Technical Sanderson Headers.....does the "no gasket" seal work

Sanderson advertises that they don't need a gasket, just some sealer. I plan to make my own headers for an engine/car that there are no readily available headers made. Thinking about starting with a thicker flange material and machining it like the Sanderson flanges if its worth the effort.

 

Always has worked for me. I have had 3 sets. Sanderson is the best. Did my BB Buick the same way with stock manifolds. Had them resurfaced.

 

Not sure if this is a wives tale, but I believe none of the stock manifolds had gaskets in the early years…..

 

Did the non gasket thing, following Sanderson's instruction, ended up with a small leak.. Redid the silicone set and had a leak again. Finally went with with soft aluminum crush gaskets no more leaks

 

Don't know what engine you're working with, but the secret is to cut the flanges apart so that each pipe is bolted to it's individual port. That way, differential expansion between the parts ( head, flanges, etc.) doesn't break the seal and cause leaks.

 

Russ Martin, the Buick spe******t says to not use gaskets on the exhaust as they never used them.

 

The only other thing I would do is to lay a straight edge across the exhaust ports to make sure they are flat. I understand back in the day, it worked with no gaskets, but my luck is never that good.

 

Are these Sandersons cast headers or tube headers?

 

I’d guess you would need pristine mating surfaces to run without any gaskets

 

I have a set of Sanderson Zoomies that I run on the track. Being that I switch back and forth from my street headers to zoomies the silicone method is not a option and did not work when I first installed the zoomies- (leaks). I use header gaskets from Speedway that are reusable, and work great, sorry I do not have the part# right now. I was told by the local police not to run the coupe through town with the Zoomies on because apparently, it sets off car alarms going down the road in town.

 

I did the Google thing, seems that Sanderson (on their site) uses a 3/8th flange plate, then has a weld run around the sealing surface, then machined flat across.
Pretty interesting idea. I’m guessing the weld bead is not affected by torque?

 

I have Sandersons on my flathead. I have a leak with the sealer. Maybe I'll go with gaskets on the Sandersons.

 

348 Chevy with Sanderson Lakes pipes. Silicone and no leaks in the 3500 miles I’ve had them.

John

 

Ford Y-blocks didn't use exhaust manifold gaskets.

 

Been doin it for years and never had leaks, even using offshore headers

 

Yes, I think it is worth it. Sanderson uses a 3/8" flange. They even say not to use a gasket as it may distort the flange. I was skeptical about using their silicone method when I bought my first set of Sandersons. I am a firm believer now. No leaks where I had previously fought leaks with several different gaskets. I even use this method on my non-Sanderson headers now.

 

If you do independent flanges, it would be pretty difficult to machine them all after building the header...unless you started with one piece, and cut it after machining. Might want to find the mill you plan to use to do the machining first, and see what will fit in it?

But yeah, a thick, flat surface should not need a gasket (or sealer) to seal exhaust. Several carmakers did it this way with exhaust manifolds for many years, usually on V8 engines.

 

Been thinking about this for a while. Could a machine shop check for level surfaces on both the head s and header flange surface to ensure a perfect seal without a gasket??...........

 

I'm asking about tube headers, but if a cast header/manifold had enough material, I'd think it would help. Its kind of the same idea when someone slips a hose on a tube. If the tube has a bead, it seems to work better than just a straight surface.

 

Yes a machine shop could do it but its pretty simple to check it yourself. You can lay a straight edge on each surface and take a .0015 (thousandth and a half) and see if it slips between the straight edge and the head or manifold. When I say a straight edge, it can be a decent metal yardstick or something, but it can also be a flat surface such as a table top. If you use the table top, you can try shining a light from behind the part and see if any light shows underneath. I wouldn't expect perfection, its the amount of difference that matters.
Another way to check is to put spray on ****m blue on the parts. Then glue some sandpaper to some gl*** or a flat surface..........and rub the surfaces on the sand paper. That will show if you have differences, but won't tell you how much.
You are looking for out of parallel as much as not being flat.

All of that said, simply bolting the heads and exhausts onto a milling machine and a quick skim cut will make everything right if there is enough material. Sometimes headers do not have enough to cut.

Edit add: A good level will work for a straight edge. You don't care about being level, just straight and flat.

 

sometimes it takes a pretty hefty cut to get it flat, too....

 

When I first put the Sanderson block hugger headers on my nailhead, I had an exhaust leak on the left side. I had used the silicone sealer that Sanderson recommends. I had that header on and off multiple times to figure out where the leak was. It leaked with the silicone and it leaked with a set of stock gaskets. After close examination of the header I found that they didn't finish welding the small diamond shaped piece that goes between the 4 pipes inside the header. Broke out my torch and finished the weld; no more leak. I'm currently running gaskets because that was where I was when I discovered the real source of the leak.

 

Yes, trying to machine them all flat and parallel after cutting them into individual flanges would be harder, as I would expect movement after separating them. I have my own milling machine, so that won't be a problem. What I was thinking is cutting the raised bead around each outlet while its all one flange. Then cut part way thru the flange with a thin wheel. Enough to make finishing the cut easier once they are bolted to a head. Then bolt them on the head and torque them down. Once they are immobile, finish cutting thru the flange.
Then take an acetylene torch and heat each tube to relieve any stress trying to move the tubes. So we are pretty much thinking alike on the cutting process.

Or I might just leave it as one flange and do the finish machining after its all welded together. I just kinda like the idea of having a protruding lip concentrating the pressure.

 

Thanks for all the response. I have yet to see a problem a hot rodder couldn 't figure out even if it didn't get fixed .................

 

Correct! BOTH mounting surfaces need to be perfect, though. Buick said to use a graphite/oil slurry. This allowed the manifold to "slide" with expansion.

Ben

 

I've been real impressed with the Remflex gaskets I used recently. Speedway block huggers on a SBC, and a lot of stuff going on in the engine compartment to make gasket replacement a PITA. I wanted to install these once and not have to deal with it again. So far 1000+ miles with no leaks.

 

Got a buddy who has sent his back twice, leaks around ports, then his collector gasket wont stop leaking, 3 different types of collector gaskets and still leaks, but the ports finally are sealed up. He hates his sandersons and wants manifolds I think finally again.

I will say that I am a fan of Percys Dead Soft aluminum gaskets, reusable and no cleaning up each time you put it back together. Best investment I ever made when I was pulling headers frequently.

 

Yes and no, the trick is to let the silicone set up a little while on the header flange before installing them, I could not get my flathead to get a good seal but it did work on a Red Ram hemi. I just used copper gaskets on my flathead which has been fine since.

 

Years ago I built a deuce roadster with a ZZ4 with Aluminum heads and Sanderson cast iron headers. I never could get a good seal and ended up using the aluminum style gaskets.

 

Every set of headers I have used spent some time with Mr File. Until I learned that, They all leaked. Double gasketed, gaskets soaked in water, etc. It didn't matter. A good file makes them all better.