ok i know people gonna say its a bad idea and all, but here's my question. I'm putting together a b20vtec. Bottom end is completely stock with arp rod bolts, arp headstud. with the Cometic headgasket. stock gsr head. planning on turboing it at 8lb of boost and was wondering if that's ok. it'll get tune right after i put everything together and would only bring it up to 7500 rpm MAX since the bottom block is not meant to be reving high. so i would like some opinion from you guys.

 

got one of the tuners here that are usin the stock b18 with gsr head at 0.7bar,tuned right,car hurts ur neck tho wen boost is reached,so im sure urs shuld be fine,but people say the b20 sleeves are weak,thats jus wat they say

 

i got stock b20 block with arp rod bolts ad stock gsr head with arp head bolts.....had a drag manifold with a ebay turbo kit........i beleive it was 25 to 30 psi but dont quote me cant remenber now and the car made 451hp at the dyno. motor is still alive lol and running better then ever. to be honest its all about the tune and for that i go to my family...( clm motorsport)

clm 1st in the 8's running aem

 

sounds to me your heading the right direction mine is boosted at just over 10 and pulls very well. you will enjoy it. get a quality tune spend the money to keep it alive thats my advice, good luck.

 

lsvtec, are bad for boost ahhhh. well alot of boost that is, if your planning on keeping that motor for awhile i wouldent run 12 psi + stock. if you build it however im sure it will work fine. you might be spending alot of money tho on that head. vavles will bend over time. just my opinion tho, could be wrong.

 

he said 8psi max. not 12+. anyways tho. you will be fine on that build with everything stock. nothing more than 10psi tho..also if you plan on building it as in rods pistons etc. just get a b18 block do to b20 blocks sleeves are weaker than b18. do to bore size etc. OEM headgastket ditch the cometic

 

Explain your reasoning behind ditching the Cometic.

 

meh i was just bluntly saying that, you kids building these lsvtecs. i know what you guys stand for but i wouldent waste money on a lsv for boost been there done that. stick with a ls complete, or just boost a b16 if your going to spend the money on the bouild, from my experiences lsvtecs are crazy fastwhen built right, but if your looking for a dd out of a boosted honda motor, a lsv is not a good idea. simply cause they dont last that long on high boost, but however. if your only gunna leave it at 8 psi then shell be good. i can gaurentee that you will be upping the pressure tho ahah. cause we all do it.

 

My LSV has lasted 3 years so far on 16+ lbs of boost. So your reasoning makes zero sense... Granted my car is not a DD, ONLY because it doesn't have AC and the clutch is a pain to drive in traffic. Please explain why they dont last long on high boost, and what your definition of "high boost" is.

 

If tuned properly you can run up to 15 psi on this motor. 8 psi is a walk in the part even for the average tuner. The b20 cylinders are weaker but you should be fine. and dont be afraid to rev it to 8200. you have the arp rod bolts you will be just fine. i just recomend a obd1 vtec oil pump or any od2 oil pump if not already on the block. obd1 ls oil pumps dont supply enough voume and you will whipe out bearings eventually.

Stock bottom ends even ls/b20 can and will last with boost with a good tune. you can grenade a built motor if not tuned right

 

the answer is R/S. R/S is the abbreviation for rod to stroke ratio. It is the ratio of the length of the connecting rod to the length of the piston stroke, or the distance the piston travels from the top to the bottom of its stroke. As the ratio gets lower, the amount of stress on engine internals increases exponentially, killing long-term reliability. The higher the number is, the slower the piston is traveling, killing power output. if you boost it it only speeds up the affair. thus being completely stock.

The ideal R/S is 1.75:1 (Three cheers for the B16A, at a near-perfect 1.74:1!). hah

Why a low R/S is bad for reliability...

A low R/S means the rod will be closer to a horizontal angle on its upstroke. This means that more of its force will be pushing the piston horizontally, rather than vertically. What does this mean for your engine? Two things.

1. There will be more stress on the sides and in the center of the rod, rather than on its ends, leaving the rod more vulnerable to breaking. Picture a straw. This is no special straw, just an ordinary drinking straw. Is it going to be easier to bend this straw by applying pressure onto its ends, or at its center? Now think of your poor connecting rods.

2. There will be more stress on your cylinder walls. Once again, the rod is pushing the piston at a more horizontal angle- right into your cylinder walls, rather than up and through them. The risk here is double: A. Putting that piston right through the cylinder wall. B. The cylinder wall will actually flex under the pressure, causing the shape to turn from a circle to an oval or oblong shape. This causes the loss of the seal created by the piston rings. What happens? A small amount of oil could slip past into the combustion chamber. Bad things happen from here: The oil gets combusted, leaving nasty carbon deposits in your combustion chamber and exhaust ports- not a good thing for flow or valve sealing.

It's also important to note that as the RPMs increase, so does the amount of stress on your engine's internals.

im not here to argue with anyone. i simply loves hondas and everyone on this site. imo the ls v isent great, but thats just me. sorry if i cause any problems mates!!

 

No need to quote wikipedia for me. I know what R/S is and the concept behind it.

A factory GSR and Type R have R/S ratio of 1.56/1.57. A LS/V has a R/S ratio of 1.55/1.56. To me that is not much of a difference in the terms you are making it sound.

The main difference between a GSR/R and LSV is increased compression (if using pr3 pistons it is damn close to 12:1) and a tad bit more displacement. Granted I personally wouldn't boost a 12:1 motor unless my tuner was very confident in his abilities and then I probably still wouldn't.
Basically what you are saying is that every motor is crap in terms of reliability compared to a B16 because of the R/S ratio......

I'm not here to argue either, this is actually a good discussion. But you should mention that what you say is either opinion, actual experiences, or what you read what other people say.
I have had B20s, B20 Vtec, B16, LS, LSV, GSR all turbo and not. Everyone has had its pros/cons. They were all build differently too. I can share plenty of personal experience with the motors and how they performed. And again I say personal and not my friends, or friends friend, customer...ME

 

lol, good job mate!! im not gunna argue. you knows your ****. im just not a fan personally of lsv builds. sorry for grindin your gears ahah

 

WTF valves will bend over time? lsv bad for boost, Im running 15 on my lsvT in my db8, clearly you do not no what you are talking about that is my opinion.

Boost that b20v

 

thanks for all the output guys. i should be getting everything in by end of feb. or beginning of march. should be a pretty fun car to drive around on the weekend..

 

A b16 motor puts out the least amount of tq and power IMO. this is why there not used. so the 3 cheers are more like 3 boo's.. if having issues with sleeves and Cylinder walls, get a sleeve motor, problem solved. no more weak cylinder walls. although there are many people that have ran stock sleeved lsv for years with no problem. you say you had problems.. but that could just mean you're doing something wrong. i'm not here to argue either but very few people are going to use a b16. there just not up to pep like the b18/b20 motors.

 

one more question is a gt35 .63ar turbo too big on the set up im planning on doing?

 

its really all about the tune.. but id advise you to build your block more.. im doing the same build as you with a turbonetics t04e on 28 pounds. and im going all out on my block. already have sleeved cylinders, je pistons, scat rods w/ arp bolts, eagle knife edged crank, moroso oil pan tapped, arp head studs, greddy headgasket, much more. dont cheap out your sh*t. just take your time and build it right. i made the mistake of not building my block on a boosted b18c and blew it up on 12 pounds.. dont be a ricer running around yelling "im boosted, wanna race". ive learned to just take your time

 

it s all in the tuning.......................
here s real proof!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! !!!!!!!!!!!!!!!!


we tried out two stock block b20vtec s
one was allready hurt(but thats because we pushed it hard on 91)

p.s don t take the captions in the wrong way its only a joke lol!!!!!!!!!!!!!!!

1st car
-b20vtec turbo coupe 14psi on 91 makes 339whp (makes 372s when it goes to 17psi)stayed at 14 at track

stock b20vtec turbo dyno tuned at revspeed 91octane(boost problems stop going to 17psi will only do 14psi)
http://www.youtube.com/watch?v=m5zm_Fo0fEI

first run
b20 vtec turbo coupe first run

second run
12.1

third run
http://www.youtube.com/watch?v=MIBvWr1-UvM

4th car
-towed b20vtec turbo hatch (hurt motor-going to have fun!)395whp on e85 19-20psi

vid of motor hurt
will be updated

91 octane dyno
http://www.youtube.com/watch?v=VMDSwR27jsw
e85 dyno (motor hurt three hair line cracks and two bent rods)
http://www.youtube.com/watch?v=GnJJpnO69IQ


run
http://www.youtube.com/watch?v=QEriKTWZMRc

 

Hehe. I love it when the R/S ratio argument comes in for LS/VTEC B20/VTEC. For built motors that have been done correctly, it is not nearly as relevant as one thinks in the grand scheme of things.. And yes.. I have one myself.

For the OP, you're fine. Make sure the assembly is balanced correctly, and that understanding that power isn't gained as much when over 8500rpms.. simple as that.

 

lol .....i belived it 8 years ago

 

Is that to say that you believe it is now true based upon your experience from the build? Or are you saying that you no longer go by the R/S "philosophy of thinking" when comparing displacement of the optimal Honda B-series engine. Since 1997, I've never had a problem.

 

o im saying r/s or piston speed has nothing to do with it.
it has to do with the material, builter and tuner........

 

these aren't stock b20vtec turbo is it? and i meant as in stock as in stock internal on the bottom block and head.

 

i have personally built 3, b20 vtecs....ALL BOOSTED. and only one took a dump due to 2 dead injectors it split the cylinder. B20 sleeves are NOT weaker! LOL they are basically the same thickness as all the other B blocks. It is like Zedron its the R/S. The B20 will apply more pressure to the cylinder wall on the upstroke. It tries to make the cylinder lean (to the side) thats what causes cracked sleeves at high boost. Thats why I highly recomend a block guard at the very least. I know they are cheap and some people say worthless. It does help ALOT in some cases. My B20/V is on 15 psi daily, no problems yet. One of my friends, the one who tunes and tuned mine is running his on 22 psi. and his is a using an t4 innovative .67 turbo, i dont know ALL the specifics. but it is on a STOCK block, rods, pistons with a block guard and arp head studs and rod bolts and gsr girdle. NO PROBLEMS YET....He has been on that setup about a year and a half.

I dont know if any of that helped, but good luck with the build.