The B20VTEC discussion thread

[mocchi]

anyone here used rsmachine pistons?
i know theyre cast hypereutectic like oem and thats what i want, lighter and tighter clearance.

wanna know how good they finish / pins / piston ring quality etc, say compared to oem.

[Chr1s]

Depends who you buy the kit from, sometimes I had the box come with different manufacturer rings in them, bit of research revealed that it is either Hastings (straight from RSMachine - which no longer exists now) or NPR if you got a "better" ring package (same as CP supplied). To be honest I've used Hastings more than once before and never had a problem. Both sets of rings are more than good enough for most applications.

RSMachine quality on the pistons is good, always double check the balance when you get them as with anything, there has been a couple of times when the pistons were supplied with the wrong rings and a "random" failed piston in a non B series application, didn't cause damage, was caught quick so just be sure to triple check what you have.

Otherwise you won't have a problem!

[mocchi]

Depends who you buy the kit from, sometimes I had the box come with different manufacturer rings in them, bit of research revealed that it is either Hastings (straight from RSMachine - which no longer exists now) or NPR if you got a "better" ring package (same as CP supplied). To be honest I've used Hastings more than once before and never had a problem. Both sets of rings are more than good enough for most applications.

RSMachine quality on the pistons is good, always double check the balance when you get them as with anything, there has been a couple of times when the pistons were supplied with the wrong rings and a "random" failed piston in a non B series application, didn't cause damage, was caught quick so just be sure to triple check what you have.

Otherwise you won't have a problem!

thanks for tips bor, im thinking of getting itr style 84mm/oem rods.

in regards to main bearing clearance, lets say b18c cos they use same main bearings as b20
service manual says 0.024-0.042mm

i wonder whats best for daily drive or say road race? i've always try aim for middle ground to looser side so 0.031 and above in the past and its fine
is there any benefit in going tighter clearance say 0.024-0.031?

5-30 oil.


btw does anyone here ever measure bearing crush when they did b20 build?
how did you do it lol.

[Chr1s]

With our special rotational tires, it will allow you to drive very fast. - JK Tyre

[tinkerbell]

btw does anyone here ever measure bearing crush when they did b20 build?
how did you do it lol.

it's called Plastigauge and is very easy (and somewhat accurate) to use...

[mocchi]

it's called Plastigauge and is very easy (and somewhat accurate) to use...

not oil clearance, but bearing crush.

[tinkerbell]

not oil clearance, but bearing crush.

oh, then no, never measured it.

dont think i've ever needed to?

[Rayle]

Install the bearings, then torque down the cap to spec. Then undo the bolt on one side, leaving the other torqued. The cap will rise on the side you released. Use a feeler gauge to measure the gap between the bottom of the raised side of the cap and the other mating surface. According to a book I have, it should measure between 0.075 and 0.152 mm.

More info here: http://books.google.com.au/books?id=...page&q&f=false

Never done it myself though.

[mocchi]

Install the bearings, then torque down the cap to spec. Then undo the bolt on one side, leaving the other torqued. The cap will rise on the side you released. Use a feeler gauge to measure the gap between the bottom of the raised side of the cap and the other mating surface. According to a book I have, it should measure between 0.075 and 0.152 mm.

More info here: http://books.google.com.au/books?id=...page&q&f=false

Never done it myself though.

thanks rayle
yea read that, doesnt that kinda contradict with the whole point of criss cross torque pattern though?

just wondering if bearing crush will stay the same after it has been used for say 10,000kms
or reusing old bearing if its still in good condition.

wouldnt want bearing thats still in good nick but gonna end up spinning

[Rayle]

If you're just checking the bearing crush, I don't think it really matters about the correct torquing sequence over all of the main caps (but you should still do the incremental torquing of 25 Nm then up to 76 Nm). In the service manual, it only talks about the correct sequence when doing the final install of the main caps, and not when doing main bearing clearances. You should be able to do the bearing crush procedure one bearing at a time with no issues.

I'm not sure about whether the bearing crush will remain the same though. I wouldn't think it would change significantly over time or due to use, since then you'd have a higher chance of spinning a bearing later on, and I like to think that the engineers who design the bearings know what they're doing.

Since the actual force holding the bearing in place is directly related to the circumference of the bearing, I don't really think that the length would change significantly.

Honestly, I think you'd be fine to reuse the bearing if all of the measurements come out within spec, and there's absolutely no damage on them, but there's a helluva lot of people who won't reuse a bearing (including many who know far more than me).

[gbpracing]

Hey guys, anyone here from Melbourne that has actually had or gone through a b20vtec? If so could you guys please help me. I'm contemplating on doing a b20 vtec swap into my ek4. Just want to know if their are any reputable b20 vtec builders & tuners in this area. If someone could get back to me via pm it'll be much appreciated.

Powerplay in Cheltenham built my full race B20Vtec with 173kw @ wheels and he has built many hi end race engines. He backs his work 100% not cheap but you get what you pay for. If you need any more info on my build happy to chat, just PM me.
Cheers Gary

[JDMasFCUK]

Gary your inbox is full mind emptying it? Have a few questions