Joe Gibbs Break in oil on 67 435HP - which weight

[David K.]

Hello to all;

Some members have suggested Joe Gibbs oil to me. I would like to try the Gibbs mineral "break in oil" on a freshly restored (original bore) 67 435hp car. The car currently has about 100 miles by previous owner, with unknown oil to me..... The choices of mineral oil weight are as follows with Gibbs...
5-30, 10-40, 15-50, 5-20.
Not too sure which weight to use. My other cars run with Rotella 15-40 mineral. Just wondering if I should simply stick with the Rotella 15-40 on this car as well.....?!!

Thanks in advance !!

[Larry M.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

In the "good old days" of the 1960's and 70's break in oil was straight weight SAE 20W-20 or 30wt oil + EOS if you felt the need for extra protection. EOS is GM Engine Oil Supplement.

Now days I am not sure what to use if not the old standards. Probably 10W-40 if I had to choose from your list.

Why not just stick with "tried and true"??

Larry

[Rick N.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

30 weight break-in oil.

[Guest]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

Rotella 15-40 100%

[Duke W.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

...any 15W-40 CK-4 or CJ-4. It doesn't need to be Rotella. Last time I checked Walmart's SuperTech 15W-40 was still rated CJ-4 and was less expensive than the national brands. A bottle of GM EOS is optional, but if the engine already has 100 miles since the rebuild it probably won't make any difference at this point because the cam/lifters are either "broken in" or the failure mechanism has already started.

Duke

[Dick W.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

Hello to all;

Some members have suggested Joe Gibbs oil to me. I would like to try the Gibbs mineral "break in oil" on a freshly restored (original bore) 67 435hp car. The car currently has about 100 miles by previous owner, with unknown oil to me..... The choices of mineral oil weight are as follows with Gibbs...
5-30, 10-40, 15-50, 5-20.
Not too sure which weight to use. My other cars run with Rotella 15-40 mineral. Just wondering if I should simply stick with the Rotella 15-40 on this car as well.....?!!

Thanks in advance !!

Break in oil is an old wives tale. Many moons ago before piston ring technology was what it is today and with the older oils, break in oil was needed. Almost 50 years ago a piston ring engineer told me to quit using break in oil and just use the oil that was going to be used later on in the engines life. He explained that the deposits that the break in oil left were immediately cleaned away when the oil was changed.

Just put a good CJ/CK 4 API oil in it and fergidaboutit

[Rick N.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

Break in oil is an old wives tale.

I will disagree with you.

[Dick W.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

I will disagree with you.

Rebuilt several hundred engines after he told us that, used the same oil for break in as we did for normal service. Never had any problems. Brad Penn, Joe Gibbs, etc are just marketing ploys, charging you considerably extra for something you can buy off the shelf. NASCAR teams use the same oil for break in as they do for races. Viscosity may vary depending on tracks, temps, etc

[Rick N.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

Rebuilt several hundred engines after he told us that, used the same oil for break in as we did for normal service. Never had any problems. Brad Penn, Joe Gibbs, etc are just marketing ploys, charging you considerably extra for something you can buy off the shelf. NASCAR teams use the same oil for break in as they do for races. Viscosity may vary depending on tracks, temps, etc

You're entitled to your opinion.
I will still respectfully disagree.

Many things have changed since 1968.

[Dick W.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

You're entitled to your opinion.
I will still respectfully disagree.

Many things have changed since 1968.

I am just speaking from experience. We never used a break in oil, as the engine manufacturers don't, in another engine.

A good CJ/CK oil that you buy today is all you need to break a flat tappet engine in. Lube the cam with cam lube and you are good to go.

[Larry M.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

We can debate the merits of a "break in oil" versus standard engine oil for new or newly rebuilt engines. But after re-reading the OP initial post, he stated the engine had 100 miles on it. At this point, as Duke stated, further use of a special break in oil is not even applicable.

I missed this point the first time around.

OP should just use a good brand oil with adequate ZDDP and be happy. Several recommendations have already been made.

Larry

[Duke W.]

Re: Joe Gibbs Break in oil on 67 435HP - which weight

Comparing a NASCAR engine to a road engine is like comparing the engine in a Cessna 150 to the engine in a F-16. Non-restrictor plate NASCAR engine rev to 9500 with flat tappet cams. Imagine the valve spring force required to control those valves. The engines only run a maximum of about 600 miles between rebuilds and most if not all of the rotating/reciprocating parts and valve train parts get changed at each rebuild.

Water temps run in the range of 210-230 and oil at about 250. My understanding is that they use 0W synthetic oil for qualifying and 0W-20 for the race. Since the engines run so few miles the oil needs little or no detergent/dispersant, but likely has enough ZDDP to cause long term corrosion problems if used in a road engine. Oil pressure is run at the minimum value that will keep the engine alive, which is about 40-45 psi. All of the above is to reduce friction and parasitic power loss from the accessories like water and oil pumps.

"If racers use it, it must be good for my road car". This myth has been around since I started playing with cars in my early teens.

Duke