I've been searching for over an hour for any specific information on F20B pistons, and the ONLY thing I can find is that they have a 1.221 inch compression height. I'm trying to calculate CR with a B20 block, ITR crank and rods, and a P8R head with these pistons. Anyone know dome displacement?

Edit: Nevermind, found the info, as well as a F/H series compression calculator, seen here: http://www.zealautowerks.com/hfseries.html
B- and K-series calculators are available on that site as well.

Handy stuff


Modified by Stinkycheezmonky at 11:00 PM 10/11/2006

 

chad ran this setup. said he had problems with the sleeves cracking...

the setup has potential, but looks like it cant handle the abuse of RR

 

Really. Do you know what he revved it to?

 

not sure

 

I'll PM him, but thanks for the heads-up

 

i think the sleeves craking had more to do with the thin walls (having to be bored to 85mm on stock sleeves) and the prolonged abuse of RR.

 

it aint gona work in stock sleeves, and the compression height is 1.181, the dome is around 6 or 7 cc... oh and the dome dosnt fit in a b-series combustion chamber w/o ALOT of work

 

so theres no way it will work then damn that sucks i heard of this before but i thought i was just high and i caught a bad case of riceriadis.so

 

just get the RS machine b20 pistons, at least you dont have to go a full 1mm over to use them...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by GSRCRXsi &raquo;</TD></TR><TR><TD CLASS="quote">i think the sleeves craking had more to do with the thin walls (having to be bored to 85mm on stock sleeves) and the prolonged abuse of RR. </TD></TR></TABLE>

I did a rough measurement on teh B20 wall thickness and it's more than a K20. I think even if it was bore to 85mm.

Bearsek has been running a 84.5 bore B20 block with a BDL block guard for over 2 years. Yes, it's only for drag racing but this year alone it has over 150 dyno pulls and 150 trips down the track. It also makes 275 whp.

Control detonation.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">

I did a rough measurement on teh B20 wall thickness and it's more than a K20. I think even if it was bore to 85mm.

Bearsek has been running a 84.5 bore B20 block with a BDL block guard for over 2 years. Yes, it's only for drag racing but this year alone it has over 150 dyno pulls and 150 trips down the track. It also makes 275 whp.

Control detonation.</TD></TR></TABLE>

Good info, I think coolant temperature has a lot to do with it as well. This can be very unstable on a RR motor. Here is a picture I found while searching, a b20 block with every cyl cracked... I bet it was overheated. But, I see the same cyl wall markings on all higher mileage b-series. It looks like the hot spot between cylinders causes them to go out of round first, and it more prone to crack on b20 for some reason. obviously drag racing does not tax the cooling system as much, this may explain why it led to poor results in chads RR car

 

More info on any of this? The engine in particular I'm looking at is being sold by a WCHC H1 guy, so if any kind of modification to the pistons would have been required, he has to have done it already. He ran that block with a PR3 head. I'll notify Chad of this thread so he can chime in here.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Runnerdown &raquo;</TD></TR><TR><TD CLASS="quote">

Good info, I think coolant temperature has a lot to do with it as well. This can be very unstable on a RR motor. Here is a picture I found while searching, a b20 block with every cyl cracked... I bet it was overheated. But, I see the same cyl wall markings on all higher mileage b-series. It looks like the hot spot between cylinders causes them to go out of round first, and it more prone to crack on b20 for some reason. obviously drag racing does not tax the cooling system as much, this may explain why it led to poor results in chads RR car

</TD></TR></TABLE>


The above was due to the Fram oil filter

Here's some info you may want to think about.

https://honda-tech.com/zerothread?id=1143619

 

ah yes, the #3 cylinder issue. I do remember when you made that thread. I have made some of my own observations regarding that. For example, I recently disassbled a 200k gsr engine. It suddenly was using a good amount of oil and smoked badly after decel. Turns out that the #3 piston had a good amount of sludge build up in the ring groove causing it to stick in. ONLY the #3 piston...must have been the extra heat.


Anyways, sorry to rambling off topic

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">it aint gona work in stock sleeves, and the compression height is 1.181, the dome is around 6 or 7 cc... oh and the dome dosnt fit in a b-series combustion chamber w/o ALOT of work</TD></TR></TABLE>

what are you talking about? the f20b piston is 31mm (1.221in) compression heigh and 0cc dome. 85mm. http://www.zealautowerks.com works in stock b20 sleeves, but not under RR track abuse. chad told me he saw cracked sleeves in 3 similar setups all b20's with these pistons.

edit: recent events lead me to belive that the dom might not be a 0 dome. im searching for pics of it now.


Modified by GSRCRXsi at 12:59 AM 10/12/2006

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">Here's some info you may want to think about.

https://honda-tech.com/zerothread?id=1143619</TD></TR></TABLE>

Thats an interesting read.
My #3 gives me the lowest results on my comp tests...

Not that I'm a cool B-series guy.

Sorry for the OT.

 

brad z measured my f20b pistons for some custom stuff... they are 1.181 comp height and being that the f20b is 11:1 compression with an 85mm bore, 88mm stroke and a 53.8cc chamber the dome is around 6 or 7cc, its a pretty good size dome.. i have owned 4 of these motors and have most of all of em in my shop apart atm.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by JDogg &raquo;</TD></TR><TR><TD CLASS="quote">brad z measured my f20b pistons for some custom stuff... they are 1.181 comp height and being that the f20b is 11:1 compression with an 85mm bore, 88mm stroke and a 53.8cc chamber the dome is around 6 or 7cc, its a pretty good size dome.. i have owned 4 of these motors and have most of all of em in my shop apart atm.</TD></TR></TABLE>

here ey here ey

how dare someone question senor jdogg

 

While it would be good to have legitimate hard numbers, they're close enough to each other that I don't think it matters (compression ratio anyway, who knows about piston-valve clearance issues). It winds up being 5 hundreths of a point difference. Whoopty doo.

 

yeah, h series valves are farther apart, so you gota do some grinding to make room for the valves.

 

That calculator is awwwff....the stock F22 has an 8.8:1 CR, not 10.5:1

 

no one is talking about f22. we are talking about the f20b

 

jdogg, mind getting some pictures of these pistons? ive been searcing all over to actally see them but im comming up with nothing. if youve got some on hand take some pics

 

i can get some when i go back home this weekend

 

I know these pistons will work in a bored B20, I have seen them in 2 different motors. The only thing I want to ask is why run them though? B/C they are cheaper than aftermarket pistons? Do you know how much the F20B Pistons weigh? I have the complete specs on the piston, but they are in a notebook at home, and I am overseas right now. However, i do know they weigh like 380-some grams!!! That is insane when the stockers weigh a little over 300 grams and after market slugs will be around 260-270 grams.