39 Century
Active Member
What brand and weight of oil is recommended for the Straight 8 engines ?
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Brand & Weight of OIL used in Straight 8
- Thread starter 39 Century
- Start date
jerry burger
Member
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.
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.
J
junk-collector
Guest
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 ?
B
Bernard
Guest
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
Member
havoline has a good rep,it is made by texaco which has joined up with chevron who makes the popular delo brand.
jerry burger
Member
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
B
buick8
Guest
Oil
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.
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
Member
oil
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
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
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.junk-collector said:
jerry burger
Member
oil
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.
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.
J
Jason Scott
Guest
Oil Type
I have a 53 Special with the Straight 8. Before the rebuild, I used Valvoline 30 or 40 weight, depending on the season. Now, newly rebuilt, they used 10W-30 as a good "break in" oil for 1000 miles and I was told to continue this.
I have a 53 Special with the Straight 8. Before the rebuild, I used Valvoline 30 or 40 weight, depending on the season. Now, newly rebuilt, they used 10W-30 as a good "break in" oil for 1000 miles and I was told to continue this.
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Straight Eight
Active Member
What kind of oil is good for the Straight Eight
Many years ago I was told by and employee of GM Diesel, that Shell Rotella was especially good for the poured bearings in the straight eights. I have used Rotella 30 ever since. I have been thinking of going to a mulitigrade Rotella as it is more readily available as all the diesels use it.
Many years ago I was told by and employee of GM Diesel, that Shell Rotella was especially good for the poured bearings in the straight eights. I have used Rotella 30 ever since. I have been thinking of going to a mulitigrade Rotella as it is more readily available as all the diesels use it.
Into a fresh rebuilt engine, I would suggest a quality 10W30 petroleum-based oil for break-in, then I would switch to a high-quality synthetic 10W30 or 5W30. Valvoline, Castrol, Amsoil, Redline, Motul, to name a few quality synthetics. I wouldn't use anything that was intended for diesel engines, as those contain twice the amount of detergents, which is bad for combustion in a gasoline engine
One more thing. I forgot the seals. 99% of the synthetics are PAO-based (poly-alpha-olefin), which has a tendency to shrink seals. As totally opposite, ester-based synthetics cause the seals to swell. I'm using Red Line (poly-ol-ester) but Amsoil (diester) works as well. Plus, being ester-based, these oils have the highest thermal stability = no deposits, no sludge. That's why they also like to use these brands in the air-cooled Harleys. Ester-based oils carry a premium price, too, and the STR-8 holds 8 quarts...