K20 Swap with no firewall cut.

L

leox19

Daily Driver
Hi there from down under ! Proceeding with K20 swap however I plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere and move the alternator to the opposite side of the block. Also plan to manufacture a new shorter stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
View attachment 61498
I have a low k K20Z2 (fly by wire throttle body) and ECU's are available but the immobiliser function is an issue as these units don't seem able to be unlocked.
Thanks Doug
 
Good day and welcome.

This an imperfect listing of K swaps here on the forum: https://xwebforums.com/forum/index.php?tags/box-k20/

There was a thread which covered this to a decent degree, sadly due to the pics being hosted elsewhere the images are no longer available. I may have created a PDF of part of this thread which is on my computer, I will check a bit later as I am on my iPad right now.

This is the thread: https://xwebforums.com/forum/index.php?threads/almost-no-cut-k20-swap.27825/
This is his member name and a way to contact him: https://xwebforums.com/forum/index.php?members/dennisrh.2187/

Here are a couple of snips from that thread which directly relate to your question:

I then began test fitting the engine on the subframe into the X to see where it was absolutely necessary to cut. To my surprise the only place where my engine was hitting and absolutely needed to be cut was the drivers side wheel well, where the transmission housing was hitting. I didn't take a picture of the area, but if i remember to, I will when I remove the engine to paint the engine compartment. Basically the area where the indentation is for the X 1/9 transmission needs to be opened up to allow for the larger transmission. Instead of cutting the whole frame rail like the otehr K20 builds i saw online, I cut a very small section of the rectangular frame rail out and then bent the metal together making the frame rail more triangular than rectangular. I removed about 1.5 inches width x 8 inches length. I removed a little metal at a time and then test fitted over and over again until I had made enough room for the transmission. The clearance is extremely close, but so far after driving the car for about 3 weeks I haven't had any rubbing or knocking of the transmission against the frame. The engine fit pretty nicely within the engine bay of the X 1/9 with absolutely no cuts to the front frame or firewall. Only problem was, I wasn't going to get the water pump alternator or intake manifold back on without doing some modification to the engine bay. First thing I found is that you can delete the water pump on a K20 and put an electric water pump in its place. This not only saves space and weight, it reduces drag on the engine, so more power as well and it relocates and changes the alternator from the large heavy RSX alternator to a smaller alternator from the base civic. The civic alternator is smaller and closer to the engine block than the RSX alternator and it plugs right into the RSX wiring harness, no modification necessary. (its amazing what these Honda guys have all ready figured out for this engine for drag racing)​
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I had successfully reduced the amount of room I would need for the water pump, alternator and pulleys on the engine. I test fitted the engine and installed the water pump block off plate with the alternator on it and put the belt on the pulleys. The belt hit the corner of the engine bay, so I needed to make an indentation in the frame rail to allow for some clearance. I bent the metal rather than cutting it and was able to make about an inch and a half of clearance just bending it. This was enough to allow for the belt.​
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This is how he dealt with the water pump and plumbing changes. Some have turned to the 124 type bypass thermostat as a means of dealing with that issue:
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The electric water pump kit came from K-Tuned as well as my fuel rail and various other stuff I got for the Honda engine. With the electric water pump as I have my setup​
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jhpusa.com

K-Tuned K-series Water Plate w/Alternator Brackets & AN Fittings

This new K-Tuned water plate kit now incorporates two o-rings seals. You no longer need to seal the water plate with Honda Bond. This will make it easier switching the water plate between blocks. The alternator brackets have both been redesigned to be stronger and incorporate more adjustment...
jhpusa.com jhpusa.com
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B093CDE6-3691-4340-BA16-D5E707919235.jpeg
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I will do some more digging. I hope this helps. I will check on the images/pdf (no guarantees).​
 
leox19 said:
Hi there from down under ! Proceeding with K20 swap however I plan to remove the stock K20 water pump and replace it with an EWP mounted elsewhere and move the alternator to the opposite side of the block. Also plan to manufacture a new shorter stubby inlet manifold - both these to possibly eliminate the firewall cut and box. However does anyone know about the clearance required around the starter motor ? Does it protrude into the area here ?
View attachment 61498
I have a low k K20Z2 (fly by wire throttle body) and ECU's are available but the immobiliser function is an issue as these units don't seem able to be unlocked.
Thanks Doug
Click to expand...
There is no issue with the starter motor. Here is a photo from an early fitting session with mine. You can see the starter motor tucked up under the intake manifold.
IMG_1065.JPG
 
Thankyou Karl - great coverage here.
From what I can see the conversion to EWP and smaller or relocated alternator is a no brainer.
However the K20Z1 I have appears to have a larger inlet manifold. .I guess I will have to see what happens with clearance when I begin the install. .much appreciated Doug
 
leox19 said:
Thankyou Karl - great coverage here.
From what I can see the conversion to EWP and smaller or relocated alternator is a no brainer.
However the K20Z1 I have appears to have a larger inlet manifold. .I guess I will have to see what happens with clearance when I begin the install. .much appreciated Doug
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The intakes have been an issue as you likely read in some of the threads.

Do keep us informed, it is always great to learn more in this area.

Good luck with the conversion.
 
If you have one of the later motors with plastic plenum, you will want to get rid of that for one of the earlier all aluminum (better flowing) manifolds anyway. Short runner setup is only good for +T, if that's what you're going for. NA, you want the longer runners. Mine is K24/K20 franken, and I want the low/midrange so I modded the K24A3 (JDM) split intake to tuck the large plenum under the runners. Makes no difference to the need for large firewall access though. The frame has to be cut all the way across, or you'll have all kinds of clearance issues. You can always set the transaxle/block in the bay & see what you think. The only one I've seen online with no cuts tipped the engine way back & had a custom oil pan (he never posted pics of the bay, so who knows what really happened. Messing with the center of gravity & overhang toward the rear of the chassis makes no sense to me.
 
Here are some points to consider with the electric water pump:

1) This item is intended for race car (presumably draw racing) use, so its durability for long-term use on a street car might be unproven.

2) As far as I know, there is no thermostat in the EWP outfits.

3) As far as I know, the pump runs constantly on a switch. At the volume the EWP moves, engine temp would probably fall too low in some driving conditions since there is no thermostat to close. (Maybe your idea is to add a Beta thermostat and keep a bypass in place?) If engine temp falls too low, expect poorer emissions and more cylinder wear.

4) As far as I know, the bypass circuit is also eliminated along with the thermostat.

Now, if there is no thermostat and if the bypass circuit is also eliminated, this is not the end of the world. The fan could be operated thermostatically through a simple two-wire radiator fan switch (installed on the engine, not the rad) of the correct temp wired to power a simple four pin relay that powers the pump. Early watercooled VWs had two-wire switches of several different temperatures. The engine coolant reaches target temp, and the pump starts operating. Once the pump satisfies the switch, the pump shuts off until needed again. The bonus would be a much simpler cooling system--no bypass, no thermostat, no bulky WP housing and pump, and that diagonal corner of the crossmember should be able to stay intact. The Beta thermostats are pretty good, but not perfect, in regulating temperature, whereas this thermostatic electric system should be perfect. The stock Honda thermostat works perfectly, but was keepable in only one car that I built--and that was because of more invasive cuts into the firewall for intercooler installation. In theory, it all should work great--until it doesn't.

I would be a little bit uneasy about turning over control of circulating water to an electric pump powered by a switch and relay. At minimum, I would want a water pump warning light to advise me that something had gone wrong. Or maybe power to the fuel pump relay could be cut if engine temp exceeds a certain number. I would want a safety net of some sort. Normally, those things that absolutely must function for as long as the engine is turning was directly powered by the engine. Then again, GM put electric water pumps on all LT-1 engines and made it work.
 
leox19 said:
Hey there = get with the available technology = better than the original for any pump conversion.
https://daviescraig.com.au/?gclid=C...LQ4J8SU8v3jE7p-ghKeHGv9xeK_EdJD0aAoQmEALw_wcB. Used these on many conversions. Complete kit about A$500.
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That is a more advanced solution for sure. I still wonder about durability on a road car that gets ten thousand miles per year as opposed to dozens of miles per year in a care car.

These products actually have me considering an electric pump conversion. Anybody who has done this conversion knows how much clutter is involved in making space for the thermostat, rad hoses, bypass hoses, and heater hoses in addition to the WP and housing on the front side of the engine. Plus, the pump should be able to mount somewhere behind the radiator instead of in the engine bay, further reducing clutter. It makes a lot of sense--as long as the electric pump can really be trusted.
 
Longitudinal said:
3) As far as I know, the pump runs constantly on a switch. At the volume the EWP moves, engine temp would probably fall too low in some driving conditions since there is no thermostat to close. (Maybe your idea is to add a Beta thermostat and keep a bypass in place?) If engine temp falls too low, expect poorer emissions and more cylinder wear.
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The pumps have a sophisticated controller that keeps the coolant temperatures correct by pulsating the flow. So when the car is cold, they don't pump much, when it is hotter, they simply increase the duty cycle to the pump. Very similar to how fuel is metered in a fuel injector.

Dom.
 
I think Tim Hoover (Fiat Monkey) used one on one of his K-Swaps. Might want to reach out to him on the Xweb FB page, haven't seen him on here for some time. I still wouldn't do it. I don't have faith that it will last even close to the life of a mechanical pump.
 
Longitudinal said:
That is a more advanced solution for sure. I still wonder about durability on a road car that gets ten thousand miles per year as opposed to dozens of miles per year in a care car.

These products actually have me considering an electric pump conversion. Anybody who has done this conversion knows how much clutter is involved in making space for the thermostat, rad hoses, bypass hoses, and heater hoses in addition to the WP and housing on the front side of the engine. Plus, the pump should be able to mount somewhere behind the radiator instead of in the engine bay, further reducing clutter. It makes a lot of sense--as long as the electric pump can really be trusted.
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According to Davies Craig, their pumps are regularly used on daily drivers as a replacement for a failed factory pump.
 
lookforjoe said:
I think Tim Hoover (Fiat Monkey) used one on one of his K-Swaps. Might want to reach out to him on the Xweb FB page, haven't seen him on here for some time. I still wouldn't do it. I don't have faith that it will last even close to the life of a mechanical pump.
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Right. That is my main concern. If your fuel pump dies, you get a tow home. If this pump dies, you might be rebuilding your engine if you don't realize it fast enough. All water pumps fail eventually, but the engine driven pump is more familiar to us. With the exception of plastic pump impeller explosions (you're a Volvo guy, so I know you're familiar with that happening,) they don't just suddenly fail. They give warning signs long in advance of a failure, giving us ample time to make a repair before they fail. The electric pump motor could suddenly blink out and leave you with 30 seconds to shut down.

With that being said, DC electric motors in fuel pumps and power steering pumps are pretty reliable.

Maybe we could find an electric alternator and have no belt driven accessories at all!
 
dcioccarelli said:
The pumps have a sophisticated controller that keeps the coolant temperatures correct by pulsating the flow. So when the car is cold, they don't pump much, when it is hotter, they simply increase the duty cycle to the pump. Very similar to how fuel is metered in a fuel injector.

Dom.
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Right. At the time I wrote that, I didn't know that electric water pumps were as popular as they are, and I knew only the K-Tuned setup. K-Tuned's product does not have any oversight--just give it power.
 
An electric water pump can have idiot lights just like all the other systems or one could even have the engine shut down if the pump fails to run. Like all things software the choices are limited only by the ability to code or to come up with the ideas.
Longitudinal said:
Maybe we could find an electric alternator and have no belt driven accessories at all!
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It’s called a stator and is on my 1970s garden tractor as part of the flywheel, 20 amps in that particular low speed application. :)
 
kmead said:
An electric water pump can have idiot lights just like all the other systems or one could even have the engine shut down if the pump fails to run. Like all things software the choices are limited only by the ability to code or to come up with the ideas.

It’s called a stator and is on my 1970s garden tractor as part of the flywheel, 20 amps in that particular low speed application. :)
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Right, and I am NOT the guy to go to for code. But, thinking through it, having an indicator set up to warn that the pump is not spinning seems complicated. It's not a matter of whether the pump has power, but whether it is moving fluid. A temperature-based warning system would be much easier to implement. I would bet that that Australian system above is sophisticated enough to have it all.

I have a stator on my 1982 Suzuki motorcycle, but it can't drive itself and make its own power. ;) They say that laws are made to be broken, but the laws of thermodynamics have proven to be hard to break.
 
Speaking of laws... the legislation in Australia (seeing as the OP is from Brisbane) regarding chassis mods is very clear, ANY cuts or changes to the chassis rails will require full engineering inspection and approval if the vehicle is to be registered for use on public roads, up to the point of mounting the chassis on a rig to test it for twist under load - obviously something not required in the U.S. and something that can get expensive.

Things like firewall "boxing" to get extra room are allowed and not much of a problem, but cut into or modify any of the transverse or longitudinal rails and the car will fail tech at registration, and the onus is on the owner to prove / provide evidence of the chassis' strength.

SteveC
 
Yes Steve - Thanks - my mod contact even has difficulty with firewall boxing. Chassis modification makes the K20 swap not viable here.
 
Regarding the EWP issue - it can easily be mounted at the front behind the radiator to relieve that tight engine bay and provide easy access.
Doug
 
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