Preparing For Honda K24a3/AST5 6spd Conversion

Figuring out the Heater feed/ Expansion Tank feed / Rad hose spaghetti junction. Plan is to keep them from touching the TB / inlet

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Assuming the tank is going to be in this vicinity, about level with the head, looking at Rodger's and others. -

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Rodgers pic for visual reference of tank hose placement. My fitting should be far enough forward to get a gentle arc with straight heater hose. Worst case, I get some with a elbow at one end.

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Worked on the heater / recirc / expansion tank feed / rad feed setup today.

Welded the rad hose neck, braised the exapnsion tank feed & organized a rad feed layout that brings a hose into the drop area. How those actually connect I will deal with once I have the engine setup in the frame. At least the overall layout is on hand. My heater return on the body is a hard line that comes up the firewall instead of a long length of heater hose.

Much the same as my rough fit, dropped the angle of the expansion feed elbow though.

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All hoses have slight air gaps between

Will have to use studs (92900-08040-0B) 8x40mm and flange nuts (94050-08080)
in all four positions - no way to insert a bolt under the rad neck. Gasket #
18714-RAA-A01
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expansion feed pipe braised, rad feed will have the Aluminum 1 3/8" joiner shown.

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Hose (3514629) tucks in around the extension housing, keeps in inboard of the water pump/ancillary bracket outer edge

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All Volvo rad hoses (feed hose 3507930) There will be a cushion/support where the tie wraps are now.
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Just curious, could one just use a continuous piece of hose making stabilizing mount points along the way? Looks like more than enough places to spring a leak if your that unfortunate. Might be a bugger to get to all those clamps once the engine is in place.

https://www.advancedfluidsolutions....oolant-hose-heater-pipe-1000mm-cut-4265-p.asp

https://www.viperperformance.co.uk/silicone-hoses_9853_flexible-silicone-hose.html

Thanks for the input. One could conceivably use that stuff, however personally not a fan of those flexibe lines, and I prefer regular hoses to silicone for coolant. Mine is pretty minimal in terms of junctions. The heater hose only needs to go straight forward to the firewall, it's not going down & under like stock X1/9s.

Have you looked at the other K20 Cooling hose layouts? I'm unlikely to find one generic hose that happens to curve just the way I want it. I think modular is preferable to allow access for the starter, etc. However, I will look to see if I can get it down to two hoses rather than three. Since the lower end has to make a 90 to meet the coolant pipes I'm not going to worry about that until I'm test fitting the motor.
 
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Got some work done on the runners / plenum layout today. Got the upper sections cut & tapered to fit. I'll tack the upper sections back first, then align the plenum elbows & tack those to the plenum, then weld the two sections back together. Gonna be a PITA to weld in-between the runners, if it's even possible, given the angles. I may need to get another outer section & recut it in the downturn instead of at the flange as I did :(

Took a bunch more material off the lower manifold, there was more webbing and material from the heating channels I didn't need to leave. Made for air passages between the runners.

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and the 2" elbows cut down, and basically figured out. Have to reweld the plenum neck where I chopped off the MAP port. Chopped the original plenum runners down to approx 1" stubs, ground them to fit inside the elbows, and tapered the outlets to get as smooth a transition to the elbows as possible.

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Thanks for the input. One could conceivably use that stuff, however personally not a fan of those flexibe lines, and I prefer regular hoses to silicone for coolant. Mine is pretty minimal in terms of junctions. The heater hose only needs to go straight forward to the firewall, it's not going down & under like stock X1/9s.

Have you looked at the other K20 Cooling hose layouts? I'm unlikely to find one generic hose that happens to curve just the way I want it. I think modular is preferable to allow access for the starter, etc. However, I will look to see if I can get it down to two hoses rather than three. Since the lower end has to make a 90 to meet the coolant pipes I'm not going to worry about that until I'm test fitting the motor.

Looking at what you can do with aluminum welding and bonkers (but very cool) intake mods, I'm thinking a clean stainless or aluminum hardline should be a piece of cake. Go from your the head outlet just above the starter and end where the t-stat exits and it'll look like it was designed that way.
 
Looking at what you can do with aluminum welding and bonkers (but very cool) intake mods, I'm thinking a clean stainless or aluminum hardline should be a piece of cake. Go from your the head outlet just above the starter and end where the t-stat exits and it'll look like it was designed that way.

Thank you :D

I had considered that route. My reticence at making a formed hard pipe for that is that the aluminum dissipates/radiates much more heat than the hoses - I’d like to avoid the potential heat soaking of the manifold if at all possible.

EDIt - I could possibly sleeve it though....
 
Got the runners all positioned where they need to be, so I tack welded them one at a time, rechecking the plenum alignment as I went.

After that, I started seam welding the runners to the flange, and the elbows to the plenum.

Not doing this on a regular / consistent basis, I forget to check the chart for little things like tungsten & cup sizing / cfm when I move away from the thin aluminum I typically weld. After I went through a tungsten in short order I remembered that the higher amp setting for this gauge aluminum meant I should be checking ALL my settings from scratch :D

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Gonna end up like this. I have to taper all the upper portions where they mate to the lowers so that they are no harsh inner transitions.

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clearances

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Stopped by my local machine/speed shop today to ask for tips on welding the runners. Based on our discussion, I ordered some gas lenses today - this setup is a real PITA to weld. I got the upper runners done (barely) with the regular torch cup, but it took hours, and used much argon. The gas lens allows the tungsten to be positioned further out of the torch cup, which is what I need. I'm gonna need the lenses for the lower runners (1st pic, previous post), I just can't get in-between them to close them off.

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I have been watching a ton of "how to weld" videos on YouTube and several of them have mentioned the gas lenses as the way to go. Good luck with the intake fab. I am impressed so far.
 
You'll still use a lot of argon with that, but it's all good. I think the hard part is getting in the tight spots between the runners. Don't weld outside (or more importantly: no wind) and a big cup will help, but you still gotta fit it in there (the cup # is based on x/16th's inch, so a #10 is 5/8")
 
While I’m waiting for the gas lenses, I worked for a couple hours on the gasket matching of the ports. Marker indicates how much can be removed, tapering into runners. I’ll look at head flange later.

Upper/outer runners
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Lower/ inner runners, not much needed here

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Looking at what you can do with aluminum welding and bonkers (but very cool) intake mods, I'm thinking a clean stainless or aluminum hardline should be a piece of cake. Go from your the head outlet just above the starter and end where the t-stat exits and it'll look like it was designed that way.

Thinking about this again. I think it would be worth having a go at an SS version. Doesn't transfer heat like aluminum, and will make the selection of hose at each end that much easier. Plus, I need a break from welding aluminum :D
 
Hussein for reasons that you stated above plus the fact that Stainless Steel is a dream to weld is why I always build in that material.

TonyK.

Grimsby Ontario Canada.
 
Worked on the heater / recirc / expansion tank feed / rad feed setup today.

Welded the rad hose neck, braised the exapnsion tank feed & organized a rad feed layout that brings a hose into the drop area. How those actually connect I will deal with once I have the engine setup in the frame. At least the overall layout is on hand. My heater return on the body is a hard line that comes up the firewall instead of a long length of heater hose.

Much the same as my rough fit, dropped the angle of the expansion feed elbow though.

IMG_6511.jpg


All hoses have slight air gaps between

Will have to use studs (92900-08040-0B) 8x40mm and flange nuts (94050-08080)
in all four positions - no way to insert a bolt under the rad neck.

IMG_6514.jpg


expansion feed pipe braised, rad feed will have the Aluminum 1 3/8" joiner shown.

IMG_6513.jpg


Hose (3514629) tucks in around the extension housing, keeps in inboard of the water pump/ancillary bracket outer edge

IMG_6510.jpg


All Volvo rad hoses (feed hose 3507930) There will be a cushion/support where the tie wraps are now.
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Hussein,

This may not be possible due to the intake configuration you are using, however I tucked the return coolant line from the coolant manifold under and around. It frees up more for room and just made sense. If I had gone the route you chose, the return line would interfere with getting to a lot of electronics and also the bleeder for the clutch slave.

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Hussein,

This may not be possible due to the intake configuration you are using, however I tucked the return coolant line from the coolant manifold under and around. It frees up more for room and just made sense. If I had gone the route you chose, the return line would interfere with getting to a lot of electronics and also the bleeder for the clutch slave.

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Thanks Tim.

With my intake, the tradeoff with not having a TB extension is less room under the intake. My rad coolant pipe has to run lower. I'm going to bring the harness for starter/ alt/ sensors in alongside the coolant pipe. I will confirm I can route it before I finalize the coolant pipe, so thanks for the reminder on that. I have a different slave that connects facing the leftside air duct, instead of top/inside like yours.
 
Worked on the intake a bit after work. Tacked the plenum half to the upper half. Everything aligns nicely. I cut the upper runners so they just fit evenly inside the lower elbow, and chamfered the inner transition to minimize any potential flow disruption.

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Had to fill the troughs in the lower runners up to the center junction. If I were to do it again, I would make a fill piece & bridge them. Filling them this way was an absolute bear.
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Started seaming the junctions
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The other issue was with the KTuned coolant housing. The opening in it doesn't align well with the hole in the head. There is minimal overlap in the inner sealing area. Pivoting it in a touch CCW, I got better surface area coverage. The next problem is that the blind hole they provide won't align with a solid flat in the head. Pivoting it in meant I had to drill and countersink a new upper mount hole inboard of the provided blind hole. Then I drilled the tap size hole in the head (M6x1)

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Pic of the redrilled KTuned housing, and the position of the coolant sensor which I drilled & tapped today. I put an oil pressure switch in there to check the fit. 14mm sensor on the way from MWB.

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This intake is killing me. I spent hours on Sat working on the runner crotches, and another hour today after work. Getting in the gaps is really difficult. If the angle isn't just right, the filler rod just builds up where I don't want it. I have spent much time grinding back down areas that I didn't want the buildup.

I am getting close though. Just hard to get in there, and the tungsten gets contaminated very easily due to that.
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It might help to pre-heat it. Also, you're using a gas-lens with a large diameter cup IIRC - I'm wondering if a smaller cup, slightly higher gas flow and aforementioned pre-heated manifold might allow you to get the material in there. That and routing out with a dremel those areas to allow you to get the filler in.

Quite a job but you'll get there. Good luck!
 
Leaving the intake for a couple days. Worked on the water pipe today. 1.5" center section, 1.375" downturn & ends. Still having some issues welding. My auto dimming helmet wasn't auto dimming immediately - I kept getting flare in my eyes, not good, couldn't actually see the weld puddle at least once on each weld. Tried playing with the sensitivity & delay. Seems like it's actually more to do with the precise angle I offer the tungsten up to the metal, which seems odd to me.

Basic layout with wiring & manifold in place.

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Made SS support brackets for the pipe, using Volvo parts of course. They are the headlamp wiper stops from a 98-00 V70.

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Downturn. Wasn't sure if I was dropping too low - but looking at Darwoodious's pic, I have around 6" or so from the (MWB) frame engine brackets down to the water pipes

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Adding an elbow at the end, so I can use a plain 90º hose to complete the connection

EDIT - looking at some weld quality articles (SS, poor color welds), I have the amperage too high here. I set it on the low end of the scale (50amps), based on 16g SS, but that clearly is too high for this batch :(
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clearance of the pipes from the top

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