what size rods would be needed to have an even better r/s ratio on a b16a block and crank? I know the b16b CTR motor has a better rod to stroke ratio than a b16a2. but thats using longer rods in a destroked b18c5 block. I would like to keep my b16a block. deckplate and longer rods perhaps?

 

you would have to reduce displacement in order to achieve this by using a shorter crank and longer rods.
why would you do this anyways, motors with r/s ratios in the 1.5x's are reving to 9k+ (ls,gsr,h22) so what is the benifit?

 

a perfect rod to stoke ratio is 1.75. a B16a is 1.74 so im not really sure what your trying to get at....whatever it is goodluck

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99B16Si &raquo;</TD></TR><TR><TD CLASS="quote">a perfect rod to stoke ratio is 1.75. a B16a is 1.74 so im not really sure what your trying to get at....whatever it is goodluck</TD></TR></TABLE>

lol...yeah I was about to say the same thing...

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99B16Si &raquo;</TD></TR><TR><TD CLASS="quote">a perfect rod to stoke ratio is 1.75. a B16a is 1.74 so im not really sure what your trying to get at....whatever it is goodluck</TD></TR></TABLE>

I have heard many times that the b16b has the best r/s ratio. I had no Idea that the b16a was that close. so does that mean the b16b is a perfct 1.75?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by z6 &raquo;</TD></TR><TR><TD CLASS="quote">you would have to reduce displacement in order to achieve this by using a shorter crank and longer rods.
why would you do this anyways, motors with r/s ratios in the 1.5x's are reving to 9k+ (ls,gsr,h22) so what is the benifit?</TD></TR></TABLE>


but If I had a deck plate wouldnt I increase displacement as far as I know Deckplate is like destroking, without loosing displacement. It's also a great way to gain displacement, while keeping your existing Geometry.

 

I really don't understand what you are trying to accomplish. You can't add a deck plate and keep the stroke/displacement the same without changing the rod length and that changes the r/s ratio. All you can do is test different rod lengths and stoke sizes until your piston reaches the top of the block with the deck plate and still has the 1.75 ratio. Personally you are basing everything on 1.75 r/s which may or may not be correct.

 

The B16 already has a near-perfect r/s ratio; there is not need to try to reengineer the motor.

The only reason you want a higher r/s ratio is so the motor will rev higher w/ less stress on it. As mentioned before, there's bigger motors w/ lower r/s's that rev really high; the stock B16's geometry is much more than sufficient.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by earl &raquo;</TD></TR><TR><TD CLASS="quote">I really don't understand what you are trying to accomplish. You can't add a deck plate and keep the stroke/displacement the same without changing the rod length and that changes the r/s ratio. All you can do is test different rod lengths and stoke sizes until your piston reaches the top of the block with the deck plate and still has the 1.75 ratio. Personally you are basing everything on 1.75 r/s which may or may not be correct.</TD></TR></TABLE>

Thats what I want to do Earl, add a plate, and the appropriate sized rods so I can increase displacment and still have a 1.75 r/s I just dont know what length rods and how high the plate has to be. my goal is to have a b16 that creates more tq and power on pump gas like a gsr does.and the ability to rev very high(9500-10,000) while still making power under boost incase I decide to get very high lift cams,headwork and a t4 exhaust housing.

 

save your time and money and buy a gsr block

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by 99B16Si &raquo;</TD></TR><TR><TD CLASS="quote">save your time and money and buy a gsr block</TD></TR></TABLE>

ok um.. I want to keep my b16 block.

 

b18a/b/c + b17 crank (81.4mm) = custom 140.8mm long rods = 1.73 RS ratio.

you sayd you wanted more displacement and a great rs ratio.
for the money that you would spend in putting a deckplate on a b16...hehe you can just get a b18 block and re-stamp it b16 for a lot cheaper...
and you know that rod lenght does not change displacement right?

 

I guess I will just do an 83mm bore and headwork..

 

if a 1.75:1 r/s ratio is "perfect" why are race cars running ratios that are miles over square?

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">if a 1.75:1 r/s ratio is "perfect" why are race cars running ratios that are miles over square?</TD></TR></TABLE>

Because it is "ideal", not perfect. That ratio gives a nice piston speed at lower RPM's while allowing you to pretty much rev as high as you need to, reasonably.

In race motors where the motor size is restricted, they must rev the motor unbelievably high in order to make the necessary power. In these cars, reliability is also a concern, since they have to last a good long race without blowing, while spinning WELL above 10k RPM's. So they design the motor so that the piston speed is slower at the higher RPM's so that longevity is increased; but these motors can't really be driven any other way than HARD.

But in drag motors, they only have to make it down a 1/4 mile before they can blow, so you will see these huge strokes w/ little to no regard to the r/s ratio, b/c they don't care if it blows after a run.

 

Just get LS length Eagle or whoever rods and pistons with the pin moved up, several people make these. That is the question you asked I think. No deck plate needed, and a better RS ratio. 1.75 being perfect is a figment of someones imagination and quoted often, but not by people who have tried lots of variations and built lots of different motors.

 

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

Because it is "ideal", not perfect. That ratio gives a nice piston speed at lower RPM's while allowing you to pretty much rev as high as you need to, reasonably.

In race motors where the motor size is restricted, they must rev the motor unbelievably high in order to make the necessary power. In these cars, reliability is also a concern, since they have to last a good long race without blowing, while spinning WELL above 10k RPM's. So they design the motor so that the piston speed is slower at the higher RPM's so that longevity is increased; but these motors can't really be driven any other way than HARD.

But in drag motors, they only have to make it down a 1/4 mile before they can blow, so you will see these huge strokes w/ little to no regard to the r/s ratio, b/c they don't care if it blows after a run.</TD></TR></TABLE>

sweet. thanks for the info.

 

ok then forget I mentioned r/s ratio. I want the ability to rev 9500-10k without a problem the way a stock b16 can go to 8k withut a problem.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by Boostage &raquo;</TD></TR><TR><TD CLASS="quote">ok then forget I mentioned r/s ratio. I want the ability to rev 9500-10k without a problem the way a stock b16 can go to 8k withut a problem.</TD></TR></TABLE>

If you maintain the b16's r/s ratio, then it will just be a matter of upgrading your valvetrain to handle the extra revs. Anything can be done with enough, time, money and patiance.

 

<TABLE WIDTH="90%" CELLSPACING=0 CELLPADDING=0 ALIGN=CENTER><TR><TD>Quote, originally posted by LsVtec92Hatch &raquo;</TD></TR><TR><TD CLASS="quote">

If you maintain the b16's r/s ratio, then it will just be a matter of upgrading your valvetrain to handle the extra revs. Anything can be done with enough, time, money and patiance.</TD></TR></TABLE>

I have rev valve springs and retainers. ctr intake cam GSR exhaust cam. JG intake, Earl will be building my motor with Pauter rods and 83mm pistons I hope 9500-10k under boost will hold.


Modified by Boostage at 3:03 PM 7/4/2004

 

If you are bying new rodsand pistons then just get the LS rod and piston with a moved pin. That will change the ratio from 1.725 to 1.77. Or for more money go custom as rod lengths of 5.531 stock pin, 5.862 18mm pin, are shelf stock. The B16 is 5.290, LS 5.394

 

all a deck plate allows you to do is run a longer rod .the only way you get displacement is by changing the bore or stroke .and a b16b has the same r/s as the b16a,but then again i could be wrong because i don't mess with b-series.

EARL my block is shipping out tues. mourning to dan benson.

 

ok thanks

 

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

I have rev valve springs and retainers. ctr intake cam GSR exhaust cam.

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

There is no reason on earth to rev the CTR intake cam that high.