Solving the inline six siamese port dilemma

[indyman13]

OK, take a look at this and tell me why it would or would not work to solve splitting the 3&4 exhaust ports. This would solve the cast iron welding dilemma up inside the head.

The steel tab would be welded to the steel header flange, shaped and filed to fit as closely as possible inside the exhaust port. Maybe even leaving 1/16" to 3/32" clearance all the way around to allow for expansion?

http://s614.photobucket.com/albums/tt22 ... flange.jpg

Sorry about the technical glitch with the photo----------direct to photobucket now.

 

[fmartin_gila]

Make it so we could look at it without registering on another forum. But now that it is mentioned, we used to install a divider in the center exhaust port of the Flathead V8. Might do some searching on that subject to come up with info.

Fred

 

[rbohm]

8) while your idea has merit, in so far as installing a port divider, unless you are going racing you are not going to gain enough to make the effort worthwhile.

 

[Vin Man]

If you are adding headers, why not take advantage of this design as well? I like the idea :idea: and certainly think it is worthwhile.

My concern would be in fabrication. When you weld the tab onto the header flange, would the heat bend the flange and impact the seal against the block?

Good idea :!:

 

[indyman13]

Increasing the heat on the flange for the weld could certainly warp the flange. I'm also thinking about making it a "T" design similar to the aftermarket port dividers already out there like below. I would probably clamp the flange into a jig to ensure straightness.

While I accept the improvement in performance is going to be marginal as referred to by a previous response, the 3 and 3 sound is what I'm after.

http://i614.photobucket.com/albums/tt22 ... langeb.jpg

 

[Gene Fiore]

I installed my port divider into the head using a high temp epoxy from Cotronics and have had no issues with it coming loose.

 

[datac]

Given the odd shape of the top heat sink at the top of the port, you'd have a tough time getting that design to fit tight enough to do any good and still be able to get the headers on and off. Besides, a good port divider should not only split the ports but make them equal in size to the remaining four.

Honestly, it's not that tough to install the standard Clifford divider. I did have an epoxied divider break loose once, so before I reepoxied it I drilled and tapped the underside of the heatsink and bolted it in with a pair of grade 8 bolts, countersunk well out of the exhaust flow. That should hold .

 

[indyman13]

All the pointers y'all have posted have been good. I'm trying to discover a simple and effective way to divide the port with the head still on the engine. Epoxy falls into that category but there's the chance of course it will break loose. I like the idea of bolting it in but it doesn't appear I'll be able to access the area I need to with the head attached. And sure, tack welding could be accomplished with a stubby little piece of rod. Since performance gain is probably marginal and I'm looking to mainly separate the sound I was thinking any "blow by" around a tab that has no more than 3/32" space between the tab edge and interior manifold wall fitted to the header (to make it easy for on and off) would be minimal--probably easily less than 3/4 of a square inch total all the way around. Problem of course with welding the tab onto the header flange is warping that in the process. Whatever happens, I'll make sure and re-post results so we'll have another example of what to do (or not to do).

 

[Gene Fiore]

In the event you decide to go the epoxy route, here is a link of where I bought my epoxy. This stuff is good to 2300 degrees.

http://www.cotronics.com/vo/cotr/rm_adhesive.htm

 

[datac]

Pulling the head's not a big deal- you'd have the job complete and back on the road in an afternoon. I've spent nearly as much time installing a set of headers. Take the time and do it right.

 

[Gene Fiore]

Shoot if we all could just plop on the aluminum head we wouldn't be having this discussion...LOL...but that's a whole other topic! But datacx is right, the hardest part of pulling the head is disconnecting the exhaust. The rest is easy.

 

[indyman13]

Sounds like I'm being steered toward removing the head......I'm not afraid to dig in there that far as long as nothing falls out when I remove it! Will it be easier to install the headers on the head and put back together from the top or should the head be reinstalled and the headers come up from the bottom?

 

[Gene Fiore]

Head installed first, then headers from the bottom.

 

[early ford fan]

maybe cut the head for more compression while its off.or modify it for a two barrel....

 

[powerband]

OK, take a look at this and tell me why it would or would not work to solve splitting the 3&4 exhaust ports. This would solve the cast iron welding dilemma up inside the head.

The steel tab would be welded to the steel header flange, shaped and filed to fit as closely as possible inside the exhaust port. Maybe even leaving 1/16" to 3/32" clearance all the way around to allow for expansion?

http://s614.photobucket.com/albums/tt22 ... flange.jpg

Sorry about the technical glitch with the photo----------direct to photobucket now.

'Picked up a set of headers on CL for $75. Interesting addition/mod on the siamese port :

(thumbs)






Hooker literature reccomends an "interference" fit, grind diverter pig until a few thousandths protrude from head, and let header keep the divider in place. Works for me.














hAVE fUN

 

[indyman13]

Thanks powerband for the nice photos of the modification. That's exactly what I'm thinking about.

 

[CNC-Dude]

I don't think epoxy is going to be a viable choice unless the head is removed from the engine, and the ports have been cleaned and sand blasted. Because, on the engine in the car, you will have carbon and junk coating the exhaust ports that will limit the epoxies ability to bond to the cast iron securely. There have been several products in the past very similar to your idea of tacking a divider to the header flange, and have even made claims of 15-20 HP gains from doing it. As for an easy, simple way to divide the port with the engine in the car, it doesn't get any easier than this.