Loads of B20 Information


blinx9900

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Thank you ek9.org user adee-ek4 for the following B20 information, here is a link to the original thread if anybody would like to see the original discussion: http://www.ek9.org/forum/engine/5855-b20-engine.html

Right Lately I have had a helluva alot of Questions regarding My B20 vtec conversion, So i am doing a Write up to try and answer as many of the question's as possible and advise on what i have done and hopefully disperse some of the Myth behind the B20 vtec.

OK a bit of Back ground on the B20vtec first.
Way back in the day (1993) in the tsukuba battle's, a Small company took a B20a(7) block (from the DOHC PGMFI 150bhp prelude) and retro fitted a b16 Vtec head to it, which from all accounts was an extremly hard job to do as the old b20 blocks were alot different to the newer B20b/z blocks of today,
It produced great horse power and torque but due to the reliabilty the idea wasnt used much and eventually left alone.
Jump a few years to 1997 when the B20b Honda CRV was launched, It was realised that the B20b had been made using the B16/18 block using different sized sleeves/pistons (84mm) there fore they figured that a Vtec head would fit, SSworks were one of the first company's to utilise the B20 for there race car and managed to set a record lap of Tsukuba in a FWD allthough this has now been beaten with the same car running a super high comp B18.
In 1999 the higher compression B20z1 was released this engine produces a further 19bhp and reved to an extra 1300rpm in standard trim.

Here are the 1997 onwards B20 specs.

B20B1 128bhp@5500rpm 1972cc 9:1 Compresion ratio.
B20B3 128bhp@5500rpm 1973cc 9:1 Compresion ratio.
B20Z1 147bhp@6800rpm 1973cc 9.2:1 Compresion ratio
B20Z3 128bhp@5500rpm 1973cc 9:1 Compresion ratio.
The above are what i have found and may be wrong.

Since 1997 the B20 has become a very common engine build in the states and is becoming a common engine buildin the UK.

Ok here is breif run down of my original B20 build before i started adding lots of go faster goodies,

B20z1 complete Bottom end.
B16a2 complete Head. inc inlet maniold, Injectors, Distributor cams etc.
Golden eagle VTec conversion Kit.*
B20 Cambelt.
B16 Exhaust manifold.
B16 Flywheel and clutch.
B16 Oil pump,
B16 UK CRX VT Y2 Gear box.
B16 Starter motor
B16 Alternator
B16 Bottom Pully.
B&M Fuel pressure Regulator + Gauge. (set to 60psi)
APR head studs
Golden Eagle Block Gaurd.

That is every thing i needed to build my B20vtec.

* You can buy the parts seperatly and DIY or buy the GE kit which has every thing you need.

I used the Golden eagle Vtec conversion kit which can be seen here,

Lightning Motorsports - Golden Eagle - Lightning VTEC Conversion Kit COMPLETE -

Which comes supplied with following:-
Oil filter sandwich plate.
Vtec oil supply line.
Stepped dowels.
Fitting for the Head.
Tube of Honda Bond,
Oil way Plug.
Tap for the above.
Re-worked head gasket (84mm+ for B20, 81mm + for ls/vtec)

Now this kit means there is absolutely no Machining required, other than tapping the head for the Oil way plug.
You can of course buy all the parts completly seperate and DIY, both ways work fine and neither are right or wrong,
I personaly went for the GE kit for ease of use nothing more nothing less,

Now the main questions I have been asked lately are :-

Q. Which block is better B20b or Z.
A. It depends on your application, The Z has a higher compresion and produces close to 20bhp more in stock form there fore for a basic build the Z would produce more power, But if you plan on fitting pistons and rods the B20b would be better as its usually cheaper to buy due to less power.

Q. Can i turbo the B20,
A. Yes you can B U T its not advisable on stock sleeves due to them being alot thinner than standard B16/18 sleeves and they do not cope to well with detination.
I looked in to turboing mine but all the info i came up with said NO unless i planed on fitting a set of Darton/Benson sleeves.
Even at low boost a small amount of DET would mean potentional engine Failure.

Q What cams can i fit.
A On a stock built B20vtec it is not advised to run anything other than stock B16/B18 cams, I have used ITR cams with stock B20 pistons but i clayed the motor and locked the vtec in to test first, If you want to go down the route of big cams it would be advisable to get your engine clayed, and/or use after market pistons you could also have your stock pistons machined to accept a deeper valve lift.

Q. Which Head do i use.
A. You can use any of the Bseries Vtec heads they will all work, On a rough principle it depends on application, B16a heads tend to flow better than say a B18c4 head, but the B18c4 head has bigger Inlet ports and coupled with a good inlet manifold would be good for more torque, the ITR head is probably the best "off the shelf" head but the B16 is by far the cheapest and easiest to find.

Q. How much will it cost me to build a B20
A. This is quite hard really as it depends on how much you get certain components for, For example I paid £500 for the B20z bottom end, I borrowed the B16 head from a mate in replacement for my old 1 when it was removed, the conversion kit I ordered via my self at DNR so cost me trade, along with the new oil, spark plugs and timing belt inc the rest of the sundrais it came close to £1000.
In a nut shell expect to pay between £800-£1200 on a B20vtec build.

Q. What exhaust Manifold do i need.
A. All B series Vtec manifolds will fit I have used stock B18, B16 and after an market 4-1 before i built my custom header, all fitted fine under the stock B20 sump. If you do decide to fit a Crank girdle you will have to fir a B18 exhaust manifold due to the Sump sitting lower.

Q. What can i rev up to safely???
A. Again a hard 1 really, I rev'd mine to 8300rpm all day every day and it has been for well over a year and 20,000+miles with no adverse affects, Allthough if you want to be super safe Simply dont rev higher than stock B20 rev limit. What you will find is that the B20vtec once in vtec will rev very easily and quickly to about 7500rpm, in basic form it starts to die out on power around 7300 and reving up to 8k is not needed really as it has noticably stopped making power.

Q. What is the B20 like on fuel,
A.This is 1 of the best things about B20's I actually have better fuel consumption than with the B16, due to the fact that you drive in a gear higher, I regularly pull away in 2nd gear with no problems, also i dont have to rev the nuts off the B20 i just simply put my foot down and she pulls , where as in a b16 you drop it down a gear and tec it away. Lots of people who have the B20 have said the same, MPG is better with the B20.

Q. What timing belt do i use.
A. I used the B20 timing belt other's can be used but i cannot give my advice as i have not used them.

Q. What Gear Box do i use,
A. Ideally the Gear box that you have with your car (unless your doing the B20 conversion to a D series) I used the UK VT Y2 gear box in my crx but in a EG/EK civic or teg the approriate Bseries gear box.

Q. What Flywheel/Clutch do i use,
A. Again i used the B16 flywheel and clutch, the B16 clutch seems to take the B20 fine. I have done 1 track day and a lot of HARD launches with the Stock B16 clutch and it has no signs of slipping yet, All though once I start upping power Iwill be getting a better clutch due to the increase in torque.

Q. What mangment do i need,
A. I am using aPW0 OBD0 ecu with a remap, Allthough I ran it for a few weeks on stock ecu but with 60psi fuel pressure for safety, I DO NOT recomend running you B20 on a stock ecu and a remap or upgrade ECU would be the safest possible thing, There are plenty of people on the forum's who could remap your car and i am sure a good base mapped chip will be available soon.

Q. What injectors do i need.
A. I am running the stock B16 injectors at 60psi. Different injectors will require remapping, H22 345cc injectors are a popular plug and play chocie though. i ran mine at 38psi once mapped.

Q. Where do i need to have Vtec cut in.
A. I have mine set at 4600 which is about right, as with Vtec in the stock settings its a little to high and comes in with a brutal kick.

Q. What does it Drive like, is it ok in traffic.
A. Its perfect in traffic it doesnt kangaroo about or have problems with over heating, i have noticed under bonnet temps being a bit higher but the Temp gauge is always about 1/3rd of the way up and never goes any higher.

Q. Is the stock CRX water system enough for the B20
A. Yes. i have had no problems with over heating even with mine in a tuned state at high RPM at the track days.

Q. Can i build a B20vtec my self,
A. If you can perform a Head gasket replacement on your car and you can swap an engine over then YES you can its as easy as that.

Q. What power will it make.
A. I have yet to Dyno mine so i have no stats to show, All though i have built 3 different B20vtec's now for customers that have made pretty good power.

Example 1 B20b home made in every way shape and form stock B16 head, intake, exhaust, walker OE exhaust system, slightly mapped ecu to cover fueling, the car made close to 180bhp and 150ft/lbs.

Example 2 B20b Home made with stock B16 ecu, manifold with a custom exhaust system, Cold air intake car made 185bhp, 156ft/lbs.

Example 3 B20z GE conversion kit, AEBS inlet manifold, Comptech exhaust, B18 ITR ecu, Tanabe exhaust 8k rev limit, ITR injectors, 196bhp, 159ft/lbs. Now these arent exactly good to go on as all are different dyno's on different days, BUT expect a good increase in torque over a stock B16. And at the end of the day its the Torque that makes the difference NOT the BHP.

Roughly a Basic Built B20b will see around 175/180bhp, and a B20z around 190Bhp with around 145/150ft/lbs.

OK hopefully that has answered alot of the Questions you have been having.

IN PART 2 HOW TO BUILD A B20VTEC.



PART 2 Rolling Eyes

OK

You may want to get your self a Haynes Manual or CRX engine manual for this job.

I am not going to run through everyting piece by peiece as if your confident enough to under take the task of building the B20 vtec you should be compitent enough to understand how to fit/re-fit the parts mentioned.

Lets start


Take your desired B20 Bottom end and check it over for any problems, cracks etc, clean the face and check the bores for marks or rust etc.

If you are going down the DIY route you will need to Pocket your pistons to stop valve/pistin touch, I personally recomend getting this done by a profesional or BUY THE GE conversion kit as it saves with this problem as it does with alot of other you will find along the way.

Its about now that you want to fit your NEW honda water pump, its always advisewd to fit a new water pump for the sake of a few quid it could save you from engine failure downthe line, once thats done you should fit your new Oil pump, you can use the oil pump from a B16 or B18vtec, its advised to use a Vtec oil pump as there designed to pump oil at higher RPM's than the stock B20 item, when fitting the oil pump use Honda bond to seal it and stop it leaking, Also if your fitting a Crank girdle now would be the right time top do so, if you are going to fit a crank girdle you will also need the following items,

B18 sump,
B18 windage tray
B18 Oil pick up. along with your Girdle,
B18 specific exhaust

Refit your apropriate sump and items to the bottom of the block. Make sure the sump is tight.

Now you can fit your Oil filter sandwich plate and filter

attachment.php


Now at this stage you may want to fit your Block gaurd and head studs if your using them the head studs have instructions in with them on how to fit as does the Blcok gaurd i used a Golden eagle Gaurd and it was an absolute pain in the AR5E to fit i had to machine it down by about 2mm inside and out to be able to get it in, Now when fitting the BG its a good idea to have the bore's checked after its fitted as in some extreme cases the gaurd can cause the bores to mis shape.

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http://i34.photobucket.com/albums/d133/Daz81/Silver VT/DSC00067.jpg
Now you need to add fittings to the back of the block for your PCV system,
To under stand the PCV system read these threads and it will help you to understand why you need a PCV system on your B20 build

Honda-Tech.com: Forced Induction: Tests on the PCV system - How Honda intended it -

Honda-Tech.com: Forced Induction: The Official Crankcase Evacuation thread for Turbo Hondas / PCV / Catchcan /

Now these are the Part numbers for the Honda fittings and washers

12207-634-300 for the washer you will need 1 of these
11107-PK2-003 For the Nipple fitting.

attachment.php


You can see the fittings i made for my Block from using the original fitings and drilling them and adding my own fittings, this idea was given to me by Mark E.

http://i34.photobucket.com/albums/d133/Daz81/Silver VT/b8f8e27d.jpg

http://i34.photobucket.com/albums/d133/Daz81/Silver VT/79b86a4c.jpg

It has come to light in testing that 2 fittings on the back of the block is to much, as the fitting on the left is the return gallery from the head,
I ONLY USED THE LEFT HAND FITTING, but you can still use the left fitting and add a 1 way valve


Once your new fitting is in your Block your ready to start building up your head.

As with the Block make sure the face is clean and the head is ok you may wan to have it Pressure and crack tested before using it. Now i fitted new B18 LMA's to my build as whilst the head was off the car it was easy to do, i also replaced the Valve stem oil seals, cleaned the Combustion chambers and re-seated the valves. its not nesesary to do this but i am a bit **** when it comes to building engine's i dont like taking risks.

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Now with the head up turned you need to Plug this hole

This is the oil supply hole from the B16 block which is not present on the B20 block and if not plugged will cause oil to seep out all over the back of your engine,

Next you need to add the fitting to the head for your oil supply there is a fitting you need to remove from the B16 head and replace with the new fitting for your supply line.



OK now you need to add your dowels now depending whether you bought the GE conversion kit or not this is where it gets a bit tricky, the GE conversion kit provides you with stepped dowels which slot in the B20 block and allow the B16 head to fit no problems, If how ever you went down the DIY route you will nedd to drill either the block or head to except the sized dowells you are using, yet another reason to use the GE kit.

Once the dowels are sorted you now need to put your head gasket on to the block, again the GE conversion kit provides you with a re-worked HG which will fit in place perfectly, if your going DIY you will need to adapt your HG to suit the sized holes for your dowells, so once the HG is in place the head is now ready to be put on your block this is easier with the head studs as it will just slide down in to the correct postion, once the head is on check to make sure you have not trapped the HG and that all is sitting correctly, Now using the CORRECT tightening guide lines for your choice of Head studs/bolts tighten away, once tight it add your Vtec oil supply line and it should resemble this

attachment.php


Now refit your Inlet manifold and the appropriate sensors bact to your head and block, the B20 water coolant temp sensor is not in the block like a B16 its situated on the thermostat hosing a lengthened the wires and added the correct plug for the sensor, now would be a good time to add a heat sheild inlet gasket aswell.
Once all your sensors and inlet manifold are fitted you can start timing youre engine up ready for your cams to be re-installed, once the cams are in and the timing has been set fit your new Cambelt,
slowly turn the engine over by hand and feel for any problems, you may want to lock the Vtec in position to feel for Piston/valve touch, you should not have any touch with the GE conversion kit if you have a stock head,

if all is well your ready to start fitting all the ancilaries like the fly wheel, clutch, gearbox, alternator and starter motor back to the engine.

You can now fit the distributor HT leads and new spark plugs aswell.

Now youre ready to drop your engine back in to your Car, once in and bolted up fit your Drive shafts, and wire the engine up,

Fill the engine and gear box with the correct oil, MTF 90 for the Gear Box and 10w40 for the Engine, make sure you have the correct dipstick for the sump you are using. Add your coolcant to the system and bleed as best you can your engine should now be reday to be started, BUT before you do make sure you have tightened every thing up and that you have no leaks etc.

You can now start her up, Once started check your Fuel pressure is at 60psi (if using a FPR to controll fueling) leave it to warm up check for CEL's and leaks, once up to operating temps, switch off, recheck all your work and then go for a spin, take it steady and keep your eye on the gauges, it may be best to have some one follow you to let you know if any thing is dripping from the car whilst driving, once your happy the engine is fine build the revs and try VTec if all is well slowly build up the revs more and more listening out for any bad noise like DET etc,

Hopefully your car is running sweet and your happy with your new toy,now go out and Play.


Dissclaimer
My self and THIS FORUM will not be held responsible for you fukcing up your engine, or hurting your self or some one else from this write up. If your not compitent or confident enough to undertake the JOB do not do it.

Please ask questions if youre unsure via this thread.

I hope this has been help full enough .

COMING SOON PART 3
HOW TO TUNE AND MAKE YOUR B20 MORE POWERFULL.



HERE WE GO AGAIN Confused :nono:

OK I will update this particular section as and when i relpace certain parts.

First tings first once you have you B20Vtec running it would be a good idea to get it on the correct managment wether it be a stand alone like Hondata oir just a re-mapped stock ECU, Hopefully as I go along this Build we will be creating a good base map for a B20 vtec that can be used for others to work from.

Now i had a quick session with a well known Tuning GURU and even in that quic sesion we made some differences to the map that were very noticable and have given me a lot more drivabilty, i later got my wide band fitted and mapped it to the nest of my abbility.

Since the basic Building of the engine I have added the following,

Custom Heat wrapped 4-1 manifold, Custom 2.5" exhaust system with as much flow and as little restricions as possible,

as you can see



This particular system was a 2" prototype version I have now adjusted it slightly and am using 2.5" id piping which has made a noticable difference,
this particular system goes under the fuel tank not around and over the rear arms, its not so good on the road as its low but for my track car its fine.

I have also added a Custom Heat wrapped intake pipe and bigger filter, so far these simple mods have made a difference on the way the vehicle drives it has alot more throttle response and pulls from lower down and revs higher easier.

The 2nd B20 I built was for a friend, but i had say in the build,

B20z bottom end
B18C4 skimmed head
ITR Cams
ARP head studs
KMS block gaurd
GE B20 kit
B18 crank girdle, windage tray anmd sump
AEBS manifold
70mm STR Throttle body
Remapped ecu
2.5" under tank exhaust
custom 4-2-1 manifold
345cc injectors

The car\ made 221bhp and 156ft/lbs.

Part 4 PROBLEMS WITH MY B20



PART 4
PROBLEMS WITH MY B20
Crying or Very sad


Yes there have been some teething problems.

The biggest problem i had been having was PCV related i had been getting serious Crank case pressure and was blowing out oil seals left, right and centre at the start.

I adpted the PCV system on my car and with trial and error i have managed to stop the oil seal issue an get rid of the excessive pressure build up.

Now i have designed and built a new catch can and have had some bigger fittings and pipe made up for me and usong some 1 way valves.

The above named PCV problem is 1 of the issues the other thing is TRACTION Twisted Evil B20vtec's tend to like wheel spining and its the low revs at which it spins at is amazing at the torque difference, 2500 rpm and mine just starts spining even on very good tyres at 26psi. its crazy.

I hope this write has been help full.

And I am hoping there wont be a Part5 (engine blown up B20 for sale lol) Laughing

The first Motor i built has no been running for well over 1 year on the same spec as when it was sold the owner has been very happy with it and uses it as a daily driver, and has yet to have any reliabilty issues.
 
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wow..
I can improve my knowledge by reading this thread,hee..
how much power if we use b20 shortblock and b16 head??
:)
thx..
 
wow..
I can improve my knowledge by reading this thread,hee..
how much power if we use b20 shortblock and b16 head??
:)
thx..

assuming stock b16 cams and decent intake exhaust and header i think the average is about 175whp
 
good info...dude
get new knowledge by reading this thread for me...
 
Glad you enjoyed it, user adee-ek4 was the one who originally posted it :nice:
 
the only thing about the golden eagle kit is that i seen and heard of them popping off a few cars i personally think its better to go threw the oil pressure sensor

but those cars had crazy hp
 
need to kno about the exhaust system for b20...
piping 2.5 or 2.3?
muffler?
midbox?
header/extractor?

thanx guys
 
need to kno about the exhaust system for b20...
piping 2.5 or 2.3?
muffler?
midbox?
header/extractor?

thanx guys

my daily driven b20vtec, combo of stock b18type R & b20zbottom

down pipe is 2.5 in
muffler is 4 inches in diameter
resonator power flow 3in diameter
header is 2.5 in

sounds like a jet
 
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my daily driven b20vtec, combo of stock b18type R & b20zbottom

down pipe is 2.5 in
muffler is 4 inches in diameter
resonator power flow 3in diameter
header is 2.5 in

sounds like a jet

really good info guys...thanx..

how about the performance?
 
Considering going down this route now as i could use all parts from the b16 that is in my car, seen this thread on another forum and i can say is Extremely helpfull!!!!:nice:
 
will i run more bhp with my b16b head or will it be the same as the b16 no type r.
 
Hmmmmmmmmmmmmmmmmmm......

What kind of work am I looking at to run a B20b/z bottom end, a B16A2 head with JUN Auto springs, retainers and Type 3 cams, with a Mugen head gasket?! :nerv:

May also upgrade to B16B pistons.....
 
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