Valley Pan

[steve from staten island]

My block was decked, I have no idea how much. The rebuilder used the valley pan with a very small about of sealant. The car idle's bad. Trying to adjust the carb does not help and the same with the timing. The vacuum gage read about 15 on a fresh engine and it fluctuates slightly. The tailpipes are extremely hot. I feel there is a vacuum leak. Im am using a aluminum intake. New Edelbrook carb.
What's the opinions on the paper gasket with the valley pan or just the valley pan
thanks

 

[WileE]

Take the intake off & see if you can visibly see leakage. Did you use sealant on the bolts ?

 

[Xp29h]

Don’t know if this will help you or not, but on my old 383 which I replaced, it had been decked and the heads had some work too all before I got it. After messing around with vacuum leak search and no luck finding it, I tried to replace alum intake with another one and found it didn’t fit, angles were off! I had all the surfaces measured and angles checked and the intake resurfaced to match.. but I had to use the paper gaskets along with the alum valley pan and it sealed right up fine. Oh yes, and some permatex! It was a total pain to figure it all out! Now it sits on an engine stand!

Good luck! Hope it helps a little

 

[493 Mike]

I recently pulled my intake and found the 4 paper gaskets I had installed the last time so I put it back together with the same stuff. It ran fine before. I pulled the intake to blast and reclear after running new fuel lines and replacing float bowl gaskets. Perhaps the fuel leaks will stop now!
Mike

 

[Dajkzo]

I'm known to over do things. There is a 4 gasket set which are .015" thick so they work in conjunction with a standard valley pan. I use hi-tack on the gaskets and a bead of Ultra-black Permatex on the ends of the valley pan.
I don't see an issue with using the Ultra-black with just the valley pan (on all surfaces). The ultra-grey is also a very good product. Make sure your base timing is advanced enough. Most guys like 15-18º at idle and 36 max. If it's retarded the exhaust will be hotter.

 

[moparnation74]

When you say "decked"...How much was it decked?.........Does it appear the intake lays flat against the heads?

Have you inquired with the rebuilder?

 

[steve from staten island]

thanks to all.... Rebuilder did use what looked like liquid Teflon on bolt threads. I did find some oil on the valley pan which tells me there is a leak and it didn't look like it came from the bolts. I put the manifold back on with no pan gasket and it looks like a paper gasket might fit with the valley pan.
The old motor had the same issue a vacuum leak from the intake and I redid it but really laid in the sealant but the leak did stop.....
I have a new pan and getting the gaskets tomorrow.

When you say "decked"...How much was it decked?.........Does it appear the intake lays flat against the heads?

Have you inquired with the rebuilder?

Hello Justin, I was told he had to surface grind the block slightly, I dont know how much but I was told the manifold lined up perfect with the heads.
My feeling is he went a little to light with the sealant and there was hardly anything on the part between the ports.
Im trying to find out id I should try the paper gaskets or not.

 

[moparnation74]

thanks to all.... Rebuilder did use what looked like liquid Teflon on bolt threads. I did find some oil on the valley pan which tells me there is a leak and it didn't look like it came from the bolts. I put the manifold back on with no pan gasket and it looks like a paper gasket might fit with the valley pan.
The old motor had the same issue a vacuum leak from the intake and I redid it but really laid in the sealant but the leak did stop.....
I have a new pan and getting the gaskets tomorrow.

Hello Justin, I was told he had to surface grind the block slightly, I dont know how much but I was told the manifold lined up perfect with the heads.
My feeling is he went a little to light with the sealant and there was hardly anything on the part between the ports.
Im trying to find out id I should try the paper gaskets or not.

If thats the case then your fine with the decking.....I use only the pan with the right sealant...Sounds like your on the right track....

 

[beanhead]

Steve often when these blocks get decked the shop does not account for the front and rear 'china walls' unless being told to mill these by the customer. (Real mopar builders will do it without being told!) Aside from the obvious intake/head surface possibly needing milling to fit, if the only thing done is the actual deck surface, a stock valley pan can be thrown into all kinds of caddywompus...even if the intake bolts down okay. Leaks under the pan, at the bottom edge of the intake ports is common. If you're having issues maybe look at hughes' 2-piece tray. Takes a little more work to install but they've worked good for me in the past.

 

[moparnation74]

My current build the heads and intake were milled more than the norm for the build configuration I wanted....Stock valley pan was used and no leaks....So?

You have to have the "right" builder......

 

[69Bee]

Steve often when these blocks get decked the shop does not account for the front and rear 'china walls' unless being told to mill these by the customer. (Real mopar builders will do it without being told!) Aside from the obvious intake/head surface possibly needing milling to fit, if the only thing done is the actual deck surface, a stock valley pan can be thrown into all kinds of caddywompus...even if the intake bolts down okay. Leaks under the pan, at the bottom edge of the intake ports is common. If you're having issues maybe look at hughes' 2-piece tray. Takes a little more work to install but they've worked good for me in the past.

Being one of those "shops", I need to disagree. I always cut the valley rails, even when the intake doesn't seal to it. Yes, it does make the valley pan seal better, but is not absolutely necessary. I usually am the one telling the customer what needs to be done, why it needs to be done, and how I am going to do it. When the customer understands why something needs to be done, he doesn't feel like he is being taken advantage of. When I "Square" a block, I use a BHJ fixture to ensure the angles are correct. I also align hone the block first so that the main bores are round and straight. Everything has an order, and each step properly sets up for the next one. Also, when you use the BHJ Block True fixture, you know the block height, and can ensure both decks are the same.

 

[beanhead]

View attachment 786261
Being one of those "shops", I need to disagree. I always cut the valley rails, even when the intake doesn't seal to it. Yes, it does make the valley pan seal better, but is not absolutely necessary. I usually am the one telling the customer what needs to be done, why it needs to be done, and how I am going to do it. When the customer understands why something needs to be done, he doesn't feel like he is being taken advantage of. When I "Square" a block, I use a BHJ fixture to ensure the angles are correct. I also align hone the block first so that the main bores are round and straight. Everything has an order, and each step properly sets up for the next one. Also, when you use the BHJ Block True fixture, you know the block height, and can ensure both decks are the same.

I don't really see a disagreement? You are obviously one of the guys that knows the ins & outs of a mopar engine; sadly not all shops do..at least around here. I always appreciate when you and the other pros weigh in..

 

[69Bee]

Hence, no red X... I started out learning out ALL I could learn about Mopar, but being a machine shop, I have to know a lot about a lot of different motors. I like to think I am not like most other shops as I try to go the extra mile for customers. Oh, and do it properly...

 

[bolson6333]

if the exhaust pipes are running real hot timing could be too retarded

 

[khryslerkid]

Once you get everything cleaned up again, set the manifold on without any gaskets and check the fit.

I had a slight leak under the manifold. It was from gas purging in the back carb. I noticed a small stain on the valley pan. I just used one gasket on top of the pan to make up the difference. Good to go.

Btw, I loosened all the bolts, removed the bolts on one side and slid the gasket in. Then replaced the bolts on that side but left them loose, then did the same to the other side. Just a short cut on a newly installed manifold.