Mod Guide: L26 UIM/L67 Throttle Body Swap Guide (Pic Heavy)
#31
08-25-2014, 09:56 PM
Glad to read this right up is of value for you and I have zero issues with anyone wanting to mimic what I did.
As for performance gains, bear in mind, I did this 90%+ for looks and a little % for security that the aluminum will never crack or damage like the old plastic. Despite that, I do feel the car is a bit "peppier" then it was. It just "feels" better. But I have no proof to the claim, it's just my perception (and some may claim it's a the placebo effect). I'm currently working on re-tuning the car my self by street tuning it (which is another learning experience).
As for the plastic UIM warping, I believe that is an extremely rare situation (and probably a sign that the UIM was improperly torqued down). The plastic L36 UIM is more likely to explode due to issues with a failed fuel pressure regulator or have EGR stove pipe and the coolant erode the coolant passages that feed the throttle body (spraying coolant into the intake). I never had the happen, but helped someone who did and read a good amount of people on the Internet that had this happen. The plastic UIM was a bad idea, it's eventually going to get brittle and fail. And I agree, while you are changing the UIM (or any reason to have it off), replace the LIM gaskets with the Fel Pro aluminum backed gaskets.
As for the throttle bodies of an L36 and L67. They are interchangeable even with the L36 UIM. I was running one for a while but I did a lot of work to make it blend in the same manner as the L36. Here's a link to my info about that project on my web site: '04 Monte Carlo SS - L67 Throttle Body. One thing I don't think I have on the web site, I had to oblong the 3 mounting holes (otherwise the L67 throttle body hangs a little low and does not line up right). You could use an L36 throttle body on this mod (a member Frank put an entire L26 engine in his Monte to replace a failed L36). But I was already running an L67 throttle body (as an inexpensive alternative to the ZZP High Velocity Throttle Body). Keep in mind, as I understand, porting the inlet of the throttle body as I did requires re-tuning of the MAF because you have changed the MAF readings. And if you check the link about my first L67 ported throttle body, I do mention, there are two different generations of the throttle body.
As for the adapter plate between the UIM and the throttle body, some type of adapter is a must (unless you can weld aluminum). I wish it did not need the adapter, as the snout on the L26 UIM is already longer then the snout on the L36 (which makes mating the air duct for the CAI more challenging the longer the throttle body is pushed out). But there really is no good way around it. I had one idea, but I did not like it, so I did not even attempt it.
If you are going to go through all this AND change the LIM gaskets, you may want to fab a port matched LIM (and expand the coolant bypass on it). Here's info on the LIM in my car now (been in since 2011, with a host of other mods that went in at the same time):
'04 Monte Carlo SS - Port Matched LIM
And the ZZP aluminum coolant elbows. It's just a guess, but I am betting those are just Dorman aluminum elbows you can buy at any local parts store these days (ZZP just takes them out of the blister pack). I am still running plastic elbows I replaced a couple years ago (and then had to replace with genuine GM a year later), pre-dating any of the aluminum elbows.
As for performance gains, bear in mind, I did this 90%+ for looks and a little % for security that the aluminum will never crack or damage like the old plastic. Despite that, I do feel the car is a bit "peppier" then it was. It just "feels" better. But I have no proof to the claim, it's just my perception (and some may claim it's a the placebo effect). I'm currently working on re-tuning the car my self by street tuning it (which is another learning experience).
As for the plastic UIM warping, I believe that is an extremely rare situation (and probably a sign that the UIM was improperly torqued down). The plastic L36 UIM is more likely to explode due to issues with a failed fuel pressure regulator or have EGR stove pipe and the coolant erode the coolant passages that feed the throttle body (spraying coolant into the intake). I never had the happen, but helped someone who did and read a good amount of people on the Internet that had this happen. The plastic UIM was a bad idea, it's eventually going to get brittle and fail. And I agree, while you are changing the UIM (or any reason to have it off), replace the LIM gaskets with the Fel Pro aluminum backed gaskets.
As for the throttle bodies of an L36 and L67. They are interchangeable even with the L36 UIM. I was running one for a while but I did a lot of work to make it blend in the same manner as the L36. Here's a link to my info about that project on my web site: '04 Monte Carlo SS - L67 Throttle Body. One thing I don't think I have on the web site, I had to oblong the 3 mounting holes (otherwise the L67 throttle body hangs a little low and does not line up right). You could use an L36 throttle body on this mod (a member Frank put an entire L26 engine in his Monte to replace a failed L36). But I was already running an L67 throttle body (as an inexpensive alternative to the ZZP High Velocity Throttle Body). Keep in mind, as I understand, porting the inlet of the throttle body as I did requires re-tuning of the MAF because you have changed the MAF readings. And if you check the link about my first L67 ported throttle body, I do mention, there are two different generations of the throttle body.
As for the adapter plate between the UIM and the throttle body, some type of adapter is a must (unless you can weld aluminum). I wish it did not need the adapter, as the snout on the L26 UIM is already longer then the snout on the L36 (which makes mating the air duct for the CAI more challenging the longer the throttle body is pushed out). But there really is no good way around it. I had one idea, but I did not like it, so I did not even attempt it.
If you are going to go through all this AND change the LIM gaskets, you may want to fab a port matched LIM (and expand the coolant bypass on it). Here's info on the LIM in my car now (been in since 2011, with a host of other mods that went in at the same time):
'04 Monte Carlo SS - Port Matched LIM
And the ZZP aluminum coolant elbows. It's just a guess, but I am betting those are just Dorman aluminum elbows you can buy at any local parts store these days (ZZP just takes them out of the blister pack). I am still running plastic elbows I replaced a couple years ago (and then had to replace with genuine GM a year later), pre-dating any of the aluminum elbows.
Last edited by Cocky3800; 08-25-2014 at 10:04 PM.
#32
08-26-2014, 12:28 AM
One more thing, I'm sorry if I'm being a pest with this, but is it possible that you could comment a list of everything that was involved with this project? As far as supplies, tools, chemicals, anything. Could you simply make a list of everything you used/is needed to do these mods. That would be extremely helpful. The most specific the better! Thanks so much for all your help with all this. I will be doing a full Intake Assembly Build as soon as I have the money and resources for it so all the knowledge I have access to will make everything about this project much more enjoyable and efficient. Thanks!
-Tony
-Tony
#33
08-26-2014, 06:58 PM
Guess what The_Manic !? I found a used parts dealer that is sending me a L26 Lower Intake Manifold, an L26 Aluminum Upper Intake Manifold, and an L67 Throttle Body for only $100 shipped!! I'll be ordering them as soon as I can! Can't wait to start this project!! Now I just gotta get gaskets and an HV3 Intake Insert to put it all on the car! By the way, the MAF and all other sensors are the same for the L67 as the L36 TB right? I believe I'm just getting a bare throttle body and was gonna obviously use the throttle body sensors that are already wired in the car.
#34
08-26-2014, 10:00 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,195
OK, you asked for a list of supplies, I'll do my best (but it may not be all inclusive, it's from memory). Also, I may just give some URLs to items.
For cleaning, you can experiment with degreaser products. I got a big plastic tote and soaked the LIM in mineral spirits, once a day agitating the LIM with a a variety of things from a tooth brush, nylon dish washing brushes, paint brush and wire brush (I've soaked about 3 LIMs and my L26 UIM in this set up and the tote is warping). I've re-bottled the mineral spirits and re-used the stuff for other nasty cleaning products. By the time I'm done, any odors in the metals from the mineral spirits are gone.
I've heard of people throwing this stuff in the dish washer, but I could not bring me to do it (did not want sharp or rough surfaces on car parts damaging the coating to the wire racks in the dishwasher and I don't think my wife would have approved of it lol).
In the future, I might consider other products like Simple green (I used sprays of Simple Green on the last throttle body and it didn't do too bad). Just have to experiment.
Now for tools, make sure you have a corded drill motor and a good Dremel. I also recommend the flexible extension for the Dremel. If you have access to a drill press and a cone rotary rasp, that helped me a LOT with machining down the step on the exit of the throttle body (so it blends smoother to the adapter plate and the UIM).
- Vermont American 1/4 in. Black Steel Rotary Rasp-16682 at The Home Depot (this was helpful to enlarge the opening from the UIM snout into the main UIM chamber, don't enlarge below where the HV3 ends up sitting, otherwise, you now have a step you probably don't want).
- Vermont American 5/8 in. x 1-3/8 in. Rotary Rasp-16684 at The Home Depot
Note: Learn to Love WidgetSupply.com for Dremel accessories!
- It's hard to say which de-burring bits are the best. Over the course of these projects, I feel I've used one of each from these pages:
Dremel Inverted Cone Steel Burrs and Cutters
Dremel Cylinder Steel Burrs & Cutters (the large cone bit I've used a LOT)
Dremel Bud Steel Burrs & Cutters
Sanding Drums/Bands (you'll go through a LOT of them, I found I worked off about 2 grits, a really abrasive one and then a finer one for finishing).
Dremel Sanding Index
Also, I have an 80 and 120 grit flap wheels, they are nice but not an end all be all with this project.
Polishing buffs:
36pc 15/16 inch 180 Grit Abrasive Buff Wheels Fits Dremel
36pc 15/16 inch 240 Grit Abrasive Buff Wheels Fits Dremel
Step Drill Bits - Helped a LOT in removing the first part of the MAF bridge on the 99 and earlier Throttle Body and boring the MAF opening close to size (had to finish that manually with a de-burring bit and honing it out). Also, there is a lot of "fine" grinding on the top of the throttle body for the MAF to rest properly.
If you are not porting the inlet of the throttle body OR use a 2000+ that has a MAF Hump instead of a MAF bridge, no need for the step bits.
2 Piece Titanium Nitride Coated High Speed Steel Step Drill Bits
And lastly a kit like this (also getting some fine sanding disc for it helps too):
2 in, 3 in. Fiber Disc Sanding Kit
A lot of this is having an idea of what tools, bits and accessories to try. Then try them out and find what works. The UIM and throttle body will involve HOURS of work. If you want a polished look, that takes even longer. Greg/Zippy02, I believe he had his UIM chrome coated (which can cut down some of the effort required in the project).
Also, wear safety glasses when doing this work. When doing my original L67 throttle body years ago, I took a metal shard in the eye and a trip to the ER with a hefty bill (kinda negated my attempted cost savings).
For cleaning, you can experiment with degreaser products. I got a big plastic tote and soaked the LIM in mineral spirits, once a day agitating the LIM with a a variety of things from a tooth brush, nylon dish washing brushes, paint brush and wire brush (I've soaked about 3 LIMs and my L26 UIM in this set up and the tote is warping). I've re-bottled the mineral spirits and re-used the stuff for other nasty cleaning products. By the time I'm done, any odors in the metals from the mineral spirits are gone.
I've heard of people throwing this stuff in the dish washer, but I could not bring me to do it (did not want sharp or rough surfaces on car parts damaging the coating to the wire racks in the dishwasher and I don't think my wife would have approved of it lol).
In the future, I might consider other products like Simple green (I used sprays of Simple Green on the last throttle body and it didn't do too bad). Just have to experiment.
Now for tools, make sure you have a corded drill motor and a good Dremel. I also recommend the flexible extension for the Dremel. If you have access to a drill press and a cone rotary rasp, that helped me a LOT with machining down the step on the exit of the throttle body (so it blends smoother to the adapter plate and the UIM).
- Vermont American 1/4 in. Black Steel Rotary Rasp-16682 at The Home Depot (this was helpful to enlarge the opening from the UIM snout into the main UIM chamber, don't enlarge below where the HV3 ends up sitting, otherwise, you now have a step you probably don't want).
- Vermont American 5/8 in. x 1-3/8 in. Rotary Rasp-16684 at The Home Depot
Note: Learn to Love WidgetSupply.com for Dremel accessories!
- It's hard to say which de-burring bits are the best. Over the course of these projects, I feel I've used one of each from these pages:
Dremel Inverted Cone Steel Burrs and Cutters
Dremel Cylinder Steel Burrs & Cutters (the large cone bit I've used a LOT)
Dremel Bud Steel Burrs & Cutters
Sanding Drums/Bands (you'll go through a LOT of them, I found I worked off about 2 grits, a really abrasive one and then a finer one for finishing).
Dremel Sanding Index
Also, I have an 80 and 120 grit flap wheels, they are nice but not an end all be all with this project.
Polishing buffs:
36pc 15/16 inch 180 Grit Abrasive Buff Wheels Fits Dremel
36pc 15/16 inch 240 Grit Abrasive Buff Wheels Fits Dremel
Step Drill Bits - Helped a LOT in removing the first part of the MAF bridge on the 99 and earlier Throttle Body and boring the MAF opening close to size (had to finish that manually with a de-burring bit and honing it out). Also, there is a lot of "fine" grinding on the top of the throttle body for the MAF to rest properly.
If you are not porting the inlet of the throttle body OR use a 2000+ that has a MAF Hump instead of a MAF bridge, no need for the step bits.
2 Piece Titanium Nitride Coated High Speed Steel Step Drill Bits
And lastly a kit like this (also getting some fine sanding disc for it helps too):
2 in, 3 in. Fiber Disc Sanding Kit
A lot of this is having an idea of what tools, bits and accessories to try. Then try them out and find what works. The UIM and throttle body will involve HOURS of work. If you want a polished look, that takes even longer. Greg/Zippy02, I believe he had his UIM chrome coated (which can cut down some of the effort required in the project).
Also, wear safety glasses when doing this work. When doing my original L67 throttle body years ago, I took a metal shard in the eye and a trip to the ER with a hefty bill (kinda negated my attempted cost savings).
#35
08-26-2014, 10:12 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,195
So you got a package deal on an L26 UIM and L67 throttle body? Did you compare any of the L26 numbers with the info I have in this thread to know which one your getting (as GM has two different styles but to my knowledge there is no difference in how they list them, but I had both in my garage and shared stamping notes from the two).
Also, does the L67 throttle body have the MAF bridge or the MAF hump? If it has the bridge, you can port the inlet and use the same MAF you currently have on the car (or you can re-tune the MAF table and use the MAF for that generation throttle body).
TO my knowledge the TPS, MAF and IAC from a 2000+ L36 and L67 are the same. The only difference is how the MAF table is tuned. But, your not running a boosted set up, so even if they were different, it doesn't matter. I'm using the sensors that came with my Monte from the factory with the set up I am running. But, because I wanted a ported inlet, I had to get the PCM re-tuned for the MAF table to be adjusted to the change. PCMforLess.com did the tune I've been running on.
Hope all this info helps. Best of luck with your project
Also, does the L67 throttle body have the MAF bridge or the MAF hump? If it has the bridge, you can port the inlet and use the same MAF you currently have on the car (or you can re-tune the MAF table and use the MAF for that generation throttle body).
TO my knowledge the TPS, MAF and IAC from a 2000+ L36 and L67 are the same. The only difference is how the MAF table is tuned. But, your not running a boosted set up, so even if they were different, it doesn't matter. I'm using the sensors that came with my Monte from the factory with the set up I am running. But, because I wanted a ported inlet, I had to get the PCM re-tuned for the MAF table to be adjusted to the change. PCMforLess.com did the tune I've been running on.
Hope all this info helps. Best of luck with your project
#38
08-27-2014, 07:47 PM
So you got a package deal on an L26 UIM and L67 throttle body? Did you compare any of the L26 numbers with the info I have in this thread to know which one your getting (as GM has two different styles but to my knowledge there is no difference in how they list them, but I had both in my garage and shared stamping notes from the two).
Also, does the L67 throttle body have the MAF bridge or the MAF hump? If it has the bridge, you can port the inlet and use the same MAF you currently have on the car (or you can re-tune the MAF table and use the MAF for that generation throttle body).
TO my knowledge the TPS, MAF and IAC from a 2000+ L36 and L67 are the same. The only difference is how the MAF table is tuned. But, your not running a boosted set up, so even if they were different, it doesn't matter. I'm using the sensors that came with my Monte from the factory with the set up I am running. But, because I wanted a ported inlet, I had to get the PCM re-tuned for the MAF table to be adjusted to the change. PCMforLess.com did the tune I've been running on.
Hope all this info helps. Best of luck with your project
Also, does the L67 throttle body have the MAF bridge or the MAF hump? If it has the bridge, you can port the inlet and use the same MAF you currently have on the car (or you can re-tune the MAF table and use the MAF for that generation throttle body).
TO my knowledge the TPS, MAF and IAC from a 2000+ L36 and L67 are the same. The only difference is how the MAF table is tuned. But, your not running a boosted set up, so even if they were different, it doesn't matter. I'm using the sensors that came with my Monte from the factory with the set up I am running. But, because I wanted a ported inlet, I had to get the PCM re-tuned for the MAF table to be adjusted to the change. PCMforLess.com did the tune I've been running on.
Hope all this info helps. Best of luck with your project
Thanks so much for that list that's gonna make things so much easier.
And I got a package deal on a
2004 L26 Aluminum Upper Intake,
2000+ L67 Throttle Body with the MAF "Hump",
AND a 2004 L26 LOWER Intake Manifold!
All for $105 shipped! and I included the casting number of the "good one" so hopefully Morad Auto Parts will check the number on the casting with the email I sent him. I also included the casting number in the "note to seller" portion if the paypal invoice so hopefully it will be the right one. If its not, can I not use it in this build?
I got the TB with the hump cuz I didn't feel like monkeying around with the MAF bridge and porting the MAF inlet so I got one that'll fit, and that's good to know that the ports are the same for sensors cuz I'm pretty sure its just a bare throttle body. So if its the "hump" and I only do a little bit of porting on the inner walls of the TB and not touch the hump, or change too much on the inside but just polish it and smooth it out, will I have to have to retune the MAF..? This is my daily car so I can't really afford to have it down that long with sending in my pcm. that's why I'm getting salvage arts and pre-prepping them.
I'm ordering a
full L26 intake assembly to machine and polish and port myself,
New FelPro gaskets all around,
TB Adapter Plate Kit by ZZP
ZZP L26 HV3,
stainless bolts,
aluminum elbows,
TB heat shield, and installing it all at once so that once this build is done, ill never have to touch the top of my engine again beyond injectors
And yes I have access to a corded Drexel or "Rotary Tool" that has that attachments hose extension and a drill press. Really a whole pull barn that is owned by my Grandfather who used to own a service station and was a mechanic for a long time. So hes got everything you'd need for for working on cars, lucky for me. I will surely order all those bits you listed above. I'm ordering everything I need at once before I install anything. Gradually doing the porting/machining lil bit at a time (starting school soon), and when I have the money and everything is done with the metal parts, I'm making one last big purchase from ZZP of gaskets and adapters and other add-ons that have anything to do with this part of the engine so that when I'm done, I'm done and when I go to turbo the car awhile from now, everything having to do with air and making sure everything is solid and can handle boost will be done and ik its done right and will handle it and last longer, and ik in my head that I wont have to worry about the 3800's most common coolant related problems.
BTW, I really like the style valve covers you have rather than the ones you can buy for the car that are aluminum and the top of it is flat, you know like the ones on ZZP? I like the style you have. They're Aluminum and they have that 3-Raised-Strip detail going down the middle that I think looks tougher. So Where did you buy the FBody Valve Covers From? I wanna get a front one at least and polish them to a high-shine and clear coat them so that theyll be a lil different than yours but the same casting.
and also, why does everyone talk about filling in the ports for coolant Er something like that? stopping coolant from entering this place and that place with the intake manifolds and the Tb?.. ik u mentioned it but didn't quiet clearly show what you did and why and how.
Thank you SO much for all your in depth help with this. I'm only 17 and just getting into serious performance modding on this car and greatly appreciate all the help I can get.
After this intake build is done and I have my ZZP CAI to go with it, ill be adding a power log, and ER rockers to really make use of the added air and exhaust flow! My grandfather also mentioned he'd by an aftermarket good oil pump. Which after thinking about it would be another mod that would extend the life of the car and be really use full in a turbo application where more oil is being used. But I'm rambling haha sorry just love talking about cars! Thanks again Jason your the best.
Last edited by Cocky3800; 08-27-2014 at 08:14 PM.
#39
08-27-2014, 10:53 PM
Join Date: Apr 2010
Location: Mentor, Ohio
Posts: 12,195
Nice package deal for the three pieces. So you know, from all my reading and such, the L26 and L36 LIMs are the same, so you have a great donor to port match!
Regardless of which UIM design you get, it will all work. I have nothing that validates one design truly better then the other. But the one I call "good" has what appears to be a bigger and more rounded inlet into the main chamber of the UIM. Also, the "fins" on the inner roof of the UIM of the "good" one better match the ones found in the stock L36 UIM.
Since you got a 2000+ L67 throttle body with the MAF hump and you don't plan to do anything to the inlet, I don't know for a fact (only from what I've read), should be no tuning issues. Once you do all the mods you mentioned, tuning would help, but I don't believe it's a requirement.
As for my valve covers, the front and back are covers from a 3800 powered F-body. A member on a Bonneville forum I sometimes hit up already cleaned them and clear coated them. I bought them and slapped them on. Well worth it.
If you have not seen, I worked with a company that now offers a stainless steel LIM and UIM bolt kit for the L36. Check out http://www.alloyboltz.com.
Now the coolant ports you asked about. The factory has two small ports next to the EGR stove pipe. Those ports run coolant up into the UIM, then towards the throttle body. The throttle body has a pocket to then move the coolant to the opposite port and back down a reverse path. I've read various ideas why this exists. One idea is to prevent the throttle plate from sticking in the winter. I don't buy into that idea for a variety of reasons. The other reason I read and I think I can buy into a little is for fuel economy. FOr more HP and performance, you want cold/dense air. Well, for more MPG, this may not be the best case. So by flowing HOT coolant up to the throttle body, it helps slightly warm the air temp as it goes into the UIM.
I wanted to focus on performance, so I originally plugged the ports on my LIM (and I filled the pocket on both my old and current L67 throttle body). When I did the UIM swap, I filled the passages on the L26 UIM with JBWeld (and as mentioned, unless you were to modify the adapter plate, it's going to cut off coolant flow into the throttle body, but unless you block it at the LIM, you will still have coolant warming the snout of the UIM). Also, plugging the coolant ports on the LIM prevent any future issues of coolant leaks at the UIM gasket. If you have a plastic/factory L36 UIM, preventing coolant from getting into it also wards off the problem of heat from the EGR stove pipe making the plastic walls brittle and coolant eventually spraying into the UIM.
Here are some pics and info about my LIM with the coolant ports plugged and the coolant bypass opened up:
'04 Monte Carlo SS - Port Matched LIM
I hope all this information is helpful. Take you time, don't rush, don't expect it to be done quickly and in one night. Study the pieces before jumping into anything. Also, in areas that you have a LOT of metal work to do, experiment with the bits and find what works best for the different tasks. Took me a long time to get the hang of the different bits and what I liked and didn't. BTW - In my opinion, the rotary rasps I've used for the Dremel were very lack luster in performance, but those Vermont rotary rasps for the drill and drill press, wonderful! Also when I modded the outlet of the L67 throttle body, I bolted it the adapter plate and used a Sharpie marker to mark how much material I had until the throttle body would be properly feathered down to the adapter plate.
I hope this all helps.
When you get your parts and start, go ahead and start a thread regarding your process and what you're doing. It's a neat project and very few actually end up going forward with it (neat to see how others may find a different way to tackle it).
Regardless of which UIM design you get, it will all work. I have nothing that validates one design truly better then the other. But the one I call "good" has what appears to be a bigger and more rounded inlet into the main chamber of the UIM. Also, the "fins" on the inner roof of the UIM of the "good" one better match the ones found in the stock L36 UIM.
Since you got a 2000+ L67 throttle body with the MAF hump and you don't plan to do anything to the inlet, I don't know for a fact (only from what I've read), should be no tuning issues. Once you do all the mods you mentioned, tuning would help, but I don't believe it's a requirement.
As for my valve covers, the front and back are covers from a 3800 powered F-body. A member on a Bonneville forum I sometimes hit up already cleaned them and clear coated them. I bought them and slapped them on. Well worth it.
If you have not seen, I worked with a company that now offers a stainless steel LIM and UIM bolt kit for the L36. Check out http://www.alloyboltz.com.
Now the coolant ports you asked about. The factory has two small ports next to the EGR stove pipe. Those ports run coolant up into the UIM, then towards the throttle body. The throttle body has a pocket to then move the coolant to the opposite port and back down a reverse path. I've read various ideas why this exists. One idea is to prevent the throttle plate from sticking in the winter. I don't buy into that idea for a variety of reasons. The other reason I read and I think I can buy into a little is for fuel economy. FOr more HP and performance, you want cold/dense air. Well, for more MPG, this may not be the best case. So by flowing HOT coolant up to the throttle body, it helps slightly warm the air temp as it goes into the UIM.
I wanted to focus on performance, so I originally plugged the ports on my LIM (and I filled the pocket on both my old and current L67 throttle body). When I did the UIM swap, I filled the passages on the L26 UIM with JBWeld (and as mentioned, unless you were to modify the adapter plate, it's going to cut off coolant flow into the throttle body, but unless you block it at the LIM, you will still have coolant warming the snout of the UIM). Also, plugging the coolant ports on the LIM prevent any future issues of coolant leaks at the UIM gasket. If you have a plastic/factory L36 UIM, preventing coolant from getting into it also wards off the problem of heat from the EGR stove pipe making the plastic walls brittle and coolant eventually spraying into the UIM.
Here are some pics and info about my LIM with the coolant ports plugged and the coolant bypass opened up:
'04 Monte Carlo SS - Port Matched LIM
I hope all this information is helpful. Take you time, don't rush, don't expect it to be done quickly and in one night. Study the pieces before jumping into anything. Also, in areas that you have a LOT of metal work to do, experiment with the bits and find what works best for the different tasks. Took me a long time to get the hang of the different bits and what I liked and didn't. BTW - In my opinion, the rotary rasps I've used for the Dremel were very lack luster in performance, but those Vermont rotary rasps for the drill and drill press, wonderful! Also when I modded the outlet of the L67 throttle body, I bolted it the adapter plate and used a Sharpie marker to mark how much material I had until the throttle body would be properly feathered down to the adapter plate.
I hope this all helps.
When you get your parts and start, go ahead and start a thread regarding your process and what you're doing. It's a neat project and very few actually end up going forward with it (neat to see how others may find a different way to tackle it).
#40
08-28-2014, 12:59 AM
It definitely does!! Once again, thank you so much! I am defiantly going to take lots and lots of pictures of my process and do a write up on the forum! And ill be sure to give you credit for all your help.
And about the Bonneville Forum, I tried to go to the links you posted to get more info on the PCV and EVAP relocation and they don't work
so imma just try to look up articles on L26 swaps and see what I can find on that. And I did read everything in your website and went to all the sites you mentioned! I'm putting together a game plan with parts and pictures and links and prices in a OneNote document right now haha.
And btw I do wanna to do SOME porting in the TB so that it has smooth transitions from the Tb to the UIM. I'm just going to keep it minimal. I do plan to get a tune eventually. But I was just gonna get a ZZP PCM v1.0, will that be sufficient in taking advantage of these increase air flow mods? Otherwise imma check out pcmforless and see if I can buy a tuned pcm, or maybe talk to will overkill!
Where did you get the brass fittings btw? Can I get them in stainless? This should bring an end to my questions for awhile 😂. I just wanna make sure I do this right... its an extensive and expensive project and I want everything to work out the way its supposed to, and for my car to run the way its supposed to (or better) when its done. As I said, this is my daily.
So thanks again Jason for all your help with this ik I've been demanding alot of typing outta you 😆 so many thanks. Can't wait to start this. When I'm done imam polish the old throttle body and LIM and put them as decorations in my room hahaha.
It'll be about another $500 before I have everything to do the install. So. it'll be a long time coming (as yours was)..!