Go Back   EcoModder Forum > EcoModding > EcoModding Central
Register Now
 Register Now
 

Reply  Post New Thread
 
Submit Tools LinkBack Thread Tools
Old 03-03-2018, 09:59 PM   #1 (permalink)
MPG Addict
 
mpg_numbers_guy's Avatar
 
Join Date: Feb 2018
Location: USA
Posts: 270

Silver Aero - '04 Honda Civic EX Sedan Automatic
90 day: 41.96 mpg (US)
Thanks: 98
Thanked 46 Times in 42 Posts
Future lean burn engine swap into 7th generation Civic sedan? CRX HF, HX?

Found a 1991 Honda CRX HF for sale for $800. Needs some bodywork and has a few issues (fuel leak, left rear tire, master cylinder). And are those the famous wheels off the lean burn civics?? Honestly if I had spare cash and more mechanical know-how () I would probably buy this thing myself and turn it into a 60+ MPG fuel sipper.

I had looked around a bit for CRX HFs out of curiosity before buying my '04 Civic EX but found next to nothing. Of the two I did find, one looked like it had been towed away from a junkyard, and the other had almost 300K miles--decent condition albeit--but the seller was still asking close to $6K for it.

Out of curiosity, would it be possible to (in the future, if I decide not to sell my Civic later on) swap out a lean burn engine from a CRX HF or even the previous generation Civic into an '04? Or would it be too complicated and expensive?

(Here's the link to the CRX HF if anyone's interested since I won't be benefiting from it: https://www.facebook.com/marketplace...61025957979589)

__________________
Silver Aero, 2004 Honda Civic EX Sedan Automatic. Daily driver, very little highway driving with mostly short trips.
Best single trip: 58.2 MPG (US) / Best day: 57.7 MPG (US).


Last edited by mpg_numbers_guy; 03-05-2018 at 07:44 PM..
  Reply With Quote
Alt Today
Popular topics

Other popular topics in this forum...

   
Old 03-03-2018, 11:55 PM   #2 (permalink)
V8 guy
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 5,567

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Shocker - '11 Nissan Leaf SL
90 day: 130.28 mpg (US)
Thanks: 127
Thanked 1,356 Times in 1,001 Posts
You don't have to swap the motor if you want to run lean burn.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white 240v evse mod, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 03-04-2018, 07:39 AM   #3 (permalink)
one of thOOOse people
 
Join Date: Mar 2009
Location: the cloud(s)
Posts: 278

twitchy - '98 honda civic dx + sir + ls
90 day: 30.2 mpg (US)
Thanks: 0
Thanked 77 Times in 62 Posts
Is it possible? yes. But you can not drive it on the road. To be road legal in the US the engine must be the same year or newer than the chassis. It would be preferable to swap a modern engine into the older light weight CRX.

Judging by the clear corner lights and hood-pins I seriously doubt that HF still has an HF motor. These were sought after for engine swaps to higher output engines.
  Reply With Quote
Old 03-04-2018, 07:52 AM   #4 (permalink)
V8 guy
 
oil pan 4's Avatar
 
Join Date: Jul 2011
Location: NewMexico (USA)
Posts: 5,567

Sub - '84 Chevy Diesel Suburban C10
SUV
90 day: 19.5 mpg (US)

camaro - '85 Chevy Camaro Z28

Riot - '03 Kia Rio POS
Team Hyundai
90 day: 30.21 mpg (US)

Bug - '01 VW Beetle GLSturbo
90 day: 26.43 mpg (US)

Sub2500 - '86 GMC Suburban C2500
90 day: 11.95 mpg (US)

Shocker - '11 Nissan Leaf SL
90 day: 130.28 mpg (US)
Thanks: 127
Thanked 1,356 Times in 1,001 Posts
Oh I forgot about that.
I will have to start with a 8.1L block instead of a 7.4L block if I want to build an engine for my firebird. Darn.
__________________
1984 chevy suburban, custom made 6.5L diesel turbocharged with a Garrett T76 and Holset HE351VE, 22:1 compression 13psi of intercooled boost.
1989 firebird mostly stock. Aside from the 6-speed manual trans, corvette gen 5 front brakes, 1LE drive shaft, 4th Gen disc brake fbody rear end.
2011 leaf SL, white 240v evse mod, trailer hitch, new batt as of 2014.
  Reply With Quote
Old 03-04-2018, 05:21 PM   #5 (permalink)
Master EcoModder
 
Join Date: Jun 2016
Location: WV
Posts: 505

IGL - '04 Saturn Ion
Team Saturn
90 day: 45.78 mpg (US)
Thanks: 11
Thanked 130 Times in 98 Posts
I wouldn't recommend swapping the older engine into your car, but maybe swapping to a manual transmission... Do some research and find a compatible trans with the highest(numerically lowest) final drive ratio... However getting that CRX as a project could yield some good
__________________
My current Ecotec project...


My last Ecotec project...
  Reply With Quote
Old 03-04-2018, 07:28 PM   #6 (permalink)
MPG Addict
 
mpg_numbers_guy's Avatar
 
Join Date: Feb 2018
Location: USA
Posts: 270

Silver Aero - '04 Honda Civic EX Sedan Automatic
90 day: 41.96 mpg (US)
Thanks: 98
Thanked 46 Times in 42 Posts
Would swapping in a used '04 HX coupe motor work in the '04 EX sedan? Planning ahead for future reference...in another 100K miles I'll have to change the timing belt again, and maybe by then it'd be more worth it to put in a used HX motor from a same generation Civic with only 40K or so miles on it.

And yes, if it still had the HF motor inside it does seem like a nice project car, but as aforesaid, cash and no mechanical know how limit me. One can always dream though!
__________________
Silver Aero, 2004 Honda Civic EX Sedan Automatic. Daily driver, very little highway driving with mostly short trips.
Best single trip: 58.2 MPG (US) / Best day: 57.7 MPG (US).

  Reply With Quote
Old 03-05-2018, 07:15 AM   #7 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: Vermont
Posts: 2,449

Gaptooth - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 62.72 mpg (US)

Such Fit - '07 Honda Fit Sport
90 day: 41.27 mpg (US)

Velomobile - '13 Sun Seeker EZ-TAD SX
Last 3: 2142.86 mpg (US)
Thanks: 819
Thanked 942 Times in 598 Posts
I can't say for certain, but I imagine the '04 HX motor would bolt up to the '04 sedan's transmission, and have mounts in the same place. Part of why the HX gets great mileage is because it has a much taller transmission though.

The HX has a wideband O2 sensor, so you'll have to do a bit of custom wiring there. Most of the rest of the harness will probably be the same.
  Reply With Quote
The Following User Says Thank You to Ecky For This Useful Post:
mpg_numbers_guy (03-05-2018)
Old 03-05-2018, 08:48 AM   #8 (permalink)
Master Novice
 
elhigh's Avatar
 
Join Date: Jan 2008
Location: SE USA - East Tennessee
Posts: 2,190

Josie - '87 Toyota Pickup
90 day: 29.48 mpg (US)

Tiptoe - '03 Honda Civic Hybrid
Team Honda
90 day: 46.49 mpg (US)

Felicia - '09 Toyota Prius Base
90 day: 51.77 mpg (US)
Thanks: 373
Thanked 539 Times in 394 Posts
"To be road legal in the US the engine must be the same year or newer than the chassis."

You sure about that? Is that nationwide?

<looks online>

In fact it is:

https://www.epa.gov/sites/production...ngswitch_0.pdf

Second paragraph, second page. Spells it out in such a way that includes engine swaps. However an exemption is offered, in that a swap is permissable if it can be demonstrated (or reasonably assumed, according to the text) that a swap will not make emissions worse as "described in Memo 1A," whatever Memo 1A is. No link. But if you do a swap and run it through someone's exhaust analyzer and whistle up better numbers than stock, that might suffice to win you a pass on an older-into-newer swap.
__________________




Take it easy
  Reply With Quote
The Following User Says Thank You to elhigh For This Useful Post:
mpg_numbers_guy (03-05-2018)
Old 03-05-2018, 08:50 AM   #9 (permalink)
Master EcoModder
 
Ecky's Avatar
 
Join Date: Dec 2011
Location: Vermont
Posts: 2,449

Gaptooth - '00 Honda Insight
Team Honda
Gen-1 Insights
90 day: 62.72 mpg (US)

Such Fit - '07 Honda Fit Sport
90 day: 41.27 mpg (US)

Velomobile - '13 Sun Seeker EZ-TAD SX
Last 3: 2142.86 mpg (US)
Thanks: 819
Thanked 942 Times in 598 Posts
As for putting an older motor into the newer car, the HF's engine probably doesn't have the power to push your Civic down the road, with the same gearing the HF had, since your car is so much bigger. It may even be less efficient, since it's a non-VTEC motor without coil packs. It was really the whole packaging of the HF that made it an efficient vehicle.
  Reply With Quote
Old 03-05-2018, 05:29 PM   #10 (permalink)
MPG Addict
 
mpg_numbers_guy's Avatar
 
Join Date: Feb 2018
Location: USA
Posts: 270

Silver Aero - '04 Honda Civic EX Sedan Automatic
90 day: 41.96 mpg (US)
Thanks: 98
Thanked 46 Times in 42 Posts
Quote:
Originally Posted by Ecky View Post
I can't say for certain, but I imagine the '04 HX motor would bolt up to the '04 sedan's transmission, and have mounts in the same place. Part of why the HX gets great mileage is because it has a much taller transmission though.
Are you saying the taller transmission is more responsible for the increased MPG than the learn burn engine itself?

Quote:
Originally Posted by Ecky View Post
The HX has a wideband O2 sensor, so you'll have to do a bit of custom wiring there. Most of the rest of the harness will probably be the same.
If I had the mechanical know how (I am waayyy too limited in that area ) I would do it. Or try. If I were able to do it myself an HX engine swap would be around the same $ as having someone replace my overdue timing belt. I would have to convert my car to manual too.

Quote:
Originally Posted by Ecky View Post
As for putting an older motor into the newer car, the HF's engine probably doesn't have the power to push your Civic down the road, with the same gearing the HF had, since your car is so much bigger. It may even be less efficient, since it's a non-VTEC motor without coil packs. It was really the whole packaging of the HF that made it an efficient vehicle.
Makes sense, including it being illegal. Plus the mounts probably being totally different. Still like the idea of installing a same gen HX engine though, if only.

__________________
Silver Aero, 2004 Honda Civic EX Sedan Automatic. Daily driver, very little highway driving with mostly short trips.
Best single trip: 58.2 MPG (US) / Best day: 57.7 MPG (US).

  Reply With Quote
Reply  Post New Thread


Tags
crx hf, engine swap, for sale, honda civic, lean burn

Thread Tools




Powered by vBulletin® Version 3.8.7
Copyright ©2000 - 2018, vBulletin Solutions, Inc.
Content Relevant URLs by vBSEO 3.5.2
All content copyright EcoModder.com