Ok, well all the prelude guys are gonna hate me, but I am getting a 97 civic ex coupe and going all motor... Time to get rid of the turbo kit and use a lighter chassis... Here is the plans for the new setup:

-F23a1 Block -
-F23a1 Crank - 97mm Stroke (Rod journals widened to accept .935 B-Series rods)...
-Custom 147mm (5.788 in) B-series rods...(Possibly notched for GSR rod bearings)
-Weisco Pistons (.940 compression height) - 86 or 87mm - 11:1+ c/r... https://honda-tech.com/zerothread?id=1323338...
-H22a1 Head (Most likely using Custom Cams, RM valvesprings/retainers)...
-RMF Exhaust Manifold
-Removed: Balance Shafts, PS, AC, CC, IAB, EGR...
-Lightweight: Crank Pulley, Alt. Pulley, Flywheel...
-CM Stage 3 Clutch, Quaiffe LSD...
-KTeller 2.5" Mandrel Bent Exhaust

2253.6cc with 86mm bore... 2306.5cc with 87mm bore ...

Not sure on the exact power but I'm sure I'll make well over 200whp and more torque than jesus... Looking for 12's all day long... With the shortened compression height and longer rods, it brings the rod/stroke ratio from 1.45 to 1.52 which isn't anything spectacular but should be enough(in combination with the wider rod journals) to prevent me from spinning rod bearings at moderately high RPMs... My expected rev limit is to obviously be around 7200 to be safe, and I am definitely considering custom cams to accentuate the low-end/midrange and to keep the powerband from going to high... As always, any questions/comments/ideas and suggestions are welcome...



Modified by Sam1am26 at 9:52 AM 7/31/2005

 

Looking forward to see what it can do. But you might want to reconsider your cam choice if youre only going to 7200 rpms.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The_Head &raquo;</TD></TR><TR><TD CLASS="quote">Looking forward to see what it can do. But you might want to reconsider your cam choice if youre only going to 7200 rpms.</TD></TR></TABLE>

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">I am definitely considering custom cams to accentuate the low-end/midrange and to keep the powerband from going to high...</TD></TR></TABLE>

 

Sounds fun. If you pull the bottom end apart I'd recommend that you look into adding custom oil baffling around the crank and baffle the oil pan as well. As it is there is not much to keep the oil in the pan like on the H22. You will have interesting issues with high speed left hand sweeping turns and the OEM valve cover ventilation system... I know from experience. Baffling is your friend. Good luck with the build.

Pirate

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">
-H22a1 Head(Crower Stage 3 cams or Custom...</TD></TR></TABLE>

 

sticking with the h22 head then? do you still need those h23 parts?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by PirateMcFred &raquo;</TD></TR><TR><TD CLASS="quote">Sounds fun. If you pull the bottom end apart I'd recommend that you look into adding custom oil baffling around the crank and baffle the oil pan as well. As it is there is not much to keep the oil in the pan like on the H22. You will have interesting issues with high speed left hand sweeping turns and the OEM valve cover ventilation system... I know from experience. Baffling is your friend. Good luck with the build.

Pirate</TD></TR></TABLE>

Is it possible to bolt in the baffling from an H-series?

 

Well,

I'd like to know the specs you end up going with on the cams, but I saw you're going to have the crank modified to accept B-series rods and rod bearings... won't that solve the high RPM reliablility problems?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by The_Head &raquo;</TD></TR><TR><TD CLASS="quote">Well,
won't that solve the high RPM reliablility problems?</TD></TR></TABLE>

Just the wider rod bearings should help somewhat but I don't know if you noticed I am using longer rods so my r/s will be about 1.52 instead of 1.45... Still doing some more reasearch and trying to come up with ideas to increase the r/s further without losing stroke or using a deck plate, but I am limited by deck height...

 

no to be retarded or anyhing but wouln't it be a h23 vtec and not g23 vtec?

 

i think he was going more so "G" is between f and h, lol

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by projectTeG &raquo;</TD></TR><TR><TD CLASS="quote">no to be retarded or anyhing but wouln't it be a h23 vtec and not g23 vtec?</TD></TR></TABLE>

Oh sorry... This isn't an H23 VTEC... It is an F23 block with an H22 head... PirateMcfred kinda gave it the nickname because G is in between F and H and this is a cross between the two...

 

interested..good luck and keep us posted..btw what mounts do you need for this swap into an ek?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Sam1am26 &raquo;</TD></TR><TR><TD CLASS="quote">

Oh sorry... This isn't an H23 VTEC... It is an F23 block with an H22 head... PirateMcfred kinda gave it the nickname because G is in between F and H and this is a cross between the two...</TD></TR></TABLE>

oh, opps....so now its more like a f20b right? imma hav to look into the g23, got a buddy that needs some help

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GOLDBERG &raquo;</TD></TR><TR><TD CLASS="quote">btw what mounts do you need for this swap into an ek?</TD></TR></TABLE>

Same mounts you would need to put an H-Series into an EK... The only difference is the mount bracket on the driver's side.. The F23 mount bracker doesn't bolt up to the H mount... However, the 90-93 Accord F22 mount bracket bolts to both the F23 block and the H mount... Problem solved...

 

bump...planning on an all motor g23/vtec myself.

 

sounds like a pretty sweet, unique project, good luck

 

I closely followed the original build of this as posted in the Prelude forum. I'm very interested in seeing what something like this could do with sleeves and headwork.

 

whats the purpose of using b series rods v.s. h series rods?

 

Sorry for the delay sam, No you can't bolt the H-series baffling into the F23 block. You might be able to drill and tap some similar locations, but otherwise it is pretty different. I will say that the crank girdle appears to be more stout than the H-series. Conversely, the H23/22A1 blocks are closed-deck so I guess that there are compromises left and right.

If you are going to use custom forged pistons an alternative to crankwork and B-series rods would be to spend the extra money on lighter pistons and wrist pins. The following shows how the difference in piston weight results as a higher rpm for the same piston deceleration force.

419g ...... 369g ....... 344g ..... 319g
OEM g ... -50g ....... -75g ..... -100g
6500 ...... 6925 ....... 7175..... 7450

At the stock F23A5 at redline (6500rpm) the piston experiences ~3082Gs of deceleration at TDC. The F23 piston/pin/rings weighs 419 grams. That translates to 1,291 kilograms of force that the rod bolts experience. 419 grams is pretty heavy for a piston. Basically, if you can drop 100g off the piston weight then you can effectively rev to 7500rpm on stock rods with a high degree of reliability as the rod bolts experience the same loads as the stock engine at the original red line.

The only wear that I might consider is that the OEM rod bearings are designed to handle ~140hp at the crank and if you build the engine you can get well over 240 at the crank. So the narrow rod bearings might wear prematurely if you incessantly beat on them.

Short story: lighter pistons = higher revs reliably for less money.

Pirate

 

Good info Pirate... So I have the civic now... Gonna pull the prelude motor out when I get the chance... Put the prelude seats in the civic though... looks good... Slight change in plans though... I'm staying boosted but just switching to an H23 head... I'm tired of testing the limits on how high these motors can rev... I figured keep it simple and go with the H23 head and run at least 10 psi... I'll try and make the turbo kit a little more efficient as well... So a 97 civic coupe with a G23 Non-VTEC at 10 psi, That should be a daaaamn fun daily driver...

 

word keep us updated

huess i'll have to keep you guys updated on my all motor g23/vtec build then

 

I gots Prelude seats in my Civic as well. A much cheaper alternative to Del Sol or Teg seats.

 

haha desreguard my IM since i just read the whole thread. Good luck with all of this, if you are going to be doing the swap down here in winter park i can probably give you a hand

 

I still have those mounts/axles if you need them Sam.

Let me know.