292 vacuum leak

LD-Ordie

Member
So after 6000 miles or so on a new complete rebuild, I noticed something change with the low idle. It's a mild built 292 with a Edelbrock tri-power & Holley 94's. All fresh. Anytime I have any kind of carb issue, I remove the secondaries, block everything off and focus on the center carb. After verifying the carbs or good, i hooked up a smoke machine and found the far left port leaking, but also a fair amount coming from the front area of the lifter valley pan. So, it seems odd to have a gasket fail like this on the intake when all is tight, but the smoke coming from the lifter valley has me confused. could I be having a major issue here? Any advice will be appreciated!!
55%20Ford%20vacuum%20leak-640.mp4
 
... i hooked up a smoke machine and found the far left port leaking, but also a fair amount coming from the front area of the lifter valley pan


Are you describing an intake runner port or carb port?

From the lifter valley itself or just the general area?
 
Are you describing an intake runner port or carb port?

From the lifter valley itself or just the general area?

It appeared to me that it is coming from around the far left port against the head and from the gasket area of the front of the lifter valley pan. But this area never leaked any oil before, so it could be deceiving. My smoke machine has 2 pump settings, this is on low, when it is on the normal settings, it will put out so much smoke from the whole intake area, that it will fill the engine compartment. Is there some sort of way a vacuum leak could be in the lifter valley area? Engine ran fine say above 1500 RPM. Only at an idle I noticed something off
 
Is there some sort of way a vacuum leak could be in the lifter valley area? Engine ran fine say above 1500 RPM. Only at an idle I noticed something off


If the valley pan gasket is leaking or warped whereas it won't seal, it will cause a vacuum leak with an operational PCV System (causing a lean condition), road draft to a lessor degree. If the seal is bad, the smoke machine will show it.

As for the intake runner(s) leak, what does a vacuum gauge show while idling?

How are you introducing the smoke into the engine?

Interesting.
 
So no PCV system, only the road draft. Have not installed a vacuum gauge yet. Definitely running lean by pulling all the plugs. They do seem equally the same white. Getting back on it today. Does anyone make a better lifter pan? Thanks for the input!!
 
OK, found the cast aluminum valley pan from John Mummert. Is his stuff worth while? Any opinions on buying the one with a rear breather or not?
 
So no PCV system, only the road draft. Have not installed a vacuum gauge yet. Definitely running lean by pulling all the plugs. They do seem equally the same white. Getting back on it today. Does anyone make a better lifter pan?

Thanks for the input!!

If you are introducing the smoke via the intake manifold and see leakage at the 5/6 runner(s), your main problem is there. Once you have established with a vacuum gauge a vacuum leak, concentrate on those runners. OEM intake?

OK, found the cast aluminum valley pan from John Mummert. Is his stuff worth while? Any opinions on buying the one with a rear breather or not?

MUMMERTS pieces are first class (IMO). You need a rear breather option if you are planning PCV. If you decide to retain the road draft, it is not needed.
 
Thank you much Kultulz! I'm fine with the old road draft, so will order a pan this morning. I guess no real need to continue with trouble shooting with a vacuum gauge, intake is definitely leaking, so it's coming off and will go back together when the new pan gets in. So I'm spoiled with working on early small block chevy's, I'm not seeing a lot of options with gaskets. Any preferred brands out there? Thanks again!
 
Y block gaskets for the intake can be put on wrong. At first they look the same. Lay each one on the head to make sure they are on the correct side before the intake goes on. I like to use the studs to hold them. Make sure everything is very clean, and tighten the intake evenly. Be sure the bolts are not too long and bottoming.
 
Y block gaskets for the intake can be put on wrong. At first they look the same. Lay each one on the head to make sure they are on the correct side before the intake goes on. I like to use the studs to hold them. Make sure everything is very clean, and tighten the intake evenly. Be sure the bolts are not too long and bottoming.

Will do, thank you much!!
 
the engine was built by Tim the Y-Block guy. Here is the link to the You Tube page showing the run-in and engine details. All from the previous owner. He's supposed to have a very good reputation. The main thing I changed was turning the secondary carbs to sealed dumpers using the kit from Charley Price. I really think it's a better way to go. I will be double checking the intake while it's off!!

https://www.youtube.com/watch?v=IsdF7vi6Jng

Engine details from his page

292 Y-Block Ford V8 +.040 270* cam with ported C1TE heads with 1.85" intake valves. Factory re-finished 573 Edelbrock intake with three "New" Edelbrock/Holley 94 carbs. Will be installed into a 1955 "Courier" sedan delivery.
 
He's supposed to have a very good reputation

It doesn't get much better than that.

You will need the 57/ Intake Set. I agree on the end dumpers.

What made you to decide to go thru a SBC Exorcism?

voodoo-smiley-emoticon.gif
 
You will need the 57/ Intake Set. I agree on the end dumpers.

What made you to decide to go thru a SBC Exorcism?

What do you mean by the 57/ intake set? As in gaskets?

So I also like old chevy's I own a 55 3100 big window with a 327, 5spd Tremec with 3 2G carbs. Wife drives a 52 Style line deluxe with the original 235 3 on the tree. They are all fun!!
 
What do you mean by the 57/ intake set? As in gaskets?
Yes. There are basically three different size intake ports over the years so you need to know how they progressed in size to select the correct intake set.

I do appreciate all car makes and the SBC was the most competitive on the street. Besides, some of my best friends drive a STOVEBOLT ... :D

Just kidding ...


OH! Charlie is correct on L and R so be careful.
 

Attachments

  • Gasket Selection - FYB BEST GASKET.JPG
    Gasket Selection - FYB BEST GASKET.JPG
    27.5 KB · Views: 7
  • Gasket Overhaul Set- 55-56 312 - BEST RS572G-2.jpg
    Gasket Overhaul Set- 55-56 312 - BEST RS572G-2.jpg
    332.6 KB · Views: 8
I have Mummerts valley pan on two engine and haven't had any problems. I did find that I had to groove the front where the thermostat housing is on both. A friend had the same problem. Check this area when installing the intake.
 
Y block gaskets for the intake can be put on wrong. At first they look the same. Lay each one on the head to make sure they are on the correct side before the intake goes on. ...

I have Mummerts valley pan on two engine and haven't had any problems. I did find that I had to groove the front where the thermostat housing is on both. A friend had the same problem. Check this area when installing the intake.
photo 1. intake gasket on the wrong side
photo 2. different size openings in the intake gaskets
photo 3. valley pan bolt under the thermostat was preventing the intake manif from sitting all the way down onto the heads. Had to shave 1/8 inch off of the rubber grommet. Also notice the groove under the thermostat housing in this oem valley pan that paul2748 had to add to his aftermarket version.
 

Attachments

  • intake, driver side head.jpg
    intake, driver side head.jpg
    47 KB · Views: 25
  • 54 vs 55+ intake gasket size c.jpg
    54 vs 55+ intake gasket size c.jpg
    27.7 KB · Views: 24
  • valley pan bolt.jpg
    valley pan bolt.jpg
    64.9 KB · Views: 27
Last edited:
This is all great info!!! I sure appreciate the assist!! Parts were ordered thru Mummerts machining, should see them early next week, I'll be paying close attention to the details and will share end results
 
Back
Top