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N/A Ka24E Build


VintageRice

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Hey guys, I want to start building my KA. A hopped up street version is my goal. Going into my 510.

 

I plan on carbing it with R1 carbs. So I want to rebuild the motor and do some moderate performance upgrades while I'm in there.

 

I want a decent Cam, any suggestions on a good one? One I can run with stock lifters and springs.

 

Can I bump the compression on this motor by shaving the head? Or are pistons the only option? How much can/should I go.

 

Was thinking I'd lighten the flywheel. Get the head ported.

 

Anything else I should do??

 

Thanks Ratsun.

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With the SOHC KA it is pretty difficult to squeeze out a lot of hp all motor meaning getting near the 200 mark N/A. Maybe I shouldn't say difficult but pretty pricey.

 

For cam I know Crower makes a decent one, the stock lifters and springs are actually already decent on the KA head, and the cylinder head can be honed out for a little better airflow, but thats about it. someone has bored one out before and cleaned it up and found out, that the head is designed for its purest potential when its pretty much stock, because when he ran tests it didn't improve the airflow by much.

 

As for rod and pistons. unless you ever plan on running boost, the stock rod and pistons are usually pretty bitching. My first SOHC had 167k miles on it, and I ran 8psi on it to about 200k. Thank the car got totaled and the motor still ran perfect and was sold to someone else who boosted it right after me lol.

 

 

As for raising compression, same goes to as above, unless you stroke it and raise the compression to above 10, you will not squeeze out much power out of it.

 

The KA however responds beautifully to boost, which is what Im going to do, after I rebuild my carb intake :)

 

As I remember more, or if you have questions let me know.

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Ha, yeah good video.

 

This cam seems to be the most affordable. .270 .445 O&J Performance.

http://www.ojperform...&cat=280&page=1

 

The nismo cam is same duration but much less lift. .270 .402

http://www.frsport.c...HC_p_18262.html

 

 

 

 

Huh. What is gained by the higher lift? I guess a bigger hole for gas/air to suck through. Drawbacks to higher lift ??

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If ya want a great street motor duration and tight overlap is a good thing. the single cam is not the best revving motor, increasing the lift will move the powerband up so unless you can really open up the head its kinda pointless. as far as using R1 carbs with a build motor ya might max them out pretty quick as far as airflow goes if they arent maxed out with a stock engine???

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I don't know how much sense this will make, but Il try it this way first, if not Il explain it :).

 

The lift is how much volume of air and fuel you let in the cylinder, the duration is the time you allow that volume to enter into the chamber.

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If ya want a great street motor duration and tight overlap is a good thing. the single cam is not the best revving motor, increasing the lift will move the powerband up so unless you can really open up the head its kinda pointless. as far as using R1 carbs with a build motor ya might max them out pretty quick as far as airflow goes if they arent maxed out with a stock engine???

 

Good info, didn't know lift was what affected higher rpms.

 

The R1 carbs I've done a fair about of reserch on. I think they'll be fine but will look into it more. They are 40mm carbs and accept weber jets.

I'd love to get a set of side draft webers on this motor but that just isn't in my budget. ~200 for the R1 carbs vs. ~800 for webers. My mind is made up. :)

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are the r1 carbs a cv style carb? I once had a set of 40mm mikuni round slides on a fairy straight foward built l20. It took a long time, and a bunch a mikuni brass to get them to work the way they should. with all the time and money I spent on them a set of side drafts would have saved me a ton of headache.

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The R1's will run out of breath on the KA by 6500 for 100%. Thing is if you stay with the stock cam, there really is no power above 6500 anyways hehe.

 

 

Well, thats what I wanted to find out, how much air they can flow.

 

 

I heard they work well under boost. I wonder is the 40mm body's will work well turboed. If flow restriction works the same way under pressure. I'm going to have to do some research. If the turbo thing ever happens it'll be way in the future anyway.

 

Just going N/A for now and thought i might as well do a few upgrades while i"m in there. Cam, flywheel, and porting can't hurt.

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the reason i asked if their cv carbs is because big cams usually lower the vacuum and with a cv style carbs they might have a sluggish throttle response and general that can make em hard to dial in. Ive worked on 100s of 4cyl bikes so motorcyle carbs are kinda my forte! lol

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the reason i asked if their cv carbs is because big cams usually lower the vacuum and with a cv style carbs they might have a sluggish throttle response and general that can make em hard to dial in. Ive worked on 100s of 4cyl bikes so motorcyle carbs are kinda my forte! lol

 

 

GOOD TO KNOW! :)

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  • 3 weeks later...

I have been wanting to do the same thing. Some things I have found. the KA24e head has the mount for a mechanical fuel pump from the L motors. The cam lobe that pushes the pump can be unbolted from the L cam and installed on to the KA cam, you will need a 3psi reg. As far as intake manifold goes, I haven't desided if it would be better to build an adaptor onto the lower hald of the manifold and not have to worry about the coolant passage, or build from the head. As far as air flow it looks like an R1 1liter at 14000 rpm should be about the same flow as a 2.4 KA at 5800 rpm? I hope there would be room to push higher. Good luck on your build. Please post updates, I need moto-vation :D .

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  • 2 weeks later...

What're your thoughts on running a Weber downdraft? You'd need to get a plate made to adapt it to the throttle body holes, but it could be done.

 

 

Weber downdraft, biggest possible is what a 38/38? The R1 carbs ar 40/40/40/40 so thats alot more flow from the R1's.

 

 

I'm now seriously considering hunting down some DCOE's. :)

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Weber downdraft, biggest possible is what a 38/38? The R1 carbs ar 40/40/40/40 so thats alot more flow from the R1's.

 

 

I'm now seriously considering hunting down some DCOE's. :)

 

True... How bout a Holley, or Edlebrock? Cheaper and easier.

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I don't think any of those options are easier or cheaper than R1's.

 

 

 

Tha manifold woul dbe much easier for the R1's cause theres no collector for 4into1 just 4 seperate runners going out and ending. The carbs clamp right to them.

 

 

 

Plus a new Holley or edelbrock 4 barrel would be about 250-300 bucks. R1's are doable for $100.

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I've been looking into this as well, a real bitch to find legit info on hp numbers with carbs. There is a guy who goes by greaser on fresh alloy that has done the most work I can find but it's on a ka24de itb setup, similar.... From what I can find there are no backed up numbers with a carb setup.

 

Anyway o&j performance has cams for the ka24e but no real info on performance, like dyno sheets.

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  • 3 months later...

Hello:

 

I will like to introduced myself to this forum.My name is Omar Lopez owner of O&J Performance Inc.To me is a pleasure being mention in some of the KA24E builds that are taking place in this forum.If you anyone have any question about any of our products please feel free to email us or call us there will be someone ready to answer the phone.Most of the time is me on the line so you get to talk to someone with knowledge about your build.The following numbers where taken from one of our customers review on one of our cams and the results speak for themselves.

 

KA24E Stock cam:

 

3500- 280wtq

4500- 265wtq

5500- 230wtq

6500- 200wtq

7000- 170wtq

 

3500- 190whp

4500- 240whp

5500- 270whp

6500- 250whp

7000- 225whp

 

 

O and J stage 2 mech cam

 

3500- 265wtq

4500- 320wtq

5500- 320wtq

6500- 275wtq

7000- 245wtq

 

3500- 170whp

4500- 240whp

5500- 325whp

6500- 335whp

7000- 325whp

 

 

Basic facts

 

-Added about 100whp at 7000rpms

-Added about 90wtq at 5500 rpms

-Meth added 30whp

-turbo added 20whp

 

So put together added about 50whp and 45wtq and completely changed the powerband from 3000-5000 to 4200-6800

 

Here is the link for review http://www.ka-t.org/forums/viewtopic.php?t=44965&start=0

 

Once again than you for your time and if you have any questions call us 407-436-4832 or visit http://www.ojperofrmance.com

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Hey Welcome to the forum O&J !!

 

 

 

Are any of your cams good for use in a N/A motor? I assumed they were but thats with a turbo setup. What would you recommend for a N/A Cam with hydro/stock lifters ??

 

I have some customers with N/A applications most of them for road racing set up.Don't have any dyno sheets for N/A but as far as my customers review all of them report back that they were getting a better response coming out the corners and more torque at top end.As far as hydro or mech lifters the response with the mech lifters was a little better than the ones with hydro lifters.If you have any questions you could always call me at 407-436-4832

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