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KyleCrews · 03-25-2003, 11:52 PM

I was wondering if anyone can tell me what the stock compression ratio on a H23 prelude engine. Also what is the easiest way to bump of the compression ratio?

KyleCrews · 03-26-2003, 12:02 AM

I meant to say bump up the compression ratio. Sorry....

KyleCrews · 03-26-2003, 12:37 AM

Anything?

BlackJDMdeath · 03-26-2003, 02:15 AM

an easy way? replace your head gasket, honda uses a 3 piece head gasket, if you remove a layer it will bump up compression.

KyleCrews · 03-27-2003, 01:31 PM

How much would this raise my compression ratio and would it be safe to do still running stock internals? I don't want to blow this engine cuz i've only had it for about 4 months.

2fastaccord · 03-27-2003, 01:58 PM

The other way is just to replace the pistons with higher compression ones. It would cost you a bit more than the head gasket but you would probably want to do that at some point and time anyway.

Peace*

nuc79 · 03-27-2003, 04:31 PM

The Ultimate Honda Engine Swap Guide has all of the compression ratios and hp and torque ratings.

The H23A1 is 9.8:1, 160hp, 156ft-lb. of torque. B)

BlackJDMdeath · 03-27-2003, 08:39 PM

great advice 2fast... although you might want to add in that if you go with anything but OEM pistons you will have to sleeve your block.

KyleCrews · 03-28-2003, 12:15 AM

will it hurt my engine if i raise the compression ration by removing a layer of the gasket while using stock internals. I'd hate to blow it up since i just go it.

tab · 03-28-2003, 01:55 AM

I think the bottom end could handle it. However, I am not sure that you understand how hard it would be for you to replace that head gasket. It would take a long time, and a little money. Would it work, yes. Do you want to, no. The few horses that you would gain could be gained on a dyno, or with some bolt ons. Don't fool with a good thing, experiment on a shitty engine. Just my opinion.

KyleCrews · 03-28-2003, 09:23 AM

I just planned on tdoing it which I convert my h23 to vtec next month and i figured i could do it then with no trouble. Thanx for the help though guys.

dohcvtec_accord · 03-28-2003, 09:24 AM

Shit, if you're converting to VTEC anyway, why not just install some Prelude Type S pistons? 11.1:1 compression y0!

KyleCrews · 03-28-2003, 09:29 AM

How much would those cost me and where could i get them? Also i plan on putting a head from a '97 up prelude so i can supercharge it. Can my crank and rods hold that compression ratio and boost without blowing up?

KyleCrews · 03-28-2003, 10:50 AM

any thoughts?

dohcvtec_accord · 03-28-2003, 01:15 PM

No, I wouldn't run that compression if you're planning on boosting.

What OBD classification is your car/chassis right now?

KyleCrews · 03-28-2003, 02:30 PM

My car is an OBD1. Its a '94 prelude Si. Back in november i had to put another engine in it and i found a good deal an an h23 ordered from Japan. I want to put a head from a '97 up prelude so i can add a supercharger because i prefer super over turbo. I'm hoping the vtec head will swap on to my h23 block and i know i'll have to get the ECU for the '97 up and get a wiring harnes to go from OBD1 to OBD2 which is whats in the '97 up. I just dont know how easy this swap will be since i've never seen anyone else do it. Also will the instrument panel in my dash still work cuz i know the dashes in the 2 cars are very different. I know i kinda got of teh whole compreesion ratio topic but any help on these questions would be great. I can get a head from a 92-96 and 9'97 up for about the same price and pretty cheap because my friends dad owns a just yard and said he'd give me everything i needed (IM, Head, EM, ECU) and anything else for like 500 bucks. Just tryin to make a decision so i can get started.

BlackJDMdeath · 03-28-2003, 03:34 PM

im not sure what all you would have to do to get that head on there, you have to remember that the 4th gen h22a has a different block design than that of the 5th gen, 4th gen being superior of course. if you plan on throwing boost at it, keep the h23 compression. ummm good luck?

ludeconduct · 03-29-2003, 05:11 AM

^ word, you don't want high compression with boost. Also not only are the blocks different between 4th and 5th gens but since you have a OBD1 setup, I've heard there will be issues when putting on the OBD2 head in a very recent post on hondaswap

dohcvtec_accord · 03-30-2003, 05:42 PM

I think it's a pretty bad idea to try get get an OBD2 head onto an OBD1 block. BlackJDMdeath had a good point about the two different block designs (closed deck vs. open deck), and I think that's just going to give you even more headaches.

KyleCrews · 03-30-2003, 06:08 PM

Thanx for the advise. I think i'm just going to try to sell my h23 and swap in an H22. I think it will save me alot of time and headaches.

dohcvtec_accord · 03-30-2003, 06:17 PM

Quote:

Originally posted by KyleCrews@Mar 30 2003, 04:13 PM
I think it will save me alot of time and headaches.

03-25-2003, 11:52 PM	#1
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	I was wondering if anyone can tell me what the stock compression ratio on a H23 prelude engine. Also what is the easiest way to bump of the compression ratio? __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-26-2003, 12:02 AM	#2
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	I meant to say bump up the compression ratio. Sorry.... __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-26-2003, 12:37 AM	#3
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	Anything? __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-26-2003, 02:15 AM	#4
BlackJDMdeath Senior Member Join Date: Sep 2002 Location: Wichita, KS Posts: 1,146 iTrader: 0 / 0% Rep Power: 24	an easy way? replace your head gasket, honda uses a 3 piece head gasket, if you remove a layer it will bump up compression. __________________ uhhhh... im confused with this stupid signature thingy!

03-27-2003, 01:31 PM	#5
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	How much would this raise my compression ratio and would it be safe to do still running stock internals? I don't want to blow this engine cuz i've only had it for about 4 months. __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence


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03-27-2003, 01:58 PM	#6
2fastaccord Senior Member Join Date: Dec 2002 Posts: 538 iTrader: 0 / 0% Rep Power: 18	The other way is just to replace the pistons with higher compression ones. It would cost you a bit more than the head gasket but you would probably want to do that at some point and time anyway. Peace*

03-27-2003, 04:31 PM	#7
nuc79 Senior Member Join Date: Dec 2002 Location: SE Georgia (near Jacksonville, FL) Posts: 164 iTrader: 0 / 0% Rep Power: 14	The Ultimate Honda Engine Swap Guide has all of the compression ratios and hp and torque ratings. The H23A1 is 9.8:1, 160hp, 156ft-lb. of torque. B) __________________ My Honda Chronology: 90 Civic(traded), 88 CrxSi(totalled), 90AccordLXcpe F22A1turbo(still own, soon to be H23A1turbo), 94 GSR4dr(traded), 01Civic(traded), 89ZCsedan(traded 6/03 for 2 CRXs), 93CivicEX(sold 7/03), 99OdysseyLX(still own)

03-27-2003, 08:39 PM	#8
BlackJDMdeath Senior Member Join Date: Sep 2002 Location: Wichita, KS Posts: 1,146 iTrader: 0 / 0% Rep Power: 24	great advice 2fast... although you might want to add in that if you go with anything but OEM pistons you will have to sleeve your block. __________________ uhhhh... im confused with this stupid signature thingy!

03-28-2003, 12:15 AM	#9
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	will it hurt my engine if i raise the compression ration by removing a layer of the gasket while using stock internals. I'd hate to blow it up since i just go it. __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-28-2003, 01:55 AM	#10
tab Super Moderator Join Date: Jan 2003 Location: Aberdeen, Washington State Posts: 3,733 iTrader: 0 / 0% Ride: 03 Avalanche Rep Power: 49	I think the bottom end could handle it. However, I am not sure that you understand how hard it would be for you to replace that head gasket. It would take a long time, and a little money. Would it work, yes. Do you want to, no. The few horses that you would gain could be gained on a dyno, or with some bolt ons. Don't fool with a good thing, experiment on a shitty engine. Just my opinion. __________________ -------------------- -------------------- 2003 Chevy Avalanche Leather, Moonroof, Z71, tow package, bose+six disc, nice. 1992 Accord EX (sold to good friends) JDM H22A H22A Auto Tranny w/LSD I/H/E -- All stainless w/2.5 inch Catback 1968 Oldsmobile Toronado Project car, 455 ci front wheel drive, nasty.

03-28-2003, 09:23 AM	#11
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	I just planned on tdoing it which I convert my h23 to vtec next month and i figured i could do it then with no trouble. Thanx for the help though guys. __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-28-2003, 09:24 AM	#12
dohcvtec_accord WRX Sellout Join Date: Sep 2002 Location: The left lane Age: 31 Posts: 8,498 iTrader: 0 / 0% Ride: 2002 WRB Impreza WRX Rep Power: 97	Shit, if you're converting to VTEC anyway, why not just install some Prelude Type S pistons? 11.1:1 compression y0! __________________ This space left intentionally blank.

03-28-2003, 09:29 AM	#13
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	How much would those cost me and where could i get them? Also i plan on putting a head from a '97 up prelude so i can supercharge it. Can my crank and rods hold that compression ratio and boost without blowing up? __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-28-2003, 10:50 AM	#14
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	any thoughts? __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

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03-28-2003, 01:15 PM	#15
dohcvtec_accord WRX Sellout Join Date: Sep 2002 Location: The left lane Age: 31 Posts: 8,498 iTrader: 0 / 0% Ride: 2002 WRB Impreza WRX Rep Power: 97	No, I wouldn't run that compression if you're planning on boosting. What OBD classification is your car/chassis right now? __________________ This space left intentionally blank.

03-28-2003, 02:30 PM	#16
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	My car is an OBD1. Its a '94 prelude Si. Back in november i had to put another engine in it and i found a good deal an an h23 ordered from Japan. I want to put a head from a '97 up prelude so i can add a supercharger because i prefer super over turbo. I'm hoping the vtec head will swap on to my h23 block and i know i'll have to get the ECU for the '97 up and get a wiring harnes to go from OBD1 to OBD2 which is whats in the '97 up. I just dont know how easy this swap will be since i've never seen anyone else do it. Also will the instrument panel in my dash still work cuz i know the dashes in the 2 cars are very different. I know i kinda got of teh whole compreesion ratio topic but any help on these questions would be great. I can get a head from a 92-96 and 9'97 up for about the same price and pretty cheap because my friends dad owns a just yard and said he'd give me everything i needed (IM, Head, EM, ECU) and anything else for like 500 bucks. Just tryin to make a decision so i can get started. __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

03-28-2003, 03:34 PM	#17
BlackJDMdeath Senior Member Join Date: Sep 2002 Location: Wichita, KS Posts: 1,146 iTrader: 0 / 0% Rep Power: 24	im not sure what all you would have to do to get that head on there, you have to remember that the 4th gen h22a has a different block design than that of the 5th gen, 4th gen being superior of course. if you plan on throwing boost at it, keep the h23 compression. ummm good luck? __________________ uhhhh... im confused with this stupid signature thingy!

03-29-2003, 05:11 AM	#18
ludeconduct Senior Member Join Date: Oct 2002 Location: Near Sac CA Posts: 102 iTrader: 0 / 0% Rep Power: 14	^ word, you don't want high compression with boost. Also not only are the blocks different between 4th and 5th gens but since you have a OBD1 setup, I've heard there will be issues when putting on the OBD2 head in a very recent post on hondaswap __________________ 1993 Lude Vtec JDM H22 Lude S 5 spd Tranny Cross Drilled Slotted all the way around Big Mouth Bumper CF Hood 14.92 Stock 15 flat on new engine tranny setup

03-30-2003, 05:42 PM	#19
dohcvtec_accord WRX Sellout Join Date: Sep 2002 Location: The left lane Age: 31 Posts: 8,498 iTrader: 0 / 0% Ride: 2002 WRB Impreza WRX Rep Power: 97	I think it's a pretty bad idea to try get get an OBD2 head onto an OBD1 block. BlackJDMdeath had a good point about the two different block designs (closed deck vs. open deck), and I think that's just going to give you even more headaches. __________________ This space left intentionally blank.

03-30-2003, 06:08 PM	#20
KyleCrews Senior Member Join Date: Mar 2003 Location: Jacksonville, FL Posts: 157 iTrader: 0 / 0% Rep Power: 13	Thanx for the advise. I think i'm just going to try to sell my h23 and swap in an H22. I think it will save me alot of time and headaches. __________________ I took part in a Survey of 100 Men, What do men like best about a blow job 99% answered The 10 miniutes of silence

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Compression Ratio