Raise

iTrader: (31)

First of all, my last few LS1 cars have been run with regular oil until h/c installs, then Ive switched to synthetic. My current project has run synthetic since new. When i do my h/c install next month, will it be ok to switch back to regular oil just for the break in, then switch back to synthetic? I just dont wanna waste money on synthetic for just a couple hundred miles. I only ask this because I read once that switching after a significant amount of time will cause problems with seals. Any truth to this? Would it be ok to switch back to regular for the break in, then switch back to synthetic?

Scoggin Dickey

iTrader: (34)

You shouldn't have a problem

BlackTTC6

Why switch back? Running synthetic is fine during break in.

Most new cars are factory filled with synthetic from the factory.

Scoggin Dickey

iTrader: (34)

Because he is only going to leave it int eh engine for a few hundred miles and he doesn't want to spend the money on expensive oil just to end up changing it right away

Grimes

iTrader: (3)

you wont have a problem switching to regular for the break in period

Medic/Z28

iTrader: (9)

I have only heard of running regular oil on breakin motors during the first 500-1000 miles due all parts breakin in. Once you run several hundred miles on the motor breaking it in at several rates of speed, than you can drain the oil and put in synthetic fluids and get it tuned. Again, I have only heard of this from several engine builders. That's what I did when I had my Olds. My .02.

RB185AFM

Not true. Synthetic will not work for initial break in of piston rings. Dont think it will matter for swapping heads cam. The rings need to have enough friction to score the cycliner walls. Engines that come with synthetic from the factory had the engines broken in with regular oil before the where shipped to the dealer. In diesels synthetic is not used until after 15,000 miles to get a proper break-in.

-ZW-

He is talking about just a h/c swap so it does not matter, you can switch from conventional to syn. and visa versa. If you are breaking in a new motor then it depends on how much ZnDTP is in the oil.

Raise

iTrader: (31)

Thanks fellas. I will just run some cheap advance auto oil for the first couple hundred miles with the new heads n cam.

lastcall190

iTrader: (36)

I've done what you are thinking of doing for each time I did a cam. No adverse effects and I run it for a couple hundred miles. I used SuperTech from Walmart last time... CHEAP.

-J

JJD49

You should be fine. On the day I took delevery of my 05 GTO the dealer told me it had Mobile 1 in the engine. I told him to drain the oil and install regular oil . IF I used the Mobile One the car would never break in properly. I went to Full Synthetic at around 2500 miles

Raise

iTrader: (31)

I would think all manufacturer would break the engine in with regular before shipping it to the dealer. Is this not the case?

GMmexican

iTrader: (7)

Are you breaking in a new motor or are you just installing h/c on a motor that has already been broken in?

ShevrolayZ28

iTrader: (4)

I did the same thing when I did my H/C. It's been around 5 kmi since then and there are no problems that I am aware of. I say go for it.

Raise

iTrader: (31)

h/c on 30k motor

davered00ss

iTrader: (4)

Use Wal0Mart synthetic. The supertech or whatever it is. It's the same cost as a regular oil.

BlackTTC6

And is made by Mobil 1

Gauge

iTrader: (3)

I don't think that switching for such a short time will be a problem at all. I've always been told that the problem comes from using dyno oil for a long time (tens of thousands of miles) and then switching to synthetic. The dyno oil causes the seals to swell, and if you switch back to synthetic, then eventually they will lose that swelling, and the recession will cause them to leak.

So, if what I hear is true, then a couple hundred miles of dyno oil won't cause a problem.

JJD49

When the 04-06 GTO were shipped to the dealer they had Mobile One 5 W 30 in them. They were not broken in at the factory. They test ran them to make sure the motors were good and there were no leaks.
TESTED , YES . BROKEN IN, NO

Raise

iTrader: (31)

So is it true that a motor cannot properly break in on synthetic?