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ESR2005
02-03-2008, 09:38 PM
is there any horsepower gain if i swap my sohc 8g to dohc and keep it n/a b/c i heard it lowers my compression thanx
ShiZnitH
02-03-2008, 09:46 PM
Uhm, why two threads? :P Dont think its so much to gain with the head swap. Was thinkin to do the same my self but after a while and some comments i decided to forget it ;)
YIKES >>^My post nr.666
WarmAndSCSI
02-03-2008, 09:48 PM
Wow, this not only doesn't need two threads, but doesn't need to be posted at all. Search before you post
RAZ_76
02-03-2008, 11:07 PM
Uhm, why two threads? :P Dont think its so much to gain with the head swap. Was thinkin to do the same my self but after a while and some comments i decided to forget it ;)
YIKES >>^My post nr.666

Uhhh, there is if you upgrade parts and not just do the swap and call it a day. Over 350 whp, I believe.
WarmAndSCSI
02-03-2008, 11:16 PM
350 WHP with a 16G, maybe... You're not making 350 WHP on stock internals on a 4G64.
underated
02-04-2008, 12:44 AM
you could get pretty close
http://www.club3g.com/forum/rs-gs/52866-new-numbers-stock-4g64.html

i bet if he had the head swap done he could have picked up that extra 30hp
galant3333
03-09-2008, 02:08 PM
350 WHP with a 16G, maybe... You're not making 350 WHP on stock internals on a 4G64.

I am making 280 to the wheels with stock internals and auto transmission.
WarmAndSCSI
03-10-2008, 11:04 AM
I am making 280 to the wheels with stock internals and auto transmission.

This is a far cry from 350 WHP as far as the stock 4G64 is concerned.
galant3333
03-10-2008, 11:09 AM
This is a far cry from 350 WHP as far as the stock 4G64 is concerned.

haha yea you are right. GOtta admit tho, my piston rings are giving up.
WarmAndSCSI
03-10-2008, 11:15 AM
haha yea you are right. GOtta admit tho, my piston rings are giving up.

Should have regapped them to somewhere around 0.018" top and 0.024" 2nd. Top gap can remain about the same so long as you open up the second gap a bit. 0.018" should still be a good deal wider than stock. It's a good way to get away with keeping stock internals.
RAZ_76
03-10-2008, 01:33 PM
Next year Im doing the Evo DOHC swap and Im dropping 5000 on top of parts, port and polish, wiseco pistons, turbo..hole nine yards. Full build! Build top and bottom end. Thats my goal anyways. Thats why I did the 5 spd swap this year.
galant3333
03-12-2008, 05:49 PM
yeah, i am about to buy a evo head from the dealer and a transmission of a 3g and do the swaps before summer. Probably getting a 350z and keeping the galant as a project car. How hard do u think the transmission swap was ray?
RAZ_76
03-12-2008, 05:56 PM
Not hard! Im not done though. All I have left is to mount the flywheel, clutch and transmission, everything else is done.
spdracr
03-12-2008, 06:28 PM
yeah, i am about to buy a evo head from the dealer and a transmission of a 3g and do the swaps before summer. Probably getting a 350z and keeping the galant as a project car. How hard do u think the transmission swap was ray?

there is an evo head for sale on evolutionm.net for $900

our engine can handle 350whp but the internals are meant to fail sooner or later but building our engines up will give u as much horsepower as swapping the head with the 4g63
GOOSEY2099
03-12-2008, 08:25 PM
280 to the wheels? at how many turbo/lb? and what dyno?
underated
03-13-2008, 01:47 AM
lets see some pics of the setup
GOOSEY2099
03-13-2008, 08:32 AM
^And lets see a dyno sheet
broken
03-17-2008, 08:46 PM
Just a little relevant tidbit of info.

Evo head is 43cc

4G64 SOHC is 47cc

Hyundai head is 56cc

Keep this in mind when you choose a headgasket!
galant3333
04-09-2008, 06:28 PM
280 to the wheels? at how many turbo/lb? and what dyno?

i am running 15 psi right now and its about 276 whp i believe. I just bought a 4g64 dohc head of a kia in a junk yard. I am currently working on building that and buying new pistons and piston rods.
Galantfan88
01-02-2009, 01:47 PM
Wooooo we went wayy off topic here, but having 280hp on stock intternals I find that hard to believe man. But I dont think theirs much of a difference having a single cam or a twin cam. Well I was thinking of getting an Evo head and trying it, but to many people are doing it, so im ganna try working with my single cam head for my 4g64 motor. Port out the cylinder head with bigger valves and see what my results are. Im going to try to hit up 350 hp, I have a feeling I might need alot of boost to do that but well see.
Shadow19
01-02-2009, 03:20 PM
Wooooo we went wayy off topic here, but having 280hp on stock intternals I find that hard to believe man. But I dont think theirs much of a difference having a single cam or a twin cam. Well I was thinking of getting an Evo head and trying it, but to many people are doing it, so im ganna try working with my single cam head for my 4g64 motor. Port out the cylinder head with bigger valves and see what my results are. Im going to try to hit up 350 hp, I have a feeling I might need alot of boost to do that but well see.

280 on stock internals isnt hard to believe.
ESR2005
01-02-2009, 10:37 PM
well wiseco crunched my numbers with all the parts i have and they came up with a guess of 655 whp with their custom specced pistons 272 cams aem ems and a gt35r with rc 880cc injectors and a magnus intake manifold and 45mm wastegate..o yea and runnin at 30lbs of boost
Shadow19
01-03-2009, 06:50 AM
well wiseco crunched my numbers with all the parts i have and they came up with a guess of 655 whp with their custom specced pistons 272 cams aem ems and a gt35r with rc 880cc injectors and a magnus intake manifold and 45mm wastegate..o yea and runnin at 30lbs of boost


They can crunch numbers all day long man. Reality kicks in when you hit that dyno and you put down 378 WHP and youre just standing there with a WTF look.