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Exhaust Manifolds by str8maxn
Started on: 01-26-2021 04:23 PM
Replies: 24 (430 views)
Last post by: str8maxn on 02-21-2021 04:41 PM
str8maxn
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Report this Post01-26-2021 04:23 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
Hello all,

I purchased a set stock exhaust manifolds , I am in the process of porting.

I have a question; Do all three ports lay flat and level across all three ports?

I currently have a gap between ports.




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Report this Post01-26-2021 05:44 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post

All three ports need to be flat and level with each other. A buddy of mine used a large belt-sander to level mine when we ported my manifolds.
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str8maxn
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Report this Post01-26-2021 05:57 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:


All three ports need to be flat and level with each other. A buddy of mine used a large belt-sander to level mine when we ported my manifolds.



I figured as much but want to certain. I was thinking going the same route with the belt-sander as well. Harbor Fright has on for $75 but I don't think it has enough HP to get the job done.

Do you what grit was used?


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Report this Post01-26-2021 06:10 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by str8maxn:
I figured as much but want to certain. I was thinking going the same route with the belt-sander as well. Harbor Fright has on for $75 but I don't think it has enough HP to get the job done.

Do you what grit was used?



I used this sander to do mine, I had to remove the tool rest or the flange wouldn't lay flat.

https://www.harborfreight.c...sc-sander-61750.html

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str8maxn
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Report this Post01-26-2021 06:52 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
ericjon262 --- what Grit did you use for the process?
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Report this Post01-26-2021 09:29 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by str8maxn:

ericjon262 --- what Grit did you use for the process?


120 I think... maybe 80? whatever came with the sander.

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RayOtton
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Report this Post01-29-2021 11:15 AM Click Here to See the Profile for RayOttonClick Here to Email RayOttonSend a Private Message to RayOttonEdit/Delete MessageReply w/QuoteDirect Link to This Post
Heck, I used a very large, coarse hand file to even mine out and then some 220 emery cloth to make it a bit smoother, then a couple of coats of VHT high temp paint.

Been on the car 5 years with no leaks.

[This message has been edited by RayOtton (edited 01-29-2021).]

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eti engineer
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Report this Post01-31-2021 09:57 AM Click Here to See the Profile for eti engineerClick Here to Email eti engineerSend a Private Message to eti engineerEdit/Delete MessageReply w/QuoteDirect Link to This Post
I have heard comments in here that porting can weaken the welds from the flange to the pipe itself and lead to cracking of the welds, resulting in an exhaust leak. I am in the same mode right now. I have a manifold in a vice, getting ready to open up the ports with a die grinder. I have been holding off because I have had other things come up. After reading in here about the weld cracking, I was going to ask if this is just one case or if it is a common thing. Anyone have an opinion/experience on this?
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Report this Post01-31-2021 03:06 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by eti engineer:

I have a manifold in a vice, getting ready to open up the ports with a die grinder. After reading in here about the weld cracking, I was going to ask if this is just one case or if it is a common thing. Anyone have an opinion/experience on this?


If I were you (or anybody else about to port their exhaust manifolds), I'd forget about using a die grinder.

 
quote
Originally posted by Patrick Here:

My buddy has a Hole Saw kit (similar to what's pictured below) which includes a cutter which is the exact same size as the inside of the manifold ports.

...it takes about ten seconds per port to do a perfect job! I'm not kidding. I'm surprised more people don't use this method.



[This message has been edited by Patrick (edited 01-31-2021).]

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WKDFIRO
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Report this Post01-31-2021 03:17 PM Click Here to See the Profile for WKDFIROClick Here to Email WKDFIROSend a Private Message to WKDFIROEdit/Delete MessageReply w/QuoteDirect Link to This Post
I'm about to embark on that very situation but I've also noticed through the years the consistency of the legendary front exhaust manifold cracks on the 85-87 V6s.

First, the root cause of the crack ONLY being on the front at the first first flanges is because (I believe) of a weakened or broken Tranny mount and the weakening of the torque strut (aka the Dogbone). Running the engine with these weak points can easily see the engine twisting point is right at the front exhaust manifolds where the Y-pipe joins. Any replacement of the manifolds should have these two points addressed first or the exercise will be repeated, ported or un-ported. I'm going to a urethane tyranny mount and torque strut to solid up this configuration.

The twist is, that its my 88 Formula that is having the ticking noise and based on past experience, I've taken into consideration of having to replace the Y-pipe due to cracking. 88's are the only one with the "Baked Potato" shield and concern has been made over the amount of moisture, over the long run, the Y-pipe cracks at the Y-welds along with the mount situation. Pre-88 Y-pipes are not the same length. I've taken into consideration removing the shielding and going to the pre-88 Y-pipe shielding. The lack of an air pump to the coil in 88s concerns me and I may fabricate additional layers of shielding or maybe relocation. We shall see. I'll be posting a question to the collective mind to see how many 88s took off the heat shield.

If I'm lucky on the 88, I will only have to replace the Y-pipe and I can continue on with the exhaust upgrades (spintech muffler, 2" maybe 2.5 inch exhaust). If the manifold has to be replaced, I'll have a set prepared and ported. Ported exhaust manifolds yield impressive throttle response, I would recommend it.
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Report this Post01-31-2021 04:12 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by WKDFIRO:

88's are the only one with the "Baked Potato" shield and concern has been made over the amount of moisture, over the long run, the Y-pipe cracks at the Y-welds along with the mount situation. Pre-88 Y-pipes are not the same length. I've taken into consideration removing the shielding and going to the pre-88 Y-pipe shielding. The lack of an air pump to the coil in 88s concerns me and I may fabricate additional layers of shielding or maybe relocation. We shall see. I'll be posting a question to the collective mind to see how many 88s took off the heat shield.


I've had my '88 Formula for eight years now, always parked outside (and we get a lot of rain here), and so far no problems with the Y-pipe cracking. When I ported my exhaust manifolds, I would've also liked to have done the modification to the Y-pipe, but eventually decided against it as I didn't wish to disturb/wreck the "Baked Potato" shield.
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Report this Post01-31-2021 05:07 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
Patrick ---

Are you drilling with a 29MM (1 1/8") hole saw all the way thru? down into the long pipe?

I've pickup a Milwaukee hole saw and was not able to punch thru before the teeth were gone.

[This message has been edited by str8maxn (edited 01-31-2021).]

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Report this Post01-31-2021 05:26 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by str8maxn:

Are you drilling with a 29MM (1 1/8") hole saw all the way thru? down into the long pipe?

I've pickup a Milwaukee hole saw and was not able to punch thru before the teeth were gone.



Porting of my manifolds was done 7-8 years ago, so details are getting a little vague, but... When I acquired my Formula, it required a lot of work (including a clutch replacement), so I had the car towed to a friend's garage which had a lift. We decided to port the exhaust manifolds while we had easy access, and it was a hole saw kit that my buddy actually owned which was used.

All I recall from the process was that the particular hole saw we used fit the inside diameter of the port perfectly... and yes... I admit to being rather surprised myself that the hole saw chewed through the "blockage" in the manifolds so easily. Perhaps there is a difference in quality of hole saws. Maybe some are only designed for use with wood. All I can say is that whatever it was we used had absolutely no problem cutting through metal.
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Report this Post01-31-2021 05:58 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
FYI-

a 1" hole saw can be used to cut thru the blockage. It slides thru the exhaust port and Cuts right thru with little effort. Just be careful that the drill bit does doesn't drill thru the bottom.

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Patrick
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Report this Post01-31-2021 06:45 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by str8maxn:

I've pickup a Milwaukee hole saw and was not able to punch thru before the teeth were gone.


 
quote
Originally posted by str8maxn:

a 1" hole saw can be used to cut thru the blockage. It slides thru the exhaust port and Cuts right thru with little effort.


Okay, you've now confused me.

[EDIT] I have to assume that you're talking about two different hole saws here, and that the first one was not designed to be used on metal.

[This message has been edited by Patrick (edited 01-31-2021).]

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Report this Post01-31-2021 07:12 PM Click Here to See the Profile for ericjon262Send a Private Message to ericjon262Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Porting of my manifolds was done 7-8 years ago, so details are getting a little vague, but... When I acquired my Formula, it required a lot of work (including a clutch replacement), so I had the car towed to a friend's garage which had a lift. We decided to port the exhaust manifolds while we had easy access, and it was a hole saw kit that my buddy actually owned which was used.

All I recall from the process was that the particular hole saw we used fit the inside diameter of the port perfectly... and yes... I admit to being rather surprised myself that the hole saw chewed through the "blockage" in the manifolds so easily. Perhaps there is a difference in quality of hole saws. Maybe some are only designed for use with wood. All I can say is that whatever it was we used had absolutely no problem cutting through metal.


Bimetal holesaws tend to do a much better job on metal than the cheapies.

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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."

cognita semper

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Report this Post01-31-2021 07:25 PM Click Here to See the Profile for pmbrunelleClick Here to Email pmbrunelleSend a Private Message to pmbrunelleEdit/Delete MessageReply w/QuoteDirect Link to This Post
Part of using hole saws successfully is to run them with a slow enough RPM and a lot of torque.

With a consumer-grade drill-press (that doesn't run slow enough), you need to take frequent breaks to keep the saw from overheating.
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Report this Post01-31-2021 07:55 PM Click Here to See the Profile for dremuClick Here to Email dremuSend a Private Message to dremuEdit/Delete MessageReply w/QuoteDirect Link to This Post
Can't speak to the specific task, but in general, cutting metal, especially something like cast iron: yes, bi-metal holesaw, not those made for wood, yes, going slow with breaks to keep the teeth cool, and also, use cutting oil. There's a bazillion kinds; I like Sprayon LU208 and Rapid Tap, the latter being more viscous and might work better here.

-- A
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Report this Post01-31-2021 08:11 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by ericjon262:

Bimetal holesaws tend to do a much better job on metal than the cheapies.


 
quote
Originally posted by dremu:

...in general, cutting metal, especially something like cast iron: yes, bi-metal holesaw, not those made for wood.


Out of curiosity, I contacted my buddy a few minutes ago and asked him what was it about his hole saw that allowed it to cut through the blockage in the exhaust ports so easily... and yes... bi-metal was his response!
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Report this Post01-31-2021 08:25 PM Click Here to See the Profile for eti engineerClick Here to Email eti engineerSend a Private Message to eti engineerEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:




Funny you should mention this, because I was looking into this exact thing. I was in Harbor Freight the other day and saw one of these kits and it crossed my mind that I should check into using something like this for the job. A die grinder would take much longer. Thanks for bringing this up. If I do this, this way, I will let you know how it went.
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str8maxn
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Report this Post01-31-2021 11:47 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Patrick:

Okay, you've now confused me.

[EDIT] I have to assume that you're talking about two different hole saws here, and that the first one was not designed to be used on metal.



Maybe this will help.. I am a visual person. 1 1/8 " vs. 1" Hole Saw


[This message has been edited by str8maxn (edited 01-31-2021).]

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Report this Post02-01-2021 04:24 PM Click Here to See the Profile for PatrickClick Here to Email PatrickSend a Private Message to PatrickEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by str8maxn:

Maybe this will help.. I am a visual person. 1 1/8 " vs. 1" Hole Saw


In the post of mine that I linked to from seven years ago, I stated that we had used a hole saw "which is the exact same size as the inside of the manifold ports".

What we weren't doing was hogging out the exhaust manifold ports to be equal in size to the openings in the exhaust gaskets.

Perhaps this is where some of the apparent confusion comes from in regards to the size of hole saw required for the task.

This photo taken from an old porting thread shows the factory restrictions which we were targeting for removal.



It's the hogging out of the ports to match the gaskets which is what's probably responsible for the flanges often needing to be re-welded. Limiting the porting to just removing the internal restrictions doesn't seem to create this issue... and it's a heck of a lot less work.
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Report this Post02-02-2021 09:00 AM Click Here to See the Profile for RayOttonClick Here to Email RayOttonSend a Private Message to RayOttonEdit/Delete MessageReply w/QuoteDirect Link to This Post
As for the welding issue.

Weld around the outside of each of the ports BEFORE porting to avoid the cracking problem. The reason is that some little balls of metal will form on the inside of the manifold. If you port first, then weld, you end up doing the job twice. (Ask me how I know).

BTW, I made a fixture to bolt the manifold to which kept the manifold from warping during the welding operation.

I used a Dremel tool for the job. First I used a milling bit to rough out the hole and then I doubled up cutting disks for polishing. Purely by coincidence the disks were the perfect diameter too.

It takes dedication though, that manifold steel is TOUGH. Went though probably 30 disks for the whole job. You can buy them in packs of 100 for a reasonable price on Amazon.
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Report this Post02-02-2021 10:13 AM Click Here to See the Profile for dremuClick Here to Email dremuSend a Private Message to dremuEdit/Delete MessageReply w/QuoteDirect Link to This Post
Wrt the welding, Rodney has a jog premade:

http://rodneydickman.com/pr....php?products_id=434

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Report this Post02-21-2021 04:41 PM Click Here to See the Profile for str8maxnSend a Private Message to str8maxnEdit/Delete MessageReply w/QuoteDirect Link to This Post
Did I ruin my manifold?

I was grinding the ports true , got distracted and didn't realize I was grinding away the back of the manifold .

Are these still useable?

Is it repair needed? If so, how?

[This message has been edited by str8maxn (edited 02-21-2021).]

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