what's a good vtec head for a b20?

[outatime]

hi guys need your advise..

would it be better to use a b18cr head and pair it with a b20 block? if say a b16 full head in immac condition cost about 1000 and a b18cr head is the same price but unsure of the condition, which one would you prefer ?

what are the differences between b16 and b18 by the way? why do most people use a b16 head for a b20 conversion?

[NightKids]

Why b16? It's all bout the flow...

[outatime]

what do you mean? lol :o

can u please elaborate?

[GSi_PSi]

Be specific with the head types because A B18CR head is PR3 B16A Head aswell.
These are my opionions why people use certain heads for B20
B18C2 (P72-VTiR) Head- More Compression, , In stock form a B20 bottom will benefit with a B18C2 Head due to its adding more compression (41.cc) to a B20 block. VTi-R head also will be good to modify but i believe the PR3 head when both modified will outperform the P72 head.
B16A - (PR3-VTiR) Better flowing, People will use this head and do certain modifications, such as porting, better cams, valve train etc. Much cheaper to build this head up rather than buy a ITR head
B18C7 (PR3-ITR) Type-R head, comes with a factory mild port polish job, More aggressive cams, valve train etc. People will use this because they got a good deal or cant be bothered modifiying the head.

[outatime]

nice one Sam! you are becoming an expert on this! lol +1 for you!

[NightKids]

Hey where's my +1? his simply ellaborating what I'm saying! lol

[B18cEG]

Ok for all you people that are still stuck with the frame of mind that the b16a (P73) head out flows the b18c P72 head you are mistaken and it has been proven many many times, unless you are talking about a p73 head from a b18c5/7 (type-r) that comes with the factory port job then there is no real benefit it using the b16a head over the b18c P72 head but like stated before with the b18c P72 head you gain a tiny bit of compression, i would definatly use a b18c head for that reason, plus the shape and angle of the b18c allow for a better flow if you decide to ever port/polish and is the reason there is alot of companies able to get higher flow figeres from them.

[Slaz]

PR3's or B16 or B18 Type R's as it has been said are the same casting that has recieved some mild hand finishing and assoc valve train upgrade for the cams they are fitted with, but they are also ( but not always ) the better castings that havnt suffered from core shift which is a common flaw in B series heads an should be a consideration when buying any B series head.

The P72 has a higher intake port angle not to mention different inake manifold flange but the same centre's between the ports, exhaust side is unchanged, it is also different in its water outlet compare to a PR3.

Type R's are often worth the money if your not going to modify and it doesnt have core shift, but as i said, if your going to port, change valvetrain for cams and upgrade your LMA's then a PR3 with no core shift should be your weapon of choice, unless your looking for the higher compression the P72 will give you due to the combustion chamber volume.

Ported they can be made to flow the same, though benefit does come from the inatke port angle on the P72, but a decent inlet manifold to match it will need to be had, which alot of companies do a copy of the type r with the P72 flange, some brands dont however match the runner angle and its just a PR3 type r copy, so look out for that, the performer x or victor x's depending on the level of build would be the better ones if you were going that way.

[GSi_PSi]

Its alll to do with your budget,.. how much do u have to mess around with
And what is your bottom end going be like. Whats the compression going be like?

[KLR-16A]

Slap a d16y head on it :p

[GSi_PSi]

got the b16 head ay..looking forward to your build

[outatime]

yah it's cheaper and we're gonna replace all internals and parts anyway.

[MikeyG]

i hope your doing it with a good builder.. some one that has done may many b20 vtec before not just one or two... or calls up people for advice on b20

[Chr1s]

yah it's cheaper and we're gonna replace all internals and parts anyway.

Good stuff, you're learning :)

Most people think its better to start with a type R head because its... type R?

[Benson]

Ill start with a type R head

[Chr1s]

Reasons?

[Samm928]

cause its "Type R" y0!

[GSi_PSi]

because its got a red rocker cover yo. nah but seriously if your planning on moding the head its a waste of money and a half unless you can the itr head little price difference between the p72 n B16a

[Benson]

Reasons?

Its on our engine and it works great. Stock ITR ports are the bomb :)

[GSi_PSi]

i hope your doing it with a good builder.. some one that has done may many b20 vtec before not just one or two... or calls up people for advice on b20
Thats a good point ay . Best to do a b20 with someone clean history of building engines not someone that will build it dodgy and maybe say the coolant will spill from the headgasket

[Chr1s]

Thats a good point ay . Best to do a b20 with someone clean history of building engines not someone that will build it dodgy and maybe say the coolant will spill from the headgasket

Everyone makes mistakes Sam, keep it in mind. :)

[FastFwd]

What would the difference be in completely rebuilding a b16 or a b18 compared to making a b20vtec?

making sure you have all the correct parts would be the only difference really. The build would be the same wouldnt it? Instead of chuck a b16 head on a b16 block it would be like chuckin a b16 head on a b20 block.

[string]

There's some funny business involved in using a VTEC head on a non-VTEC block. Dowels, oiling, headgasket choice. Nothing difficult but requires some research.

[FastFwd]

There's some funny business involved in using a VTEC head on a non-VTEC block. Dowels, oiling, headgasket choice. Nothing difficult but requires some research.



yeh but like i said though with the correct parts etc, which would need to be researched before doing any build. After that the build process wouldnt change to much.

So the mechanic or DIY mechanic like myself as long as you got a half decent IQ and some time to research it wouldnt make much difference in the physical build right?

[Chr1s]

yeh but like i said though with the correct parts etc, which would need to be researched before doing any build. After that the build process wouldnt change to much.

So the mechanic or DIY mechanic like myself as long as you got a half decent IQ and some time to research it wouldnt make much difference in the physical build right?

The topic isn't related to the quality of the build, there is differences in the B16 and B18 (non type R) heads - which is why the question was raised initially.

[FastFwd]

chris please read through the thread properly. Someone mentioned that they better get someone that has built b20's in the past to build his project. I was just clearing this up by explaining after research and buying the correct parts needed the physical build process would be fairly much the same as building a normal b series.

dont even know why i spent time explaining myself

[Chr1s]

I see what you mean now,

Yes there is some things that need to be rectified during the assembly process, but research online/reading will only get you so far, you need to do it to learn properly. As they say, with time comes experiance.

:)

[kraiye]

can someone point me in the direction of some b16/b20 vtec info please?
really keen to start researching this

[GSi_PSi]

http://hondaswap.com/general-tech-articles/how-build-reliable-lsvtec-b20vtec-70187/
http://www.c-speedracing.com/howto/b20vtec/b20vtec.php

[kraiye]

cheers
:thumbsup:

[BlitZ]

what are ur aims?

std bottom end? u gonna run cams? keep it stock Frankenstein..

and ofcourse budget.


and dont tell me you have limitless budget.. if so get a 2jz in there... ;)

[vampzzz]

how about if i was planning to do cams and the whole shebang?

would it be better to start off with a b16 head or a b18c7 head?

[Chr1s]

how about if i was planning to do cams and the whole shebang?

would it be better to start off with a b16 head or a b18c7 head?

B16 head purely for the reason that they can be sought after for cheaper, or ITR if it is cheaper than a B16 of course.

[DR HONDA]

Be aware of the two different PR3 (B16A & B18C C7) cylinder heads. Once the heads are stacked up together the combustion chambers are different which will alter your CR. So chose carefully as a motor build can go backwards with comp easily. :thumbsup:

[Chr1s]

Be aware of the two different PR3 (B16A & B18C C7) cylinder heads. Once the heads are stacked up together the combustion chambers are different which will alter your CR. So chose carefully as a motor build can go backwards with comp easily. :thumbsup:

Let the confused people with questions begin :p

[tinkerbell]

Be aware of the two different PR3 (B16A & B18C C7) cylinder heads. Once the heads are stacked up together the combustion chambers are different which will alter your CR.

english please???

stacking heads?

[tinkerbell]

what is the difference in cc?

[fatboyz39]

Sorry tinkerbell didnt mean to confuse you. The PR3 heads arent identical from a B16A to a B18C in cr


Any CC figures for both Phil?

[tinkerbell]

Sorry tinkerbell didnt mean to confuse you. The PR3 heads arent identical from a B16A to a B18C in cr

so there are three different CC's of VTEC heads?

42.7cc for B16A (PR3 head)
4X.xcc for B18C7 (PR3 head)
41.6cc for B18C2 (P72 head)

i alwawys thought B18C5/6/7 combustion chamber was 42.7cc???

[tinkerbell]

Great I was just reading into it I guess B series is old news

so what are you saying? still not sure.

maybe you are confused?

these are the various B-series VTEC head derivations:

PR3 head = B16A, B16B and B18C5/6/7 engine
P72 head = B18C1/2/3 engine

these are (AFAIK) the combustion chamber volumes:

PR3 combustion chamber = 42.7cc
P72 combustion chamber = 41.6cc


Be aware of the two different PR3 (B16A & B18C C7) cylinder heads

this is your information that i am confused by? i never knew there was a difference between PR3 combustion chamber volumes?

or were you mistaken? or mis typed?

[tinkerbell]

Keep the aggression down sunshine this is a learning site for all members. I am just adding my two cents into this thread and your jumping like a bean.

agression? huh?

i am trying to clarify what you have posted?

for all the members benefit.

[DR HONDA]

agression? huh?

i am trying to clarify what you have posted?

for all the members benefit.

Ill leave it up to you

[ZeForce]

I have said it before and I will say it again, I would rather have the better combustion chamber design of the P72 head over the extra flow of the PR3 head any day of the week and twice on Sundays.....

[GSi_PSi]

^ This debate will go on....

Why did honda use it on their ITR B18CR?. Was it cheaper to use or > more simplier reason it is better :thumbsup:

[ZeForce]

^ This debate will go on....

Why did honda use it on their ITR B18CR?. Was it cheaper to use or > more simplier reason it is better :thumbsup:

Still, I dont see that as a valid arguement.... Why didnt honda use the B20b block for the ITR....

[GSi_PSi]

If Honda Ported a P72 Head Vs Stock ITR head (Mild Port)

http://img2.imageshack.us/img2/7701/b16vsgsrcompheadwork.jpg

[outatime]

Why didnt honda use the B20b block for the ITR....

because b20b is non-vtec:wave:

[GSi_PSi]

Still, I dont see that as a valid arguement.... Why didnt honda use the B20b block for the ITR....

Then what engine could we build frankensteins from :p

[Chr1s]

It's not always about flow,

Ports are there to guide the air into the combustion chambers, porting them out is what people do to try get the air into the chambers as efficiently as possible, while ignoring the fact of certain laws - fluid dynamics laws for example.

I would like to maintain the size of the stock port while increasing the flow for a given application. Air goes off the same principles as fluid dynamics, to put it simple, air doesn't know if there is a big port present and "speed itself up" (which doesn't happen mind you), you can have a large port and a small port flow exactly the same figures. Anyone who says porting is the way to go is an idiot.

[tinkerbell]

Anyone who says porting is the way to go is an idiot.

um, didn't honda apply some porting work to the ITR head?

or is that different to the "porting" you are referring to?

[Chr1s]

Obviously there is gains to be had over porting out various areas of the throat to suit a different application, as a 1.8 DOES flow a different volume of air than a 1.6 would, right?

When I mean porting, I mean in the essence of - you MUST port your head if you want to make massive power, rararar. Bullshit.

[Benson]

STOCK ITR PORTS + CNC Combustion cambers! Proven to work

[Slaz]

ITR heads work as they are selected heads, no or very reduced core shift ( which if present can make a massive difference to the heads performance ) and people who know what they are doing at Honda removing small dags and cast marks that were still present on the raw castings.

The original B16B/b18cr heads seem to have got more attention then the later model b16b or b18cr motors maybe as they were the 1st to be a performance version of the b series engine and that includes the chambers but if you look at some pr3 or p72 chambers including some b18cr heads, they are rough, raised, sharp edges everywhere from the seat install and not cc'd at all so addressing this in any head is going to draw alot of benefit, many wont pay for hand finishing and cc'ing of chambers but with cnc machines, this hasd become very affordable and accurate between cylinders, often the amount of hand porting afterwards putting them out, but a valve or two recessed deeper then others can throw off their volumes as well.

Saying that, a well ported head, is going to shite all over a stock itr ported head in any combo motor or build, your increasing its efficiency all over but in saying that, depending on application and fuel, then bigger v's smaller ports do come into it, as does port angle and if its n/a or turbocharged.

As ive said earlier, in a mild build that the owner isnt going to have the head professional ported or seen to and maybe just serviced, then a type r head although dearer to being with will more often then not be worth it.