When to switch to Synthetic Eng. Oil

SmokinBBC

SmokinBBC

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There is a lot of info out there about Synthetic vs Conventional motor oil. My engine builder said I could use synthetic. He said that I could switch after 500 miles when I need to make the second oil change. EDIT WRONG: After talking to him again, he said switch at the 3rd oil change or about 3k miles. He made the first change when he broke the engine in on the dyno with conventional oil. He is a trusted builder who does all types of engines from classic cars to all out race engines.

My engine has roller lifters and rockers. The rings were seated on the dyno. After 500 miles, I have no oil consumption that I can tell from the dipstick or spark plugs. The oil is clean.

So here's my question. Just when do you switch to Synthetic? Most articles that I read suggest waiting until the motor (new and rebuilt) are fully broken in which is 6000 to 8000miles. Royal Purple says to wait until there is a minimum of 2000 miles on the engine before switching. I know that some new high performance cars come from the factory with synthetic oil, so there is some "slop" in these articles.

I have not yet decided to switch to synthetic since I'm not fully convinced that it would benefit my engine. I am using conventional oil for the 500 mile change.
 
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Is the engine really new? Or did you use an old block with new parts? There is a difference. The block takes more time than any other component to break in (from what I've been told). And an engine with a bored block will not take nearly as long to reach it's potential as an engine with a fresh block.

I made the switch at 500 miles, 3 years and 15K miles later the engine runs great. Just pulled the cylinder heads off and the cylinders are wearing nicely :D No signs of excessive wear on the lifters or anything else that I can see. And the engine was really clean, there's no need for me to clean the combustion chambers or pistons. :smash:
 
The most critical are the lifters and valvetrain. Since you have rollers I think you can safely use synthetic.

Remember that new engines also use synthetic and block technology has not advanced that much regarding seating of the rings.
 
It's the original block/heads with all new parts bored .030. I have been doing my best to break it in the good ole fashion way:D as the builder suggested.

Which oil do you use?
 
Mobil 1 10-30 fully syn. If I wasn't poor I'd use Redline, or Royal Purple, in that order. I use redline in my trans and my diff, I'd put it in my supercharger too if I could. Always synthetic, in everything.

I have hyd rollers too btw.
 
We build build a lot of circle track engines and after they come off the dyno we have the customers get the engines warm and change over to the AMSOIL and so far after alot of years building engines we have no issues with cam and lifter failuars and some of our flat tappet engines run 170 to 180 at the seat and 430 over the nose and some have 1.9 ratio rockers and no problems.

Mobile 1 has changed there formular to many times over the years and a shop we do some work for found out the hard way about Mobil 1 and flat tappet cams.

If it doesn't say racing on the container its probably low in zinc and phosephate.

Being a roller engine its not a criticle and if your blocks was plate honed correctly the ring take no time to break in.

Good luck with your build
 
I was wondering just what if any MPG improvement can be gotten by switching....is it worth 4x the price for it anymore?? frigging 6-8 bux/quart kinda runs the price up there....

:fishing:
 
mrvette said:
I was wondering just what if any MPG improvement can be gotten by switching....is it worth 4x the price for it anymore?? frigging 6-8 bux/quart kinda runs the price up there....

:fishing:
Click to expand...

Hard to tell. Some of the claims say 10 to 25%. If that is the case, then the math is easy. You don't know until you try.

I was checking prices for syn. Royal Purple and Red Line look to be the highest. RP = $7.29 per quart at the local parts store. Redline is about $9.63 per qt. but you have to pay delivery charges if you don't have a local seller. The closest seller to me is > 90 miles away.
 
I dunno, I tend to run 20-50 or 40 something in the summers in Florida...street temps have to be 140f in the sun easy...stuck in traffic.....

so the oil should be thin as water, and with roller motor I should think there is not much friction differences in there.....

but if I missing a good bet, well.....

maybe 10-30 syn?? hell, my piss is thicker than THAT.....

:fishing:
 
mrvette said:
I was wondering just what if any MPG improvement can be gotten by switching....is it worth 4x the price for it anymore?? frigging 6-8 bux/quart kinda runs the price up there....

:fishing:
Click to expand...

Part of the synthetic oil thing has been the extended oil changes. The real question is if you extend your oil changes to 10,000 miles (arbitrary number, BTW) how long will it take to recoup your investment in fewer oil changes. Keep in mind that the filter is still a throwaway item at whatever interval you choose, preferably NOT the 10k mark and then the make up oil for that. So instead of a $30 oil change it has now become a $80 oil change. Over the life of the engine, how many LESS oil changes are you going to do? Most of us will have something on that engine apart at the minumum of every 2 years that will require (or, hell, we just will anyway, while-I'm-at-it-itis) replacement of the oil and filter. Now you just tossed $80+/- worth of synthetic oil and filter in the trash.

How much horseypower are you going to gain by switching? Every synthetic oil maker will give you their own version of that one.

One drawback that I have seen with synthetic oils in older cars is they usually start leaking. But on a fresh engine that should not be an issue.
GM built lots of SB's and BB's with a rear bearing that was .0005 to .001 tighter than the rest of the bearings just to combat rear seal leaks.

I use AMSOIL synthetic in my diesel pickup- and I have since 25k miles. Change every 10k, and have a sample done every oil change too. So add $25 to my costs per oil change. I can't see dumping 10 quarts of dino oil every 3k, which is what GM recommends.
 
TimAT said:
mrvette said:
I was wondering just what if any MPG improvement can be gotten by switching....is it worth 4x the price for it anymore?? frigging 6-8 bux/quart kinda runs the price up there....

:fishing:
Click to expand...

Part of the synthetic oil thing has been the extended oil changes. The real question is if you extend your oil changes to 10,000 miles (arbitrary number, BTW) how long will it take to recoup your investment in fewer oil changes. Keep in mind that the filter is still a throwaway item at whatever interval you choose, preferably NOT the 10k mark and then the make up oil for that. So instead of a $30 oil change it has now become a $80 oil change. Over the life of the engine, how many LESS oil changes are you going to do? Most of us will have something on that engine apart at the minumum of every 2 years that will require (or, hell, we just will anyway, while-I'm-at-it-itis) replacement of the oil and filter. Now you just tossed $80+/- worth of synthetic oil and filter in the trash.

How much horseypower are you going to gain by switching? Every synthetic oil maker will give you their own version of that one.

One drawback that I have seen with synthetic oils in older cars is they usually start leaking. But on a fresh engine that should not be an issue.
GM built lots of SB's and BB's with a rear bearing that was .0005 to .001 tighter than the rest of the bearings just to combat rear seal leaks.

I use AMSOIL synthetic in my diesel pickup- and I have since 25k miles. Change every 10k, and have a sample done every oil change too. So add $25 to my costs per oil change. I can't see dumping 10 quarts of dino oil every 3k, which is what GM recommends.
Click to expand...

Tim, some of the "marketing" that I have read states improved gas mileage. Some say 10%...some say more. Has your mileage improved in the pickup?
 
I gained 3MPG- but that was from going to an Edge programmer, opening the air cleaner box (cut the side out of it) and 4" exhaust from the turbo back. I didn't see any additional gain from the switch to synthetic. Those 3 mods were the biggest improvement.
 
Tim, depends on the oil pan capacity and the type of syn oil you're using.

My Neon:

5 qts of Valvoline + a Fram filter = $18 which is good for 3K miles (so saith the car Gods)

VS.

5 qts of Mobil 1 + a Fram filter = $27 which is good for 7K miles (so saith the marketing team at Mobil 1 :D)

Obviously the Mobil 1 could cost up to twice as much as the Valvoline since I'm more than doubling my mileage in between oil changes. Not to mention the labor that I save. Assuming that 7K miles is an ok interval. So in this case it is cost effective, not to mention the peace of mind to have syn oil on my bearings while I drive for 4 hours at 4K rpm.

My Vette: (Takes about a year to put 3K miles on it, so I go by months)

7 qts of Valvoline + a Bosch filter = $27 which is good for 3 months.

VS.

7 qts of Mobil 1 + a Bosch filter = $40 which is good for 6 months, supposedly. And $40 is still less than doing a $27 oil change twice as frequently.

Not to mention I would never run organic oil in my Vette! Other than during break in, or to flush the motor.
 
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SmokinBBC said:
There is a lot of info out there about Synthetic vs Conventional motor oil. My engine builder said I could use synthetic. He said that I could switch after 500 miles when I need to make the second oil change. He made the first change when he broke the engine in on the dyno with conventional oil. He is a trusted builder who does all types of engines from classic cars to all out race engines.

My engine has roller lifters and rockers. The rings were seated on the dyno. After 500 miles, I have no oil consumption that I can tell from the dipstick or spark plugs. The oil is clean.

So here's my question. Just when do you switch to Synthetic? Most articles that I read suggest waiting until the motor (new and rebuilt) are fully broken in which is 6000 to 8000miles. Royal Purple says to wait until there is a minimum of 2000 miles on the engine before switching. I know that some new high performance cars come from the factory with synthetic oil, so there is some "slop" in these articles.

I have not yet decided to switch to synthetic since I'm not fully convinced that it would benefit my engine. I am using conventional oil for the 500 mile change.
Click to expand...

I spoke to my engine builder today and I am glad I did. Contrary to what I initially posted, he said I could switch to syn. at my THIRD oil change or at about 3k miles.

I must not have been paying attention when he gave me the instructions the first time :lol:
 
I switched to Royal Purple XRP after 500 miles,and change it twice a year.
My motor now has 900 miles on it,think i need to drive it more often :lol:
 
Kevin,

Be carefull with the Royal Purple products. They are full of moly. Moly and water make a very bad combo! The Moly makes for a slick product, but it has its price.
 
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