Colin Wood
Colin Wood Associate Editor
6/3/20 7:59 a.m.

Honda may be known for its high-revving inline-fours, but did you know that they also produced a five-cylinder engine? Known as the G-series, this engine saw limited use in the Honda Ascot, Rafaga and Inspire in Japan, as well as the U.S.-market Acura Vigor and the later TL. Listen to a G-seriā€¦

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Tom1200 Dork
6/3/20 9:35 a.m.

Are the motors RWD compatible?


Colin Wood
Colin Wood Associate Editor
6/3/20 9:48 a.m.

In reply to Tom1200 :

I'm not certain. The engine is mounted longitudinally, but the aftermarket for the G-Series is pretty limited considering it's not particularly popular.

It would make for quite the swap, though, if you could figure out how to make it work.

aw614 Reader
6/3/20 10:22 a.m.

Werent they originally rumored to go in the S2000 before they went with the F20c? I recall reading several  90s era Car Magazines mentioning the Honda SSM concept had a 5 cylinder. 

Tom1200 Dork
6/3/20 11:13 a.m.

I have a 1600lb car so the stock 190hp would be more than enough. I do know the motors can be had pretty cheaply.

Woody GRM+ Memberand MegaDork
6/3/20 11:24 a.m.

I always thought this would make a great mid engine rwd donor. 

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
6/3/20 11:32 a.m.

huh. the 1991 - 1994 acura vigor had the 2.5l i5, logitudinal mounting, manual trans, and limited slip diff. (engine is basically behind the drive wheels though, 'mid-front'wd design). 

Would make a really cool swap I think. 

CrustyRedXpress (Forum Supporter)
CrustyRedXpress (Forum Supporter) Reader
6/3/20 11:40 a.m.

My first thought was, "Well this is obviously what we should put into the GRM europa." 

CrustyRedXpress (Forum Supporter)
CrustyRedXpress (Forum Supporter) Reader
6/3/20 11:52 a.m.

In reply to aw614 :

Sure seems that way. I wouldn't be surprised if the engine itself was a F-series with an additional cylinder.

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
6/3/20 11:55 a.m.
CrustyRedXpress (Forum Supporter) said:

My first thought was, "Well this is obviously what we should put into the GRM europa." 

I like the way you think. Actually, this drivetrain should be a good fit into a stock europa frame, based on what I know about europas. 

bobzilla MegaDork
6/3/20 12:20 p.m.

I remember the 2.5TL that replaced the Vigor from 95-97 had issues with manifolds cracking. They had the cat integrated so it wasn't cheap. I'd recommend the Vigor (still cracked them but no cat).

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
6/3/20 12:58 p.m.

Always wanted a vigor when I first got my driver's license, but they were new then! So I ended up in an '87 integra for $500 :)

irish44j (Forum Supporter)
irish44j (Forum Supporter) MegaDork
6/3/20 1:12 p.m.

A running, manual transmission one (photos show a  manual)is $700 in North Carolina at the moment. Just sayin'...

Robbie (Forum Supporter)
Robbie (Forum Supporter) GRM+ Memberand MegaDork
6/3/20 1:37 p.m.

In reply to irish44j (Forum Supporter) :

dang. that's awesome. 

GameboyRMH GRM+ Memberand MegaDork
6/3/20 3:42 p.m.

Interesting sound, it somehow reminds me of a Bugatti EB110, but the wood paneling on the dash may be contributing to that.

sobe_death Dork
6/3/20 3:50 p.m.

The G-series is SOHC, and the internals are all D-series with an extra cylinder tacked on.

Tom1200 Dork
6/3/20 5:19 p.m.

So the question would be does it rotate clockwise or counter clockwise.

In reply to sobe_death :

When you say "internals are all D-series" do you mean that the rods/pistons will swap over? 

Wondering about an h-beam/vitara setup.

mad_machine (Forum Supporter)
mad_machine (Forum Supporter) GRM+ Memberand MegaDork
6/4/20 10:28 p.m.

Amazing that five cylinders all howl like that. Reminds me some of the engine in my old Volvo 850

slowbird SuperDork
6/4/20 10:38 p.m.

It's on my bucket list to own a car with a 5-cylinder engine someday. And by that I do not mean a V6 with one cylinder not firing, although that would be easier to acquire. laugh

DillonCrump None
6/11/20 2:34 a.m.

In reply to Colin Wood :

So, funny thing is Honda actually did develop and toss in a 6 speed manual transmission along with the rest of a rear wheel drivetrain behind a completely stock G25a4 to power their Honda Argento Vivo prototypes from Pininfarina.

Several of those prototypes ended up in the Sultan of Brunei hands, where the Honda powertrain was swapped out for 7.3L V12 AMG units according to this Benz forum. 

What do I need to do to get the Sultans old 6 speed gear boxes!?  :)

DillonCrump New Reader
6/11/20 3:08 a.m.

In reply to sobe_death :

Not exactly all D series.  The SOHC valve train layout is very similar if not identical to the 89-95 D15/16 non VTEC and 90-93 F22a non VTEC engines, with the orientation of the intake rocker arms forming a " V " between the spark plug tubes, leaving the exhaust rocker arms to come straight back on the outside of the intake arms V formation.  However unlike the D series, the G and F series have identical combustion chamber design and share the same 34mm intake and 29mm exhaust valve diameters.  

But the biggest difference comes from the bottom end.   These things are all F series inside.  The crank, rods, wrist pins, pistons and oil pumps are so similar in design and built to the same "size" or "class" as the F series are with the exception of the crank stroke and extra cylinder and oil pump configuration.  Otherwise the G series is basically the early Japanese and European market 2.0L F20a/b engine with an extra cylinder slapped on and shorter stroke!   

I discovered this when looking at Pauter Rods (who happen to offer rods for the G25!) listed the Honda rod sizes and specs to compare with.  Big end, small end diameter and widths and wrist pin diameters are all the exact match to the F20a/b engine and in the Honda parts catalog the non-floating wrist pin part numbers are shared between F, C and G series engines.   And then there is the obvious, 85mm bore (D series psychically cannot be bored out that far), the semi open deck, the block webbing and design alone mimics F series structure, and even the oil filter is nearly in the exact same location.   Oh yes, and they spin CCW.  

I don't mean to come in here being all Mr.Know it all, I have been doing some independent research on this engine the best I can, trying to see if I could scrape together some aftermarket possibilities, and thankfully the F series may be lending a small hand to it's distant redheaded G series cousin.  I want to try and ensure the correct information gets around on this little known engine incase anyone would want to help out or follow a similar path. :)        

CrustyRedXpress (Forum Supporter)
CrustyRedXpress (Forum Supporter) Reader
6/13/20 9:38 a.m.

In reply to DillonCrump :

Love that somebody is looking at these! The more I think about it the actual value might be in the transaxle...if it mounts to a F series engine. 

The f-series are cheap as hell and have good aftermarket-rods, turbo, ECU. Wish we knew how much power that transaxle could take without generating shrapnel.

That Honda Argento Vivo is a weird duck. I see the front end suspension components from an NSX.


Jerry From LA
Jerry From LA SuperDork
6/18/20 9:43 p.m.

There's an odd-order harmonic to the sound that I dig. 

johndej HalfDork
6/18/20 10:15 p.m.

Sounds great! I was there that evening and remember thinking at first it was a legend but spotting the vigor after taking a closer look.

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