Why stroke the **** out of the KA to 2.7liter, With a brian crower stroker kit?
2.6 is suppose to be the maximum tolerable for the KA block. I spoke with Brian Crower in person and was explained the frictional losses to the piston rings when exceeding 2.6 liter, not to mention the KA cast iron wallsbecome much to thin.


Anyway KA head is much more simple in design and meant for high rev, the SR engine unfortunately isn't. Bucket Hydraulic valve assembly> Rocker Valve assembly

KA is a heavy engine and sr is lighter each engine has it's pro's and cons

 

The motor is not exactly a 2.7 liter. I do what every car company in the world does. The 2.4 liter is actualy 2.38 or something like that, but they call it a 2.4 liter, My stroke and bore brought the motor up to a 2.675 or somewhere close to that so I just call it a 2.7. I have not exceded the tollerable bore or stroke. I spoke with Dustin at brian crower when I did the stroker kit about a year and a half or two years ago, and he said that I was still within the tolerances. I talked to my machinest as well and we went through his books and found the KA and its tollerances and there was no issue with the size of bore I was planning to go. I also plan on boosting it and building the entire head with brian crower parts. After every thing is said and done I will have plenty of power all the way up to about 7.5 - 8 thousand RPMs. the only downfall with the sroker kit on a stoc head was the powerband ended at around 5.5 thousand RPMs. that is where the turbo and the BC head will come in to play to compensate and then some.

Sorry it took so long to reply I have been too bussy working on the car and at work to get on the forum in a while.

 

good **** steve i cant wait to start on this..

 

The engine runs out of power at 5.5 RPM because the displacement is to large for such a small MAF. The hot wire cools so fast that the injectors are limited to peak duty cycle.

Increasing MAF diameter size shifts the K value of the ecu MAP over so that your CAS value can deliver more fuel.

Looking at your build "before turbo" you are using a stock header, that will also limit your "rev range"

So where did you get the custom pistons? Brian crower sells the kit as a 2.6 liter stroker and I believe that piston is custom with pin height adjustments for the shorter rod used. Pin height is also adjusted to reduce friction for high rev, so who do I get in contact with to get this special piston?

 

AAAAAAAAAAAAAAAAAAAAAND meet vinnie steve our NA KA GURU

 

Dude I'm just saying I talked to Brian Crower personally about this kit at formula drift.

At a 90mm piston bore that is already a.020 bore. For a 2.6 liter stroker.

At a 91mm piston bore that is already a .040 bore, for a little under 2.65 liters.


A 2.65 liter stroker is 6.495, or the equivelent of 2648cc's which is under what it would take for it to be a true 2.7 liter. It would have to be over 2655cc's to be considered a 2.7 liter stroker. I believe that is how the Japanese have rated it for years.
At .050 bore that would be 2.7 liters, and I don't believe that is possible on the KA block. I don't think brian crower or CP offer a piston that large. Als with any head milling that would probably be done you can count on your cc's being around 2580~2640cc's depending on your 90 or 91 mm bore size. Like I said these kits are not designed for 2.7 liter.

 

no doubt vinnie lol i was just telling steve all about your vast knowleadge bro... lol i can get sideways with a 1.2 liter if i had to HAHAHAHA.

 

man wish i had the money to do the 2.6L kit and just keep it NA, i think that would be pretty sweet personally

well if i ever come by $3K somehow that will be where it goes

ps the car sounds awesome man

 

CP will make any piston size you request if you have the dimensions and of course money. It has been a really long time since I had the numbers in front of me. I need to research again but it has been about a year and a half since I did the build. I have been realy busy working on more inportant things than a hopefull motor build getting ready for JCI and repairs from my last drift accident. I snapped the passenger side (RHD) fender in half and broke all the mounts on the S13 headlight off. Just got the new headlight in and need to glass the fender back together. Need to get new tierod ends and a couple of other things. It might be only a 2.6 liter Like I said before it has been a while. I will get more details after JCI and after winter time. You seem a bit more inteligent than I am, Ihave only doneone motor rebuild in my life and the KA26/KA27 was the first. I was actually suprise that i was able to build the motor myself and have it start right up on the first try. I do know however that when I did the build everyone I talked to said it could not be done, but I got rid of every vaccume line on the motor except the fuel pressure regulator, but I rerouted it directly to the intake manifold. Thank you for your inputs. I will reasearch the numbers again and get back to you later on the stroker kit after winter. Pardon my spelling, my computer is sloer than I type and I cant spell to bgin with.

 

Not to be a jerk. But I simply don't believe you. First to get the specs you would have to buy the pistons from Brian Crower. He doesn't hand out patents for free.
Secondly CP doesn't offer a piston for an engine any higher than .040 bore. Never seen them any higher and probably never will since .040 bore keeps it within safe tolerances.
Third of all I've tried pistons which would be a .060 bore equevelant and stock rods using the VH45de pistons from the Q45. It doesn't work the walls are to thin between cylinder chambers. It poses cracking and fractures along the cylinder walls when it is bored and honed....
Fourth and for most spending all this money on a Brian crower kit and brag about it you would have pictures, and or a Dyno, none which have been presented for a $3500+ rebuild performance kit.
Not to mention I've seen these kits in action and they clearly make power to 7000+ RPM HP Peak, and you claim that it won't mke power over 5500RPM.
I'm calling B.S.

Thread Closed...

 

Wow, Vin, you close the thread without giving him a chance to reply?

 

Without mathematical facts, which we won't be getting. A dyno which we probably won't see. Or actual internal pics of the motor which we probably won't see. I have no time or patients to deal with blah blah.

This forum is designed to present information that could be useful, not wasted bandwidth.
If you want to leave it open go ahead. waste of internet IMO.

 

Extremely true, but alternatively, may I present that I see a lot of threads started (at least monthly) that - in that instance - should be closed. I find myself talking to a lot of new drivers who don't quite live up to the life in which they propagate. I don't close their threads, I just let them speak their minds and continue to disprove everything they say. Eventually, they give up, and I delete the thread.

Trust me Vinnie, I am with you 100 percent, you and I go back pretty far on S-Chassis and I look up to you as a veteran member, I just feel that we should give him a chance to at least 1.) come clean or 2.) present his side. If, from there, it goes into this huge, off topic or ranting/venting rampage, then yes, by all means close it. I just don't think it's fair to close it having only presented your case whether or not you're right.

^_^

-Dave

 

when i asked about the amount of boost it was an indirect question about the thinned cylinder walls. i'm a bit skeptical about the 2.7l claims but i'm willing to chalk it up to bragging rights or whatever. having an engine with a greater displacement that the already ample approximation of 2.4l would be something i'd brag about for sure.