Si 2020 Si 0 miles block build thread

Shoebox_Civic

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Update:

I’m checking bearing clearance with a Mitutoyo digital micrometer and a set of Telescope Gauges, along with a final plastigage verification. My machinist just had a few major life events so he is unable to work on my block notching. I’ve been attempting to take as little material as possible using a Dremel. The problem arises in that the ductile iron sleeves are very different to the aluminum block so grinding stones have been taking a little bit. the Saenz rods are supposed to need the least notching of all H beam rods, but “minimal notching” is relative.

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nice build so far, just make sure to round out those notches so there aren't any sharp transitions - see Larry from Endyn's example for some excellent notches

Honda Civic 10th gen 2020 Si 0 miles block build thread Notching%20Block%203


sucks to see Honda only using a half-counterweight crank a la D15B7, and just plain main caps instead of a girdle or bedplate, but I suppose these L15s don't spin up that high.
 
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mrburgerUS

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It’s been a while since I posted last, but I have been working on the Trans and a few electrical problems with swapping. Since it’s a 2020, there is Honda Sensing, which the Si has as well. I made this handy spreadsheet comparing the 2018 Sport MT to 2018 Si ECU pins, and they match up besides the MAF ground! I am currently searching for a Head on ebay to attach to my block.
 

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It’s been a while since I posted last, but I have been working on the Trans and a few electrical problems with swapping. Since it’s a 2020, there is Honda Sensing, which the Si has as well. I made this handy spreadsheet comparing the 2018 Sport MT to 2018 Si ECU pins, and they match up besides the MAF ground! I am currently searching for a Head on ebay to attach to my block.
Nice job so far! In your OP you wrote you will be using a CR-V head for the project. If you dont mind me asking, what led you to choosing a CR-V head over an Si head? Also, have you decided on camshafts?
 


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I am going to start an engine build shortly, which I have never done before but I am doing a lot of research, so my questions will be newbie style. That short block with part number 10002-5AM-A02, does it come with oil pump, squirters and it looks like crank shaft? Also can you advise generally how much it costs to machine a new deck and add a CSS. What machining operations are required for a new block? Thanks!
 
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I am going to start an engine build shortly, which I have never done before but I am doing a lot of research, so my questions will be newbie style. That short block with part number 10002-5AM-A02, does it come with oil pump, squirters and it looks like crank shaft? Also can you advise generally how much it costs to machine a new deck and add a CSS. What machining operations are required for a new block? Thanks!
Hey!

I think that number is the 2017-2019 block assembly, I am not sure though. my assembly did come with all that. Honestly, I am not doing CSS but i think it’s about $500? I was going to have a friend assemble and balance my pistons and rods but he has a baby now, so I did it myself and I came to the conclusion the balancing wouldn’t be super critical for my purpose. What are your goals? If under 350 WHP i’ve heard CSS is excessive, and honestly it does have a non-negligible impact on the blocks ability to cool the piston sleeves. I’m sure it’s not enough to really cause issues, but I elected not to get CSS because my goal is 300 ish WHP. honestly, with a W2 Ball-Bearing and 7k redline (with 93 pump gas), I think I can make it there?
 

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Are you going to pull your engine and then swap over your stock cylinder head? Is there anything special we need to do for that, do you have head studs ordered? Are you sticking with stock motor mounts? I’m just really starting to get into planning. I’m also trying to figure out a list of parts that may need to be replaced during the swap. I understand some parts shouldn’t be used twice when rebuilding.
 
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This is amazing.
Thanks! Im realizing quickly the "easy" way to get Si power out of a Hatch is most likely a harness, ECU, and MAF swap: to use the features the Si ECU has over the Sport. Ive been reading the official wiring diagrams and comparing the basemaps provided by Hondata and Ktuner (I have both rn), and naturally the Hatch ECU is more economy focused. The Si uses a digital MAF sensor, while the FK7 uses an analog voltage reading. I am attempting to devise an adapter harness, since the Si is 4 wires instead of 5 - less is good. It looks like with a proper-year Si ECU, plus a new harness, the engine can be more freely tuned. Beware though, the extra compression could induce knock at higher boost.

What I would really like to see, even though the ECU are in fact programmed very differently, is feature parity or even a re-code to make the Sport act more like the Si ECU. It is a pipe dream, and since this is going into a fully-built "sleeper" FK7, I will be swapping for an Si ECU to raise redline to 7k with a built valve train.

Very off topic, this is an engine build! I am currently searching for a Si -OR- CRV head from an L15B7, with the taller fuel pump and intake cams. I am looking at one for $500 on ebay, but I would be buying sight unseen. The OEM one costs nearly $2000 at best online. For now, I am trying to decide what to do.
 


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Thanks! Im realizing quickly the "easy" way to get Si power out of a Hatch is most likely a harness, ECU, and MAF swap: to use the features the Si ECU has over the Sport. Ive been reading the official wiring diagrams and comparing the basemaps provided by Hondata and Ktuner (I have both rn), and naturally the Hatch ECU is more economy focused. The Si uses a digital MAF sensor, while the FK7 uses an analog voltage reading. I am attempting to devise an adapter harness, since the Si is 4 wires instead of 5 - less is good. It looks like with a proper-year Si ECU, plus a new harness, the engine can be more freely tuned. Beware though, the extra compression could induce knock at higher boost.

What I would really like to see, even though the ECU are in fact programmed very differently, is feature parity or even a re-code to make the Sport act more like the Si ECU. It is a pipe dream, and since this is going into a fully-built "sleeper" FK7, I will be swapping for an Si ECU to raise redline to 7k with a built valve train.

Very off topic, this is an engine build! I am currently searching for a Si -OR- CRV head from an L15B7, with the taller fuel pump and intake cams. I am looking at one for $500 on ebay, but I would be buying sight unseen. The OEM one costs nearly $2000 at best online. For now, I am trying to decide what to do.
This is interesting. A couple of things:

1. What made you go this route instead of finding a salvaged L15B7 and just doing rods and pistons? Apparently the CRVs that came with these can be quite easily found, albeit automatic versions. I think it just needs a different alternator bracket and a couple other bits to manual swap it though. Getting the head is what makes this so difficult.

2. Is the Si ECU really necessary? I've been talking to a local guy who has worked out how to swap the L15B7 into the hatch. He was telling me an ECU swap isn't necessary, but to basically work with Ktuner/Hondata to unlock the ability to flash an Si tune to the FK7 ECU. I would think this might carry over the increased redline and knock control logic.
 

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This is interesting. A couple of things:

1. What made you go this route instead of finding a salvaged L15B7 and just doing rods and pistons? Apparently the CRVs that came with these can be quite easily found, albeit automatic versions. I think it just needs a different alternator bracket and a couple other bits to manual swap it though. Getting the head is what makes this so difficult.

2. Is the Si ECU really necessary? I've been talking to a local guy who has worked out how to swap the L15B7 into the hatch. He was telling me an ECU swap isn't necessary, but to basically work with Ktuner/Hondata to unlock the ability to flash an Si tune to the FK7 ECU. I would think this might carry over the increased redline and knock control logic.
Agreed.. I'd think the SI's ECU would be looking for the non-existent, extra suspension dampening senors and stuff also..??
 

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what made you decide on the Saenz rods? Most people are doing the Saenz S over the BC. I am just wondering why. Is the difference on notching that big of a deal? The BC are less expensive. Thanks
 
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mrburgerUS

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Resurrecting this thread after a bit to annotate progress and my thoughts:

I think buying a used L15 out of an EX-T might be the best course of action right now. I would of course use Si Camshafts, and the bottom end I’ve built, but the engine head from an Si is nearly $2200! I would of course get the head resurfaced before transferring it, but even out of wrecked cars an L15 Si engine commands a high price, much higher than 2 camshafts and a whole regular L15 engine.
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