Gracie II the D21

[HRH]

So I've been doing some research and the question of spring under and spring over comes to mind. Spring over is cheaper by far, but also lends to more axle wrap problems. Spring under is much preferred to lessen axle wrap. However, coil gets rid of both of those issues. Now I'm back to considering other options. We shall see. I'll let you know when I start the build and decide which way it's actually going to go.

https://www.motortrend.com/how-to/154-0 ... ing-under/

https://www.motortrend.com/how-to/131-0 ... -or-under/

[HRH]

It's time to start putting the engine together! All the parts are finally ready! Minor porting on exhaust side, would have taken much more labor to make significant gains.





And it looks like I drug the donor engine home last year in January! Not bad, a year and 2 months to have everything together to actually build the engine!

[Taterhead]

Happy Birthday brother!

[HRH]

Thanks man! Also, since I've been updating instagram and Facebook regularly, I know it's been lacking here. Gonna dump a bunch of photos from the phone and finish it up on the laptop since it's much easier to type quickly on the laptop.

[HRH]

Alright, big picture dump! There have been quite a few developments since my last posting. Namely, I realized too late when I went to get an intake manifold gasket, I built a California head! Much bench racing ensued as I tried to figure out if I had screwed myself or not.

The good news is back in the early 90's, the dreaded "Cali" head often wasn't as bad as later that would choke flow. I surmised that the way the port looked, I can't imagine it flowing worse. My theory is the larger flat to the side of the injector divot would effectively make one side of the intake have a pressure drop, which in turn would work one side slow, one side fast, much the same as the staggered intake valve opening design of the Colt Cams regrind. As Geoff stated, if you open both intake valves on the KA at the same time, the flow is crap. But if you stagger the opening, it does a two-step and moves nicely. (General paraphrasing here)

Anyway, Andrew at Gibson Performance had a further idea after flowing the two varieties. He's thinking with the same cam it's effectively just making the engine more efficient, which would have helped emissions though not for the sake of flow. In all actuality, I'm tickled pink. I was severely worried the Cali head would flow worse. However, as you can see from the flow sheets down the page (and don't forget we're only going to mid .450 lift), the Cali head trounced the federal head. What's also interesting is the RB20DET has the exact same intake port shape as the KA.

The only number I don't have is an actual exhaust port original number for the Cali head since I ported that a bit before I sent it to Gibson for the final go through and all new valves, etc. Notice the Int/Exh are switched on the first sheet. Compare against the second sheet though. That's the chopped off head (3 and 1 cylinder) that I cut up to see how much porting I could do before I hit water jacket.

For the federal head, the untouched exhaust valve at .100 lift is only 19 cfm!! It's 48 on the Cali head I prepped! And if you go through the other points, it's just way the heck better everywhere. Who would've thought? The only downside is I have to use the fatbody side feed injectors which aren't as nice as top feed. Still, they've been working fine as that's the style I have in the current KA24DE that's in the truck. I have a '95 intake manifold that should work fine for the task.

Also of interest is after 95, all the heads are Cali heads. 96-97 are there own separate year, but mainly only due to peripherals related to the intake manifold. Using the 95 intake, all the 93 stuff fits on it, though it has the correct port shape for the Cali head.

While the cut apart head was being flow-benched for research, I also had them powder coat the valve cover wrinkle black. It came out super nice! Anyway, not doing much this weekend but in the next few I'm planning on getting the engine put the rest of the way together. Still need to rework the welds on the head since I haven't done that, but I'm looking forward to finally getting this thing in the truck. It should be a pretty damn nice engine when I'm done!

[HRH]

A lot of progress has been made on the KA24E. It's ALMOST together and ready for install. Still a few things left to do. I'm hoping I can actually get the engine removed this weekend, but it's still touch and go. Figured out .030" off the head results in .85 degrees retarded for the cam, so I put it a degree advanced. Should be right on. Can't wait to hear it go and get it broken in. Got some Amsoil break in oil all ready!

I also need to update Martin at Martin industries and Geoff at Colt Cams after I get it all run in and do a dyno day to get some numbers.

[HRH]

Since I haven't been updating here much, here's a photo dump for you all! I highly recommend checking out my instagram account. Wow, I sound like a porn bot, lol. I decided I wasn't going to pay to have someone rebuild my trans. It's time I learned. So far it's not quite terrible, though the counter shaft gear was an absolute bitch to get off.

Datsun_matt_adventures

[Taterhead]

Making shit happen. Looks like you got it figured out.

[HRH]

Here's the video. Found the smoking gun. Loose mainshaft nut.

https://www.instagram.com/reel/CsAZ0JNA ... BiNWFlZA==

[HRH]

Well there's been a ton of updates since the last posting. It's all on instagram/facebook though. Short of it is there's been a lot of learning. However, the shafts are separated and I think I have most everything figured now. The only downside is I have a 1 piece 2nd synchro that I don't have. But it was so stinking hot today that I gave up. Should be able to get a different bearing kit with the correct synchros tomorrow and I'm taking Thursday off work as it's supposed to be a lot cooler. Hopefully I'll have the transmission back together then with a shitload of new parts.

[HRH]

Latest updates: Solid lifter conversion with Tri-flow II camshaft from Colt Cams is in. I need to advance the cam a bit as it's still a little too long legged. Header is now on, that helped a ton on top end. Going to readjust valves now that I have 100 mile in since putting them on. Also had a chain tensioner guide issue that was shaped wrong and ate into the last 3 inches. Found out the chain tensioner guide from ITM was ramped completely wrong and the bottom securing bolt wasn't flush with the block face. Ate the last 3 inches and at a pretty good angle. No metal went through anything important. Pulled a bearing cap to make sure and resintalled new chain, tensioner, and shoe. Took out the ratcheting tensioner as I thought it was the issue. Annoying. If I ever have it apart, I can probably put it back in again, but oh well. Chain isn't rattling and it works, so good enough!