Road Tube/PCV Questions

5

5falfa5

Member
I call on you, Gurus of the 348/409,

Just putting the finishes on my 348 tri power in my 36 coupe. I do not have a planned crancase ventillation system. I do not have a road tube yet as I built this motor from scratch. My plan is to put pcv on this motor by running a tube from the road draft hole at the back of the manifold to a pcv valve then to the vac port on the bottom of the center carb. Then I would use a vented fill cap on the fill tube. I am running a set of original Edelbrock finned valve covers and want want to drill them.

I also find a hole drilled in the intake on passenger side that appears to be crancase passage. My plan was to plug this as I feel no need to use it unless I use that for the pcv valve and put the stock road draft tube on... Whadda ya think???

Thanks,
Bob
 
petepedlar

petepedlar

Well Known Member
Supporting Member 3
That will work fine. I hope you put the splash pan on the bottom of the intake though?

Dave
 
5

5falfa5

Member
Yes, I did put the plate back under the intake. Thanks for the advise.

Fathead,
Why do you think that pcv and draft tube together wont work together? Dont get me wrong, I'm not disagreeing with you, I'm trying to learn from you guys. My thought is pcv from the intake to suck in the gasses when needed and the draft tube and the vented breather would balance/provide intake air to the crankcase?


I have found in the past with an open engine compartment, the filler tube/cap blows oil all over the windshield. So again I'm trying to balance the crankcase pressure and suck in and burn in gasses. Comments please??

Thanks,
Bob
 
Skip FIx

Skip FIx

Well Known Member
A PCV system actually is better than just breathers as it sucks out the bad air(acidic etc) and has a slight vacuum to help prevent pan seal issues. Why the race motors run a full vacuum pump.
 
5

5falfa5

Member
Skip,

Do you agree with my plan or do you think I will have a problem?

Also does antbody know about that threaded hole in the intake that appears to be crankcase passage?

Bob
 
Skip FIx

Skip FIx

Well Known Member
As long as the baffle pan is there it should be good, no baffle and it WILL suck oil.You figure the factory put that baffle there to keep oil form spewing out the road draft tube. The breather tube up front allows a source for air to come in or pressure to go out if more than the PCV can handle.
 
petepedlar

petepedlar

Well Known Member
Supporting Member 3
When I said it would work I understood that you were going to eliminate the road draft tube and connect the PCV to that outlet in the manifold. I don't think you will have much sucess trying to use the R.D. tube and a PCV connected at the same time. The PCV will just suck from the R.D. tube because it's easier. You must close the system to make it suck from the filler cap through the engine.

Dave
 
5

5falfa5

Member
OK,

I get it. I will plan to use a kit from Show Cars that adapts th RD tube to tri power center carb vac with a pcv valve on it. Does anybody know of this adapter kit? I will put a K&N filter/breather cap on the filler tube. I will plug that hole in the intake unless that is supposed to be used for something. Can anybody tell me what that is for? Im gonna try to post a picture of it on the next reply. I tried earlier and lost my post.

Bob
 
5

5falfa5

Member
Well,

I cant seem to make the file size smaller to post the photo. Its about a 1/4-3/8 pipe thread on the pass side up by the T-Stat housing. The water temp is on the drivers side.

Bob
 
5

5falfa5

Member
Show Cars PCV Adapter

Gentlemen,

Just a FYI, I ordered Show Cars Part #6945 Custom PCV Kit for 3X2.
Looks pretty slick. Im gonna plan to use this with K&N type breather on the fill tube.
Thanks for all of your comments and replies.

Bob
 
DonSSDD

DonSSDD

Well Known Member
Supporting Member 2
5falfa5 said:
Well,

I cant seem to make the file size smaller to post the photo. Its about a 1/4-3/8 pipe thread on the pass side up by the T-Stat housing. The water temp is on the drivers side.

Bob
Click to expand...

Source of vacuum for distributor?

Don
 
Rickys61

Rickys61

Well Known Member
Supporting Member 3
I always wondered what that pipe plug was for, everyone I've ever seen has been plugged. Hey Bob, if you can, post some pics of that PCV system after you get it on, I'm interested in seeing how it looks installed.

Rick
 
5

5falfa5

Member
I am waiting for the parts to come in. I will attempt to upload photos if I can figure out how to make the file size smaller. I will get with my IT Guru on this.

Just food for thought: That drain back hole in the intake would make a great source for pcv valve as it is right there on the top of the motor (and next to vacuume source)??????

One more thing.. I find a carb stud with a hole in it, I would assume that would be dist vac?

Thanks,
Bob
 
Fathead Racing

Fathead Racing

Well Known Member
Supporting Member 7
5falfa5 said:
I am waiting for the parts to come in. I will attempt to upload photos if I can figure out how to make the file size smaller. I will get with my IT Guru on this.

Just food for thought: That drain back hole in the intake would make a great source for pcv valve as it is right there on the top of the motor (and next to vacuume source)??????

One more thing.. I find a carb stud with a hole in it, I would assume that would be dist vac?

Thanks,
Bob
Click to expand...

The solution for the PVC is the road draft tube hole, Big block Chevy valve cover rubber grommet is the right size. Hollow carb stud is correct connection for the dist. vacuum, if you were running a powerglide tranny you can split the vacuum hose and use it for both tranny and dist.
 
D

don decker

New Member
5falfa5 said:
I call on you, Gurus of the 348/409,

Just putting the finishes on my 348 tri power in my 36 coupe. I do not have a planned crancase ventillation system. I do not have a road tube yet as I built this motor from scratch. My plan is to put pcv on this motor by running a tube from the road draft hole at the back of the manifold to a pcv valve then to the vac port on the bottom of the center carb. Then I would use a vented fill cap on the fill tube. I am running a set of original Edelbrock finned valve covers and want want to drill them.

I also find a hole drilled in the intake on passenger side that appears to be crancase passage. My plan was to plug this as I feel no need to use it unless I use that for the pcv valve and put the stock road draft tube on... Whadda ya think???

Thanks,
Bob
Click to expand...
 
D

don decker

New Member
I am going to run a power brake setup on my 58 BelAir it has a 348 tri power motor and what I would like input on is could I run the Show Cars custom PCV kit and the split the vacuum with a T on my middle Carb and would the Brake booster and PCV work well together by splitting vacuum or is there a better way for me to do it. Please any help would be appreciated. Don
 
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