B20 VTEC Piston

ddv_nk12

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ddv_nk12

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May 18, 2011
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For NA B20 VTEC, what type of 84mm pistons should i be looking at?

Cast or forged? I came across in another forum where they mentioned that cast pistons are better. I was thinking that forged pistons were better.

Brands? The prices vary quite a lot depending on the brands. So, will it affect me in any way if i go for the cheaper brands? I'm new in this car mods scene but i know brands like Wiseco, CP and Mahle are the branded ones. Hence, being more expensive, it is better. Am i right to say that?

Compression ratio. I'm looking to build a daily driven car but with high compression. I dont want it to be a purely track car. Maybe i'll hit the tracks every now and then but it must be more suitable as my daily car. So, what CR i should be looking at?

Now, i found myself a Ford TX3 84mm 11.2 CR high comp cast iron piston. According to the seller, it will fit my B20 block. I have also read before that pistons of other car makes can be used on B20 blocks. Just need confirmation before i commit myself. Besides, will there be any P2V clearance issue? And if i were to upgrade my camshaft to say Skunk2 Stage 2 or other aftermarket cams, is it possible with these pistons? Again, as far as i know, my stock 84mm B20 pistons cant be used for aftermarket cams. So, i dont want to buy these pistons now only to find out that it wont be usable with the aftermarket cams.

I know this is my second post in this forum (the other being in Honda section) regarding this but the reason being is i need answers because the seller has only 1 last set of the TX3 pistons. If its all good, then i'll prolly get that as its very much cheaper.

Many thanks in advance.

p/s correct me if any of my statements above are wrong.

---------- Post added at 12:11 AM ---------- 6 hour anti-bump limit - Previous post was at 12:07 AM ----------

Another thing that i would like to know is whether its ok to get used pistons and re-coat it and then use them? My friend was saying this is cheaper and should not be a problem in the future. True?
 

mADmAN

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mADmAN

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i already replied in ur other thread...also a quick mention about the TX3 pistons.

as for recoat...recoat with wat??
 

ddv_nk12

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ddv_nk12

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thanks man!! i dont know, he said recoat but i dont know what he was talking bout. so i didnt ask more. hehe. i usually get lost when ppl start talking bout stuff like this. i have to come back and google or ask here.

this is the video of recoat the pistons. i dont know if this is what he meant.

Corvette 21 - Recoating Pistons + New Throttle Body - YouTube
 

satria_neo

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satria_neo

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Aug 1, 2011
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Forged pistons are pretty common and they can be machined to very good tolerances. As you have said, Wiseco, JP, etc all makes very good pistons. Mahle and Cosworth also are very good.

---------- Post added at 09:45 AM ---------- 6 hour anti-bump limit - Previous post was at 09:42 AM ----------

Regarding piston coatings, there are things like ceramic coating as well as dry MoS2 piston skirt coating to reduce friction.

All you need to do is just tell them the compression desired as well as any excessive valve lift you may run 12-14mm and valve size. Valve is not that critical cause they will usually machine sufficient valve clearance.

Then tell them you need it for NA and so min expansion is better.
 

ddv_nk12

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ddv_nk12

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Forged pistons are pretty common and they can be machined to very good tolerances. As you have said, Wiseco, JP, etc all makes very good pistons. Mahle and Cosworth also are very good.

---------- Post added at 09:45 AM ---------- 6 hour anti-bump limit - Previous post was at 09:42 AM ----------

Regarding piston coatings, there are things like ceramic coating as well as dry MoS2 piston skirt coating to reduce friction.

All you need to do is just tell them the compression desired as well as any excessive valve lift you may run 12-14mm and valve size. Valve is not that critical cause they will usually machine sufficient valve clearance.

Then tell them you need it for NA and so min expansion is better.
hey man, thanks. but the statement highlighted, does this mean that i can get a piston say the CR is 11.5 and tell them that i want a 12.5 CR piston and they can do it for me? i'm sorry if this is silly but i really dont understand. still new.

Whats ur stand on the cast iron pistons? If i get the a cast iron and a forged piston with the same CR, which will perform better? i just learned that forged are stronger but causes wall slap. This isnt good. but like u mentioned i can tell them to minimise the expansion. right?

---------- Post added at 11:10 AM ---------- 6 hour anti-bump limit - Previous post was at 11:08 AM ----------

Can't view Youtube in my office but I think in this particular context, 'coating' means 'shot peening':

Shot peening - Wikipedia, the free encyclopedia
yeah bro. i guess thats what my friend meant. in this vid, it was more like spraying with something and then put it in the oven. ??? This cant be it right?
 

DeaconFrost

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DeaconFrost

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Now, i found myself a Ford TX3 84mm 11.2 CR high comp cast iron piston. According to the seller, it will fit my B20 block. I have also read before that pistons of other car makes can be used on B20 blocks. Just need confirmation before i commit myself. Besides, will there be any P2V clearance issue? And if i were to upgrade my camshaft to say Skunk2 Stage 2 or other aftermarket cams, is it possible with these pistons? Again, as far as i know, my stock 84mm B20 pistons cant be used for aftermarket cams. So, i dont want to buy these pistons now only to find out that it wont be usable with the aftermarket cams.
Boss, have you run your setup through the Zeal calculator yet?

If you're gonna put GSR head to a B20B block, if you have had the head skimmed before, even 0.7mm will result in 10.29:1 CR (that's more than B16A CR already).

Stock B20B engine may have low CR but matching it to a different head will yield different CR.

Not sure about Ford TX3 pistons but piston diameter is one thing, piston material is another, then you have to look at the valve reliefs. Even B20B P3F piston valve reliefs are not sufficient for VTEC.

Safe bet is too look for pistons designed for B20 VTEC applications:

HONDA / ACURA - HONDA B20 VTEC WITH A B16A HEAD - JE Pistons

I surf only, money tak ada...

---------- Post added at 12:04 PM ---------- 6 hour anti-bump limit - Previous post was at 11:50 AM ----------

yeah bro. i guess thats what my friend meant. in this vid, it was more like spraying with something and then put it in the oven. ??? This cant be it right?
I also don't know, need to ask the otais lah bro. This old thread also no feedback:

http://www.zerotohundred.com/newforums/car-modification/352519-where-can-i-shot-peened-conrod.html

For conrod, if you can't shot peen, just use ARP conrod bolts. Overseas forum says they are mandatory. Logically true if you ask me because B20B was not designed to rev high like B18C.
 

satria_neo

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satria_neo

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Aug 1, 2011
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hey man, thanks. but the statement highlighted, does this mean that i can get a piston say the CR is 11.5 and tell them that i want a 12.5 CR piston and they can do it for me? i'm sorry if this is silly but i really dont understand. still new.

Whats ur stand on the cast iron pistons? If i get the a cast iron and a forged piston with the same CR, which will perform better? i just learned that forged are stronger but causes wall slap. This isnt good. but like u mentioned i can tell them to minimise the expansion. right?

---------- Post added at 11:10 AM ---------- 6 hour anti-bump limit - Previous post was at 11:08 AM ----------



yeah bro. i guess thats what my friend meant. in this vid, it was more like spraying with something and then put it in the oven. ??? This cant be it right?
Yes, just tell them the compression you require (the bore as well) and desired valve lift so they could cut the valve relief for you.

As for pistons, I have not heard of cast iron ones, only aluminum ones. Even if there is you would not want it. Weight reduction is critical for NA engine.

For piston slap, its mostly on turbo engines only due to excessive clearance needed for expansion. Its not that critical for NA.

Btw, this assumes you are getting custom pistons. I bought custom Wiseco ones before. Cost around Euro 150 each before shipping. Pretty ok price.

Just check out the net about the various properties of pistons eg. materials used etc. Also things like oil spray holes, so-called anti-detonation groves (don't know if it really works) etc....