<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jerseykid609 &raquo;</TD></TR><TR><TD CLASS="quote">again how many people do u know building a motor with cast pistons ? </TD></TR></TABLE>

several, me being one. I also know several others that would have opted for a cast piston in their B20 had they had the chance to buy a set. Street engines that run na don't need forged.

 

arent the tolerances of cast pistons closer than forged units? just a question I thought I'd ask...

 

Fixed:
<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WAFFLES &raquo;</TD></TR><TR><TD CLASS="quote">some street engines that run na don't need forged.</TD></TR></TABLE>
there are alot of things that street engines dont need, that people still run. that isnt the point.
there are plenty of bad designed products that sell plenty due to good marketing and whatnot. the opposite doesnt work when you say that since no one is selling a cast 84mm piston, that it isnt needed. just because no one sells it doesnt relate to if the conceptual product will perform or not.

 

Most cast pistons can be run much tighter wall clearance for better oil control and blow by.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DC2-99 &raquo;</TD></TR><TR><TD CLASS="quote">arent the tolerances of cast pistons closer than forged units? just a question I thought I'd ask...</TD></TR></TABLE>
depends upon who you compare. most forged pistons are accurate because they are cnc machined. cnc machining is uber accurate.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Rob @ K-Series.com &raquo;</TD></TR><TR><TD CLASS="quote">Fixed:

. just because no one sells it doesnt relate to if the conceptual product will perform or not.</TD></TR></TABLE>

 

Its a matter of demand.The manufactures need to see the need.As a builder I can see the advantages of a cast piston in the right application, but the customer will see it as a downgrade.United Engine (keith black pistons) makes a huge variety of cast pistons and I'm able to sell those to customers who are tight on money.They have a good rep and most people that are into cars (domestic) have heard of them.But if the guy has the money,they always want the forged pistons (even if the cast will fit his app. better).Most people now buy CTR or ITR pistons because " they don't have the money for forged".For most of the people those are a better option than forged anyway.
Glenn

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by WAFFLES &raquo;</TD></TR><TR><TD CLASS="quote">several, me being one. I also know several others that would have opted for a cast piston in their B20 had they had the chance to buy a set. Street engines that run na don't need forged.</TD></TR></TABLE>

I would love a set of cast, mild dome 84mm pistons to put compression in the high 10s / low 11s.

I think it would make for a street engine with great performance and a long life.

 

i would love to see a cast 84mm ctr/itr copy piston,i think this is a gold mine waiting to be opened........btw i have a friend down here that has an all motor eg ls vtec with ctr pistons making 222hp@151 torque, was a daily driver for 6 months and now is a track car,it runs 12.00 @113 and this a well abused motor and still running strong,not even smoking yet,its been running for about a year and half,still makes 275 psi per cylinder!thats enough to convince me that cast pistons can get the job done!!!!he also revs to 8700 rpms........someone make these cast piston asap!


Modified by nos51 at 7:12 PM 1/15/2005

 

does anyone know the average difference of running temp in forged pistons and cast? or any numbers to give us a idea in the difference.....

with blocks like b20's and ls blocks without oil squirters it seems cast pistons may get a little hot. i know people run these all the time but im interested in hard numbers.

the temp cast pistons reach while being in a higher reving vtec engines had to be significant for honda to add oil squirters in them.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nos51 &raquo;</TD></TR><TR><TD CLASS="quote">i would love to see a cast 84mm ctr/itr copy piston,i think this is a gold mine waiting to be opened........btw i have a friend down here that has an all motor eg ls vtec with ctr pistons making 122hp@151 torque, was a daily driver for 6 months and now is a track car,it runs 12.00 @113 and this a well abused motor and still running strong,not even smoking yet,its been running for about a year and half,still makes 275 psi per cylinder!thats enough to convince me that cast pistons can get the job done!!!!he also revs to 8700 rpms........someone make these cast piston asap!</TD></TR></TABLE>

built lsvtec making 122whp and running 12.0's?

 

edit: sorry,222hp thanks for catcjing that!

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DC2-99 &raquo;</TD></TR><TR><TD CLASS="quote">arent the tolerances of cast pistons closer than forged units? just a question I thought I'd ask...</TD></TR></TABLE>

tolerances of a cast piston from Honda are incredibly close. I am sure there are aftermarket forged pistons with much worse tolerances. I am sure aftermarket cast pistons can have even worse tolerances, as well.

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by nos51 &raquo;</TD></TR><TR><TD CLASS="quote">i would love to see a cast 84mm ctr/itr copy piston,i think this is a gold mine waiting to be opened........</TD></TR></TABLE>

I think a jdm p73 dome configuration would be best. An 84mm piston with a ctr dome, with 6.3cc like omniman quoted, even with the stock b20 compression height, and stock headgasket with a b16 head is going to be a good bit into the 12's for compression. A gsr head or thinner HG will put you closer to 13:1. Also, this is assuming the pistons are 84mm and not 84.5.

I don't see the point in making a production run of cast pistons that are going to give the b20, which is known for having weak cylinder walls, high compression. That will increase the cylinder pressures a good bit. . .

I'm not a pro engine builder, or a ME, and I dont have a b20, so I am not speaking from experience about the cylinder pressure thing, but it makes sense to me. . .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by DC2-99 &raquo;</TD></TR><TR><TD CLASS="quote">arent the tolerances of cast pistons closer than forged units? just a question I thought I'd ask...</TD></TR></TABLE>

Tolerances are determined by the manufacturing quality. Not the material from which the piston is made. On the other hand, cast pistons expand less when heated than forged pistons. For this reason, they can be run with a tighter piston-to-wall clearance than forged pistons. This is perhaps the main reason why cast pistons are really not inferior to forged pistons. Rather, they are just a better way to go for certain applications. Specifically, if you want a motor that is not the wildest thing out there BUT you want good reliability (ie a good, daily-driven street motor), forged pistons are more than just simple overkill. They won't do the job as well since they must be run looser. This will (1) require that you warm up your engine before driving off, (2) increase wear and decrease longevity, (3) increase oil consumption, and (4) increase noise. Forged pistons are best used for applications that really need them.

I should also note that there ar two types of forged pistons: high silicon and low silicon. Low silicon pistons are stronger but expand more. And high silicon pistons are not as strong but expand less. I am not sure how the expansion of high silicon forged pistons compares with cast pistons. But high silicon forged pistons are not very common. The vast majority of forged pistons are of the low silicon, race-only variety.

 

I don't know if it's been said yet, but getting higher CR cast iron piston will require more work from your engine to get them moving. Also, the additional mass/weight will create more stress on your rods and may cause them to give way and if that happens, it probbly make your cyl. head go thru the hood of your car!

Caleb

 

Last i knew, everyone here was talking about cast aluminum pistons. Cast iron . I think there would be a decent market for a nice set of 11.5 to 1 cast pistons for the b20 vtec crowd.

 

I think cast pistons are old technology, not that it isn't used anymore, but forged is far better and stronger than cast. Plus, the turbo and NOS crowd needs more durable and reliable pistons to keep from toasting his $5-10K engine, right??

Caleb

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by supercreed2002 &raquo;</TD></TR><TR><TD CLASS="quote">I think cast pistons are old technology, not that it isn't used anymore, but forged is far better and stronger than cast. Plus, the turbo and NOS crowd needs more durable and reliable pistons to keep from toasting his $5-10K engine, right??

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

read this entire thread. cast pistons are good, nice tight piston to wall and plenty strong enough for street use under 12:1

i think its obvious theres enough people in here that said they would like to see some 11:1 cast pistons produced, hopefully someone will catch on.

 

doesn't the s2000 come stock with forged pistons?

 

How about some stock 85mm pistons?

https://honda-tech.com/zerothread?id=990644

Only $125, can't beat that.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by SMSP &raquo;</TD></TR><TR><TD CLASS="quote">How about some stock 85mm pistons?

https://honda-tech.com/zerothread?id=990644

Only $125, can't beat that.</TD></TR></TABLE>

Also has a hemi-dish for improved power production.

 

good thread.

 

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

ever considered tuning?</TD></TR></TABLE>


waffles is right.

forged pistons are heavier and slap on cold start-up.
if they can handle omnimans 240 whp then they're certainly good enough for me.
and finally, if we're so dumb as to use cast pistons then let us make our own
mistakes. there is no need to hate on everyone with a different opinion.

why build a ten foot high brick wall when all you need is a chain link fence?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by wesisrael &raquo;</TD></TR><TR><TD CLASS="quote">forged pistons are heavier and slap on cold start-up.</TD></TR></TABLE>

psst... forged pistons are lighter.

 

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

psst... forged pistons are lighter.</TD></TR></TABLE>

REALLY............................?? AND WHO TOLD YOU THAT?