PCV question for 66 c-10 230 inline six

[Mojito66]

Hello.

I am a newcomer to the classic truck community and new owner of a 66 c-10 with the original 230 inline six. I recently noticed that someone decided to plug up the PCV valve slot. I am wanting to put the valve back in and hook it back up, but I am having a hard time deciphering exactly which valve and parts I need to do this. I have recently began diving into the world of DIY mechanics and restoration, so I apologize for my naivety when it comes to some of this stuff. I believe I know which PCV valve I need, but here are my questions:

I have seen about 3 different PCV valves for the 230 l6. One goes right in, and one looks like it screws in. Which one is the right one? I think its the one that goes right in, but I want to make sure.

Do I need to get the grommets for it as well or will it directly fit into the slot?

For the front slot, is it okay to keep the regular sealed oil cap or do I need a ventilated one?

Basically, any information I can get to help with this install is greatly appreciated! Kudos to everyone on this forum, it has been extremely helpful and I'm glad to finally be part of it.

Of course, this post wouldn't be complete without a pic!

[sanford66]

Welcome from Kansas. Man, that is a seriously good looking truck! The 230 uses a push in pcv valve with a rubber grommet. Any local parts store should be able to help you out. Now with that out of the way please post some more pics of your truck. Joseph

[Mojito66]

Joseph,

Thank you. Man, that is exactly what I needed to know. You're the man! I really appreciate it. Quick question, the oil cap, I can leave that the same, right? I figure I can just want to make sure.

As soon as I am back from traveling I will post more pics up, but here are some. I'm really glad you like her! I would love to see your projects as well, perhaps post or send some links and photos? Thanks again for the kind words and advice, and Happy Easter!

E.

[sanford66]

The oil cap on my 230 is the twist on tall breather style. I honestly can't tell you which to use, or if it makes much of a difference. Again, nice looking truck. Joseph

[Mojito66]

Thanks again Joseph! I figured the oil cap was fine. I'm trying to keep her as original as possible. She is a lot of fun!

E.

[Heater63]

On that engine you would typically have a breather cap and the PCV valve in the valve cover. You need a grommet for a tight seal around the PCV valve.
If you run a plain oil filler cap, your PCV system will not work. You must have a source for air to enter the crankcase, that is what the breather cap is for. Clean air goes IN through the breather cap (or pulled from the air cleaner housing), crankcase air/fumes go OUT through the PCV valve/hose to the pcv port on the carb.
On a V8, the air inlet is on one valve cover, the pcv on the opposite side. On the I6, the breather cap is on the front, the PCV on the rear.

[Mojito66]

Originally Posted by Heater63

On that engine you would typically have a breather cap and the PCV valve in the valve cover. You need a grommet for a tight seal around the PCV valve.
If you run a plain oil filler cap, your PCV system will not work. You must have a source for air to enter the crankcase, that is what the breather cap is for. Clean air goes IN through the breather cap (or pulled from the air cleaner housing), crankcase air/fumes go OUT through the PCV valve/hose to the pcv port on the carb.
On a V8, the air inlet is on one valve cover, the pcv on the opposite side. On the I6, the breather cap is on the front, the PCV on the rear.

Heater, thank you so much, this makes perfect sense. I'm going to pick up the parts hopefully this weekend and give it a whirl. Just a side question, do you know why they would cap off the ports? Someone told me it was just laziness on the part of the previous owner. It seems like such an easy thing to fix.

Thanks again for the explanation.

E.

[Old Bleu]

It won't make a difference for your PCV installation, but I believe your 66 truck would have the 250 engine rather than the 230. The difference is in the stroke. Good looking truck by the way!

[Mojito66]

Thanks Old Bleu! You know what? After thinking about what you said, and doing some research, I think you're right! I think the previous owner was just told what engine was in it, and told me it was the 230. Though a mechanic looked at it as well, and didn't say any different.

What an epiphany! I am going to take a look at the cast numbers tomorrow morning and research it verify, but again I think your right. I am grateful for the catch Old Bleu! I'll post an update when I know for sure, and also when I get the PCV valve installed. Hopefully it will help others as much as you guys have helped me!

E.

[Mojito66]

One more question guys. Again, I am eternally grateful for your willingness to help, and to this forum for housing such great and knowledgeable people.

Is there an easy way to tell if the engine has the air injection reactor?

E.

[Heater63]

Originally Posted by Mojito66

One more question guys. Again, I am eternally grateful for your willingness to help, and to this forum for housing such great and knowledgeable people.

Is there an easy way to tell if the engine has the air injection reactor?

E.

A smog pump? you would have a belt driven pump with lines injecting into the exhaust manifolds.

You can't really tell 230 vs 250 from the block casting, same numbers were used for both... if there is stamping on the block ID pad that can tell the tale. Also, 230 usually had a single groove pulley, 250 usually a 2 groove. Another way as I understand it to pull a spark plug and bore scope it. My understanding is the 230 and 250 used different pistons, flat top vs a dished out...google that.

[Mojito66]

Heater, that is perfect. I will research it and find out soon enough! I might just pull a spark plug and check it out.

E.