Removal of Intake and Exhaust manifold. Austin Healey BJ7

[BLong63AH]

The first time I have attempted to remove the Intake and/or Exhaust manifold on my BJ7.
The only reason I am trying to remove is I wanted to install my Moss exhaust but the down pipe connection to the exhaust manifold I can’t break free. Tried everything, PB Blaster, Seafoam, 50/50 Acetone and ATF and lastly heat but it was so difficult to get to I decided to try and remove the manifold.
I have freed the nuts on the Intake manifold (read it is better to remove it also) but can’t get the manifold to break loose. Being new to this I am worried I will crack or break something. Any guidance on next steps would be appreciated. I will attach photos of my progress and the exhaust I am trying to break loose from the Exhaust manifold.
Thank you for any help. FYI I am rebuilding carbs and that kind of started the whole mess.
Bryan

 

[red57]

Hi Bryan,
In your first picture look at the front carb area - there is a vertical bolt head just to the rear of the carb mounting flange and just towards the head there are two vertical bolt heads going down thru a bracket (possibly throttle linkage?). Now look at the rear carb area and see the same three corresponding bolts..... These all go down thru the intake manifold into the exhaust manifolds. You will need to remove those six bolts to separate the intake from the exhaust. Then remove the intake first, and then you can free the exhaust. Moss catalogue has a pretty good exploded view showing the bolts.

As to getting them loose, you may need to tap the manifolds with a soft mallet or sometimes drive a screwdriver into the gap where the manifolds meet the head - but be very careful/gentile if a gasket surface is affected.

Good luck.
Dave

 

[BLong63AH]

Dave, Thank you. I was not sure how they were connected. Is it best to go ahead and remove both Intakes and put on a new gasket?
Bryan

 

[red57]

Bryan,
Tough question - you never know what kind of hornets nest you may find when exploring new territory.

If I was going to remove them, I think I would probably separate them. However, the first test I would do is try loosening the 6 bolts - I think they go into tapped holes in the exhaust manifold but

may go thru and have nuts on the bottom. ​

Either way they may be rusted too so they might be difficult too. I've got headers and it's been awhile since I've had the stock ones apart.

There can also be areal argument for doing all the exhaust system at once and be done with it. It should be maintenance free for a long time and

you know the condition of all of it.​

What ever you end up doing, do yourself or some future owner a real favor and generously apply anti-seize when you put things back together, someone will surely thank you .

Dave

 

[aero3113]

An impact gun and socket will probably help get the bolts out.

 

[BLong63AH]

Thank you both. I was able to remove the nuts from the studs so hopefully no issues with the bolts through the Intake into the Exhaust manifold. I will be generous with the anti-sieze for sure. I actually found one stud with no nut or washer at the bottom of the intake. So might be a good idea to take both off and evaluate.
Bryan

 

[BJ8Healeys]

Thank you both. I was able to remove the nuts from the studs so hopefully no issues with the bolts through the Intake into the Exhaust manifold. I will be generous with the anti-sieze for sure. I actually found one stud with no nut or washer at the bottom of the intake. So might be a good idea to take both off and evaluate.
Bryan

Be careful removing the vertical bolts that connect the intake and exhaust manifolds. It's possible to break them off in the blind hole. Go slow, use a lot of penetrant, and when they move turn them out a bit, then turn them back. Work them out gradually until they turn freely. Use anti-seize when reinstalling them.

 

[BLong63AH]

will do.Thank you Steve

 

[BLong63AH]

Thank you to everyone for their advice. I was able to remove both Intake and exhaust manifolds. Does anyone know the original color of the exhaust manifold. I would like to go ahead and paint if necessary while I have everything off.
Thank you again,
Bryan

 

[BJ8Healeys]

Thank you to everyone for their advice. I was able to remove both Intake and exhaust manifolds. Does anyone know the original color of the exhaust manifold. I would like to go ahead and paint if necessary while I have everything off.
Thank you again,
Bryan

Bryan, whatever you use to paint the exhaust manifolds is not going to last very long anyway due to the high heat. Some people have used barbecue grill paint. For long-term durability, I have found the Jet-Hot coating to be the thing to use. Twenty-one years and 90,500 miles after having my exhaust manifolds Jet Hot coated (aluminum color), they are pretty much unchanged except for some minor traces of rusting on the sharp corners. The cost in 1998 was $185.
www.jet-hot.com

 

[BLong63AH]

Steve,
Thank you. I have been looking into Jet-Hot and I believe there is a location in Oklahoma City (about an hour and a half) that does it. I will check with them on cost.
Have a great weekend!
Bryan

 

[Bob_Spidell]

I had my BJ8's exhaust manifold Jet-Hot coated three years ago; the cost was around $400 (I got mine in a dark grey). I believe the company went through bankruptcy a few years ago and may be under new ownership. Service was acceptable. I had hoped the coating would eliminate the warm-start problem caused by fuel vaporization, but the improvement was negligible if at all (but I didn't get 'before and after' temperature readings with an IR sensor).

There are other coatings providers; I can't vouch for them but suspect the result is similar to Jet-Hot (it ain't rocket science, and I think the process is similar to powder coating). There was one in southern California that, IIRC, was featured on 'Wheeler Dealers,' and you might be able to save some money if you shop around. I used high-temp paint on my BN2's manifold, and it has held up for the few hundred miles I've put on it.

Edit: A quick google search produced at least one alternative (Jet-Hot came out on top of the search, so they're internet marketing-savvy; some of your cost probably goes to that):

https://boneheadperformance.com/high-performance-coatings/

 

[steveg]

Specialized Coatings in Huntington Beach, CA did my Kirk Headers in matte black ceramic (same as JetHot) in 2007 - they still look like new.
A friend had his cast manifolds coated in a "cast iron grey" a couple of years ago and they look like new.

Prices & turnaround are reasonable.

 

[BLong63AH]

THank you Bob and Steve. I will look and shop around. Just broke a stud off trying to get off the old exhaust pipe. Next to last one. Well another thing to figure out. Probably find a machine shop on this one. Spent two hours with heat & ice water, then candle wax to no avail.
Thank you everyone again,
Bryan

 

[Bob_Spidell]

I broke a downpipe stud with the manifold in the car. Was able to MIG weld a nut on the remnants of the stud and extract it.

 

[BLong63AH]

Bob,
Wish I could weld and I would give that a shot. I might try going by a shop and see if they could do that.
THanks,
Bryan

 

[90DegreesSouth]

Hey Steve G,
I'm curious about a few things with respect to your Kirk headers:\
1. What kind of performance improvement did you experience by using Kirk headers over standard equipment?
2. What do you use to connect them to the muffler/tailpipe?
3. What did they cost
Thanks for your insights,
Mark

 

[steveg]

Hey Steve G,
I'm curious about a few things with respect to your Kirk headers:\
1. What kind of performance improvement did you experience by using Kirk headers over standard equipment?
2. What do you use to connect them to the muffler/tailpipe?
3. What did they cost
Thanks for your insights,
Mark

Mark,
At the time, 2007 ish, Kirk told me they were no longer making the Healey headers. The ones i bought were returns from a customer who said they couldn't install them. Cost was around $170 but they were used. Probably around the same price for ceramic coating inside and out. I had no trouble installing them - a bit of a fiddle but doable. Info on my gallery.

Maybe they either make them again or maybe you can special-order them.

I installed my DMD manifold at the same time as the headers and the combination provided a noticeable seat-of-the-pants increase in acceleration.

I used stainless flex pipe (from JC Whitney) to make connectors between the header collectors and clamp connectors to the front stubs of the muffler. These are in-place mockups before welding.

Later I added bungs for O2 sensors on the downstream side of each collector flange. They're at the 4-o'clock position but it hasn't mattered as I live in a dry climate.



See my gallery:
https://pbase.com/stevegerow/kirk_headers

 

[red57]

Mark,

A follow up to Steve's post. Kirk does still make them. I just bought a set and paid $295 plus S&H so my total was $382. I don't think they get many requests anymore 'cause it took about 2 months to get them. They are the only ones I know of using 1 1/2" primaries which are better for low & midrange scavenging - DW and others are bigger bore primaries and better if you are spending a lot of time at 6000rpm. I have quit racing and am building a strong street motor now, so I think these will be better.
http://www.kirkracing.com/

Dave

 

[Patrick67BJ8]

Mark,

A follow up to Steve's post. Kirk does still make them. I just bought a set and paid $295 plus S&H so my total was $382. I don't think they get many requests anymore 'cause it took about 2 months to get them. They are the only ones I know of using 1 1/2" primaries which are better for low & midrange scavenging - DW and others are bigger bore primaries and better if you are spending a lot of time at 6000rpm. I have quit racing and am building a strong street motor now, so I think these will be better.
http://www.kirkracing.com/

Dave

Several years ago I purchased Headers that were made by Paeco. I think I bought them through Sports & Classics at the time.