So lately i have been reading up on these Vitara pistons in a d-series and it sounds like a pretty sweet setup. But i have a few questions, you are supposed to use vitara pistons rings correct? As for rods will any rods work with the pistons? What CR ratio would you end up with if you used them on a stock d15b7 block? Also what psi can these pistons along with good rods safely hold up too on a good tune?Thanks.

 

they are not as good as you think. They are stronger and lower compression (too much IMO, you would have about 8.5:1CR) They arent THAT strong, I've seen people blow a hole through them with the same power stock pistons can handle. It may have something to do with them having a very odd shape for the valves (for a suzuki engine), or the fact that people use them with a stock bore and don't even check the cylinder walls.

If you have your engine apart, you should get forged pistons. You will probably be happier.


Modified by ham at 8:28 AM 10/10/2005

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ham &raquo;</TD></TR><TR><TD CLASS="quote">
they are not as good as you think. They are stronger and lower compression (too much IMO, you would have about 8.5:1CR) They arent THAT strong, I've seen people blow a hole through them with ~350whp tuned. It may have something to do with them having a very odd shape for the valves (for a suzuki engine), or the fact that people use them with a stock bore and don't even check the cylinder walls.

If you have your engine apart, you should get forged pistons. You will probably be happier.</TD></TR></TABLE>
Most people that get these pistons have intentions of about 270 whp, on a stock block not sleeved, their ideal for that goal, if you are going to sleeve the block then i suggest getting forged pistons, .
Im building my setup with vitara pistons and scat rods, stock bore, not sleeved,. I could care less what the haters say, Ive done a lot of research before going this route .

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by ham &raquo;</TD></TR><TR><TD CLASS="quote">
they are not as good as you think. They are stronger and lower compression (too much IMO, you would have about 8.5:1CR) They arent THAT strong, I've seen people blow a hole through them with ~350whp tuned. It may have something to do with them having a very odd shape for the valves (for a suzuki engine), or the fact that people use them with a stock bore and don't even check the cylinder walls.

If you have your engine apart, you should get forged pistons. You will probably be happier.</TD></TR></TABLE>

Umm yeah..... blowing a hole threw a piston and being "tuned" do not belong in the same sentence. I guess tuned on 116 octane and running 75 on the street then yeah maybe.

 

i still dont understand the hype about Vitara pistons. Maybe I just havent read enough about it. So anyone with information, please enlighten me.

1. Do the valve reliefs match the SOHC heads exactly?
2. Do the Valve angles of the piston match the SOHC heads exactly?
3. What makes the Vitara pistons better to use than OEM Honda Pistons?
* I've seen OEM Honda pistons handle over 250hp on sohc setups, so why the need for the Vitaras?

SOHCPOWER: How much are Vitara Pistons? I'm assuming $200 for rings and the pistons. IF you are building a setup with already upgraded rods, why not another $250 more to get EVEN better pistons such as ARIAS for your setup. Its not much more and that will even have better potential for boost.

Are the SCAT rods for floating wrist pins, such as used in Forged Pistons such as ARIAS? What about the Vitaras? If the rods are used for Floating wrist pins, dont you have to machine the pistons to fit the floating style? And would that cost a bit more money too?

Any info is appreciated. I've read stuff on the Vitara, but only second hand info, not from people that have actually done it.

 

I am only looking for a power goal of 250whp(thats excutable on pump 93, correct?). I figure leave it stock bored with a clean hone. Now say if I wanna raise compression slightly to about 9.5:1 how much could i safely mill off the head to achiev that? Thanks for the help.

Good choice of the Scat rods jdmhunter.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmhunter racing &raquo;</TD></TR><TR><TD CLASS="quote">
i still dont understand the hype about Vitara pistons. Maybe I just havent read enough about it. So anyone with information, please enlighten me.

1. Do the valve reliefs match the SOHC heads exactly?
2. Do the Valve angles of the piston match the SOHC heads exactly?
3. What makes the Vitara pistons better to use than OEM Honda Pistons?
* I've seen OEM Honda pistons handle over 250hp on sohc setups, so why the need for the Vitaras?

SOHCPOWER: How much are Vitara Pistons? I'm assuming $200 for rings and the pistons. IF you are building a setup with already upgraded rods, why not another $250 more to get EVEN better pistons such as ARIAS for your setup. Its not much more and that will even have better potential for boost.

Are the SCAT rods for floating wrist pins, such as used in Forged Pistons such as ARIAS? What about the Vitaras? If the rods are used for Floating wrist pins, dont you have to machine the pistons to fit the floating style? And would that cost a bit more money too?

Any info is appreciated. I've read stuff on the Vitara, but only second hand info, not from people that have actually done it.</TD></TR></TABLE>

The cost 115 shipped, I paid 130 cause i live in canada, I bought them of fjt, im sure youve seen his thread, I choose the scat rods because there equal to eagles H beam rods but come with arp bolts, oh and they are cheaper, The only thing is the block has to be notched which is no big deal, youd have to do that with eagles also.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by jdmhunter racing &raquo;</TD></TR><TR><TD CLASS="quote">
i still dont understand the hype about Vitara pistons. Maybe I just havent read enough about it. So anyone with information, please enlighten me.

1. Do the valve reliefs match the SOHC heads exactly?
2. Do the Valve angles of the piston match the SOHC heads exactly?
3. What makes the Vitara pistons better to use than OEM Honda Pistons?
* I've seen OEM Honda pistons handle over 250hp on sohc setups, so why the need for the Vitaras?

SOHCPOWER: How much are Vitara Pistons? I'm assuming $200 for rings and the pistons. IF you are building a setup with already upgraded rods, why not another $250 more to get EVEN better pistons such as ARIAS for your setup. Its not much more and that will even have better potential for boost.

Are the SCAT rods for floating wrist pins, such as used in Forged Pistons such as ARIAS? What about the Vitaras? If the rods are used for Floating wrist pins, dont you have to machine the pistons to fit the floating style? And would that cost a bit more money too?

Any info is appreciated. I've read stuff on the Vitara, but only second hand info, not from people that have actually done it.</TD></TR></TABLE>

The pistons are dished, have you seen alot of dished pistons with valve reliefs?
They are better than oem pistons because:
They are lower compression.
They are designed for boost and made out of stronger materials than are oem pistons.
The ring land design is far stronger than our oem pistons.
They use a floating wrist pin useful with after market rods.
They cost $120 shipped with hastings rings.

Yes I am sure you can run 250 whp plus on stock pistons. These I know you can get 50-100 more. This of course, depends, as always, on the tuning. Are they the last set of pistons you will ever need? No of course not. D-series ia all about having fun and replacing broekn stuff for cheap. It's not about walking around with ur hand on your **** thinking you motor is indestructable.

If your $400 Arias pistons run lean or have too much, not enough timing they will blow just the same. They may not blow holes through them or crack ring lands, but they will seize the rings and be useless too.

 

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

The pistons are dished, have you seen alot of dished pistons with valve reliefs?
They are better than oem pistons because:
They are lower compression.
They are designed for boost and made out of stronger materials than are oem pistons.
The ring land design is far stronger than our oem pistons.
They use a floating wrist pin useful with after market rods.
They cost $120 shipped with hastings rings.

Yes I am sure you can run 250 whp plus on stock pistons. These I know you can get 50-100 more. This of course, depends, as always, on the tuning. Are they the last set of pistons you will ever need? No of course not. D-series ia all about having fun and replacing broekn stuff for cheap. It's not about walking around with ur hand on your **** thinking you motor is indestructable.

If your $400 Arias pistons run lean or have too much, not enough timing they will blow just the same. They may not blow holes through them or crack ring lands, but they will seize the rings and be useless too.</TD></TR></TABLE>


Good stuff

 

Nice.. thanks for the info. Don't hear much straight answers on other Vitara posts like this one.

OH as far as Dish pistons, yes almost all pistons actually have valve reliefs in them. I have never seen a honda piston that are dished and doesnt have reliefs for valves.
The reason I was concerned is because how much oversize you can do on the valves so that it will still clear the pistons.

Also, are the Vitara pistons available in oversized set? Not the stock 75mm bore.

 

they are available in .40 over lol, not .040 over, so that makes them in 75mm and 85mm lol

 

so they are made in .040 over from 75mm?
or the final bore is 75mm?

 

no they arent made in .040, they are made in .40 over people keep getting mixed up i tried to clarify, the stock bore of the pistons is 75mm, the .40 over are 85 mm

 

WTF, so the stock bore of the vitara pistons are 75mm and the next size up by the manufacturer is 10mm overbore?

I've never seen anything like that, are you sure? 10mm over bore on each piston, the cylinder walls must be so Wide apart that you can do 10mm overbore on each cylinder? DAYM.

OH ya, another thing: How far down do they stick below the deck?


Modified by jdmhunter racing at 1:38 AM 10/10/2005

 

he doesnt know what he is talking about. Its a 75mm bore with a .040" (INCH) overbore, which is about 1mm, or a 75mm bore with a .40mm overbore.

 

Theyre made in STandard size of 75mm and in Oversized of 76mm(Or .040 over)

People have already passed the 300whp barrier with them(I expect around 325whp in my setup ..soon). Theyre a much stonger piston than Hondas OEM, they have better ringlands...

Id really like to see a stock Honda Piston take 20+PSI je je je...

 

jeez thats what I thought. what company is going to make a 10mm oversize piston. haha

 

 

I will get some more pics up of mine. I have the head off mine right now, replacing the head. I like the lower compression, it is nice seeing the boost gauge at 20 or so, makes for a fun ride and makes pump gas actually useful.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by fjt &raquo;</TD></TR><TR><TD CLASS="quote">Theyre made in STandard size of 75mm and in Oversized of 76mm(Or .040 over)

People have already passed the 300whp barrier with them(I expect around 325whp in my setup ..soon). Theyre a much stonger piston than Hondas OEM, they have better ringlands...

Id really like to see a stock Honda Piston take 20+PSI je je je...</TD></TR></TABLE>

I got mine today from fjt, U can add me to your vouch list, Id be more then happy to vouch for u.

 

I too built a motor(team mates car) with the vitara's from fjt and they work great seem to be taking a good beating for a motor that we spent 500 on including another short block for this budget build and for fjt

 

I just had a quick question about which rods to use for these pistons. I know you can use any aftermarket rods and notch the block or you can use ls rods with bushings (because the small radius of the ls rods is larger than the wristpin). Correct? I am interested in using the ls rods because my bro has some that were shotpeened and magnafluxed which he will give me if I want em'. Anyone know where to get the bushings, I heard crower has them is this correct? P#? So for a complete d block I would need the vitaras, ls rods (in my case) and the bushings? That's it right (Besides of course the typical oem bearings, gaskets and other stuff)? TIA for any help.

 

I believe that LS rods have to have the top of the rod ground down a bit too (very little room between pistons/pin).


As for the differences between OEM Honda and Vitara's:

*Valve reliefs: Vitara reliefs are farther apart (vs. my y8's; in ham's picture, farther left and right)
*Bigger dish (12cc)
*Lower piston-to-deck height (piston top is sunk in/not flush with deck when TDC)
*STRONGER alloy, also heat treated
*MANY more oiling holes
*Stronger ringlands
*Floating wrist pin
*Slightly smaller diameter than OEM (useful with 20psi+ and thermal expansion of cast alloy)
*Slightly smaller skirts (made up for with oiling holes on skirt below oil ring)
*Puerto-Rican Tested, mother approved

Chances are a bad tune will melt the pistons or punch holes in them. OEM's would scar the cyl walls with broken ringlands, and forged would take abuse for a while then spin a bearing. Neither 3 are limited to just that, but those are common problems for each. I'd rather have pistons that coushin my motor's demise, much like a crumple zone. As much as I want forged pistons, I'm not about to spend more on pistons than I did for the ENTIRE stock obd1/z6 swap.

 

Im interested in those pistons on my build. I have a d15 block can they work for me? Also i wanna do a mini me swap which is better for boost and which is better for all motor? If someone could pm me with the info id much appreciate it.

 

Also would stock d15 rods work for those pistons?