Oil for a Ford 390 FE?

[RandyBarnett]

I have a Ford 390 that I built with the following specs:
Bore 4.08"
Stroke 3.784"
TRW Forged Pistons
SpeedPro Rings, Clevite 77 bearings. The tolerence was on the loose side. "Race clearenced" is what the machinist said.
Edelbrock Heads, intake and Hydrolic flat tappet cam.
Cam has 232 degrees @ 0.050 and 0.572 lift, Shaft mounted Roller rockers with needle bearing trunions.
This is going to see high rpms and be run in a high dirt enviroment.
http://members.cox.net/randy-barnett/
I broke it in with Castrol GTX 20-50 for the first 20-15 hours. and was told that was too thick for the rings to seat properly. Although I think they are doing just fine. No smoke out the exhaust.
What would you run?

 

[Ken E.]

Castrol GTX 20/50

 

[RandyBarnett]

Oh yeah, It never gets below 35F here and No more than 75F in the summer. Average daytime temp is probly around 58-62F
Thanks.

 

[Russ300H]

I rebuilt my '63 Chrysler 413 to similar specs except for clearances and a bit less cam. I use 15W40 diesel oil (various brands) for the extra additive package. I beat on it, but I do not race it. My experience has been that the best oil for extended hard driving/competition is Redline.

Nice truck - good luck with it!

 

[Chris142]

I was gonna say that with the flat tappit cam and no smog equipment to use Delo 15w-40 with it's Moly and Zinc.

20w-50 would be a good 2nd choice.

 

[Black Thunder]

I'd also say 15w40

 

[RandyBarnett]

Thanks for the input. So the person/shop that told me that the 20-50 was too heavy of a oil to use during the break in was full of it?
So it is between the Dino 20-50 and the Diesil 15-40. I am leaning toward the Diesil 15-40. Any other thoughts. Any point in running a straight 30w Diesil oil?
Thanks again.

 

[GoldenRod]

Back in the day the common practice was to break in a new motor with straight 30 weight for the first 1000 miles; then switch to a 10W40.

 

[e anderson]

I have a V-8 solid lifter cam , 20/50 I thought was a bit to thick so I switched to Delo 15/40 and the necessary additives are in Delo for the flat tappet cams.

 

[Russ300H]

If you can find any of the closeout AZ Delo 30wt. for .99/gal use it, otherwise 15W40 is fine. The 30wt. is much less common and not worth searching out.
All the diesel oils are excellent. The general consensus I read here is amongst the three most popular, Delo ranks #1, Delvac #2 and Rotella #3. The scale is not the same as Pure 1 filters vs. Fram.

 

[RandyBarnett]

Thanks again for all the input. This is a very helpful forum.