High Boost questions

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

You'll have to forgive these first few questions guys, I'm in Japan and have been racing Skylines for the last 3 years.

I'm looking at building an S13 when I get back next year. I'm already familiar with what mods have to be done to run high boost, so please don't post things like FMIC and Fuel pump.

My questions are: What is the static CR of the KA24DE?What RPM do they redline at?How much HP is the transmission good for?Do the pistons have oil squirters like the RB series?

Also, has anyone built a KA24DE running really high boost, say 30psi?

Thx ahead of time...

WD

Post by **I am Technoman** » Mon Nov 25, 2002 2:28 am

The KA24DE has 9.5.01 compression and yes it does have oil squirters to cool the pistons. It is an Americans Dream motor Built out of Iron with a really nice aluminum head. But the KA does not like real high revs dew to its long stroke. It is very possible to boost this monster of a 4 cylinder but the pistons are not made to handle boost but many people who are real good tuners can make it work with impressive Hp numbers.Not to mention the torque numbers are impressive as well. I have seen a few stock KA motors make unbelievable HP with none forged pistons. The key is the tuner! Not the motor….

My KA redlines at just under 7000rpm

The only thing I dont like about the KA is the stock cams Nissan went with some crappy 232 degree cams in 95 that underpower this motor. It is my opinion that 248 degree cams should have been stock.

Post by **macdaddy** » Mon Nov 25, 2002 2:28 am

a word about the cams. go to pdm-racing.com and thay can hook up your cams

Post by **I am Technoman** » Mon Nov 25, 2002 2:28 am

macdaddy wrote:a word about the cams. go to pdm-racing.com and thay can hook up your cams

Any cam is better than stock.

Post by **96_S14_SE** » Mon Nov 25, 2002 2:28 am

Think about it though If they used the 240-248 cams found in the s13 then the base hp would have been around 166. Just one step closer to the NA Z 2+2 pushing away its already low sales.

Im kinda glad it came with 232's as from what I hear the 248 ex mated to a 232 int is a nice low buck turbo cam setup. Since I have the 240-248's in now when I turbo it Ill give it a whirl, then swap out the intake cam with my still lubed and bagged 232 and see what I like better. Itll take less then an hour to put it in then test, then depending on what works better possibly another 45 mins to reswap it out, if it is worse....

As far as redline its 6900 stock. Can run safely up to 7100 (jwt retune sets it here), possibly 7200. They can go higher but you must balance out the crank shaft and other reciprocating parts must be upgraded, like valve springs and the likes.

I dont know if it has squirters like an RB but it has them like a VG30DE (IIRC). The VG30DETT squirts higher then the VG30DE and my Z nut friend says they swap em out with the NA type for I dont rem what reason, oh forged pistons, and something else. If If its like the NA VG30 (Im pretty sure it is but there is a slim chance in my mind its like the TT VG) then it squirts more into the rods, horizontally, then actually into the inner of the piston (like the VG30DETT), vertically.

As far as trannies I wouldnt worry about it. People have been laying some serious power pown to the wheels on the stock gears. Put it this way there was a guy pushing 240hp to the wheels (320 crank hp at 25% loss) in a nearly stock ( LVL10 valve body mod) 240 automatic transmission (just to show the toughness of a nissan trany in any form).

Its basically the same, if not exactly the same (cant rem right now), internals as found in the s13 and s14 5 speed Silvia trannies, that get swapped back in after the s15 6 speed guys break theirs. But being in japan you know about the silvia gearboxes and their output levels and the 6 speed probs

So you know this answer hehe, Its solid.

Post by **C-Kwik** » Mon Nov 25, 2002 2:28 am

I am Technoman wrote:It is very possible to boost this monster of a 4 cylinder but the pistons are not made to handle boost but many people who are real good tuners can make it work with impressive Hp numbers.

The stock pistons have no problem handling boost. It's detonation that it can't handle. Lower compression pistons are able to run more boost with less chance of detonation. Forged pistons are able to withstand more detonation before they fail becuase they are built stronger and pistons destined for turbo motors have thicker ring lands. But subject them to enough detonation and it will still fail.

Post by **C-Kwik** » Mon Nov 25, 2002 2:28 am

I am Technoman wrote:Any cam is better than stock.

On a turbo motor, a cam with minimal overlap is optimal. Too much overlap and the pressurized air from the turbo will go right out the exhaust valve.

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

C-Kwik wrote:The stock pistons have no problem handling boost. It's detonation that it can't handle. Lower compression pistons are able to run more boost with less chance of detonation. Forged pistons are able to withstand more detonation before they fail becuase they are built stronger and pistons destined for turbo motors have thicker ring lands. But subject them to enough detonation and it will still fail.

I'm quite familiar with detonation and what causes it.

I'm not going for a slightly modified motor. I'll be doing a complete engine balance and tune. I already plan on having the crank lightened and balanced. I'll probably see about having 4 bolt mains installed. All of my bearings will be replaced. The rods and pistons aren't going to hold much more the 450 hp for any length of time, so they'll be replaced. The block will be O-ringed as well as the head. The cam specs will be custom grinds, somwhere in the 260 series. Complete titanium valve train. I'll be looking for an 8000 to 8500 redline.

On another note, why are you guys using different in/ex cams? Has there been testing done to show power improvements?The Skyline uses the same cam profile, I tried 256in and a 264ex but the idle went to ****. I also tried a 240in with a 248ex with the same result. No matter where I put the cam gears the idle and timing just wouldn't mix. I found the 264's to have a very nice smoothe idle when timed properly.

Thx for the info guys, especially on the squirters.

WD

Post by **george** » Mon Nov 25, 2002 2:28 am

"The stock pistons have no problem handling boost. It's detonation that it can't handle. Lower compression pistons are able to run more boost with less chance of detonation. Forged pistons are able to withstand more detonation before they fail becuase they are built stronger and pistons destined for turbo motors have thicker ring lands. But subject them to enough detonation and it will still fail."

C-kiwi the stock pistons DO have a problem handling boost the ring landings are too small and as the piston is pushed down it pinches the piston ring and breaks it.

Post by **s13 ka24det** » Mon Nov 25, 2002 2:28 am

Im planing on runing 20-24psi do i need to o-ring the block and head?

Post by **george** » Mon Nov 25, 2002 2:28 am

i ran 25 psi with stock head gasket no o ring no studs..i raced the crap out of the motor. it held up well. i am now rebuilding it to run 30psi and nitrous.

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

I'll see you at the track George...

WD

Post by **I am Technoman** » Mon Nov 25, 2002 2:28 am

WD your going to build my dream motor!One could only dream of a Ka pushing boost at 8500rpms I wonder how it will turn out? :thinker

Post by **george** » Mon Nov 25, 2002 2:28 am

dream motor except for the 8500rpm part...stock KA crank wont take it. the motor will self destruct.

Post by **C-Kwik** » Mon Nov 25, 2002 2:28 am

george wrote:"The stock pistons have no problem handling boost. It's detonation that it can't handle. Lower compression pistons are able to run more boost with less chance of detonation. Forged pistons are able to withstand more detonation before they fail becuase they are built stronger and pistons destined for turbo motors have thicker ring lands. But subject them to enough detonation and it will still fail."

C-kiwi the stock pistons DO have a problem handling boost the ring landings are too small and as the piston is pushed down it pinches the piston ring and breaks it.

Where did you hear that? and at what boost levels? There are a few guys running 15 psi on stock pistons and getting over 300 HP easy. Chances are, if that happens, it's because of detonation. And so far, every blown KA that I hear about has been due to detonation.

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

george wrote:dream motor except for the 8500rpm part...stock KA crank wont take it. the motor will self destruct.

Did ya see the part above where I said it would be lightened and balanced. I'm not sure if the KA uses a forged crank or not. I have plenty of friends in machine shop, if the crank won't handle 9500 rpm then I won't install it. I only say 9500 because all parts should be able to clear an additional 1000 rpm at a minimum. I've seen alot of engines with stock redlines of 7500 run up into the 13000 range. Its all how there built. I won't be rushing anything.

C-Kiwi...lol.

Most people don't recommend more thn 20 psi on the stock RB20 internals either. But I've run mine up to 28. Like C-Kwik said, it's all about controlling detonation.

HAPPY THANKSGIVING

WD

Post by **I am Technoman** » Mon Nov 25, 2002 2:28 am

The KA has a forged crank but thats it nothing else.

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

It should be fine then. Just a good NDI, shotpeen, lightening, and balance job should do the trick.

WD

Post by **s13 ka24det** » Mon Nov 25, 2002 2:28 am

????NDI?????whats that i want to run high Rs but everone says i cant

Post by **Turbo_Nismo_EC** » Mon Nov 25, 2002 2:28 am

There is a guy I know in Maine who claims to be running upwards of 10,000 rpm in his KA24E powered Nissan p/u. He says he had everything custom made, including a custom crank. Now I cannot really prove this is true, but he has sent me a video of him doing a top fuel dragster burnout through 4th gear...and I've heard many KA motors and I have never heard one rev this high. I'll see if I can get him to e-mail me the video again. Look for it in the next couple days.

Post by **RykrosGT** » Mon Nov 25, 2002 2:28 am

someone over in Japan wants a USDM motor?

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

NDI means Non Destructive Inspection, Its somthing alot of aircraft parts have to go through when removed. Basically the part is magnetized then a metal flake compound is applied to show any cracks, it is also xrayed for lack of a better term to show any internal damage.

It costs me a case of beer for the guys over at the shop to do it for me. I'll be having the block and crank done for sure.

I'll be home in a year or so, I'm pretty damn tired of JDM stuff. Its pretty damn expensive for aftermarket stuff. Atleast on Skylines anyway.

WD

Post by **ADAMHU** » Mon Nov 25, 2002 2:28 am

thats magnafluxing no....

WDRacing wrote:NDI means Non Destructive Inspection, Its somthing alot of aircraft parts have to go through when removed. Basically the part is magnetized then a metal flake compound is applied to show any cracks, it is also xrayed for lack of a better term to show any internal damage.

It costs me a case of beer for the guys over at the shop to do it for me. I'll be having the block and crank done for sure.

I'll be home in a year or so, I'm pretty damn tired of JDM stuff. Its pretty damn expensive for aftermarket stuff. Atleast on Skylines anyway.

WD

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

NDI is the military term...Sorry, ten years of brainwashing.

WD

Post by **I am Technoman** » Mon Nov 25, 2002 2:28 am

WD Tell me your going to bring that skyline back to the states!!!

ANd please post some motor pics geeeezz!!:)

Post by **WDRacing** » Mon Nov 25, 2002 2:28 am

To be street legal I'm looking at 10grand after shipping, So the ***** stays here. I want to build an engine that the country I reside in actually has the parts for.

I post some pics when I transfer them from my old PC.

WD

High Boost questions

High Boost questions

Nissan Forums

Infiniti Forums

Datsun Forums

Technical Forums

Classifieds / Marketplace

Nissan Motorsports

General Forums