Synthetics in AMC V8's...

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Nikkormat
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Synthetics in AMC V8's...

Post by Nikkormat »

I've got the opportunity to switch to synthetics. So I think I will. I'm leaning towards royal purple because its formulated for our older engines and flat tappet camshafts. Plus it's available in any auto parts isle or store in north america.

What synthetics are you guys running in your AMC's?
What brand and weight are you running? Different in the winter and summer?
Do you like the oil you have chosen?
What adatives are you running with your oil?
Gabe, "reformed" Jeep hoarder.
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Tatsadasayago
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Re: Synthetics in AMC V8's...

Post by Tatsadasayago »

I run RP 15/40 down here in Cali and their 5/30 in Montana during the winter.

The only gripe I have with synthetics is if you have the SLIGHTEST leak, a synthetic will find it quicker than regular oils!

I've been running RP in this engine for just under 5 years and when I did an intake swap a year ago I peeked at the rockertrain, camshaft and intake valley. No brownish coke buildup, lobes wearing well and best of all: No sludge or black crispy critters.
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fulsizjeep
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Re: Synthetics in AMC V8's...

Post by fulsizjeep »

I am back to Rotella 15-40 after trying several other brands in our 401s. The synthetic probably works well for an engine with fresh seals but leaks popped up all over when I started trying different brands.
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Re: Synthetics in AMC V8's...

Post by AwesomeJ10 »

fulsizjeep wrote:I am back to Rotella 15-40 after trying several other brands in our 401s. The synthetic probably works well for an engine with fresh seals but leaks popped up all over when I started trying different brands.
X2

No way would I run synthetic in an AMC V8. Rotella is all you need.
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Re: Synthetics in AMC V8's...

Post by carnuck »

If it's a high miler, I run Napa 15W50 synthetic, but since it's natural base, I'd call it a semi-synthetic even though Castrol won that suite against Mobil 1 on the definition of synthetic.
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Re: Synthetics in AMC V8's...

Post by Herk »

Rotella T6 5w40 in everything

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Re: Synthetics in AMC V8's...

Post by rocklaurence »

I run the cheapest 10-40 diesel oil I can find. It's not as good as synthetic but if I replace it every 5K miles I'll never have a oil relate failure. I've been running the cheap stuff for 30 years without issue. I saw a consumer reports study on oils and decided not to spend the money. Even my new vehicles I run 5-30 Dino' oil.

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Re: Synthetics in AMC V8's...

Post by surfwagoneer »

I switched to mobil 1 15w-50 synthetic. My leaks got a lot worse at first but after another 1k miles things seemed to seal back up. My driveway is as clean as its been in a long time now and my engine seems to be pretty happy.
89 GW- Rebuilt 360 w RV camshaft, 4 inch Rustys spring lift, 1" body lift, dana 44HD front, 14 bolt rear 3.73's.
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Nikkormat
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Re: Synthetics in AMC V8's...

Post by Nikkormat »

Well that's all fine and dandy but this is a fresh motor and the oil will get changed every 3.5 thousand miles religiously. I had an oil related failure after only 2k on the pensoil 5w30 dino and a new carquest filter.

So I want to go synthetic, the real question is why did you choose your brand and weight.
Last edited by Nikkormat on Sat Oct 25, 2014 7:26 am, edited 1 time in total.
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Re: Synthetics in AMC V8's...

Post by serehill »

The carquest filter would be in question. Synthetics still offer superior lubrication. I run it. My engine is now 5 years old & has been rode hard & put up wet in the Cherokee. The Honcho has ran synthetic since the engine was rebuilt in it. Nothing really against petroleum based oils but I like synthetics.
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XJChad
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Re: Synthetics in AMC V8's...

Post by XJChad »

I run synthetics also, Amsoil 10w30 and a Napa Gold filter.

Penzoil, Trop Artic, Quaker State are some of the worst to run. They turn into a wax and build up like crazy.

Amsoil, Mobil 1, Castrol, Valvoline, Napa's store brand, and Royal Purple are some of the better oils to run.
1989 Grand Wagoneer, 4" Rusty's Lift, LS 5.3L swap (in progress), 4L60e, NP241c.
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Re: Synthetics in AMC V8's...

Post by KJ Ryu »

XJChad wrote:I run synthetics also, Amsoil 10w30 and a Napa Gold filter.

Penzoil, Trop Artic, Quaker State are some of the worst to run. They turn into a wax and build up like crazy.

Amsoil, Mobil 1, Castrol, Valvoline, Napa's store brand, and Royal Purple are some of the better oils to run.
One of my first jobs was working for a motor machine shop. After seeing the inside of an engine that ONLY ever had Pennzoil in it, I have NEVER used it. There was wax build up everywhere that there wasn't moving parts! Oil pan couldn't hold more than 2-3 quarts and the pump had to be pushing some of that crap through the motor.

I usually use Valvoline. Haven't tried synthetic in my FSJs. When I had my KJ, I only used Mobil1.
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XJChad
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Re: Synthetics in AMC V8's...

Post by XJChad »

KJ Ryu wrote:
XJChad wrote:I run synthetics also, Amsoil 10w30 and a Napa Gold filter.

Penzoil, Trop Artic, Quaker State are some of the worst to run. They turn into a wax and build up like crazy.

Amsoil, Mobil 1, Castrol, Valvoline, Napa's store brand, and Royal Purple are some of the better oils to run.
One of my first jobs was working for a motor machine shop. After seeing the inside of an engine that ONLY ever had Pennzoil in it, I have NEVER used it. There was wax build up everywhere that there wasn't moving parts! Oil pan couldn't hold more than 2-3 quarts and the pump had to be pushing some of that crap through the motor.

I usually use Valvoline. Haven't tried synthetic in my FSJs. When I had my KJ, I only used Mobil1.
Yep! A friends dad bought a truck with about 50k on it. The P.O. ran Penzoil only. He pulled the valve covers and the heads were caked with that crap. He started running Valvoline and it actually cleaned that wax build up out of it. After about 10k.
1989 Grand Wagoneer, 4" Rusty's Lift, LS 5.3L swap (in progress), 4L60e, NP241c.
1991 Grand Wagoneer, all stock, a work in progress, for sale soon.
1982 Cherokee Laredo, 360ci, aluminum intake, Edelbrock carb, HEI, w/32x11.50x15, warn 8000, Dana 44/AMC 20
2001 Cherokee Sport, Old Man Emu lift (worn out), front/rear C4x4 bumpers, Smittybuilt 10,000 winch, 31x10.50x15, Edge Tuner kit w/throttle body & AFE cold air, Gibson exhaust-my daily driver until the '89 is finished.
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Re: Synthetics in AMC V8's...

Post by FSJunkie »

Castrol Edge 5W50.

High zinc synthetic that costs <$9 a quart. All my engines run it whether they have 3000 miles or 100,000.
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Re: Synthetics in AMC V8's...

Post by Cheap Hobby »

Your first concern is the break in oil and filter you use. Talk to your engine builder and do your research. Don't let the price scare you off. RP makes one that is well regarded.
Your choice of filter will effect your engine life as much or more than the oil. I run only Wix (they supply Napa) The Amsoil system relies on top filters and regular filter changes to achieve max life.
My 360 was run on Valvoline synthetic and Wix filters until it was parked 14 years ago. It looks great inside. My 2000 Triton V10 was started on Valvoline syn and has 446000 miles and just passed smog as clean as a 5 year old Lexus. As the Tritons eat a qt every 1000 miles I often top off with Chevron 5/30.

Run RP if you like pick a good filter. Choose you weight based on the temperature you are operating in. One thing to consider is your change intervals. Changing oil every 3.5k miles is pissing away your money on synthetics. Synthetics are designed to extend your change periods. My fleet gets changed twice a year unless there is a long towing run scheduled. The Amsoil system changes filters at regular intervals.
Oil technologies are changing daily you have to stay up on the claims. I have never run Havoline, wont run Penzoil and will only run the top line Quaker State if that is all I can get for some reason. My trans all get RP and you can feel the difference when it is at end of life.

The choice is yours do you your research and don't cheap out.
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Re: Synthetics in AMC V8's...

Post by bwwhaler »

Mobil 1 full synthetic 10w 40 with a wix filter every time. Still burns around a quart every two weeks, so it stays pretty fresh in the pan.
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Re: Synthetics in AMC V8's...

Post by letank »

Used synth castrol 10w40 on the 74 about 15 years ago at 250kmiles after I replaced the gaskets... no leaks, barely used any oil ... on long trips... but the 15 miles of commuting was not long enough to warm up the engine and I was using 1q per 1000miles... , so at the next oil change went to part synth which was about the dame oil use at half price.
Now still on part synth.
The 85 was such an oil burner until I changed the valve seals that I used rotella 15w40...in gallon jugs. Still on rotella dino.
In both cases oil is changed when it get too dark... so 2500 to 4000miles... depends on use.. AC filters.
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Re: Synthetics in AMC V8's...

Post by racerx12003r1 »

Hey guys. Thought I'd chime in on this one. I have a funny break in deal, but it has always worked for me. when I get the engine set, I fill it with a cheap as dirt oil (clean but cheap) and a cheap filter. I use a primer and a drill for about an hour barring the engine around till I turn it 2 complete revolutions of the crank. Then I drain it and change the filter. (thats why I said cheap) Then I refill it with Havoline in whatever weight I want (ususally sae30) and a good ZDDP zinc additive. and run it for 500 miles. At that time, I change the filter and top it off. This is run till 5000 miles. once I'm sure of break-in (no oil use, good compression, good oil pressure) the next change is with a synthetic oil. I like royal purple myself, but am gonna try Amzoil next time. I have heard really good stuff about it. A buddy of mine runs it in his daily driver. He changes his oil once a year and the filter every 6 months and has never had a problem. Oh, I usually use a 10w/30 after.
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Re: Synthetics in AMC V8's...

Post by rocklaurence »

The CR video I saw 20 years ago ran tests on taxi fleets in Detroit and New York cities. They ran different oils [ all had the required OEM rating] in the taxis for 300K miles and found that they all performed the same [very well]. Their findings stated that they all do a great job and that the oil needs to be replaced every 5000 miles to minimize wear. IMO, most vehicles that we drive will rot off the frame or be sold before the motor wears out as long as we keep clean oil in them. Oh yeh, what kind of engine Break-n procedures do the OEMs do on new motors? There's all kinds of Voodoo ideas on breaking in new rebuilds and plenty of night mare stories link to new motor start ups----I dont know. :oops: I know, I'm opening a Can of Worms ;)
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Re: Synthetics in AMC V8's...

Post by Tatsadasayago »

I went with the dealership owner back to the factory in 89' and got a chance to talk with some engineers and a bunch of assembly people.
When I asked the plant manager about engine break-in procedures they employed he laughed at me! This is a rough quote: "We start them as they come off final assembly and if there is 25 PSI oil pressure and nothing is rattling or knocking, it gets driven to the lot to wait for transport."

The engine team honcho told me the same thing and I asked him about break-in his reply was: "Break em in slow, they'll never go, break em in fast, they are sure to last."
He recommended the usual oil and filter change after 50-100 miles to clear out the bits and assembly lube then follow the service intervals. He mentioned that after the first oil change, I should drive it like I stole it on the freeway for another 100 miles at high RPMs to seat the rings and set the ring ridge high point in the bore.

That explained why all but a rare few Jeeps rolled off the transport for PDI with more than 1-4 miles on the clock from being driven around storage lots etc.
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