New here because I heard!!

Joined
Jul 28, 2009
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22
Location
Massachusetts
I finished building a Cj-7 last year. The Chevy 350 I stuffed in it was also a complete rebuild. The engine is a 1976 four bolt,bored .030 over,flat tops,76cc heads,and a Rhodes flat tappit cam (.450 lift int./exh). I have well over $30,000 dollars invested just in parts. A Jeeper stopped to look at it the other day and asked what I was doing about the SM oil. I go "HUH"? Well that launched a search. I always thought the newest API rated oil was THE BEST, and could be used in ALL engines. When I first started the engine I used Moroso assembly lube on all parts but also used GM break in lube with some Pennzoil 10w-40. After 500 miles I changed and used the same thing. After 1000 miles I used straight Pennzoil 10w-40. I think,after what I have been reading my thoughts on API ratings have been wrong. I only have about 300 miles on this oil change. Did I do any damage to this engine? What should I do different considering the low levels of ZDDP in the big three oils (Pennzoil,Valvoline,Castrol). For now I ordered Redline break in oil, but that will be a week away. What about STP red bottle? I am kinda mad about this whole deal with SM oils considering what I have put in this CJ. Did I also say it took over ten years to build! I also have a 97 Blazer and a 2000 Wrangler both with flat tappits. Have I shortened the engine life span on these? I am just looking for some straight answers.
 
Joined
Jun 5, 2006
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Peterborough
This is a great group of guys, you will find. If I were you, in the built 350, Id run a Deisel 15w40 or something similar. They'll have the additives your looking for. Some of the other members can chime in. For the Jeep engines, I wouldnt worry about it. A LOT of guys have posted on here that have the 4.0 and 4.2. I actually have a TJ 4.0 as well, and ran into the same issue. Apparently in the Jeeps, the pressures in the valvetrain are no where near those found in the higher output flat tappet motors. From what Ive read, most 4.0 owners, go many thousands of km's on the current rated oil without ANY issues. I'm using castrol GTX, and it seems to love it.
 
Joined
Oct 27, 2005
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KY
+1 on what was said about 15w40. And your other two vehicles have roller lifters so no worry there.
 
Joined
Jan 10, 2008
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Milwaukee, WI
I doubt there would be any damage to your engine, and while the zddp/flat tappet thing is blown completely out of proportion here all the time I doubt you would find anyone who would think 300 miles could cause significant wear. I would look for a 15w-40 or 5w-40 HDEO, like Rotella, if I had that application. As stated, your other engines should be rollerized. If someone was really mass producing a flat tappet engine in 2000 they should be... well.... we'll leave that one alone. SM is better than SL in 99% of cars. Your jeep is just somewhat unique (which I hope you were shooting for anyway).
 
Joined
Apr 18, 2008
Messages
1,093
Location
Kentucky
You could also consider a 10W-40 synthetic motorcyle oil. They run ZDDP from about 1300 to about 1800. They also have excellent anti foam, anti rust, super antioxidants, and higher HTHS. Amsoil 10W-40 motorcycle and Mobil 1 10W-40 are readily available. The motorcycle oils do not have friction modifiers but neither do the diesel oils. Mobil 1 makes a synthetic 15W-50 oil with a 40C cSt of 131.2. You might want to give it consideration. It is full SM, has 1200 ZDDP, friction modifiers, HTHS of 4.5, and it is readily available. I have used this oil since 1990 in all of our family vehicles from 1.5L DOHC, high RPM I4, to 350 V8's that never went over 2500 RMP.
 
Joined
Oct 28, 2002
Messages
48,024
Location
Everson WA - Pacific NW USA
 Originally Posted By: bepperb
I doubt there would be any damage to your engine, and while the zddp/flat tappet thing is blown completely out of proportion here all the time I doubt you would find anyone who would think 300 miles could cause significant wear. I would look for a 15w-40 or 5w-40 HDEO, like Rotella, if I had that application. As stated, your other engines should be rollerized. If someone was really mass producing a flat tappet engine in 2000 they should be... well.... we'll leave that one alone. SM is better than SL in 99% of cars. Your jeep is just somewhat unique (which I hope you were shooting for anyway).
I agree with this. First thing is that your valve drive train seems to have been broken in properly. I'll bet you could run SM oil in XW-40 grade ;\) and never, ever have a problem with oil.........
 
Joined
Jan 18, 2009
Messages
1,081
Location
oklahoma
I think Mystik 10w30 or 10w40 would be a good choice...you just need an oil with a higher amount of zddp. Heck my flat tappet 4.0L Jeep likes SM oil just fine but it is a stock motor with stock valve spring pressures. Rotella T is also a good choice; but I would not run synthetic int hat motor, I think I would prefer dino oil or a blend. OR maybe a straight 30wt like Castrol HD?
 
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Joined
Jan 16, 2006
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1,841
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United We Stand
 Originally Posted By: Pablo
I'll bet you could run SM oil in XW-40 grade ;\) and never, ever have a problem with oil.........
Whose money are we betting with?
 
Joined
Oct 11, 2002
Messages
22,187
Location
Colorado Springs
 Originally Posted By: TaterandNoodles
 Originally Posted By: Pablo
I'll bet you could run SM oil in XW-40 grade ;\) and never, ever have a problem with oil.........
Whose money are we betting with?
I was thinking the same thing. The ZDDP deal (or lack there of) might seem like it's blown out of proportion here, but go read some posts on the hot rod boards, and you'll quickly find out that it truly is a real problem for older engines with flat tappet high lift cams. Why chance it? Any CJ-4 10w-30, 15w-40, or 5w-40, or something like Valvoline VR-1 would also work.
 
Joined
Oct 25, 2007
Messages
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Somerset County, PA
 Quote:
Why chance it?
Indeed!! One of the CJ-4 oils listed will provide all the peace of mind you'll ever need. Rotella 10-30 is another good choice. \:\!
 
Joined
Oct 11, 2002
Messages
22,187
Location
Colorado Springs
I'm not looking for a fight and I didn't call you a bonehead Pablo! I'm giving practical advice. You and the API can say anything you want. Real world experience amongst hotrodders and people with high performance motors is the only evidence I need to see. But hey, it's not my motor!
 
Joined
Oct 11, 2002
Messages
22,187
Location
Colorado Springs
I've read it. I'll still take the real world experience of guys who build engines over the API. If zinc levels are not a factor in wear of high lift/high spring rate valvetrains, why does Amsoil, Valvoline, Redline, and Joe Gibbs offer oils with high levels of zinc to protect valvetrains? It's not your motor, and it's not my motor. If it was my motor, there wouldn't be a snowballs chance in helll I'd run a GF-4 oil in an old small block Chevy with a flat tappet cam!
 
Joined
Oct 11, 2002
Messages
22,187
Location
Colorado Springs
Most, if not all API SM passenger car oils in 10w-40 and 20w-50 still limit phosphorous. Look at the data sheets. The only oil I know of that doesn't is Havoline and Chevron Supreme. Something like 10w-40 Valvoline still has 800 ppm phosphorus.
 
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