K20 Swap with no firewall cut.
- Thread starter leox19
- Start date
Longitudinal
True Classic
That last bit is where things will get hairy. Welds can be finished down to make it look like it never happened, but left side and right side clearance cuts are necessary with the K20. The only question is how much is *really* necessary. I always cut liberally but with discretion because I like to have room to work. Maybe maybe maybe there is space for the crank pulley on vehicle right with the possible caveat of having to remove the engine to change serpentine belt, but the left side cut for trans clearance is unavoidable. The whole package really needs clearance cuts on both ends to fit happily.
Longitudinal
True Classic
This is all very interesting. I like it for the extent to which it can simplify the cooling system--no tstat, no bypass circuit, no WP and housing on the engine. And all of those things hang out on the firewall side of the engine, which gets super crowded. I'm not so keen on $1000 (between this Australian EWP setup and the WP plate from K-Tuned) not-strictly-neccesary expense on the build and turning over the responsibility for pumping coolant to an electric motor. I've got to think more about this setup, because I like more about it than I dislike.
My project will use a Haltech Elite 1500 ECU rather than Factory Honda - too many issues with immobilisers/security and as far as I can find nobody has hacked the Honda RSP version ECU. The Haltech can manage all cooling functions, drive the fans etc, provide alarms etc. so all I need will be the Davies Craig EWP. The engine I have is a K20Z2 which has DBW throttle. And the bonus with this is I get cruise control for free =again managed by the Elite 1500. Sounds like fun to me! My TIG will make the K20 water pump plate for me as well.
Hello again on this thread.. I would like to determine the clearance between the intake side of the K20 to establish what is actually possible in terms of inlet manifold clearance with no cut. Is there anybody who could do a simple measurement for me - basically the distance between as below. It looks like the LH tappet cover bolt roughly lines up with the slotted section on the X rear top X member ? With the Bayless kit naturally- also some indication of the relative height of the K20 WRT the X member would be great. I am convinced I can modify existing manifold options to do the job. My K20 Z2 does not have variable length intake system .Of note, there are a number of online intake runner length calculators available and if you stuff some data in and have a play they all predict a relationship .. the shorter they are the peak torque moves up in RPM. I am happy to lose low end but really why not just Rev it !!
Doug
Doug
jimmyx
True Classic
I can't help you completely because my swap is a K20Z1 into a '74 which has a different upper member than '75 up. The distance on mine is 3.25" from the edge of the cover to the face of the upper member. That measurement is to the bare member and does not take into account the depth the latch will eat up. The later upper member should be the same UNDER the top (curved) section on yours. The upper protrusion adds about .5" in the flat section and more where it curves out for the striker opening. The K20 sits approximately 2" below the top of my upper member. Not sure if this is at all helpful, but I'm hoping that someone with a later swap will chime in.
Rodger
True Classic
It’s hard to photograph because they are at two different heights but on my car it looks like about 6 cm.
Great Rodger exactly what I needed.
Based on that it looks like the existing manifold I have would then intrude into the firewall by approx. 50mm.
However there is more space there than I thought. The Z2 inlet is actually two pieces - the runners/injectors etc. one the head, and the additional longer runners, plastic tuning chamber, throttle body inlet etc. bolts on the that. So I can remake the latter basically as a plenum of significant volume and position the existing DBW throttle appropriately.
Doug
Based on that it looks like the existing manifold I have would then intrude into the firewall by approx. 50mm.
However there is more space there than I thought. The Z2 inlet is actually two pieces - the runners/injectors etc. one the head, and the additional longer runners, plastic tuning chamber, throttle body inlet etc. bolts on the that. So I can remake the latter basically as a plenum of significant volume and position the existing DBW throttle appropriately.
Doug
lookforjoe
True Classic
Same design as JDM K24a3 & USM a2 - runners are separate from plenum. I resolved mine by tucking the plenum under, however the 2.4 plenum is larger than the 2.0, also, making smooth transitions for the plenum runners still occupies much space - Does not preclude cutting the firewall though.
Hmmm! I might have to reconsider the thread topic - change from "No Firewall Cut" to "No Cross Member Cut". It seems that relocation of the water pump alone would avoid cross member cut and still allow for a decent inlet manifold with only a firewall box. But maybe existing standard manifold options all intrude the cross member area - not sure about that.
Cheers
Doug
Cheers
Doug
lookforjoe
True Classic
I don't think any stock intake/plenum goes anywhere near the crossmember. Mine is not much higher than stock, just tucked rearward
Hi all , I now have the MB conversion kit - cost me a lot in terms of freight, duty, and Aus. GST charges. However I still reckon it is good value at A$6000 landed. Now to my K20Z2 - this is commonly available here and higher power K20's are not so I am looking at a few upgrade options.
This motor has "economy" VTEC - ie only 2 inlet cam lobes/cyl. and nil VTEC on Ex. - one valve hardly opens until VTEC engages and rockers lock - unlike say K20A/others which has 3 lobes and "proper VTEC" So I am looking at installing standard used Honda cams from the latter engines. Change the rockers to suit, upgrade the exhaust to bigger 4:2:1 system ( the standard Z2 has very small 4:1pipes) I have removed the Z2 oil pump/balance shaft assy. and will replace with standard pump = RPM. Still pondering inlet manifold options for "no cut". If I can push this 155Hp stock engine to say 180 I will be happy.
This motor has "economy" VTEC - ie only 2 inlet cam lobes/cyl. and nil VTEC on Ex. - one valve hardly opens until VTEC engages and rockers lock - unlike say K20A/others which has 3 lobes and "proper VTEC" So I am looking at installing standard used Honda cams from the latter engines. Change the rockers to suit, upgrade the exhaust to bigger 4:2:1 system ( the standard Z2 has very small 4:1pipes) I have removed the Z2 oil pump/balance shaft assy. and will replace with standard pump = RPM. Still pondering inlet manifold options for "no cut". If I can push this 155Hp stock engine to say 180 I will be happy.
Hello all who have contributed to my knowledge here. Now I have the K engine and gearbox and the MB kit layed out I have an increased understanding of the issues with the firewall and chassis cuts. But looking at is now I estimate that the water pump housing and pulley may not interfere anywhere but the alternator definitely will. The water connection to the plastic thermostat housing would maybe be an issue ?
Any inputs would be appreciated. Thanks Doug.
Any inputs would be appreciated. Thanks Doug.
lookforjoe
True Classic
Water outlet/return has been covered in my Preparing thread, and by Roger & Darwoodious, if you look for theirs. I indexed my threads on the first post, so you can scan the contents of each page from there for either the Preparing or Installing threads.
Water pump pulley will be an issue. This is mine, with the crossmember cut. Without the cut, the pulley would be sitting at/on the crossmember, never mind clearance for the belt.
Hussein,
Thanks - my thinking ignored the way the cross member curves backwards at the sides - obvious now from your photo. The housing/casting that the WP and alternator attaches to appears to have a function to cool crankcase vapors being intimate with coolant in the housing - so I guess they would return to the sump upon condensing to reduce intake manifold clog - very clever Honda!. So I think a good thing to retain that process. Do you think I can achieve clearance to the standard X member by eliminating metal on the housing - all would be removed below the black lines. I can weld in a new 32mm tube for the water connection facing the starter side..... What do you reckon?
Cheers
Doug
Thanks - my thinking ignored the way the cross member curves backwards at the sides - obvious now from your photo. The housing/casting that the WP and alternator attaches to appears to have a function to cool crankcase vapors being intimate with coolant in the housing - so I guess they would return to the sump upon condensing to reduce intake manifold clog - very clever Honda!. So I think a good thing to retain that process. Do you think I can achieve clearance to the standard X member by eliminating metal on the housing - all would be removed below the black lines. I can weld in a new 32mm tube for the water connection facing the starter side..... What do you reckon?
Cheers
Doug
lookforjoe
True Classic
Hey Doug
Just basing it off my photo before, I would say probably, but I don't have any before pics that indicate original crossmember height. My suggestion would be to check it with the motor in the bay, with the housing removed from the block, then you can take all the measurements you need to figure out the water pipe routing & EWP placement for the setup you are going for.
Just basing it off my photo before, I would say probably, but I don't have any before pics that indicate original crossmember height. My suggestion would be to check it with the motor in the bay, with the housing removed from the block, then you can take all the measurements you need to figure out the water pipe routing & EWP placement for the setup you are going for.