K24A4 Rebuild

[Sinub]

Hello everyone!! I recently got a k24a4 engine. I'm also taking an automotive machining and blueprinting class in college so woop time to have fun at school!! Planning to make a k24/20 motor with a fully built head and bored out to 2.5L and raise the compression. And yes I know k24a4's don't straight bolt up to a k20a2 head, they need to have different shaped pistons to fix that The car I'm planning to slap it into? Well not so sure yet but my dream is to put it into a MIATA!!! I even found a perfect Miata in my area for $1000 with no motor in it so lol only thing holding me back is all the custom fabrication and wiring, athough I am also taking a welding class and electrical class so it might become a reality. So that's what I'm aiming for atm. anyways Here's some pics of my progress so car, I fully took everything apart. Tomorrow I'm going to start doing my measurements and next week hopefully the machining.


Please note the picture of the guy flicking off the camera is not me haha

 

[Sinub]

Here's some more pics since I can only do 10 at a time.

 

[Sinub]

And the block.

 

[Dar-Dar]

You also have access to machine your engine? Im really hating your guts right now... And putting a lightweight engine in a light weight Miata. Oh man. That would be fun.

 

[webby]

subscribed for future updates. Interested to see your build

 

[Sinub]

You also have access to machine your engine? Im really hating your guts right now... And putting a lightweight engine in a light weight Miata. Oh man. That would be fun.

I really am lucky hahaha but this is a learning process for me, never had done any type of machining so hopefully I don't mess up.

 

[Sinub]

UPDATE: I hot tanked my engine today her golden shine disappeared though ): Also checked for cracks in the block and there are no cracks so so far so good. Scrubbed her real nice with a brush kit in her oil passages and coolant jackets. I've run into a problem though. The warpage limit on the block is 0.003 so I have to either deck the block or somehow even it out. Anyone got advice on it?

 

[Sinub]

More pictures

 

[webby]

I've run into a problem though. The warpage limit on the block is 0.003 so I have to either deck the block or somehow even it out. Anyone got advice on it?

So I take it the block is warped over .003, or what is the "problem"?

 

[Sinub]

I checked the deck for warpage. The end where it would hook up to the transmision is dipped .003 so i guess its under lol. If that part was over I would just shave it off no problem

 

[Sinub]

Either way Im going to have to shave something off so I guess I'm going to have to deck it. At least my compression ratio will increase, just worried that with performance cams on the k20 head will still be good without valve to piston contact. I plan on having it rev to 8kish rpms. And higher rpm engines generally require more deck hieght and more piston to head clearance. Maybe Im over thinking this lol

 

[Sinub]

UPDATE: So plans never go how you want them lol so what's new? Anyways so our rottler broke down to machine the 4 cylinders ): So I can no longer bore out my block. But I did end up decking the block, and am about to hone it. I have cleaned everything, balanced my rods, pistons, and crankshaft. Now here's something interesting that will prove Honda's reliability for the doubters out there. When I went to weigh the rods and the pistons, to my surprise the rods were already all withing 1gram of each others weight from the factory!! The pistons were all within 1.5 grams except one that was off 3 grams but still great!! For those of you who don't know about engine balancing. Engines with pistons and rods balanced to within a gram of each other are usually for racing engines that are going to be put through a beating at the track for hours and that are going to be revving quite a bit. All my other classmates had their pistons and rods all off by AT LEAST 4 grams. Some even up to 6 grams on their pistons. This includes a lot of V8's, inline 6's and even two nissans engines and a toyota engine.(not sure with the exact engine the toyota was). So Honda already pretty much has this Accord engine prepped and ready for some heavy duty driving from the factory!!! Now here's something very very odd. The crankshaft that is in the engine when I took it apart is forged. I'm pretty sure it is from the factory like that since I don't see why anyone would just get a forged crank and leave everything else untouched. So this is what I Found truly amazing, a forged crank in an accord engine meant for daily driving. And it was only off by 5 grams. I have brought all the pistons and rods within half a gram and the crank to one gram. Also just picked up a 1987 crx Si and I believe that's where I'm going to end up dropping the engine soon. I'll update this a bit more next week with pictures and videos!

 

[webby]

I honestly don't know myself, but a mechanic from honda-tech said this in a thread a few yrs back -

"yeah, all honda cranks from the late 80's til now are all forged."

 

[Sinub]

I honestly don't know myself, but a mechanic from honda-tech said this in a thread a few yrs back -

"yeah, all honda cranks from the late 80's til now are all forged."

What?? That's insane!! Honda is really doing it right if that's true. I would see why anyone would buy an aftermarket crank besides changing the stroke if people knew this.

 

[Sinub]

so I dont know how to upload videos on my phone. anyways here's pictures until tomorrow. Just ball honing, balancing a piston and my crank next to a ka24 crank(240sx crank)

 

[Dar-Dar]

Very nice!

 

[XdemonicfleasX]

Subscribed

 

[Sinub]

All my measurements. the box with 4 cylinders is notes I took down when I wasdecking the block. 9.114" Is the specs for deck height believe, my block measured 9.1184"before and after it was 9.1147" with a fine finish. Next week I will start short block assembly and checking final clearances. Then a month break and then start working on the head.

 

[Sinub]

UPDATE: Starting working on the head, here is a bit of footage I've gathered here and their during the process. If anyone wants to know more in detail in what I'm doing or how a process is done I'll be more than happy to explain and try to make a video for it!

 

[Word3k]

Greatest build so far. Can't wait to see how this pans out.