boostnubII

to make a long story short...
my crankshaft is trash, the keyway tore it up so i need to replace it...
i currectly have a B20 short block w/ gsr head... NO SLEEVES...scat pistons 9:1:1... eagle h beam rods...block guard...t3/t4

since i now need a valve job and new crankshaft i am planning on putting in a new B20 bottom end BUT i will NOT be getting the bottom end built... no pistons... no rods... stock compression... but YES on a block guard (not like it will help much)...

here are my questions...

1.) what is the stock compression on the b20... i heard they have 2 different levels for b20's...IS THAT TRUE?!

2.) i know that 10 psi is safe for stock sleeves... but how much boost is safe for the bone stock b20's pistons and rods ?

3.) what other issues would i be looking at since i am not going to rebuild the bottom end?

thx alot for ur help.

EK FLY

i would run no more than 18, 15 psi on a forged internall b20 reving to 8000Rpm's

komat

psi doesnt matter its the hp/tq

boostnubII

18 PSI WILL CRACK A SLEEVE ON A BONE STOCK B20 NO MATTER IF IT HAS FORGED INTERNALS... the internals will not save the -=WEAK SLEEVES=-... komat... any more info about how much hp/tq those pistons and rods can manage... i heard there might be an issue with the b20s stock rod bolts... can those be changed out WITHOUT removing the crank from the bottom? or do the bolt heads face UP towards the head?

JDMs1eeper

My B20B's have anywhere between 160-170 cylinder pressure.
My B20Z's have anywhere between 210-215 cylinder pressure.

Be careful and keep a safe tune. I've boosted all my stock B20's w/ no problems. The most I ran on the b20b was 15 but DD on 10psi. The B20Z I drove around on 6-7psi always. I kept stock LS rev's also.

Good Luck, be safe, have fun

komat

so what you saying if i ran 20psi on a t25. the sleeves would crack on me.... or if i ran 6psi with a gt42rrrr whatever the bigest gt42 turbo is. and i be fine since im under the psi limit?

JDMs1eeper

who me? lol

I was just saying what I've ran w/ zero problems

The B20B i ran 10-15psi on a 84AR/70AR twin scroll turbo

The B20Z i ran 6-7 (WG spring) on a .48/.50 t3/4 turbo

Could have ran more i know, just was all i was happy w/ as a fun DD

komat

nah to boostnubII.

boostnubII

i guess the easyst way to explain it is this... i WILL NOT be going over 10-12 psi so for me to continue down that road is pointless to the thread...

SHOULD I... replace the rod bolts... i read about a year back that they will strech...JDMs1eeper did you do ANYTHING to your bottom ends... or were they BONE STOCK... that is very impotrant here...
thx

*komat im ONLY talking about the B20b

Runnerdown

Rod bolts will stretch with rpm. I would'nt worry about those.

boostnubII

so what would be a safe estimate to what hp a STOCK B20 BLOCK would be able to handle?
im ordering the block some time this week... anxious to see what i can get away with before i sell this baby.

boostnubII

does 300 hp sound safe on a bone stock b20b bottom end?

Blaze45

Wow, lot of miss information floating around in this thread. I had a boosted
B20 that I ran 15+psi on for over a year and never had an issue. It was pushed by a t3/t4 57 trim 63ar which was calc'd to flow some 680cfm @ 12psi I believe. It saw 18psi on quite a few occasions. It dynoed @ 277hp @ 15psi and 255trq. So if my math is right I was pushing somewhere just above 300whp when I turned the boost up to 18psi. If the head is stock, then there is no need to rev to 8k becuase you just are not making any power up there. Why rev it if it isnt making any power? Get it dynoed & tuned by someone who knows what they are doing and find out where it stops making power and depending on what tranny you have will be a factor in deciding on what RPM for you shift at. Ideally you want to drop right back into your power band but not too early becuase you dont want to fall out of boost. You dont need to have it sleeved. I know, Ive ran the setup for over a year @ 15-18psi and never had an issue. If you have the fuel, I would crank the boost.... Keep the timing conservative, this will help keep the cyl. presssures down... Also, stay away from the blockguards. They are not worth the hassle and the have been known to cause hot sopts. If you are stuck on having one installed, you need to make sure that its done properly. The block must be heated to operating temp and you must use a deckplate (not sure if thats what its called) to simulate the head being on the block and then have the guard itself properly welded in. Once this is done you need an align bore and hone to make sure that the cyl. isnt out of round. The information about the blockguard was all per endyn's web page.

I would of turned up the boost more but I could never get my hands on set of 550s before I sold the car.

PM me if you need anything.

Blaze

boostnubII

thx alot blaze... be counting on hearing from me sometime soon....
the tranny i have is a LS tranny... the builder said it would be prime for taller gear ratios... not sure what that really means.*(any advice?)

during the first tune the car started to run lean because of the stock fuel pump so the tuner *(Shawn Church) stopd' ...(logical reasoning... )

my question to you is... was ur block COMPLETLY STOCK or did you have pistons/rods/rod bolts or anything of that nature...

let me just say a few things as a refresher...
the head is stock GSR head
& as stated above... im getting rid of my old block because of crank strip...
installing -=bone stock=- B20b just to get the car sold off... i will NOT be putting in another B20 block guard... and i will just be tuning it for best results for sale and dyno chart...

-should i tune with race gas or pump?

Blaze45

My block was all stock, the only thing I ever did to the engine was a headgasket cause I had the head off to make sure that I didnt bend any valves when the t-belt skipped a few teeth. You can swap in the Mitsu VR4 fuel pump. Its a 190lph I believe, but should handle your power easily and its a drop in mod for cheap. I got mine with 50k on it for $30 bucks. O wait, that was in my CRX. I dunno if the VR4 pump will fit any other Civic models, sorry. You could get a walbro 255lph but that would be a bit overkill but it would give you a pice of mind. I had the LS tranny and the B16 tranny. I hated the LS tranny but got used to it and it was nice for freeway cursing. The B16 tranny was sweet when I had it, I definetly miss it. I loved the short gearing. I myself tuned on 91 and then always put 94 in it for just another safety guard. What turbo are you planning on using?

boostnubII

still sticking with the big 70 t3/t4 thats currently on the motor... that will be sold with the car as well... this car seems like its ALWAYS in the shop.... time for another project. sad to see her go tho' she is the first car i ever bought, alot of time spent learning about honda's and motors while before i got this car i didnt know what a timing belt did... car is a cop magnet... fully kitted...lexus is 300 grey...greddy exhaust... rims & tires... plus many extra.... im just tired of gettin pulled over... car impounded... harassed...
i need something reliable... low profile... good speed.... great suspension... im not really one of those JDM kinna guys... but it seems like they get alot less tickets...

jsj221991

hi honda tech people
i have a crv00 with a jdm b20b engine...km stand. 135.000km.. can i bold on a t3/t4 turbo charger on low psi on it and do nothing else on the engine.. just a bone stock b20b that has driven 135.000km and than install a turbo charger on it.. is it possible???
if yes.. how much psi can i run?