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@chr1s and todaau: what preperations apart from acid washing, apply multi angle valve job, replace valve stem seals and shaving would you need to be done, and what is the ideal PTV clearance on b18c2 head with stock cams.
I know the PTV will also depend on what piston is used however from experience what is safe and ideal?
what is a PTV by the way?
what headers would you use, B18C or B16A? because i have heard B18C headers dont clear on B16A. so i thought it would be similar for the B20
maybe you got it backwards... please check your information source.Quote:
Originally Posted by riruiz_88
approx. 50 thouQuote:
and what is the ideal PTV clearance on b18c2 head with stock cams.
piston to valve clearanceQuote:
Originally Posted by riruiz_88
both intake and exhaust cams? this is obviously measured when by locking the vtec in.Quote:
Originally Posted by tinkerbell
0.05 is a rough guide.Quote:
Originally Posted by zeni-tani
if you are a lot (like 0.02) inside this then you should reconsider the parts you are using...
clay it with the cam gears at max and min advance/retard too...
NB - you also should consider rod stretch too...
Yes as expected i have done this before but not on a honda. Thats a good starting point, ill add in my notes i just purchased some RS machine pistons for it just going to be a simple build nothing to hectic.Quote:
Originally Posted by tinkerbell
I also never realised having a B18C2 head is a pain the ass to get manifold, i was planning on B16A manifold/OEM type R but stud pattern is diffrent, No i wish not to modify stuff to make it fit so the only choice i have i guess is a skunk or a blox.
you should try it with the dual runner first - it might work well :)
The DC2 VTIR manifold?? I dont have a manifold to start with and having to work on 2 DC2 VTIR its a pain in the ass to work with.Quote:
Originally Posted by tinkerbell
Standard manifold works well but yeah only problem with b18c head is the lack of manifolds. But they more compression then a b16a head
lol i dont doubt that, however i want to get a manifold where i can get my fat little fingers around! Specially with that pain in the ass rear engine mount. I might end up getting a blox.Quote:
Originally Posted by MikeyG
i want to know toda au and chr1s input on this too please
your welcome, anytime...Quote:
Originally Posted by zeni-tani
Hey i respect your experience and i do thank you for your kind advice, however i am open for other opinions as well.Quote:
Originally Posted by tinkerbell
Hahaha tinkerbell knows alot also since he had a b20 for some time and still growing strong I think.
I also would like inputs from ch1rs and toda au as they know and BUILD their b series
They can take a fair bit of punishment ;)Quote:
Originally Posted by Cooker
That i dont doubt because even before i posted here i watched his buidl grow.Quote:
Originally Posted by MikeyG
haha Tinkerbell, nearly left out there for a moment! This man knows his stuff too. :beer:
Zeni-tani - I would run around 0.045" on the intake and 0.050" on the exhaust as my minimum values, anything lower than that and you're asking for trouble, as mr Tinkerbell mentioned, remember rod stretch, this value will be different for each type of rod used as they have different inclusive material properties.
If you're bringing the lobe centres closer together I dare say you will have valve to valve issues before you get into some piston to valve problems.
It should also be noteworthy that lift is not to be considered as dangerous as duration is when talking about P2V clearances as the valve has peaked way before the piston is even close to it, the duration is what's going to hurt you and this is why you need to set your cam gears to full retard and advance and check both sides of the variance for any issues to save you running into them if you do try and get fancy on the dyno.
After saying what has been said, at the end of the day, there is no hard fast rule for a clearance, it all depends on how far you want to go and what parts are being used, mass has a big effect on what the clearance should be, obviously if you are using very lightweight parts with minimal interia then the clearance can be tightened up dramatically.
All in all, check on all pistons as I have seen some pistons needing work to enlarge the releif - width wise not depth.
hey chr1s - what do you think of the duel runner IM on a B20VTEC?
To be honest I havn't had experiance with it nor had the chance to break one of the manifolds down and investigate the design and possible flaws.
From first look I think they are a tad too long for high RPM gains but would produce some decent torque anything below that. Do they like the sub 5k region?
I still opt for B16 ported/ITR style manifolds.
charlie at GPC told me B16a IM is way to small even for a stock b20
Fantastic! I will certainly look in to it, having said that shed some light on some manifolds i am a little restricted i cant use B16A or ITR units cause the flange design is diffrent.Quote:
Originally Posted by Chr1s
For the record, I dont know my "shit", I'm just that kind of person that is opinionated in a certain way and always relate my view to an engineering point of view not what some fella said on honda-tech, I don't like the "bullcrap" around builds. The nissan boys from my old forum know this one :p
With regards to intake manifolds, it really depends on whats going on with the actual mechanical operation of the engine, ie - valvetrain, piston selection, combustion chamber design, header design and correct length intake piping.
A near standard B20 can get away with standard manifolds (header and intake) but once you start throwing some cams in the game, those manifolds are going to set you back. I would never use a standard manifold anyway without some massaging here and there ;)
Bring this back from the dead.
I would like some opinions on airbox setups, this is regard to street cars that need a pod filter enclosed as we know how much the police love defecting these things. I will be running an airbox on my car full stop, I can't afford to have the car tagged as a "defect machine"
Now, I know there is known units such as comptech, mugen and standard. I would like to know the gains/losses had with lets say a mugen airbox - appeals to me due to the cold air feed in a proper ducting setup. I'm chasing opinion of more experianced people, sometimes theory with these things proves to be bullshit.
/\ Mugen... :thumbsup:
By far the best & it's good for over 160kw...
Works with Plenums or Quads
There's a Mugen copy too (out of China), but it's not as good.
Std airbox reaches it's limit around 120~125kw
Comptech... Not a fan...
Can't say for sure if it's crap...
Just all the cars that have them seem to be... LOL
Plus it uses a puss foam filter
Use the B18C2 std intake manifold & keep the IAB (secondary intake runner) function.Quote:
Originally Posted by zeni-tani
For maximum output use with a 65mm throttle & you'll need to tickle the inside a little.
As I thought, cheers
1.5mm is about as close as you should dare going...Quote:
Originally Posted by zeni-tani
:honda:B20Vtec's where are all the guru's with there e-machanic knowledge
hahaha
no1 wants to share
Thanks adz so there really is no point buying a aftermarket fancy manifold, i asked since i do not have a manifold to start with.Quote:
Originally Posted by TODA AU
Chris i will re-start the build need to talk to you on msn after work aye
would u go mugen over a brand name or custom cai?Quote:
Originally Posted by TODA AU
For a maximum effort road or track car with zero defects,Quote:
Originally Posted by Killa From Manila
Yes the Mugen is a fine choice.
With excellent flow, it lends itself to use with both plenums or quads.
That said,
If you're on a budget & defects are not so much a concern,
Products like Injen, AEM, Fujita etc offer excellent value for money.
The custom CAI with a dyno tuned length & bellmouth intake,
If enough time is spent, will generally deliver the best result with a plenum.
However the cost can be comparitivley high.
thanks for that
Quick question. What would be the compression of a stock b20 block with a b16a head, will the compression remain as 9.8?
9.96:1 with PR3 B16a/B18cR headQuote:
Originally Posted by Lerlo
10.14:1 with P72 B18c head
This is using a B20B8 with the PHK pistons.....
Cool, thanks!Quote:
Originally Posted by ZeForce
Whats PHK pistons? Sorry, kinda noob.....
They are the pistons used in the B20B8 which will give you higher comp compared to the pistons used in the B20B3Quote:
Originally Posted by Lerlo
i.e they are the name of the standard Honda B20B8 pistons.
the B20B3 Honda pistons are stamped "P3F"
see the stamp here:
[IMG]http://i913.photobucket.com/albums/a...B20B8block.jpg[/IMG]
tinker it says PH? but if it doees say P3F where.. i think im going blind :(
Here's a slightly better picture
http://c1.ac-images.myspacecdn.com/i...420467a700.jpg
he's showing u the PHK pistons from the b8, not the P3F from the b3. i was a lil confused at first too. lol
Mmm intresting, thanks for the pic
Wow, thanks for the pictures!
lol!!! my bad!Quote:
Originally Posted by MikeyG
i didnt really set that post out too well eh?
at least krayie understood my sunday morning posting :thumbsup:
FWIW here is a P3F stamped piston what was fly-cut by a head shop:
http://i913.photobucket.com/albums/a...utpiston01.jpg
here is a PHK that was hand cut with a Dremel by me:
http://i913.photobucket.com/albums/a...utpiston02.jpg
oh, and see how the P3F is has a pronounced dish and the PHK is more flat?
that is the difference between the B20B3 and the B20B8 :)
You should really round off the egdes on the pistons, those sharp edges promote detonation
Quote:
Originally Posted by ZeForce
id say this was a work in progress pic and not the final product.
But , a good heads up for all those learning !
yes, you really should (remember to take pictures after you finish rounding off the edges!)Quote:
Originally Posted by ZeForce
actually , post #281 has finished pics :)
:thumbsup::thumbsup::thumbsup:
So the P3F is the one with 8.8 compression?Quote:
Originally Posted by tinkerbell
yeah that's right.
btw, how did you know how deep to go with the dremel? and what head/grinding bit did u use with it?
A standard B20 intake valve has a head diameter of 31mmQuote:
Originally Posted by kraiye
But the B16A/B18C intake valve is 2mm bigger at 33mm.
So, the intake flycut radius aught to be increased by 1mm.
I wouldn't recommend going much deeper...
For interest sake, nothing need be done on the exhaust side as the standard exhaust valve sizes are the same for B16A/B18C/B20B @ 28mm (dia)
yeah, so you don't just make them deeper as such, you take them wider (1mm) and correspondingly deeper...
great info thanks.
don't suppose you know what's required for skunk2 pro1 cams in a b16with stock valves? would that require going too deep adrian?
wat?
you wann run SK2 Pro cam's with stock B20B pistons?
i doubt that 'combination' will be any good...
i used the 1/2in and 1/4in sanding drums with the 60 & 120 grit rolls.Quote:
Originally Posted by kraiye
http://mdm.boschwebservices.com/MDMC...0/r00164v1.jpg
then 400 and 800 wet/dry to smooth it out by hand...
Whys that?Quote:
Originally Posted by tinkerbell
Do the flycuts as described...Quote:
Originally Posted by kraiye
Then assemble the motor, set the cam timing & check PV clearence with clay or platicine.
Only increase the depth if you're touching or have less than 1mm clearence.
Re cams...
Lift isn't so much of an issue as duration
compression ratio might no be high enough...Quote:
Originally Posted by Lerlo
happy to be corrected though :)
ooh... yeah thats true.Quote:
Originally Posted by tinkerbell
Thanks for the info..
I just got myself a b20 block and an engine stand.
My engine stand mounting points are 70mm long.
The Engine block has 4 threaded (10 x 1.25) holes I presume
And 3 through holes.
Which holes should I be using to mount the engine?
Sorry its 4 threaded 12 x 1.25 holesQuote:
Originally Posted by Lerlo
It doesn't matter, just use common sense and hold the engine securely.
The through hole can be used no dramas.
Cool, thanks.Quote:
Originally Posted by Chr1s
Anyone knows where I could get long 12x1.25 bolts.
Tried 2 bunnings, repco and supercheap, couldnt find any that were long enough
Check yellow pages for a fastener shop in your area
Supercheap and repco are useless. I can't beleive they are associated with that name considering what they sell, especially supercheap.
If you're in Sydney, southern area, hit up Industrial Fasteners.
Nah Im in Melbourne, will look up some bolts and nuts supppliers over here tomorrow. Thanks for the help!Quote:
Originally Posted by Chr1s
Coventry Fastners perhaps? do you have them down there?
Bunnings have long threaded rod which may work if you can't find anything. dunno what sizes they have though.
dont be shy and use a hacksaw to make them shorter... you can use std gearbox bolts then....Quote:
Originally Posted by Lerlo
yea there is conventry fasteners here in melb. more variety compared to bunnings.Quote:
Originally Posted by kraiye
FFS, just cut the ****ers shorter & use your gearbox bolts
edit... LOL.. Too slow, Dave beat me to it... :p
Cant cut it any shorter because of the dumb design of the engine stand...Quote:
Originally Posted by TODA AU
Anyway walked in to my local bolts and nuts shop, walked out with 100mm High tensile bolts. :D
$4.50 a piece though.
ouch!
Amen to that! staff there didnt know what a honda crx was LOLQuote:
Originally Posted by Chr1s
Hey guys Ive got a question.
Im thinking of running a compression of 10.5-11 on my b20.
Was wondering is it a good idea to mill the block and the head to achieve that?
Thereby keeping the stock pistons?
Would there be clearance issues running on Type R cams?