Brand & Weight of OIL used in Straight 8

**39 Century** · 06-13-2005, 08:31 AM

What brand and weight of oil is recommended for the Straight 8 engines ?

**jerry burger** · 06-14-2005, 01:10 PM

the big eights have a tendency to run (dirty)and also create more heat on the bearing surface than the small one.after trying several oils including valvoline, mobile,kendall,and castrol
which are all good oils i found that chevron 15-40 delo 400 does the best.it has a high flash point and excellent viscoscity index.85% of the semi trucks use it and has proven record.make sure your rod tolerance is .0014 to .0018.

junk-collector · 06-14-2005, 06:58 PM

i was kind of curious as if to has anyone ever tried synthetic oil in a straight eight? or would it be to thin of a viscosity ? or leak around the seal s ?

Bernard · 06-15-2005, 07:39 PM

I'm running Havoline in mine, 'cause that was what was in it when I got it and I believe in not changing brands or even viscosities. . . . but any thoughts about Havoline? I've never used it before.

**jerry burger** · 06-16-2005, 10:42 AM

havoline has a good rep,it is made by texaco which has joined up with chevron who makes the popular delo brand.

**jerry burger** · 06-16-2005, 10:47 AM

synthetic oils are a little better than regular oils they can bear more heat and go longer before breaking down.however they cost more,and if you change the regular oil often enough you cant go wrong

buick8 · 06-28-2005, 05:54 PM

Synthetics might not make old seals happy; otherwise they are great. I run Delo 400 30-W: Diesel oil has great anti-acid properties which are good for a car which sits idle. I ran Pennzoil 10W-30 for years with no problem. I think it's mostly a psychological thing: if it makes you feel better to use a particular brand, go ahead. Almost every oil on the market now is many times better than when these cars were new.

**jerry burger** · 06-30-2005, 02:32 PM

in the 40`s and 50`s some oil companies used a lot of parrifin which lubricated good but created a lot of sludge.like you i think most of this has been improved and most oils are sufficient.the delo is one of a few that can rival synthetics in performance,and gives far more protection than we actually need.but it is nice to have that
cushion.JB

**chub chub** · 07-01-2005, 06:52 PM

Originally Posted by junk-collector

i was kind of curious as if to has anyone ever tried synthetic oil in a straight eight? or would it be to thin of a viscosity ? or leak around the seal s ?

I've been told the synthetics have detergents in them. I've also been told this is bad for super old engines because it can free up some of the junk that has gradually built up in every nook and cranny in your 50+ year old engine, causing leaks in some places and sludge deposits in others.

**jerry burger** · 07-05-2005, 01:59 PM

most of the oil we buy today is high detergent,whether synthetic or regular some more severe than others.it is a good rule of thumb to remove the pan and make sure the screen is clean,and clean out the pan.this will get about 90% of the sludge.