351C intake gasket problems

[pabear89]

Well I have been collecting parts for my 351Cj motor for some time now.
I got a good deal on the motor and trans as complete and running set.
Block is a D2EA-CA 4bolt main block, I had to change the oil pan so I know that for sure.
It has 4. on the heads but not sure of the date code to tell if they are open or closed chambered.

I have the Edl 351 performer intake that I was going to replace the cast stock manifold with.
And while it was off I was going to check for the head codes for future reference.

So I set out the new intake to match it up with the gasket pan to check for portsize and match bolt pattern.

Darn victor turkeypan gasket won't fit.
If I match the ports and bolt holes on one side,
the otherside is about 1/2 in short of covering the ports.

But the bends on the pan match the bottom of the new intake across the valley area.
Glad I checked before I removed the old one,
any 351C guys have this problem?

What gasket have you used?

thanks PB

 

[D.Hearne]

Sounds like you've got a 2 bbl port, 4 bbl intake. You need the the other one that is a 4 bbl intake for 4 bbl heads.

 

[pabear89]

No it's a 4v intake for 4v heads.
the port size is a perfect match.
The gasket matches the port size and bolt pattern as it is a large hole not the oblong port of a 2v.
but when I lay the gasket on the upsidedown manifold,
the tin gasket edges do not cover what would be the upper edge of the ports correctly or center over the boltholes.

 

[pabear89]

Ok pic's :SNSign:

 

[D.Hearne]

Yea, but laying it on the intake, upside down, as opposed to installing it in the valley, then torquing it into place, is two different things. If it really bothers you, cut the valley portion off and use composite gaskets on the port sides.

 

[pabear89]

With the tin on the manifold there is not going to be that much movement in the tin to give a real good seal.
If i went with composite port seal why bother with the tin at all?

 

[D.Hearne]

It'll help keep hot oil off the belly. Should keep the intake a few degrees cooler. It can't hurt.

 

[351CFastback]

I run mine with a good set of Fel-Pro gaskets and NO belly pan. I also applied a liberal bead of copper permatex where the intake mates with the front and rear of the block. I can see D.Hearne's point about keeping the intake cool(er), but I have not run into any problems. Hope those $0.02 help.

 

[69 Rustang]

That looks wayyyy off though. A few thoughts:
1) there is a definite "front" to the valley pan--should be stamped into it. Make sure front is to the front of the manifold.
2) Are you sure it is ALL 351C 4V stuff? The alternatives are there is 2V stuff or you have 351M stuff in there somewhere.
The tin gasket ports look like 2V to me, but without having it all side by side couldn't say for sure. You said the tin matches the head, but not the intake and the intake is definitely 4V. I used the Felpro valley pan set on mine and it did line up--I did have to do some minor clearancing on the valley pan to finish my port match (Aussie 2V heads, Edlebrock Manifold), but they weren't as far off as what you are seeing.

 

[dodgestang]

Just skip the valley pan. Mr Gasket makes a nice set of intake manifold gaskets. That's what I use

 

[180 Out]

The purpose of the turkey pan is to keep oil off the intake where the heat risers go through. If you're plugging the heat risers on your heads, you have no need for the turkey pan.

(Some say the pan keeps hot oil off the intake, which keeps the intake cool, which increases charge density. I don't know. Oil runs about 250 degrees, doesn't it? So I wonder how much cooler an intake is anyway. Also, there are many engines with lifter valley designs which expose the bottom of the intake to hot oil and it doesn't seem to bother anybody too much.)

If you aren't plugging the heat risers (which imho is a bad idea on a street car, because cold start driveability takes a big hit without them), the reason given for the need to keep the oil off the intake is that it would coke up, and the resulting carbon deposits would flake off and get in your oil. However, that possibility was based on '60's oil. I do not believe that modern oils are going to do this. Synthetics, no way.

So anyway, if you must have a turkey pan, just take soe tin snips and cut off all but the flat part and use Felpro or equivalent paper gaskets on the ports, and silicone on the end rails. Or leave it off altogether.

Just another $.02 from some stranger on the Usenet. Good luck!

 

[shotsy]

I pluged the heat risers too and tossed the turkey pan in the trash and used a set of fel-pro printoseal gaskets and have never had any probs

 

[68RCodeConv]

Ditch the turkey pan. Felpro 1613 intake gaskets and silicone for the end gaskets.

 

[D.Hearne]

The oil coking on the heat riser wasn't a possibility, it was an actuality. Seen lots of em like that. As for drivability problems with it blocked off ? B.S. I block all mine off and there's no difference. And just from seeing what hot exhaust gasses do to aluminum intakes, that do have heat riser passages is the best reason to block em. I've got two FE O.E. aluminum intakes now that have cancer from heat riser exposure. It ain't pretty.

 

[180 Out]

As for drivability problems with it blocked off ? B.S. I block all mine off and there's no difference.

I beg to differ, based on my personal experience with one car. With a '70 351C-2v running an RV-level cam, an Edelbrock dual plane (F-351, iirc), an Edelbrock 600 cfm with electric choke, an MSD full mechanical dizzie and Blaster II coil, and a Crane Hi6R spark amplifier, I had terrible cold start driveability problems with the heat risers blocked. On a cold morning, if I set the choke, cranked the starter, put it in gear, and headed straight for the freeway, no worries. But if I had to make a stop on the way, like to drop off a kid at school, it was a problem. I cranked the choke pulloff full rich and it was no help.

Like I said, one guy, one car. Your mileage may vary.

 

[D.Hearne]

Any engine will have cold start problems (idling) with or without the heat riser blocked. Once the engine warms up it goes away. The heat riser may help it warm up a minute faster, but that's it. You may have needed to idle it up a bit. I ain't seen many cars with carbs that you could crank it up and drive off immediately with a carb when the weather's cold. Even those with a choke. take the time to let it warm and it should have idled after you took off. I completely remove the choke on mine plus block the heat riser,and at best, I have to baby it in the driveway a few minutes to let it warm up to where it'll idle. And that's in 20-30 degree weather.

 

[180 Out]

at best, I have to baby it in the driveway a few minutes to let it warm up to where it'll idle. And that's in 20-30 degree weather.

That's true, a good driveway warmup will crutch cold start problems. But if you live in a neighborhood with 38 x 100 lots and your car has tube headers, eight year old (=blown out) Flow 40's, and no crossover, you're neighbors aren't going to like it at 7:00 in the a.m., or ever.

 

[D.Hearne]

That's true, a good driveway warmup will crutch cold start problems. But if you live in a neighborhood with 38 x 100 lots and your car has tube headers, eight year old (=blown out) Flow 40's, and no crossover, you're neighbors aren't going to like it at 7:00 in the a.m., or ever.

Put quieter mufflers on it Or move. It really ain't good for it to just fire it up and take right off anyway.

 

[pabear89]

Well 69Rustang has a good eye.
I reordered the Felpro gasket set from the local napa where I got the first set from.
When it came in I took the one they sold me back to see if it was the same,
Seems that someone had switched the pan part.
the numbers were correct from the listing but not the parts,
By chance he looked up one for a 400m and had one on the shelf.

After cleaning the dust build up off of it, the metal pan was the same as what I had. At least they exchanged it for me for free.

Now to get to changing it. thanks for the responces. :SNSign:

As for the plugging on the crossover section,
The airgap intake I am running on the 289 does not even have one.
and it will cold start without any problems.
the auto/elec choke works fine and I don't have to have that spacer under the carb anymore to keep the heat down.

PB