The B20VTEC discussion thread

[tinkerbell]

i want to know toda au and chr1s input on this too please

your welcome, anytime...

[zeni-tani]

your welcome, anytime...

Hey i respect your experience and i do thank you for your kind advice, however i am open for other opinions as well.

[MikeyG]

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

[Benson]

Honda B series box is the B series weak point. They are weak as piss in standard form.

They can take a fair bit of punishment

[zeni-tani]

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

That i dont doubt because even before i posted here i watched his buidl grow.

[Chr1s]

haha Tinkerbell, nearly left out there for a moment! This man knows his stuff too.

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.

[tinkerbell]

hey chr1s - what do you think of the duel runner IM on a B20VTEC?

[Chr1s]

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.

[GSi_PSi]

charlie at GPC told me B16a IM is way to small even for a stock b20

[zeni-tani]

haha Tinkerbell, nearly left out there for a moment! This man knows his stuff too.

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.

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.

[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

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

[Chr1s]

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.