FZJ80 lower intake removal by sawzall

[jpoole]

I've heard mention of cutting the lower intake manifold to remove it without disconnecting the harness on either end, etc. but have never seen pictures so I thought I'd share a few.

The story is that after pulling the head on my '97, with lower intake in place but pulled out of the way, I decided that cleaning it would be difficult and risky with it near/over the open engine. With 200k+ of carbon build up the lower intake needed to be removed and since the wiring harness is one of the more fragile things on the truck I didn't want to mess with it any more than I had to. A little investigating lead me to believe that cutting the intake was the best option for my truck. I don't think strength or sealing will be adversely impacted at all.

A metal cutting blade in my cordless sawzall, plenty of protection to keep the aluminum out of the engine and a few quick minutes is all it took. The harness slid through the gap easily. Now that it's off I'll finish the cut edges a bit but only minimally.

 

[450LX]

A good option without any negative affects is my opinion. I doubt you will have any issues with sealing or rigidity. I just did my head gasket too and undid the ecm harness and slid it through. I didnt have any issues and it made it super easy to wrap the harness by the egr. However, I have heard of wires breaking while disturbing the harness. With the cutting of the lower intake one could bolt the lower intake on the head before setting it on the block. This would allow you to be able to torque all the bolts and give you a good handle to help set the head on with. I tried not to disturb the harness too much so i slid the lower intake over the harness in the natural position that the harness was in. If I tried this with the intake bolted to the head it would have been very akward. Nice work!

 

[jfz80]

There go the nuns.... kidding; Nice work. Several before you have ventured here. Beno has some good pics of his still up from 2008/9 era i just came across the other day. That harness weaving is a PITA for sure trying to get all the plugs up through the runners.

 

[fz1boxer]

i just did this but cut it after just to make it easier installation.i wanted to check the harness and make sure everything was well connected before putting the intake back on,which being cut was much easier to do.

 

[AustinKordell]

Hey man I’m doing the head gasket on my 80 right now and have reached the harness part of the job. Being shocked at the illogical design that is running the harness through the manifold I turned to mud to find a better solution and found your thread.

How is this holding up 7 years later? Any issues with the manifold sealing or notable negative consequences?

If none this will be the method I do going forward to make my life easier now and make field repairs a lot easier. Also, I’m looking for a trustworthy machine shop in east TN to do the head work, I’m in knoxville but I’m willing to drive for a good reputable shop. Thanks!

 

[Kernal]

All the way across the state but this company is known to do good work (however don't know if they do the head work themselves or send it out??)

MOSLEY MOTORS

Mosley Motors is a company that provides parts and services for FJ40, FJ60, FJ80, FZJ80, UZJ 100 Toyota Land Cruisers. Engine conversions, fuel injections kits, leather upholstery and more.

www.mosleymotors.com

 

[jpoole]

@AustinKordell

I've had no issues with the head, or whole drive train for that matter, since the head gasket replacement work that I did about 80k miles and 7ish years ago. I really don't see how removing the section from the intake could compromise the integrity of the intake manifold or cause any sealing issues and I don't think you'll have any issues if you make the same cut and then just moderately smooth/clean the surfaces without removing material in the gasket sealing area.

Dover cylinder heads here in Chattanooga did the head work and the engine has run great including towing a 3k lb camper to the Rockies and all around the Appalachians/etc. I've noticed no valve noise and haven't had any odd running issues, etc. My notes indicate that for $350 in 2017 they did:

"valve job, new stem seals installed, valve lash check/set, surface, pressure check, clean"​

I did the head gasket, etc., job as preventative maintenance because at 220k my 80 was in really neglected and rough shape but since going through the HG and a lot of little "while in there's" it's been an impressively reliable rig since. I wasn't sure all the work was going to be worth the effort back then but my belief that once "right" the 80 series platform is very reliable has proven true.

Good luck with the work.

 

[AustinKordell]

@AustinKordell

I've had no issues with the head, or whole drive train for that matter, since the head gasket replacement work that I did about 80k miles and 7ish years ago. I really don't see how removing the section from the intake could compromise the integrity of the intake manifold or cause any sealing issues and I don't think you'll have any issues if you make the same cut and then just moderately smooth/clean the surfaces without removing material in the gasket sealing area.

Dover cylinder heads here in Chattanooga did the head work and the engine has run great including towing a 3k lb camper to the Rockies and all around the Appalachians/etc. I've noticed no valve noise and haven't had any odd running issues, etc. My notes indicate that for $350 in 2017 they did:

"valve job, new stem seals installed, valve lash check/set, surface, pressure check, clean"​

I did the head gasket, etc., job as preventative maintenance because at 220k my 80 was in really neglected and rough shape but since going through the HG and a lot of little "while in there's" it's been an impressively reliable rig since. I wasn't sure all the work was going to be worth the effort back then but my belief that once "right" the 80 series platform is very reliable has proven true.

Good luck with the work.

Great to hear. Will contact that shop tomorrow and see if I can talk to someone.

Made a slight mistake tonight on my initial cut with the angle I went at (stupid mistake that’s totally on me) and ended up straying further down into the manifold then I had Intended closer to the mounting bolt.

Caught my mistake but was too late by the time I had realized, unsure if I will attempt to run this manifold or if I will just buy a used one and make the right cut. Part of me thinks it Should be fine but I’m loosely concerned with vibrations over time causing the cut to spread leading to the manifold losing its torque.

Any opinions on the matter?



Update: got a used one on the way, rather not chance it.

 

[OGBeno]

Funny how this stuff re-emerges after many years. I did this in 2007 or 2008 I think…. December 16, 2007 to be exact.

Far out.

EDIT: Found the old picture.

 

[deltapine1]

It looks like @OGBeno cut his at the flange for the upper intake manifold flange and @jpoole elected to cut the lower Intake flange to the Head. I am building a motor for Beaulah and plan to do mine when I swap engines. Is there a reasonable advantage to one or the other?

 

[AustinKordell]

It looks like @OGBeno cut his at the flange for the upper intake manifold flange and @jpoole elected to cut the lower Intake flange to the Head. I am building a motor for Beaulah and plan to do mine when I swap engines. Is there a reasonable advantage to one or the other?

I did mine the way jpoole did, 7k later and it’s been fine. I’d say both are likely fine.

 

[jpoole]

I'm sure either cut is fine since there have been no problems reported from those that have made the upper or lower cut to the lower manifold.

My logic for cutting the lower end was that I thought the lower cut made it possible for me to get the head/intake out of the bay with minimal movement of the harness. I assume you can cut the top of the lower manifold and get the manifold out with minimal harness movement as well but this is a factor to consider since less movement of the harness is a good thing.

A larger factor for me was that I didn't want to remove the upper segment of the lower manifold because it means removing a bolt or clamping point for the upper joint/gasket. Cutting the lower segment seemed less likely to impact the sealing as you aren't losing any bolt points and the bolt positioning and meatiness of the lower intake seems sufficient without the removed segment. Once bolted up to the head the lower end of the lower intake manifold is also well supported from movement.

 

[OGBeno]

It looks like @OGBeno cut his at the flange for the upper intake manifold flange and @jpoole elected to cut the lower Intake flange to the Head. I am building a motor for Beaulah and plan to do mine when I swap engines. Is there a reasonable advantage to one or the other?

Mine was a lower manifold cut.

 

[jpoole]

Yeah, it's probably worth clarifying that the question is on which end of the lower manifold to cut. Both cuts were on the lower manifold with one on the upper end and the other on the lower end.

 

[IdahoDoug]

While I hate seeing any mods from factory, it's worth noting that in the old days many intake manifolds were two separate pieces. These were also often cast iron which is heavier and more likely to cause issues if any were going to result. One comment I'd make is there is a steel support arm from the intake down to the engine block and I have seen people skip reinstalling that before. I would ensure it's reinstalled if you cut your intake just for a margin of safety.

 

[Kernal]

I've been thinking about making up a simple short brace/bracket (personal use, not to sell) to bridge the space between the bolt holes on either side of the cut if I ever have to cut my intake manifold however IDK how much that would help?? The area around at least one of the bolt holes would need a little grinding to get a flat surface for the mini-brace IMO. FWIW.

 

[OGBeno]

Yeah, it's probably worth clarifying that the question is on which end of the lower manifold to cut. Both cuts were on the lower manifold with one on the upper end and the other on the lower end.

Mine was between the two runners where the factory harness came through.

 

[jpoole]

between the two runners where the factory harness came through

Yeah, and if that's your photo in your post above then it shows you made the cut on the upper or upstream end of the lower intake. The cut I made was on the lower, head end of that lower intake.

@deltapine1 was inquiring about which end to cut the lower intake on and that's what got this conversation going again. I shared a few reasons why I chose to make the cut on the lower end above. Do you see any compelling reasons to make the cut on the upper end of the lower intake? Those may help detlapine weigh the options.

 

[NKP Garage]

the 1fz intake manifold is always an adventure to remove. I got mine out a while back without cutting, but chopping off a small piece could have helped.

I had to use a variety of wobble extensions and sockets to get to all the bolts, but finally got it off. Definitely an adventure of frustration and busted knuckles.

-

 

[lumbee1]

I search MUD all the time for hints and tricks. I'm replacing my headgasket now and found this thread. I didn't realize there were recent updates. I literally just ran outside and cut my lower intake manifold like @jpoole, smoothed out the edges of the cut and manifold, and leveled burs on the matting surface. I really hate having to disconnect the lower part of the harness to the O2 sensors and transmission and I wish I would have made this cut in 2021 when the engine was out.