Porting my Edelbrock TPI base. (progress pic's)
#1
Porting my Edelbrock TPI base. (progress pic's)
Picked up an Edelbrock TPI base a while back (actually it was supposed to be an Accel/Lingenfelter base but as it turns out, they no longer manufacture their own base and just ship out Edelbrock's version)
https://www.thirdgen.org/forums/afte...ing-accel.html
and over the past couple weeks, I've been taking my time cleaning it up a bit before I install it on the car with my new AS&M runners.
The Edelbrock was a nice piece out of the box, but it was quite clear, there was a lot of room for improvement. Having said that, it wasn't until I saw a stock TPI base a few days later, that I realized just how big of an improvement the Edelbrock base was, over stock. Seeing a bone stock TPI base in person for the first time, I have a VERY hard time believing that even with a HEAVY amount of port-work done to it,it still would not come close to an "out-of-the-box" Edelbrock base.
Still, even though the Edelbrock was clearly superior in terms of flow, as I said, there was even more room for improvement so I figured I would take the opportunity to port the Edelbrock base before I installed it on the car.
After finding out that getting it "professionally" ported would cost almost as much as the intake itself, I made the decision to do it on my own. For the record, I've never ported anything in my life and had absolutely no experience what so ever doing this sort of work but trying it out on my own would definitely be the most cost-efficient route to take and at the same time, I admit, I was kinda excited about doing the work myself. Not only would I gain experience and learn a skill that may come in handy later on, but being able to tell people you did all the port work yourself, is pretty darn cool : )
I picked up a dremel for $70 at a local hardware store and a bunch of sanding bits.
Since this was my first time porting anything, I decided that it would be safer to start off with simple sanding bit's so as to not accidentally remove too much material and destroy a brand new intake.
Although it takes much longer using sanding bit's as apposed to something like a carbide bit, the sanding bit's kept me out of trouble and allowed me to take my time.
Anyways, I've only done the intake ports on one side of the base, but I think they came out really good. Better than I expected actually, and I'd be willing to bet the work that's been is about as good as it's going to get. I really can't see how a place like, say, TPIS, could do any better. Best part is, I did it myself and saved a lot of money.
I was able to get about 2 & 3/4 inch's "into" each of the ports. Right out of the box, the Edelbrock has only "slight" porting a measly 1/4" in which you could see from the picture's below. Another thing I noticed is that there's a "lip" around each of the intake ports where there's clearly a huge amount of excess aluminum that serves no purpose but to obstruct air-flow. I basically ground them down which basically opened up each port. It's a very noticeable improvement just by looking at it in person.
Although not very scientific, my testing measure to see how my porting was coming along, was to place a golf ball inside one of the intake ports before, and then after cleaning it out.
You can see from the picture's just how much of an improvement you can make with a simple dremel and some spare time. Out-of-the-box, the gold ball wouldn't even fit. It would just sit there with 3/4 of it still sticking out. After porting, the golf ball literally drops right into each port. Yup. Big difference.
Anyhoo, thought I'd post a few pic's of my progess. I still have the other 4 intake ports on the other side to port out and then start on the exhaust ports afterwards, but I'm enjoying the experience.
Basically, I just wanted to let people know that you don't have to pay a couple hundred bucks to someone else to do port work for you. If you're willing to try it yourself, you can get really good results and save yourself some cash as well as learn something new.
Any comments, advice, or any kind of input in general, is more than welcome.
I'd particularly like to hear from the experienced porters on this forum, to find out what their opinion is on my work so far. (and take it easy on me guy's, this was my first time porting.
---------------
---------------
These are pretty self explainitory, but just for the record, the pic's on the left are "stock" while the pic's on the right are after my port work.
..![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_106_full.jpg)
..![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_103_full.jpg)
..![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_105_full.jpg)
..![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_104_full.jpg)
..![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_107_full.jpg)
-------------
https://www.thirdgen.org/forums/afte...ing-accel.html
and over the past couple weeks, I've been taking my time cleaning it up a bit before I install it on the car with my new AS&M runners.
The Edelbrock was a nice piece out of the box, but it was quite clear, there was a lot of room for improvement. Having said that, it wasn't until I saw a stock TPI base a few days later, that I realized just how big of an improvement the Edelbrock base was, over stock. Seeing a bone stock TPI base in person for the first time, I have a VERY hard time believing that even with a HEAVY amount of port-work done to it,it still would not come close to an "out-of-the-box" Edelbrock base.
Still, even though the Edelbrock was clearly superior in terms of flow, as I said, there was even more room for improvement so I figured I would take the opportunity to port the Edelbrock base before I installed it on the car.
After finding out that getting it "professionally" ported would cost almost as much as the intake itself, I made the decision to do it on my own. For the record, I've never ported anything in my life and had absolutely no experience what so ever doing this sort of work but trying it out on my own would definitely be the most cost-efficient route to take and at the same time, I admit, I was kinda excited about doing the work myself. Not only would I gain experience and learn a skill that may come in handy later on, but being able to tell people you did all the port work yourself, is pretty darn cool : )
I picked up a dremel for $70 at a local hardware store and a bunch of sanding bits.
Since this was my first time porting anything, I decided that it would be safer to start off with simple sanding bit's so as to not accidentally remove too much material and destroy a brand new intake.
Although it takes much longer using sanding bit's as apposed to something like a carbide bit, the sanding bit's kept me out of trouble and allowed me to take my time.
Anyways, I've only done the intake ports on one side of the base, but I think they came out really good. Better than I expected actually, and I'd be willing to bet the work that's been is about as good as it's going to get. I really can't see how a place like, say, TPIS, could do any better. Best part is, I did it myself and saved a lot of money.
I was able to get about 2 & 3/4 inch's "into" each of the ports. Right out of the box, the Edelbrock has only "slight" porting a measly 1/4" in which you could see from the picture's below. Another thing I noticed is that there's a "lip" around each of the intake ports where there's clearly a huge amount of excess aluminum that serves no purpose but to obstruct air-flow. I basically ground them down which basically opened up each port. It's a very noticeable improvement just by looking at it in person.
Although not very scientific, my testing measure to see how my porting was coming along, was to place a golf ball inside one of the intake ports before, and then after cleaning it out.
You can see from the picture's just how much of an improvement you can make with a simple dremel and some spare time. Out-of-the-box, the gold ball wouldn't even fit. It would just sit there with 3/4 of it still sticking out. After porting, the golf ball literally drops right into each port. Yup. Big difference.
Anyhoo, thought I'd post a few pic's of my progess. I still have the other 4 intake ports on the other side to port out and then start on the exhaust ports afterwards, but I'm enjoying the experience.
Basically, I just wanted to let people know that you don't have to pay a couple hundred bucks to someone else to do port work for you. If you're willing to try it yourself, you can get really good results and save yourself some cash as well as learn something new.
Any comments, advice, or any kind of input in general, is more than welcome.
I'd particularly like to hear from the experienced porters on this forum, to find out what their opinion is on my work so far. (and take it easy on me guy's, this was my first time porting.
---------------
---------------
These are pretty self explainitory, but just for the record, the pic's on the left are "stock" while the pic's on the right are after my port work.
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_102_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_106_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_100_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_103_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_108_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_105_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_101_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_104_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_42_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_107_full.jpg)
-------------
Last edited by LT1FUN; 02-01-2007 at 04:26 PM.
#2
One last thing, I do have a question to all those with experience porting. Is it better to smooth out the entire pathway of each port (from intake straight through to the exhaust port) or is cleaning up only the entrance's/exits sufficient enough?
Like I said, I managed to get about 2 3/4 inches in, but that's as far as my dremel can go. They sell a flexible extention which would allow me to get at least another 3-4" inwards, , but is it really worth it? Would I get much more air flow than what it does now? I'd like to hear some input from the pro's on this.
Thanks in advance.
Like I said, I managed to get about 2 3/4 inches in, but that's as far as my dremel can go. They sell a flexible extention which would allow me to get at least another 3-4" inwards, , but is it really worth it? Would I get much more air flow than what it does now? I'd like to hear some input from the pro's on this.
Thanks in advance.
#3
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Car: '87 Camaro IROC-Z
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I used the Dremel flex shaft when I ported my intake. Here's the URL with some pix and measurements:
http://users.erols.com/gcwestph/Intake.html
I wasn't able to get all the way through, there was still about 1 1/2" or so that was untouched, but I made the same improvements at the entrances that you did.
http://users.erols.com/gcwestph/Intake.html
I wasn't able to get all the way through, there was still about 1 1/2" or so that was untouched, but I made the same improvements at the entrances that you did.
#4
I used the Dremel flex shaft when I ported my intake. Here's the URL with some pix and measurements:
http://users.erols.com/gcwestph/Intake.html
http://users.erols.com/gcwestph/Intake.html
Yeah, I was just looking at that dremel flex-shaft and it goes for about $50 Canadian. Not too bad I suppose. I'll probably pick one up over the weekend and continue on with my project. I can't wait to get this thing finished so I can start on my plenum...
#5
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LT1FUN just a quick note on the Dremel flexible shaft. I’ve gone through two already, the shaft that’s inside the flexible hose has broken both times. Once at the base where it meets up with the handle, and the other somewhere in the middle. Now maybe I’m using it wrong, running it at to high of RPM, or just using it for too long of a time. It worked really well, when it was working. I’m now looking at picking up an electric motor and flex shaft from Eastwood. Sure it’s more, but will probably last a lifetime.
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#8
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Car: 1967 Camaro
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As rough cast as the base is internally, I wouldn't call it "done" until you have the entire inside finished.
p.s. Don't pay attention to 88BlackZ-51
![crazy](https://www.thirdgen.org/forums/images/smilies/crazy.gif)
...he thinks EVERYONE needs a MiniRam, StealthRam, or SuperRam.
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
#9
LT1FUN, if you're using sandpaper rolls, you can buy longer mandrels that would easily allow you to go in far enough on each side to finish the whole intake, instead of just about 3" into the port entrances. IMHO, what you have done so far looks nice, and it'd be a shame to quit before you're done. One suggestion I would offer is to bolt up a new runner on the "finished" side of the base and you can see through it to make sure the ports are lined up nicely. Same goes for the plenum...if you bolt up one runner you can see it's fitment by looking through the opposite side...then just adjust accordingly.
As rough cast as the base is internally, I wouldn't call it "done" until you have the entire inside finished.
p.s. Don't pay attention to 88BlackZ-51![crazy](https://www.thirdgen.org/forums/images/smilies/crazy.gif)
...he thinks EVERYONE needs a MiniRam, StealthRam, or SuperRam.![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
As rough cast as the base is internally, I wouldn't call it "done" until you have the entire inside finished.
p.s. Don't pay attention to 88BlackZ-51
![crazy](https://www.thirdgen.org/forums/images/smilies/crazy.gif)
...he thinks EVERYONE needs a MiniRam, StealthRam, or SuperRam.
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
I dont think that at all Big Bobby Boy!
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
----------
LT1FUN, if you're using sandpaper rolls, you can buy longer mandrels that would easily allow you to go in far enough on each side to finish the whole intake, instead of just about 3" into the port entrances. IMHO, what you have done so far looks nice, and it'd be a shame to quit before you're done. One suggestion I would offer is to bolt up a new runner on the "finished" side of the base and you can see through it to make sure the ports are lined up nicely. Same goes for the plenum...if you bolt up one runner you can see it's fitment by looking through the opposite side...then just adjust accordingly.
As rough cast as the base is internally, I wouldn't call it "done" until you have the entire inside finished.
p.s. Don't pay attention to 88BlackZ-51![crazy](https://www.thirdgen.org/forums/images/smilies/crazy.gif)
...he thinks EVERYONE needs a MiniRam, StealthRam, or SuperRam.![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
As rough cast as the base is internally, I wouldn't call it "done" until you have the entire inside finished.
p.s. Don't pay attention to 88BlackZ-51
![crazy](https://www.thirdgen.org/forums/images/smilies/crazy.gif)
...he thinks EVERYONE needs a MiniRam, StealthRam, or SuperRam.
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
I dont think that at all Big Bobby Boy!
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
![bs](https://www.thirdgen.org/forums/images/smilies/bs.gif)
Last edited by 88BlackZ-51; 02-03-2007 at 11:30 PM. Reason: Automerged Doublepost
#10
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Car: 1967 Camaro
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![blah blah](https://www.thirdgen.org/forums/images/smilies/blahblah.gif)
Sorry, they are straight, but I didn't mean to strike a nerve...
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
I was just going by every TPI intake related post (on every forum) I've ever read of yours, including numerous ones directed towards me...
You question everyone (including myself) who takes the time to try and improve what parts they have already chosen to use. Obviously, LT1FUN has already committed to a "stock style, long runner" intake setup, and is taking the time to clean it up, because the runners (internally) are very rough "as-cast"...just like the pics clearly show. Whether he runs his setup on a 305, or a 434, you weren't "curious"...Fact is, your next reply would have been WHY he should use a different intake...
Obviously, you took my joking reply above, to heart...
I don't want to crap up LT1FUN's thread.
The man asked for advice about his portwork, which I offered.
![off topic](https://www.thirdgen.org/forums/images/smilies/offtopic.gif)
![thank you](https://www.thirdgen.org/forums/images/smilies/thanks.gif)
![waveman](https://www.thirdgen.org/forums/images/smilies/waveguy.gif)
#11
Like I said, I managed to get about 2 3/4 inches in, but that's as far as my dremel can go. They sell a flexible extention which would allow me to get at least another 3-4" inwards, , but is it really worth it? Would I get much more air flow than what it does now? I'd like to hear some input from the pro's on this.
Thanks in advance.
Thanks in advance.
read this
https://www.thirdgen.org/forums/tpi/...+base+manifold
#12
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Car: 1967 Camaro
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BTW, Nice link Orr89RocZ
![thumbs up](https://www.thirdgen.org/forums/images/smilies/thumbsup.gif)
Here's what I did to my Edelbrock base. Keep in mind that this was before I got my new heads, so that area (where intake meets heads) wasn't done yet. I also hadn't gotten any runners when pics were taken, so that area (where runners meet base) is also incomplete, in these pics...
#15
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I'd suggest getting a metal bit for the dremel and the wand so you can take more material out quicker. It's time consuming enough with the bit,,, much less the barrel rolls.
Good luck.
Last edited by BadSS; 03-17-2023 at 03:53 PM.
#16
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Correct,, do no more than smooth the first three inches of the floor at the head exits. Concentrate on the outside wall and the ceiling of the head port exit. After about three inches in,,, it'll be fine to grind at the "floor".
I'd suggest getting a metal bit for the dremel and the wand so you can take more material out quicker. It's time consuming enough with the bit,,, much less the barrel rolls.
Here's a VERY crude drawing,, not to scale or extremely accurate on the orginal port shape or representation of the air flow and what happens,,,
I'd suggest getting a metal bit for the dremel and the wand so you can take more material out quicker. It's time consuming enough with the bit,,, much less the barrel rolls.
Here's a VERY crude drawing,, not to scale or extremely accurate on the orginal port shape or representation of the air flow and what happens,,,
![thumbs up](https://www.thirdgen.org/forums/images/smilies/thumbsup.gif)
I have several carbide burrs. I just needed a tad more info on where to make the best use of them. Thanks for the info!
![Smilie](https://www.thirdgen.org/forums/images/smilies/smile.gif)
#18
![blah blah](https://www.thirdgen.org/forums/images/smilies/blahblah.gif)
Sorry, they are straight, but I didn't mean to strike a nerve...
![lmao](https://www.thirdgen.org/forums/images/smilies/lmao.gif)
I was just going by every TPI intake related post (on every forum) I've ever read of yours, including numerous ones directed towards me...
You question everyone (including myself) who takes the time to try and improve what parts they have already chosen to use. Obviously, LT1FUN has already committed to a "stock style, long runner" intake setup, and is taking the time to clean it up, because the runners (internally) are very rough "as-cast"...just like the pics clearly show. Whether he runs his setup on a 305, or a 434, you weren't "curious"...Fact is, your next reply would have been WHY he should use a different intake...
Obviously, you took my joking reply above, to heart...
I don't want to crap up LT1FUN's thread.
The man asked for advice about his portwork, which I offered.
![off topic](https://www.thirdgen.org/forums/images/smilies/offtopic.gif)
![thank you](https://www.thirdgen.org/forums/images/smilies/thanks.gif)
![waveman](https://www.thirdgen.org/forums/images/smilies/waveguy.gif)
BTW, Good porting job LT1. The low end on the street is so much fun!
![Smilie](https://www.thirdgen.org/forums/images/smilies/smile.gif)
#19
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#20
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Is it really nescisarry to to go as big as the golf ball size in the entrance. The mr gasket 146 gaskets match pretty close on my edelbrock intake. Or is it better to just smooth out everything and work on the areas that BADSS mentioned.
#21
It's all about cross sectional area. One should know the minimal cross sectional area inside the intake port of the heads they have.
Ideally you want the cross sectional area of the intake manifold to be larger than the minimum CSA of the head. You don't want the choke point to be the intake manifold.
However that is the situation at hand with most aftermarket performance heads and the Edelbrock TPI intake manifold. So the runners in the intake manifold need to be opened up as much as posible to close that gap.
A slight taper of say 2% will help flow in the intake runners. The larger end is at the runner side. Also the port opening at the head should be slightly smaller than the opening in the head.
Ideally you want the cross sectional area of the intake manifold to be larger than the minimum CSA of the head. You don't want the choke point to be the intake manifold.
However that is the situation at hand with most aftermarket performance heads and the Edelbrock TPI intake manifold. So the runners in the intake manifold need to be opened up as much as posible to close that gap.
A slight taper of say 2% will help flow in the intake runners. The larger end is at the runner side. Also the port opening at the head should be slightly smaller than the opening in the head.
#22
A slight taper of say 2% will help flow in the intake runners. The larger end is at the runner side. Also the port opening at the head should be slightly smaller than the opening in the head
#24
Re: Porting my Edelbrock TPI base. (progress pic's)
It's been a while since I last updated this thread but I just haven't had any time to finish porting my Edelbrock base or to start working on my spare TPI plenum.
Well, I finally got some free time this weekend and decided to get back to work on the porting. Hopefully, everything will be good to go within a month's time and I'll be able to throw everything on the car and put her on a dyno to see how much the Edelbrock/AS&M combo is worth on an L98.
The base is 90% complete picture's coming soon) and today I finally got around to starting the work on my spare TPI plenum to take advantage of the AS&M runners.
Rather than start a separate thread for the plenum porting, I'll just use this thread instead and combine all the porting pic's together.
As you can see from the photo's below, the AS&M runners are quite a bit bigger than the ports on he stock plenum. In order to take full advantage of the larger diameter runners, the plenum opening's have to be enlarged. Using one of the gaskets that came with the AS&M's as a template, I carefully outlined the circumference of each opening with a sharp tap guide and began grinding away using both a dremel as well as a plain old round file. I've seen different ways of going about doing this. Some just cut out the divider in between each port leaving a wide "oval" shape behind (usually for SLP runners) while others just increase the size of teach port and call it a day.
Since I'm not using SLP runners, there's really no need to siamese the ports together so I just increased the size of the openings. and removed a small piece of the center section which will (hopefully) allow a bit more air flow.
I'm still not finished yet as I still have to port out the front of the plenum where the throttle body attach's to. I'll start that tomorrow...
Having never ported a a TPI base or plenum, I think I'm doing alright so far. The AS&M runner gaskets now lign up with the plenum ports perfectly. I increased the size of the openings from the stock 32mm to the appropriate 36mm needed for the larger runners.
Stay tuned for more updates.
Any advice and or suggestions would be appreciated. Thanks in advance.
...![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_127_full.jpg)
...![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_123_full.jpg)
...
Well, I finally got some free time this weekend and decided to get back to work on the porting. Hopefully, everything will be good to go within a month's time and I'll be able to throw everything on the car and put her on a dyno to see how much the Edelbrock/AS&M combo is worth on an L98.
The base is 90% complete picture's coming soon) and today I finally got around to starting the work on my spare TPI plenum to take advantage of the AS&M runners.
Rather than start a separate thread for the plenum porting, I'll just use this thread instead and combine all the porting pic's together.
As you can see from the photo's below, the AS&M runners are quite a bit bigger than the ports on he stock plenum. In order to take full advantage of the larger diameter runners, the plenum opening's have to be enlarged. Using one of the gaskets that came with the AS&M's as a template, I carefully outlined the circumference of each opening with a sharp tap guide and began grinding away using both a dremel as well as a plain old round file. I've seen different ways of going about doing this. Some just cut out the divider in between each port leaving a wide "oval" shape behind (usually for SLP runners) while others just increase the size of teach port and call it a day.
Since I'm not using SLP runners, there's really no need to siamese the ports together so I just increased the size of the openings. and removed a small piece of the center section which will (hopefully) allow a bit more air flow.
I'm still not finished yet as I still have to port out the front of the plenum where the throttle body attach's to. I'll start that tomorrow...
Having never ported a a TPI base or plenum, I think I'm doing alright so far. The AS&M runner gaskets now lign up with the plenum ports perfectly. I increased the size of the openings from the stock 32mm to the appropriate 36mm needed for the larger runners.
Stay tuned for more updates.
Any advice and or suggestions would be appreciated. Thanks in advance.
![Smilie](https://www.thirdgen.org/forums/images/smilies/smile.gif)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_124_full.jpg)
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![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_125_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_123_full.jpg)
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Last edited by LT1FUN; 09-03-2007 at 08:59 PM.
#26
Re: Porting my Edelbrock TPI base. (progress pic's)
![Wink](https://www.thirdgen.org/forums/images/smilies/wink.gif)
I attached the runners to the side of the plenum I'd just finished opening up and looked inside though the other side of the plenum, just to see if everything matched up and there was no restrictions or further grinding required and sure enough, everything lined up just about perfect. The plenum ports, gasket and runners were all the same size. A nice clean transition.
![nod](https://www.thirdgen.org/forums/images/smilies/nod.gif)
#29
Re: Porting my Edelbrock TPI base. (progress pic's)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_130_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_132_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_134_full.jpg)
![](http://memimage.cardomain.net/member_images/12/web/2376000-2376999/2376432_133_full.jpg)
Just finished grinding down the EGR walls at the entrance of the plenum. You can see from the first picture just how much of a restriction those "walls" really are. I can't for the life of me figure out why GM would come up with such a crappy design, surly they must have know it would be a huge restriction and definitely have a negative effect on the motor's throttle response
![doh](https://www.thirdgen.org/forums/images/smilies/doh.gif)
My main concern with the plenum was enlarging the ports to accept the larger AS&M runners and, of coarse, as shown above, emoving the EGR walls.
I've seen a few people on this forum grind down the "ridge" just behind each of the plenum ports, but I honestly don't think that would make much of a difference in terms of overall "flow" so I'm not going to bother...
All I need to do now is smooth out a few rough spots left behind from the carbide bit I used to grind everything down with some mild sandpaper. Clean out the old carbon stains inside the plenum itself and then paint the outside of the plenum.
I hope to have the car back on the dyno next weekend so hopefully this will all get done in time. I've already received the new fuel injectors, cold-start plug, gaskets, new stainless TPI bolts and everything else to make for a full instal.
Stay tuned...
#30
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Car: 92 1500p\u 2wd
Engine: 91 z28 tpi 355
Transmission: 91 700r4
Re: Porting my Edelbrock TPI base. (progress pic's)
does anyone hae and dyno numbers of how much power can be gained from porting the edelbrock base? i have a edelbrock base now with ported slp runners and plenum.....and now im thinkin ill have to do some work on the base when i do my AFR head swap!
great thread!!
![thumbs up](https://www.thirdgen.org/forums/images/smilies/thumbsup.gif)
#31
Re: Porting my Edelbrock TPI base. (progress pic's)
All the threads pertaining to those topic's are usually people asking what these mods are actually worth and all the replies posted are usually just "guesses" made by others. They're "estimates" based on what they "think" an aftermaket TPI set-up should be worth.
No "definitive" proof of anything ...
Those who do post dyno numbers always have other work done to their car's besides the TPI upgrade, like heads, cam or even a stroker motor so there's no way of knowing how effective a ported plenum, base and larger runners is on a car with minor "bolt-ons" (which is what most of us 3rd gen owners have).
That's basically why I started this thread. Since nobody really knows what a complete after-market TPI set-up is worth on a basically stock motor, I'm going to dyno my car with the upgrades just to show everybody firsthand, roughly what they could expect (power-wise) from these upgrades.
On the last dyno, my Iroc put out 206hp and aprox. 290lbs of torque at the wheels. (212hp with no air filters). Only mods to the motor were headers, a cat-back exhaust and a set of 1.6 roller rockers. Motor had roughly 180k on the odometer. ( https://www.thirdgen.org/forums/tpi/...no#post3070111 )
The car has remained the same since then though I changed from one aftermarket cat-back to another,but I can't see that making much of a difference until later on, when I've dived deeper into the engine since my old Dynomax system wasn't really posing that much of a restriction to begin with....
***************
I just finished painting the plenum last night and started putting the piece's together just to see what they all look like assembled. Turns out there's a single bolt-hole on BOTH of the AS&M runners, which are too small for the actual bolt to pass through. Not only that, but the angle they were drilled, doesn't quite line up with the bolt holes in the Edelbrock base either.
![Frown](https://www.thirdgen.org/forums/images/smilies/frown.gif)
As for the Edelbrock base itself, I noticed that two of the bolt holes on that, are too BIG, and on top of that, there's no thread in them so there's no way to screw in a bolt cause there's nothing to "grab onto"..
![Frown](https://www.thirdgen.org/forums/images/smilies/frown.gif)
![doh](https://www.thirdgen.org/forums/images/smilies/doh.gif)
These are also the only bolts that go in at an angle so I guess both Edelbrock and AS&M had trouble with these two spots.. I'll post some pic's in a bit. Hopefully somebody will be able to suggest something...
#32
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Car: 1991 Camaro B4C
Engine: L98 350 cid (5.7L) TPI v8
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Axle/Gears: 10 bolt w/girdle & 3.42 MotiveGears
Re: Porting my Edelbrock TPI base. (progress pic's)
Not 100% possitive.
(Since I don't have a base manifold yet.)
Could these bolts go in backwards ???
Maybe they go through the base into the runners?
Some one said that these holes ( driver side mostly)
were not completely tapped (threaded) on our AS&M runners.
This might explain why the base holes are not threaded.
and are larger while the runners are too small.
They are also at an odd angle.
Ben @ AS&M said they should be tapped
to 8mm x 1.25 thread pitch.
(Since I don't have a base manifold yet.)
Could these bolts go in backwards ???
Maybe they go through the base into the runners?
Some one said that these holes ( driver side mostly)
were not completely tapped (threaded) on our AS&M runners.
This might explain why the base holes are not threaded.
and are larger while the runners are too small.
They are also at an odd angle.
Ben @ AS&M said they should be tapped
to 8mm x 1.25 thread pitch.
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