I decided to pull the plug on this massive project after my high-side AC hose started leaking and therefore needed replaced anyway, and my timing belt needed done giving me a spare tensioner. Let me start by saying this is a substantial project--if and when Wits End comes out with 1HDT York kit, definitely DO NOT bother doing this on your own regardless of the cost of the kit.
All my detailed full-res photos are here:
What I didn't know when I started:
(Full install with tank and crap isn't yet complete, this is my Phase 1 minimalist setup)
I'm probably $1000+ into this project. My purchase list:
There's a few threads on here with a few different approaches to this mod:
1HD-T + A/C + York, tensioner between York & AC
Using a Sanden instead of a York, tensioner in stock-ish location
And finally The combined approach
The basic idea is to bolt the York to the block and attach the AC to the York. The belt tensioners are where things get variable. I mimicked the @NLXTACY approach which essentially combines the two earlier approaches: One tensioner between York + AC (reused timing belt idler), stock tensioner between York + harmonic balancer. This gets me a max of ~80lb of belt tension which seems to work fine with both York and AC running at the same time.
I went this way to save space in the hope of being able to add a front-mount IC in the future, however that seems like it would be INSANE to squeeze in there. In hindsight it would be MUCH easier to both fabricate and swap out the belt by going with the single-tensioner approach, at the expense of space where front-mount IC piping would go....that looks like this:
(Important note about this build: His York only has one pulley and it's the outer pulley which forces everything in his build back, this is NOT good for space especially between the AC compressor and the intake! You definitely want to run the belt on the inner pulley)
Cons of the two-tensioner approach: I have to take the timing cover off to screw with the belt which is a bit of a PITA, and there is a limit to the max tension because everything is so tight and it's not quite in the 100-120 lb range where this belt likely wants to be.
I would highly recommend removing the condenser/radiator, the York is HEAVY and it's nice to have a LOT of room to work.
The York Compressor
It'll come with PAG or some other crap AC oil, this needs fully drained and replaced with SAE 30 or 40 weight or equivalent. DO NOT use mixed weight oils (10W30) as they will break down under the high heat and become, e.g., only 10 weight. I just used some Ace Air Compressor Oil I had laying around that is 30 weight. Again, I learned this the hard way after trying the original PAG and it was turning brown! You will also only want to refill with 3-4 oz instead of the specified huge amount (12?) because if you add more it'll just blow out the hose. There's a mod floating around to reduce oil blowby via plugging an internal hole in the suction side, but it doesn't help enough to bother. There's a post on here where someone experimented and the biggest variable in blowby was simply oil level.
The holes on each side are tapped 3/8x16, you need to run a tap in to clean them out for a bolt to get proper depth. A 1" long bolt will fit nicely thru a 1/4" plate once the holes are cleaned out.
The Plates
I made drawings of my basic plate layout, you can download them here. Print them at 100% scaling. Note that I DID NOT dead-nuts nail the AC compressor location, I lined up the pulleys but they have different cross sections. I slotted my holes probably 3mm but it's still a bit off. I have adjusted it on these drawings to my best-guess of where it should be (5mm off from my as-made plates). I'd recommend oversizing the York attachment holes so you have a bit of wiggle room with the plate--caveat emptor, you get what you pay for here.
Both plates require additional welded elements to work correctly.
York to Block
The York-to-Block plate template seems perfect dimensionally. The forward-facing output on my York just barely touches the hood insulation so the height is dead-on.
To install the York must be bolted to the plate first because there's no clearance for wrenching. I would highly recommend using STUDS with nuts instead of BOLTS in the block to significantly easy installation (again, this is HEAVY). The studs you need are the M10x1.25 (I think) exhaust studs, 2x 90116-10171.
There needs to be a cutout on bottom to clear the turbo oil hardline (you can also see a block stud I placed here):
You need to weld on a tab with a few holes in the front to properly secure the thing (sorry don't have dims for this, make the plate then bolt it up then measure/mark/weld). Shown without tensioner block added yet:
If you go the two-tensioner route, you need to add a tensioner block....Sorry no dims, I used 2x2x1/4 angle iron modded in an intricate fashion and welded on to the plate (again, a reason to NOT go this route and also note how tricky it is to install the bolts into the block under it!). The height of the tensioning area is limited by the timing cover which needs to slide in here:
York to AC
As mentioned, the York-to-AC plate drawing isn't 100% verified to be perfect but I do believe it's close-enough now. When you get the alignment off this is what happens (you can see the belt angle onto the York pulley is weird):
You can really only check it properly while it's running which means full reassembly, total PITA. I've since adjusted it over a few mm which wasn't quite enough. Like I said, I modified my drawing 5mm from the one shown above which I think should be good.
The York-to-AC bracket is a bit of a weird monster overall:
You need a hole for the oil fill plug on the York, you need a bracket to hold the second tensioner (idler), you need clearance for the low-side port on the AC compressor, and you need standoffs that tilt the AC compressor.
I didn't bother running a leg off the bottom to the now-empty hole in the block just above the alternator, but it would be a good idea (you can see that hold in the turbo hardline cutout photo above). Everything is TIGHT TIGHT around this plate including alternator clearance:
The AC compressor needs tilted for a few reasons:
I achieved the tilt in a fairly simple manner mechanically (getting it to stay put while welding was less simple, very important too because you're putting really long screws in thru the compressor so if this is off just a little it will want to cross-thread). On the bottom I simply used 2 normal nuts and on the top I used a few 25mm tall couplers (both M8x1.25 thread). I used 2 couplers at each location on top to get me the required distance, one turned on its side and another sticking straight out (you can see this in the plate photo a few up) for a total angled offset of 38mm:
I just bought them from Amazon.
The Tensioners
For the York-to-AC plate tensioner I just re-used the old timing idler as you can see a few photos above, thanks to @NLXTACY for this idea! Pretty straightforward to execute.
On the York-to-Block plate I could have, but did not, reuse my factory tensioner because the bearings were going bad. Instead of the "expensive and not available in NA" factory tensioner I tried 88440-26090 and it worked great at <$30. As a bonus the bearing in this one is held by a removable circlip so easily replaceable! The only difference was the thickness of the washer that came with it:
It looks like this once installed:
Note the impossible clearance on the tensioning bolt under the timing cover. The timing cover must be removed to screw with the belt tension, and it takes some wiggling of that cover to get it out of there with the belt tensioned.
Clearances
There are a few problematic clearance areas to consider: AC-to-air intake tube (rear side of AC), AC-to-battery box, and then the AC lines themselves.
The rear side of the AC has just enough room from the intake tube, you can kinda see the clearance in the photo below. I also have a Denso 471-1141 which is the smaller 10PA15C, I think some folks have a 10PA17C which is slightly longer....that may not fit.
In my design, the AC-to-battery box just BARELY squeaks by without modification.....I think maybe 3/8" clearance:
But this sits exactly right where the metal hook for the battery tie-down wants to go and that was too close to comfort, so I put in a replacement tie down. I just did a gnarly offroad trip to the Maze District with no rubbing so I think this is OK. I also slightly relocated my fusible links by adding a new mounting hole to the battery box to support/hold them behind the compressor with that little clip on those lines.....and re-routed my alternator wire:
AC Lines
The first problem to overcome is that the AC charge ports are no longer accessible for charging (high side maybe but definitely not the low side). What you need are, IIRC, "port extenders". But these ports are goofy because the high side is smaller than normal so of course not all extenders will work!
These are the ones that fit the smaller high side fitting, but it ends in a flared fitting so I also added another hose from this kit to end in an R134a fitting (this latter kit is also what I used on the low side because it fit fine).
In terms of the lines themselves, like I said this was BY FAR the most frustrating and difficult part of this whole project. Super didn't see it coming. The short story is that the stock AC lines will work as-is without modification, although it's very tight as the low pressure line has to be wedged inbetween the air cleaner box and the inlet tube:
This probably isn't ideal for very long. The high pressure line just needs some elbow grease contortion but it goes on without difficulty, routed under the battery box.
I spent an absurd amount of time and money on parts trying to re-route the lines. Remember I said that my high pressure line sprang a leak and needed replaced which is what started this whole project! What I ended up doing is buying the Mastercool AC crimper and just recrimping my existing line and it's holding OK so far. The AC lines are NLA on these early 90s HDJ81s and 3FEs as well.
For nitty-gritty details on options/sources for new lines and P/Ns and such, see this thread. This thread also shows ideal low-side hose routing around/under the intake box. I'm not sure what the deal is, but it would appear as though my early 1990 fittings are somewhat different from later model (or just JDM?) because these off-the-shelf third-party adapters apparently work on later models but definitely not my rig. @NLXTACY shows custom replacement fittings he made in that thread but I couldn't find them on his website. Basically that's what you need to do this simply, custom adapters which take these Toyota fittings and adapt them to standard Female O-Ring fittings (you want Female instead of Male O-Ring because Male O-Ring has like 10% the fitting options as Female for some reason). I live 6 hours each way from the nearest AC shop that will do custom lines, hence I didn't just take it in. In hindsight I would have saved time to drive there and back and just have them do it....it would all have to be custom TIG welded using my current hose fittings since there are no adapters that fit.
I hope this helps someone in the future, and honestly I really hope it motivates a proper bolt-on kit for us 1HDT owners!
~Josh
All my detailed full-res photos are here:
What I didn't know when I started:
- A York spews oil. The biggest difference between electric and York compressors is that electric compressors will never have any oil in the airstream, which is really nice.
- A York runs super hot. I had a spare AC compressor sitting around so thought about going that hacked route instead but I didn't because I wanted a lower exit temp. However I can't imagine the York runs that much cooler.
- Trying to get custom AC lines have been the hardest part of the project, by far. I massively underestimated how stupidly complicated this could be. On the bright side, the stock hoses work it's just not ideal routing on the low side.
(Full install with tank and crap isn't yet complete, this is my Phase 1 minimalist setup)
I'm probably $1000+ into this project. My purchase list:
- A new Omega Engineering York 210-equivalent compressor
- Wit's End fittings for the York (Tube-O to AN), these are critical
- Various AN fittings and adapters....basically I used the 5/8" nipple on the air cleaner which used to have breather attached as the intake to AN10->AN8 fittings on the York, and AN8 for the outlet.
- The outlet temps get super hot (300-400 degrees) and need specialized hose to not blow apart: PTFE high temp hose or equivalent. (I learned this the hard way while airing up at midnight after my daughter broke her arm right before bed in the middle of nowhere, not a proud moment to have the new setup fail. Luckily the only gas station within 40 miles had shop air available and was only 5 miles of pavement away!!!)
- Obvious typical air setup stuff: Pressure switch, manifold, gauge, tank, fittings, coil hose.
- Because the York generates oil and runs hot you'll need not only a coalescing filter but a specialized one that can handle high temps. Wits End has the proper one with a mount. After some research it seems that this Coilhose model is really the only one out there at a reasonable price that fits the bill.
- The belt: I went with an AX56 cogged v-belt, 58" long and it's perfect. It must be cogged due to the tight bend radii involved in the two-tensioner approach.
There's a few threads on here with a few different approaches to this mod:
1HD-T + A/C + York, tensioner between York & AC
Using a Sanden instead of a York, tensioner in stock-ish location
And finally The combined approach
The basic idea is to bolt the York to the block and attach the AC to the York. The belt tensioners are where things get variable. I mimicked the @NLXTACY approach which essentially combines the two earlier approaches: One tensioner between York + AC (reused timing belt idler), stock tensioner between York + harmonic balancer. This gets me a max of ~80lb of belt tension which seems to work fine with both York and AC running at the same time.
I went this way to save space in the hope of being able to add a front-mount IC in the future, however that seems like it would be INSANE to squeeze in there. In hindsight it would be MUCH easier to both fabricate and swap out the belt by going with the single-tensioner approach, at the expense of space where front-mount IC piping would go....that looks like this:
(Important note about this build: His York only has one pulley and it's the outer pulley which forces everything in his build back, this is NOT good for space especially between the AC compressor and the intake! You definitely want to run the belt on the inner pulley)
Cons of the two-tensioner approach: I have to take the timing cover off to screw with the belt which is a bit of a PITA, and there is a limit to the max tension because everything is so tight and it's not quite in the 100-120 lb range where this belt likely wants to be.
I would highly recommend removing the condenser/radiator, the York is HEAVY and it's nice to have a LOT of room to work.
The York Compressor
It'll come with PAG or some other crap AC oil, this needs fully drained and replaced with SAE 30 or 40 weight or equivalent. DO NOT use mixed weight oils (10W30) as they will break down under the high heat and become, e.g., only 10 weight. I just used some Ace Air Compressor Oil I had laying around that is 30 weight. Again, I learned this the hard way after trying the original PAG and it was turning brown! You will also only want to refill with 3-4 oz instead of the specified huge amount (12?) because if you add more it'll just blow out the hose. There's a mod floating around to reduce oil blowby via plugging an internal hole in the suction side, but it doesn't help enough to bother. There's a post on here where someone experimented and the biggest variable in blowby was simply oil level.
The holes on each side are tapped 3/8x16, you need to run a tap in to clean them out for a bolt to get proper depth. A 1" long bolt will fit nicely thru a 1/4" plate once the holes are cleaned out.
The Plates
I made drawings of my basic plate layout, you can download them here. Print them at 100% scaling. Note that I DID NOT dead-nuts nail the AC compressor location, I lined up the pulleys but they have different cross sections. I slotted my holes probably 3mm but it's still a bit off. I have adjusted it on these drawings to my best-guess of where it should be (5mm off from my as-made plates). I'd recommend oversizing the York attachment holes so you have a bit of wiggle room with the plate--caveat emptor, you get what you pay for here.
Both plates require additional welded elements to work correctly.
York to Block
The York-to-Block plate template seems perfect dimensionally. The forward-facing output on my York just barely touches the hood insulation so the height is dead-on.
To install the York must be bolted to the plate first because there's no clearance for wrenching. I would highly recommend using STUDS with nuts instead of BOLTS in the block to significantly easy installation (again, this is HEAVY). The studs you need are the M10x1.25 (I think) exhaust studs, 2x 90116-10171.
There needs to be a cutout on bottom to clear the turbo oil hardline (you can also see a block stud I placed here):
You need to weld on a tab with a few holes in the front to properly secure the thing (sorry don't have dims for this, make the plate then bolt it up then measure/mark/weld). Shown without tensioner block added yet:
If you go the two-tensioner route, you need to add a tensioner block....Sorry no dims, I used 2x2x1/4 angle iron modded in an intricate fashion and welded on to the plate (again, a reason to NOT go this route and also note how tricky it is to install the bolts into the block under it!). The height of the tensioning area is limited by the timing cover which needs to slide in here:
York to AC
As mentioned, the York-to-AC plate drawing isn't 100% verified to be perfect but I do believe it's close-enough now. When you get the alignment off this is what happens (you can see the belt angle onto the York pulley is weird):
You can really only check it properly while it's running which means full reassembly, total PITA. I've since adjusted it over a few mm which wasn't quite enough. Like I said, I modified my drawing 5mm from the one shown above which I think should be good.
The York-to-AC bracket is a bit of a weird monster overall:
You need a hole for the oil fill plug on the York, you need a bracket to hold the second tensioner (idler), you need clearance for the low-side port on the AC compressor, and you need standoffs that tilt the AC compressor.
I didn't bother running a leg off the bottom to the now-empty hole in the block just above the alternator, but it would be a good idea (you can see that hold in the turbo hardline cutout photo above). Everything is TIGHT TIGHT around this plate including alternator clearance:
The AC compressor needs tilted for a few reasons:
- The low side port won't clear the plate (basically the cutout would need to extend to the mount), you can see how tight it is even while tilted:
- The compressor needs to clear the bolts going into the York, which it barely does even while tilted (sorry don't have a good pic of this but it's definitely sitting ON the bolts)
- If you want to retain factory AC lines, you'll need the tilt so the low pressure line can squeeze inbetween the intake box and intake pipe
I achieved the tilt in a fairly simple manner mechanically (getting it to stay put while welding was less simple, very important too because you're putting really long screws in thru the compressor so if this is off just a little it will want to cross-thread). On the bottom I simply used 2 normal nuts and on the top I used a few 25mm tall couplers (both M8x1.25 thread). I used 2 couplers at each location on top to get me the required distance, one turned on its side and another sticking straight out (you can see this in the plate photo a few up) for a total angled offset of 38mm:
I just bought them from Amazon.
The Tensioners
For the York-to-AC plate tensioner I just re-used the old timing idler as you can see a few photos above, thanks to @NLXTACY for this idea! Pretty straightforward to execute.
On the York-to-Block plate I could have, but did not, reuse my factory tensioner because the bearings were going bad. Instead of the "expensive and not available in NA" factory tensioner I tried 88440-26090 and it worked great at <$30. As a bonus the bearing in this one is held by a removable circlip so easily replaceable! The only difference was the thickness of the washer that came with it:
It looks like this once installed:
Note the impossible clearance on the tensioning bolt under the timing cover. The timing cover must be removed to screw with the belt tension, and it takes some wiggling of that cover to get it out of there with the belt tensioned.
Clearances
There are a few problematic clearance areas to consider: AC-to-air intake tube (rear side of AC), AC-to-battery box, and then the AC lines themselves.
The rear side of the AC has just enough room from the intake tube, you can kinda see the clearance in the photo below. I also have a Denso 471-1141 which is the smaller 10PA15C, I think some folks have a 10PA17C which is slightly longer....that may not fit.
In my design, the AC-to-battery box just BARELY squeaks by without modification.....I think maybe 3/8" clearance:
But this sits exactly right where the metal hook for the battery tie-down wants to go and that was too close to comfort, so I put in a replacement tie down. I just did a gnarly offroad trip to the Maze District with no rubbing so I think this is OK. I also slightly relocated my fusible links by adding a new mounting hole to the battery box to support/hold them behind the compressor with that little clip on those lines.....and re-routed my alternator wire:
AC Lines
The first problem to overcome is that the AC charge ports are no longer accessible for charging (high side maybe but definitely not the low side). What you need are, IIRC, "port extenders". But these ports are goofy because the high side is smaller than normal so of course not all extenders will work!
These are the ones that fit the smaller high side fitting, but it ends in a flared fitting so I also added another hose from this kit to end in an R134a fitting (this latter kit is also what I used on the low side because it fit fine).
In terms of the lines themselves, like I said this was BY FAR the most frustrating and difficult part of this whole project. Super didn't see it coming. The short story is that the stock AC lines will work as-is without modification, although it's very tight as the low pressure line has to be wedged inbetween the air cleaner box and the inlet tube:
This probably isn't ideal for very long. The high pressure line just needs some elbow grease contortion but it goes on without difficulty, routed under the battery box.
I spent an absurd amount of time and money on parts trying to re-route the lines. Remember I said that my high pressure line sprang a leak and needed replaced which is what started this whole project! What I ended up doing is buying the Mastercool AC crimper and just recrimping my existing line and it's holding OK so far. The AC lines are NLA on these early 90s HDJ81s and 3FEs as well.
For nitty-gritty details on options/sources for new lines and P/Ns and such, see this thread. This thread also shows ideal low-side hose routing around/under the intake box. I'm not sure what the deal is, but it would appear as though my early 1990 fittings are somewhat different from later model (or just JDM?) because these off-the-shelf third-party adapters apparently work on later models but definitely not my rig. @NLXTACY shows custom replacement fittings he made in that thread but I couldn't find them on his website. Basically that's what you need to do this simply, custom adapters which take these Toyota fittings and adapt them to standard Female O-Ring fittings (you want Female instead of Male O-Ring because Male O-Ring has like 10% the fitting options as Female for some reason). I live 6 hours each way from the nearest AC shop that will do custom lines, hence I didn't just take it in. In hindsight I would have saved time to drive there and back and just have them do it....it would all have to be custom TIG welded using my current hose fittings since there are no adapters that fit.
I hope this helps someone in the future, and honestly I really hope it motivates a proper bolt-on kit for us 1HDT owners!
~Josh
