im planning on building a b20vtec for my ITR due to a spun rod bearing?
whos here is racing one?

 

an actual b20 block is more junk than a b18b block. The sleeves are a terrible design. I wasted a ton of money building a road race b20vtec.

you're better off with a b18 block sleeved to 84mm. now thats a b20!

 

A few ECHC guys ran B20vtecs both had problems with sleeves cracking after a few races.

 

thanks for the info, but i cant afford to sleeve any blocks. what happend with your engine, and what was the setup?

 

You should try a lsvtec with ctr pistons, thats the combo i ran all season. 18 races revved to 8600, toda C's making 205hp and 136tq on a dyna pack. The B20 made the same hp 10 or so more ft/lbs but only lasted 2 races until the head gasket blew, pulled the head and discovered 2 cracked sleeves. Both blocks were stock HC does not allow aftermarket sleeves.

 

Don't use a B20 Block!!! It's a complete waste of time & Money. Believe me!
Use a B18 Sleeved & Bored. It's much more reliable. We use Cunningham Longer Rods and Custom CP Pistons 13.5:1 I can run up to 9000 safely all day long. The key to reliability is... Good Oil. Efficient Oil Cooling. Use a Moroso Road Race Baffled Oil Pan (Canton are Junk! Just ask me why... Go on ask me) Also use an Accusump.

FWIW

Kiwi

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by KIWI &raquo;</TD></TR><TR><TD CLASS="quote">(Canton are Junk! Just ask me why... Go on ask me)


Kiwi</TD></TR></TABLE>

why

 

Well to start with the General construction of the Canton Oil Pan is crappy. (Surprising, because I always thought they made good stuff?)
The B18 Oil Pan that we bought from Canton, when fitted to the block had to have chunks ground out of the edge of the gasket flange so the flywheel would not rub on it. The Gasket flange is flat, unlike the Moroso Unit which is I guess just a Modified Stock pan and has the Honda style indentation running around the middle of flange which helps locate and seal the gasket. The flange edges on the Canton Pan are so badly formed and miss aligned the CV Boot on the drivers side shredded against the flange edge!
Need I go on? Perhaps we just received a bad piece? but compared to the Moroso Pans we use now, I would never recommend a Canton to anyone!

Has anyone else had these problems?
Kiwi

 

nice info, but dont be jacking my thread, or ima haveta start bustin caps!!

well i got a b18c5 ITR w/ a spun rod bearing, what are my options?

 

is the crank still good? if so id just replace all of it with oem stuff

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Freeltec &raquo;</TD></TR><TR><TD CLASS="quote">im planning on building a b20vtec for my ITR due to a spun rod bearing?
whos here is racing one?</TD></TR></TABLE>

I built one about 5 years ago for track use and after all that time and countless miles the new owner has never had a major problem.

The answer and why it's different from other peoples is very simple, intended use. Honda built that block to see peak engine speeds of less than 6800 rpm I borrowed this from endyn to explain

B16A
77.4 mm 8000 RPM 20.6 meters/sec
8500 RPM 21.9 m/s
9000 RPM 23.2 m/s
9500 RPM 24.5 m/s
10000 RPM 25.8 m/s
B17A
81.4 mm 8000 RPM 21.7 m/s
8500 RPM 23.1 m/s
9000 RPM 24.4 m/s
9500 RPM 25.8 m/s
B18C
87.2 mm 8000 RPM 23.3 m/s
8500 RPM 24.7 m/s
9000 RPM 26.2 m/s
9500 RPM 27.6 m/s
B18A/B18B/B20B
89.0 mm 7500 RPM 22.3 m/s
8000 RPM 23.7 m/s
8500 RPM 25.2 m/s
9000 RPM 26.7 m/s
9500 RPM 28.2 m/s
B20A
95.0 mm 7000 RPM 22.2 m/s
7500 RPM 23.8 m/s
8000 RPM 25.3 m/s
8500 RPM 26.9 m/s
9000 RPM 28.5 m/s

at 7500 the lowest point for the b20 I have the piston speeds are higher than a b16 at almost 9000. There's a pretty good chance if you run a stock b16 block hard enough at 9000 rpm your going to break something. Now when you take into account an ITR head ect is still making power well into 8K and with a track built head possibly as high as 9500 simply putting a stock b20 or even a lightly built one the pistons speeds are equal to those in the b16 at 11,000 rpm.

The solution is to keep RPM's a bit lower even with a built motor to like 8K and it will run for a long time. Mine used the ITR water and oil pumps and was fully balanced and blueprinted a nurformz block gaurd and shortly there after a dampened pulley was installed.

8K means your obviusoly losing 1000 rpm but since you have esentially 10% more power and tq you won't notice a difference

If you can have the ITR bottom end rebuilt do it but try to chose someone who has an engine building area that is clean and well lit ect.

 

I run a B20VTEC. So far I've only run one race weekend with it and seems to be fine. Am concerned with what exactly is wrong with the sleeves? I have a block guard and am running an oil cooler with a Mugen pan. Is it the revs that cause it to crack?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by e9 &raquo;</TD></TR><TR><TD CLASS="quote">Mine used the ITR water and oil pumps</TD></TR></TABLE>

Why did you want to spin those slower? Just a question.

 

My b20 ran for nearly 20k before a buddy sold it after he bought it from me. Made about 210 to the wheels. Spun to 9k daily. I wouldn`t use it as a "race" motor though.

 

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

Honestly because the only people at that time who knew anything about building track b series motors told me too. The rational is that the ITR pumps were designed to run high rpms for extended distances and that they were more reliable and provided a higher volume without cavitation. Although recently one of the companies I work with pulled a b16 and an ITR oil pump apart and they were the same so it's probably more the difference between vtec and non vtec motors than anything else design wise instead of just ITR specific. Or maybe it's PR3 parts being the same vs the GSR p78 I'm going to revisit this soon as I have a spare b16 I'm going to build for track use

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by RRRex &raquo;</TD></TR><TR><TD CLASS="quote">I run a B20VTEC. So far I've only run one race weekend with it and seems to be fine. Am concerned with what exactly is wrong with the sleeves? I have a block guard and am running an oil cooler with a Mugen pan. Is it the revs that cause it to crack?</TD></TR></TABLE>

The bores are thin compared to the LS even it's not there's anything wrong it's just they are being asked to perform well beyond there means


If anyone is interested this is the most in depth article I've ever read on building any b20 vtec and the result is that this motor is capable of almost 300hp on an engine dyno with street use intended

http://www.theoldone.com/articles/badtothebone/

 

with a big stroke crank the angle at which the rod sees during a revolution is more extremet than a smaller stroked crank sees. this results in more force being "pushed" against the cylinder walls than we would like to have. this causes the piston skirts to make excessive contact with the cylinder walls which wears them quickly, as well as the fact that the cylinder walls are being rocked back and forth.

the b20 sleeves ar not individual sleeves set into a solid mold like you see with other b series. they are a one piece design. they are very brittle as well as thinner.

you can build a b20 to run high rpms by making the walls stronger. you can sleeve the block obviously, or you can post the vblock which is less expensive and still employs the factory sleeves which may be necessary for some classes.

you will also need to use stronger wrist pins, because the wrist pins in the b20 are weak sauce, adn they get a lot of stress from the bazzilon meter per second speed that they are experiencing. your piston changes direction over and over and over again. in a b20, it does so much faster per given rpm. that means that all of the momentum that the piston has forcing it in one direction is suddenly met with the piston being forced in another direction.

also you need to secure the crank with a crank girdle.

the moral of the story? you should just get a b18c5, throw in some high comp pistons, get some good tuning and some boltons, and get a really well shaped combustion chamber to work with your ubber high compression pistons, and be done with it.

i used to drive a car with a b20, and i wont ever be going back. you can make reliable high end power with b series engines and maintain great reliability. dont get lost chasing torque.

 

or just get a k20. thas the way to do 2000 cc's

 

good info man

 

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

Very good info. I learned alot.