393 STROKER SET UP

[1969_Mach1 333]

Sounds like your combination is pretty nice.  I ended up using Chevelle style tips.  They fit 2.5" tubing and had large rectangular-oval shaped openings.  They look good in the rear valance with the rectangular cut outs.  All of the OEM Ford styles for 69 and 70 Mach 1's are too petite.

[cwodjoyce 13]

yes that is the problem with mine, the Monza style tips.

[Max Power 74]

Sounds like your combination is pretty nice.  I ended up using Chevelle style tips.  They fit 2.5" tubing and had large rectangular-oval shaped openings.  They look good in the rear valance with the rectangular cut outs.  All of the OEM Ford styles for 69 and 70 Mach 1's are too petite.

There is a guy in Michigan that makes 2.5 versions of the factory style dual tips. Can't remember his name or where to find it, but I can dig through receipts if people need the info. He was a small shop, a forum guy.

[cwodjoyce 13]

Max Power if you would that would be sweet! I should be breathing now....

[barnett468 418]

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yes, the air cleaner will no longer be a restriction.

[barnett468 418]

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heres 2 1/2 but they are 5 1/4" wide

 

http://www.andysautosport.com/products/pypes__EVT19.html

 

 

......

[cwodjoyce 13]

When I put my intake on, if I need to get more clearance, I can get a drop down base. I had thought about modifying the tips I have. They could be cut down to the y and a 2.5 welded on to the wide part of the y.

[barnett468 418]

When I put my intake on, if I need to get more clearance, I can get a drop down base. I had thought about modifying the tips I have. They could be cut down to the y and a 2.5 welded on to the wide part of the y.

 

tell us exactly how wide the opening in the end of one of the twin tubes is.

[1969_Mach1 333]

When I put my intake on, if I need to get more clearance, I can get a drop down base. I had thought about modifying the tips I have. They could be cut down to the y and a 2.5 welded on to the wide part of the y.

 

That will definitely flow enough air.  K&N offers a 7/8" drop base and a 1-1/4" drop base.  One of those should work.  You can buy them individually from Summit.  If you're like me you'll end up with different air cleaner parts to get a good fit.  That looks like a 3" tall filter element?  A 3" tall filter element is about the shortest that will work with a filter lid and a 1-1/4" drop base.  What starts to happen with shorter filters combined with a 1-1/4" drop base is the bottom side of filter lid hits the choke plate and bowl vent tubes.  It's a bit of a balancing act to get sufficient clearance below the hood and still up high enough to have good clearance above the choke.

[1969_Mach1 333]

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heres 2 1/2 but they are 5 1/4" wide

 

http://www.andysautosport.com/products/pypes__EVT19.html

 

 

......

I like those.  I don't think they will fit in the valance opening without modifying it.

[cwodjoyce 13]

He actually had to neck down twice. The opening is about 2 inches, but the base of the y is much larger. I think it would work pretty well with out any restriction.

[Max Power 74]

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heres 2 1/2 but they are 5 1/4" wide

 

http://www.andysautosport.com/products/pypes__EVT19.html

 

 

......

Those are for GTOs, are made by Pypes, do not have the rolled tips and are too wide for Mustang valences. That's not what I bought.

 

I will try and remember to dig through my receipts tonight.

[cwodjoyce 13]

http://www.ebay.com/itm/Mustang-428CJ-390GT-GT-dual-exhaust-tips-2-1-2-CJ-Cobra-Jet-Cobrajet-67-68-69-/151502327109?hash=item23463e0d45&vxp=mtr

This is what I was thinking about having done.

[RPM 1,190]

http://www.ebay.com/itm/Mustang-428CJ-390GT-GT-dual-exhaust-tips-2-1-2-CJ-Cobra-Jet-Cobrajet-67-68-69-/151502327109?hash=item23463e0d45&vxp=mtr

This is what I was thinking about having done.

That is the easy and smart way. Just slip your 2-1/2" tube to the location on the tip where the exhaust tube meets. Mark and trim the tip of the excess smaller material and weld up your original tip. You'll need to bend the exhaust tube to conform to the tip shape, then weld away.

[Max Power 74]

http://www.ebay.com/itm/Mustang-428CJ-390GT-GT-dual-exhaust-tips-2-1-2-CJ-Cobra-Jet-Cobrajet-67-68-69-/151502327109?hash=item23463e0d45&vxp=mtr

This is what I was thinking about having done.

Those are the ones I am talking about.

[barnett468 418]

Those are for GTOs, are made by Pypes, do not have the rolled tips and are too wide for Mustang valences. That's not what I bought.

 

I will try and remember to dig through my receipts tonight.

 

i know it says gto, but since they are straight tubes, they will fit the same as any car that has straight tube tips . . the tips dont know what car they are going on.

 

yes, the fact it does not have rolled tips is a good thing because the roll reduces the area by around 20% which means a smaller tube can be used if the tips arent rolled which increases the possibility of finding some that will fit the cut out in the valance . . the smaller the tubes. the narrower the can be made.

 

i posted them because i done remember how wide the valance cut out is and my cars are in a warehouse so i cant measure them.

 

i asked what size the id is of a tube on the original tips but no one has mentioned it or measured the width and height of the valance so all i can do is guess at what tips might fit and let the op go out and measure his own valance if he wants to.

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[RPM 1,190]

The outside diameter of the exhaust tube is 2". However both of mine pinch down to about .190" on the end, or beginning.

 

The cutout on the valance is about 3-1/2" at the top and about 6" at the bottom. My valance is from NPD.

[barnett468 418]

http://www.ebay.com/itm/Mustang-428CJ-390GT-GT-dual-exhaust-tips-2-1-2-CJ-Cobra-Jet-Cobrajet-67-68-69-/151502327109?hash=item23463e0d45&vxp=mtr

This is what I was thinking about having done.

 

it wont be nearly enough.

 

The id of those twin tubes is not more than 1 1/2â€, therefore, at the most you only gain .40†in area or 12.7% by running a 2 1/2†tube to them instead of a 2†tube if the twin tubes are 1 1/2 id.

 

the area of two 1 1/4†tubes is 2.46 square inches.

 

the area of two 1 1/2†tubes is 3.54 square inches.

 

the area of 2 1/2†pipe is 4.91 square inches

 

the increase from 3.54" and 4.91" is 1.37" or 38.7% which means that the twin tubes combined will flow 27.9% less air than the 2 1/2" tube.

 

the area of two 1 3/4" tubes is 4.8 . . this means that when adding everything together, the approximate width of a pair of 1 3/4" id tubes will be 4" - 4 1/8" at least . . this is allowing for 1/4" - 3/8" space between the tubes.

 

based on the dimensions given, if the cut out is 2 1/2†high, then it is around 4 3/4†wide around 1 1/4†from the top edge . . since the top of the pipes are mounted at least 1/4†from the top edge of the cut out and the widest part of a 1 1/2†id pipe is at around 3/4â€, this puts the widest point of the pipe will be around 1 3/4†from the top edge of the valance. The width of the valance at this location should then be around 5 1/4â€.

 

If this is the case, then a properly made set of twin 1 1/2†id tubes, will fit the cut out and will have around 5/8†of clearance on each side of the valance.

 

 

 

 

 

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[RPM 1,190]

The dual tips are also each 2" od tube with a .015 rolled inner edge.

[barnett468 418]

The dual tips are also each 2" od tube with a .015 rolled inner edge.

 

you measured one of the twin tips on an orig factory tip where the exhaust exits and they are 2" od?

 

if they are, then the mod in the ebay photo will work.

[RPM 1,190]

i dont think original tips are quite 2" id, but if they are, then the mod in the ebay photo will work.

Well, if the od is 2", I would agree that the id is not quite 2".

 

 

 

And I disagree with your claim that original tips are not 2".

 

 

With our stroked Winsor cars that are street driven with an occasional track visit, I believe traction will be our issue, not that we got those extra HP so we now have over 500hp. I think the rolled edge of the exhaust tips are one of the cool identifying features of the 69. But what do I know, I'm just an old city boy.

[barnett468 418]

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my post does not say they are less than 2" . . i edited it to what you currently see 20 minutes before you posted your post . . also, i prefer rolled tips as well.

 

because of turbulence created by the roll in the tip, the roll on the tip will reduce flow more than a tip that had the same id of the rolled section of the tip but had no roll to it.

 

in other words, more flow will occur in a pipe that is unobstructed.

 

the area of a 2 5/8†pipe is 5.94 square inches, therefore, the largest pipe that can be used on the factory trips before the tips begin to restrict the air flow is 2 5/8â€.

[Max Power 74]

Jesus H.

 

That's all I have to say.

[1969_Mach1 333]

Yeah, the rolled tips are original and the way to go if an original appearance is desired.  But if exhaust flow is a concern and your taking time and expense to build a mandrel bent exhaust system, don't finish it off with the worse possible type of restriction in a flow path, a sharp edge.  The argument can be made the rolled edge is negligible, and it may very well be.  But it goes against the goal.

[cwodjoyce 13]

I already ordered a piece of 2.5 pipe for each side. I am going to cut off my tips and get them welded.  I have built my car to drive and enjoy. I am not planning to race although I will take it to the strip and do a run now and then after I get it finished. I am going to wait till I get the 1.7 rockers and do the manifold and rockers, next month hopefully.