FJ40 Mark/Downey Header

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Butchk said:
I’ve never been able to seal off my Manafre headers ball and socket. The suck air. I can’t tune my EFI Sniper because of that. I have had individuals muffler shops and myself. And suggestions?
Click to expand...
Hi @Butchk,
Unfortunately, I don't know a lot about those Man-a-Fre ball and socket joints. They look kinda like the old "Buick ball" which can go out of round and then don't seal perfectly. Some people find that adding a sealing "donut" between the ball and socket works, but those ball joints aren't designed to require a gasket or donut. Perhaps you could try a fibrous exhaust cement like this: Flo-Ex – Taber's - https://tabersproducts.com/product/flo-ex/ or the Walker brand muffler cement Amazon product ASIN B000CQHVLI You'll have to check to make sure those are o2 sensor safe of course. Hope that helps!

I can say that for certain that the junction that we're using on our header doesn't work like that. Our header outlet uses a CNC machined stainless steel "mandrel" that fits inside of the the pipe flares on the header and exhaust. A cast 316 stainless clamp goes around the entire assembly and applies even pressure to the joint. The inward pressure compresses the flared pipes against the spherical mandrel for an air tight fit. This design has been proven to work and has been installed on tens of thousands of high performance exhaust systems. This design also provides up to 13 degrees of articulation at the joint for easier installation and fabrication of a custom exhaust.

Good luck!
 
One of the many adjustments we are making is to the header flange.

We had to grind a small amount of material off of @bottombracket’s “Barney”!intake manifold for the lower inner mounting ears to fit the v1 header flange.

Downey's original installation notes state that some customers should expect to grind material off the flange or the manifold ears to make it fit.

We made minor clearance adjustments to the flange so grinding wasn't necessary. Then on @Dianna’s truck, we found the intake manifold didn't fit the original flange or the v1/2 modifications ether but Dianna's was far worse than Galen’s “Barney”.

Ultimate took a die grinder to the lower inner "holes" on the V2/V3 prototype. This rounded off the holes a bunch and we lost so much material on the inside that the standard washers had only a small amount of "grip" or overlap on the exhaust flange. We didn't like the looks of that.

So @S14B23Racer took the CAD (DXF) cut lines for all the versions of head flange that we've gone through and laid them over the top of one another starting with the original Downey/Mark's flange.

He then photographed and measured the gaps and compared how the holes and bolts and washers lined up with the intake and header flanges and laid out a new cut line for the header flange.

Instead of a large radiused "hole" cut, he notched the bottom of the lower bolt holes so the aluminum intake ears will sit into the notch.

He then cut a few prototypes out of acrylic on the laser and I think it works very well.

If it checks out on Dianna's truck, we’ll use it instead of the previous Downey/Mark's pattern.

We’re getting very close to being able to take actual orders.

IMG_7325.jpeg


IMG_7326.jpeg
 
S14B23Racer said:
Hi @Butchk,
Unfortunately, I don't know a lot about those Man-a-Fre ball and socket joints. They look kinda like the old "Buick ball" which can go out of round and then don't seal perfectly. Some people find that adding a sealing "donut" between the ball and socket works, but those ball joints aren't designed to require a gasket or donut. Perhaps you could try a fibrous exhaust cement like this: Flo-Ex – Taber's - https://tabersproducts.com/product/flo-ex/ or the Walker brand muffler cement Amazon product ASIN B000CQHVLI You'll have to check to make sure those are o2 sensor safe of course. Hope that helps!

I can say that for certain that the junction that we're using on our header doesn't work like that. Our header outlet uses a CNC machined stainless steel "mandrel" that fits inside of the the pipe flares on the header and exhaust. A cast 316 stainless clamp goes around the entire assembly and applies even pressure to the joint. The inward pressure compresses the flared pipes against the spherical mandrel for an air tight fit. This design has been proven to work and has been installed on tens of thousands of high performance exhaust systems. This design also provides up to 13 degrees of articulation at the joint for easier installation and fabrication of a custom exhaust.

Good luck!
Click to expand...
I’m planning the update my header when your R&D is completed and ready for orders. I’m looking forward too the finished product.
Thanks,
 
gonzopancho said:
One of the many adjustments we are making is to the header flange.

We had to grind a small amount of material off of @bottombracket’s “Barney”!intake manifold for the lower inner mounting ears to fit the v1 header flange.

Downey's original installation notes state that some customers should expect to grind material off the flange or the manifold ears to make it fit.

We made minor clearance adjustments to the flange so grinding wasn't necessary. Then on @Dianna’s truck, we found the intake manifold didn't fit the original flange or the v1/2 modifications ether but Dianna's was far worse than Galen’s “Barney”.

Ultimate took a die grinder to the lower inner "holes" on the V2/V3 prototype. This rounded off the holes a bunch and we lost so much material on the inside that the standard washers had only a small amount of "grip" or overlap on the exhaust flange. We didn't like the looks of that.

So @S14B23Racer took the CAD (DXF) cut lines for all the versions of head flange that we've gone through and laid them over the top of one another starting with the original Downey/Mark's flange.

He then photographed and measured the gaps and compared how the holes and bolts and washers lined up with the intake and header flanges and laid out a new cut line for the header flange.

Instead of a large radiused "hole" cut, he notched the bottom of the lower bolt holes so the aluminum intake ears will sit into the notch.

He then cut a few prototypes out of acrylic on the laser and I think it works very well.

If it checks out on Dianna's truck, we’ll use it instead of the previous Downey/Mark's pattern.

We’re getting very close to being able to take actual orders.

View attachment 3369688

View attachment 3369696
Click to expand...


Sweet maybe in time for winter project, can’t wait! Hopefully this will cure my last two minor issues with the sniper.
 
A quick update tonight, I can follow with more detail, but we sent a prototype off to a well respected member of the Cruiser community so they could check the fit on a 60.

Initial feedback was very positive!
 
cstav86 said:
@PabloCruise was the fit good enough to move the project to the final phase?
Click to expand...

The fit was pretty good!
We had a few changes which I believe are now locked in.
Flanges (laser-cut flanges) should be arriving this week.
We are getting close!!!
 
Hi,
Can we be put on the list for our 1977 FJ40?
Thanx,
Adrian
 
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