Fuel type for 429 cj / scj 351 c / w?

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Hello forum.....I am a newbie.....this is my first real post, so please bear with me!

I have so many questions my head is spinninglollerz.

I am finalizing the purchase of a car........I have of course asked the seller a ton of questions an'all.

What type of fuel / gas do you guys run in your 429's? Do you use additives or not?

Also, what type of oil? Synthetic or natural?

Any info is good info.

 
You will get dozens of opinions so I will start.

I would not put any additive in my engine that

was not available when the car was built, or to

be more succinct, don't use any. My understanding

is you still have access to 95 octane gas, advantage

Europe. These cars were built to run on 100.

My oil is Valvoline VR-1 racing oil, again you will get

several opinions. These engines need high zinc and

phosphorous content in the oil. I bought a bottle of

"Hy-Per Lube" zinc additive for my oil, on the back the

label says "contains no zinc". Go figure.

mike

 
Last edited by a moderator:
Thanks for the info. So, 95 octane lead free is ok?

Synthetic oil is also ok. I thought this was a big no-no in these engines. I was told 'Mineral based only'.....no worries ....keep the info coming......

 
Use the highest octane available. Octane ratings are determined differently in the US and Europe. Europe uses the RON method and the US uses AKI (RON+MON/2). US 91=Europe 95. It is not a mineral vs. synthetic issue, rather the level of ZDDP in the oil. I use Amsoil Z-Rod synthetic oil. If using mineral oil I use Valvoline VR-1. There are many other acceptable oils.

Here is a link discussing the issue. http://www.drivenracingoil.com/news/dro/training-center/articles/zinc-in-motor-oil/

 
I use VR1 and so far it's been good for my motor.

The CR should be around 11.0:1 for an early 429 so that should require around 100 octane for that motor. There are a lot of variables than that also affect what is required for a motor. I have 10.5:1 and use 93 octane with no knock. Here is a good article that explains all of this.

http://www.daytona-sensors.com/tech_tuning.html

 
I use VR1 and so far it's been good for my motor.

The CR should be around 11.0:1 for an early 429 so that should require around 100 octane for that motor. There are a lot of variables than that also affect what is required for a motor. I have 10.5:1 and use 93 octane with no knock. Here is a good article that explains all of this.

http://www.daytona-sensors.com/tech_tuning.html
I was surprised to see they did not discuss the impact of cam specs and Static Compression Ratio and Dynamic Compression Ratio. The company makes great products. Chuck

 
Ok guys....thanks for all the info. I just bought my car. YEY! I intend to use 95 octane with Castrol valvemaster PLUS additive Is this a good idea? Here in Denmark we have 92/95 octane...98 went out a couple of years ago.

I hope the above is good enough for my 429cj........

Keep the info coming.......

 
The Castrol product sounds like a good product if it does what it claims to do. I have no reason to question the the product's stated benefits. Keep an ear open for preignition and detonation. And periodically check a spark plug or two for signs of detonation. Chuck

 
Thanks fellas.

I am still a bit confused and nervous of messinng up. Does the fuel have to be leaded? I understand this is important.......so, I guess I WILL need a lead additive?

Regarding engine oil.........that is clear to me. Mineral or synthetic with zddp content OR additive.

 
Gasoline does not have to be leaded. Back in the day many brands had lead additives to help with octane and valve life. However, there were lead-free brands (Amoco) who sold 100+ octane and normal octane levels that worked just fine.

You will not damage the engine using lead-free gasoline.

Whatever you do, try to stay away from gas with any blend of ethanol. That will have a bad cumulative effect on O-rings and gaskets in the fuel system

 
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