1985 suburban mark iv 454 build. What oil do you guys like?

Nice for an off brand truck :D

Id run it hard...

Pretty sure Howards Rollers are made by Morel and while i'm not too sure i understand why. some guys say Morels don't like heavier oil.

What were the ring end gaps?
 
Txaggie76 said:
Howdy all,

We recently rebuilt a barn find 1985 c20 suburban. It was an 80k mile truck and we pulled it to clean up the motor. Like most builds, we got deeper and deeper but I tried to stay pretty conservative. We bored it .030 over to 461 and lightly polished the factory crank, reused the factory rods and replaced all bearings throughout with standard king brand bearings. Cam wise we converted to a Howard’s hydraulic roller setup with crane 1.7 gold rockers. Head wise we went with AFR 265 oval port 109cc, and small -10.00 cc domes. Intake is an edelbrock air gap rpm to a Holley sniper 2.

The engine runs insanely well and I’ve put around 2300 miles on it. We broke it in with Driven 5w-30 break in oil for 800 miles and then switched over to Driven GP1 10w30 per their recommendation. Our oil pressure is awesome but I’m eating about 1 quart for every 1000 miles. I did read that these old big blocks can sometimes do that.

Now to the main question. Am I using the right oil? Is this oil overkill or should I swap to something cheaper, different, etc?

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Well, I'll be Dipped! That is a beautiful Square Body!
 
I put the Mobil 1 15w50 in yesterday. Curious to see how it does. I can already see my oil pressure is higher at all facets (at least with this old factory mechanical gauge).
 
Txaggie76 said:
Howdy all,

We recently rebuilt a barn find 1985 c20 suburban. It was an 80k mile truck and we pulled it to clean up the motor. Like most builds, we got deeper and deeper but I tried to stay pretty conservative. We bored it .030 over to 461 and lightly polished the factory crank, reused the factory rods and replaced all bearings throughout with standard king brand bearings. Cam wise we converted to a Howard’s hydraulic roller setup with crane 1.7 gold rockers. Head wise we went with AFR 265 oval port 109cc, and small -10.00 cc domes. Intake is an edelbrock air gap rpm to a Holley sniper 2.

The engine runs insanely well and I’ve put around 2300 miles on it. We broke it in with Driven 5w-30 break in oil for 800 miles and then switched over to Driven GP1 10w30 per their recommendation. Our oil pressure is awesome but I’m eating about 1 quart for every 1000 miles. I did read that these old big blocks can sometimes do that.

Now to the main question. Am I using the right oil? Is this oil overkill or should I swap to something cheaper, different, etc?

View attachment 270936
Click to expand...
Did you redo the seals?
 
FlyingTexan said:
Ok, is a full synthetic approved for that old of an engine? Did they even exist then?
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Yes, both AMSOIL and Mobil 1 had been around for about a decade back then. All the API standards are supposed to be backwards compatible (and the seal compatibility materials list is quite comprehensive) so I wouldn't be concerned about that.

I'd personally run a Euro 5W-40 or 0W-40 in it (full-SAPS), as that's close to the OE spec viscosity, which was usually a 30 or 40 grade, and still has a generous AW additive package because it's not phosphorous constrained.
 
OVERKILL said:
Yes, both AMSOIL and Mobil 1 had been around for about a decade back then. All the API standards are supposed to be backwards compatible (and the seal compatibility materials list is quite comprehensive) so I wouldn't be concerned about that.

I'd personally run a Euro 5W-40 or 0W-40 in it (full-SAPS), as that's close to the OE spec viscosity, which was usually a 30 or 40 grade, and still has a generous AW additive package because it's not phosphorous constrained.
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Full synthetic was cautioned about in the past with older engines because of seal swelling, stopped leaks for the short term. Could be a wives tale just what I grew up hearing. It’s why conventional oil was always used.
 
FlyingTexan said:
Full synthetic was cautioned about in the past with older engines because of seal swelling, stopped leaks for the short term. Could be a wives tale just what I grew up hearing. It’s why conventional oil was always used.
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I never personally experienced that and I've run M1 in old Ford Y-blocks from the 1950's. I did have M1 expose some some leaks in my old Fox Body (cleaned up the deposits that were preventing the leaks) but that wasn't the oil's fault, the old cork gaskets were hard as a rock, a new set fixed that up. Had no other leaks. M1 FS 0W-40 has been my go-to for most of the 80's Ford Windsor projects I've been involved with.

Modern OTS "synthetic" oils are almost all Group III, so the bases are just higher VI versions of the Group II bases that most "conventional" oils are now made from. They are all hydrotreated or hydrocracked. You'd have to be shopping for absolute garbage to find something that's still the old solvent refined Group I base, which would have no modern approvals or performance guarantees.
 
Gorgeous old Suburban.
Factory paint?
Factory 454 with a sympathetic rebuild?
Wow!
 
Plus the fact that all API licensed oils have seal swelling requirements. That’s agnostic to base stock composition.

Same goes for the approvals I’ve seen.
 
fdcg27 said:
Gorgeous old Suburban.
Factory paint?
Factory 454 with a sympathetic rebuild?
Wow!
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Yessir. Factory paint and like a time capsule inside.

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