Exhaust exhaust manifold leak

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
Hi,
I thought I'd ask the experts in the hopes that someone has tackled this problem in the past.
I've got a 1969 302 with rectangular exhaust ports in the Cobra II. On the fishing road trip I hoped to shake out any issues and I noticed what can only be a leak in one or both of the exhaust headers. They are Blackjack long tubes with round holes at the flange. I was using Mr. Gasket #264G gaskets which were the same as the ones that came with the headers. The bolts are as tight as I can get them with out rounding off the hex. I'm going to buy new Header bolts also.
I'm pretty sure I'm not the only one with a similar set-up.
What gasket did you use?
What brand and type of header bolts did you use?
Thanks.
Enzio
 

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74stang2togo

NERD!
Mod Dude
Mar 7, 2002
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Replace those paper Mr. Gasket gaskets with the aluminum ones. They'll deform to fill the imperfections between the parts.

Locking header bolts also help. Standard header bolts are fine, but you'll want to check them at least every oil change. Locking bolts eliminate that extra maintenance.
 
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2Blue2

I partied with that dude!, um girl, um whatever...
Mar 5, 2019
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Still sporting cast Iron manifolds but have used copper gasket ones in the past on other small blocks with good luck
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
Thank you 74STG. Have you used and of the permatex copper on them? And what brand?
Enzio
 

LILCBRA

10 Year Member
Dec 6, 2005
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I think I'm using the copper gaskets on my engine as well, but I have aluminum heads which all but eliminate any chance of imperfections on the head side. I also used a copper gasket at the collector. I have no problems with exhaust leaks from my set up anymore. The exhaust leak that I thought I had before I pulled my engine a couple years ago was due to not having set screws in the thermacitor holes on the back side of the heads. I must've forgot about them when I first built my engine in the early 2000s. You may not have the same problem, but it wouldn't hurt to check them out to make sure they're plugged or you may end up chasing your tail for a very long time - trust me on this!! lol
 

Olivethefet

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May 17, 2018
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I just had to do this on my Fox, right side only at this point. I have BBK long tubes. I didnt use a metal gasket but I did use a BBK gasket that is made out of HTX-900. I just read about the Permatex copper sealent. When I do the left side I plan on using it.

I couldn't get the header far enough away from the head to clean the surfaces. Ended up having to unbolt the motor mounts and Jack the engine up for clearance. Also had to unhook the collector.

I bought a set of header bolts from ARP. They sell a set with 5/16 heads. Gives you a little more room to work around the headers.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
Hey I think I watched your YouTube today about the permatex copper. Did you think about the thermactor holes? I gotta check that tomorrow. I don't even know where they are.
 

LILCBRA

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This is obviously an aluminum head (which just so happens to be a Trick Flow head and what is on my car :D) , but do you see the larger tapped hole? That is where you'll want to make sure you have a plug of some sort.


tfs-51410004-m58_yj.jpg
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
I bought a set of header bolts from ARP. They sell a set with 5/16 heads. Gives you a little more room to work around the headers.
Do you have the part number for the bolts? I couldn't find them with 5/16 heads. Do they have the lock washers?
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
This is obviously an aluminum head (which just so happens to be a Trick Flow head and what is on my car :D) , but do you see the larger tapped hole? That is where you'll want to make sure you have a plug of some sort.


tfs-51410004-m58_yj.jpg
LILCBRA, I don't see any plugs. I have three bolt holes in the back of each head. The pictures are of the back of the driver side head.
Internet research says the holes are supposed to be 5/8". I'll check tomorrow but I highly doubt these are 5/8". But the research also says that Ford started to use these in 1966. So that makes my 69 right in there. Opinion please?
Thank you,
Enzio
 

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LILCBRA

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You may not see the plugs, they should basically be set screws blocking the holes off. So if there are no set screw plugs in the top holes, you may need them. I'll try to remember to double check the E7 heads on my GT later as the engine is completely stock, but I'm 99.99% sure that the top hole is what needs them. I don't recall the size, but again I have Trick Flows on the engine in my II. 5/8" sounds right for that application anyway. They may not be that size on stock heads though, I'm not sure.
 

Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
thanks.
I'm 99% sure my heads don't have them.
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
Hi, I am waiting for parts (Exhaust Manifold Gaskets) which should arrive with UPS this afternoon. I jacked up the car and disconnected the collectors and took the Rocker Cover off in order to help get the headers on and off. I noticed some gray goop around #7 exhaust valve. Not knowing what this may be I took a picture for you guys. I took the rocker off which looked fine but dry not oil covered like the others. The pushrod was wearing in two spots. I then wiped the crud off the top of the valve spring retainer and noticed that I could move the valve/spring assembly side to side and north south. I measured this also as best as I could. I'm thinking I have a problem but I'm waiting for my favorite experts to chime in. Pics following:
 

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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
me too. It was running good and maybe I avoided a disaster. We'll see what the other guys say.
 

LILCBRA

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Dec 6, 2005
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I checked out my 87 a little while ago. As near as I can tell there is 3 holes like on the Trick Flows that I shared. It's pretty hard to tell with the engine in the car with all of the accessories still mounted though.

As for your valve springs wobbling, do they still have pressure on the valves, or are they a tad loose as well? You should be able to purchase shims to ensure your valves are preloaded as they should be. That's assuming your springs are still in good shape. There are a couple things that could be in play with this. First, I think you said your engine is a 69 302? It's possible that your heads don't have hardened seats which, over time, can affect your spring pressures. Then there's the age and fatigue of the springs. That could be as easy as ordering a new set of valve springs, which may not be a horrible idea if your engine is still running the original springs. Then you could set the spring preload to manufacturer's specifications and be good for many miles.
 
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Enzio

Dang it. I was hoping mine would get 3 more inches
May 14, 2019
193
106
53
63
Minnesota
Thank you for checking. I can see where exhaust is leaking off #8.

I think they are hardened seats.
I also believe they are the original springs.
I have a lot of research to do tomorrow:
1. Is it possible to swap out the springs with the heads on the block?
2. How do you set the spring preload?
3. How do I figure out what springs?
4. Shims?

Thank you for answering.

Enzio
 

LILCBRA

10 Year Member
Dec 6, 2005
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Here are answers to your questions:

1) Yes, it is possible to swap valve springs while the head is still on the engine. You will need adapters to connect compressed air to the spark plug hole of the cylinder you're working on. That allows the valve to stay in place when you remove/replace the spring.

2) Here is a good and fairly brief description concerning setting preload. All preload is is the spring installed height.

3) It is usually called out by the cam manufacturer. Assuming you're still running a stock cam, you should be able to just ask at your local parts store for valve springs for a 1969 Ford 302. If you have an aftermarket cam, you'll need to know the specifics for that cam - I.E. manufacturer, cam model, etc. Then you should be able to locate all of the information you'd need to purchase valve springs - open/closed pressures, installed height, etc.

4) You may need valve spring shims to adjust the installed height of the springs in order to meet manufacturer's specifications. Here is a link for Comp Cams shims, but there are probably as many manufacturers that supply shims as there are cam manufacturers - probably even more than that! Really all you need to search for is "valve spring shims" and a plethora of options come up on Summit's website.

I hope this all answers your questions! :)