other than the weight of oil you're using.

You either have a broken valve spring, a worn cam lobe, a bent pushrod, or a simple exhaust leak at or near the manifold (which normally sounds like a lifter ticking).

Have you pulled the valve covers off and looked at everything?

8Mike9

Ahh, no issue. I all too many times just do a "quick read" of the post and get smacked by the details I missed.

I just happen to be sober and the kids are at g-ma's...I'm able to devote 100% attention to everything I read

8Mike9

Damn AJ, you got thr guy rebuilding his engine for a come and go tap.

You have your own shop?

z28cmr83

well heres the symptoms of the tick, thought it was exhaust, sounds like passanger side, i got under the car tighened up where the y-pipe meets the headders - didnt stop. took the passanger side headder gasket off put new one in - didnt stop.
the tick comes and goes, but when its there it increases/decreases with the rpm.

z28cmr83

and i know something is wrong and the oil is just a band-aid but im always fixing something on this car and i just dont want to bother, ive alerady dug far enough. if its not a rocker, its gonna be a lifter and i wont find that out for another few hours of stress, and right now its just not worth it to me - just today 4 hours to change that passanger headder gasket.

ede

i'd run 5w-30 and fix any problems i might have and not expect a change in oil weights to fix it for me

z28cmr83

im not looking for a fix, im looking for a temporary solution

z28cmr83

what about a blend of oils (all mobil 1) , like 3quarts 10w30 and 2quarts 20w50, or mabe all 10w40. Would anyone reccomend this or not?

Token

Do you understand what a multi-weight oil is?

z28cmr83

no... also the tick is only present sometimes, and it fades in and out, it starts off low and gets loud then it fades back into low and stops. but sometimes it does it all the time.

so what is multi weight oil, i was thinking just putting in some mobil1 highmileage 10w40 and one court of 20w50, is this bad?

Token

Well this isn't a very accurate protrayal, but I'll explain it as simple as I can. A multiweight oil has the viscosity properties of both weights listed. A 10w30 will be as thick as a 10 weight (fairly thin) in colder weather, however still be as "good" as a 30 weight oil when it's hot. It will resist change in viscosity to heat better than a single weight (ie SAE 30) oil.

ROUGHLY SPEAKING, a 5w30 is thinner than 10w30 at colder temperatures, however is about the same viscosity at operating temperature.

z28cmr83

o i c, so what whould u suggest?

Token

For oil? 5w30 or 10w30.

For your ticking problem? Get a piece of rubber hose, stick one end in your ear, and point the other end around your headers to see if you're hearing an exhaust leak. If not, then stick it in different places all over the valve covers and look for a ticking lifter/rocker. If not, then ensure that your flexplate/flywheel is properly bolted to the crank, and the converter/clutch.

z28cmr83

i just bought 6quarts of fullysynthetic castrol 10w40 and 2quarts of partial synthetic castrol 20w50, I am changing the oil this weekend and I am up for any combination of these oils... i was thinking 4quarts 10-40 and 1 20-50. keep in mind this is mainly for a summer of long distance trips... any objections??

also i herd that 10w40 is no longer ceritfied by some organization because it breakes down after 2000 miles or something... this does not bother me, i usually change my oil at 2000 (at the most)... dont ask why.

five7kid

iTrader: (14)

Castrol synthetic is not a "true" synthetic. To make up for its shortcomings (at least in the past), they add a lot of viscosity index improver polymers (the stuff that makes it multi-viscosity), which is the first part of an oil to break down. Back in the early 80's, when GM started using roller lifters in their 350 diesels, the VI improvers in 10W-40 oil would break down and gum up the roller lifters, wiping out the cam. As a remedy, GM went to a 10W-30 recommendation across the board (later 5W-30).

Mixing viscosities to come up with your own home-brew viscosity isn't a very good idea. What an additive does to the oil for which it was intended may have a very different affect when mixed with another oil. Probably not catostrophic, but certainly not beneficial.

Stick with Mobil 1 as long as you are willing to settle for it (certainly better than any other of the major's synthetics), stick with 10W-30, and figure out if the ticking is worth licking.

z28cmr83

what if i return the castrol 10-w40 for some amsoil 10w-40, would that be a better choice, since mobil 1 dosent come in at 10-40 weight?

Air_Adam

Amsoil is a far superior oil to Castrol stuff.

z28cmr83

good, ill return it, I hear amsoil is better than mobil 1 too although i would like to stick with what i know works.

Also, ticking valvetrain aside which would provide better protection on a long distance trip 10-40 or 10-30?

Token

IMO which kind of motor oil would be the least of my worries when ive got a ticking.

five7kid

iTrader: (14)

Think about this: The oil is formulated to provide the "W" number first, meaning 10W in this case, to meet the cold temp viscosity requirement. Then, the VI improvers are added to meet the high temp viscosity requirement - high temp is where you operate on long distance trips, so the thing that breaks down first is the thing giving you your hot temp viscosity. Therefore, the less spread there is between the "W" and last number, typically the less VI improver that has been added, which should be your choice for sustained high temp operation.

There are exceptions, of course, as one manufacturer may have to add a lot of VI improver to make a 10W-30, while another may not have to add much at all to get to 10W-40. And, there are oils that meet the multi viscosity requirements without adding any VI improvers - AMSOIL 10W-30 is such an oil.

Another thing to understand: These viscosity ratings are ranges which overlap, meaning a -30 weight rated oil could have the same viscosity as a -40 weight rated oil. The opposite is also true, so that the -30 barely meets the rating on the low end of viscosity while the -40 barely meets the rating on the high end of viscosity, meaning there is a significant high temp viscosity difference between the two. The only way to know for sure is to sample what you're putting in and have an oil analysis performed on it.

There, does that confuse things sufficiently?

z28cmr83

you know what, i think im just gonna find some time, adjust my rockers and continue using mobil 1 10w-30. I Just hope its a loose rocker and not something else.