New at engine rebuild L16

[Richie]

6 minutes ago, Crashtd420 said:

Are you sure? That would be some really deep scratches.... 

If the scratches are that deep you might be better off having a machine shop prebore the block to confirm how far they would have to bore it to clean up the cylinders.... what if they are deeper and the block is useless ...

It took me a minute to understand but yea I seriously don’t think the scratches are that deep. My finger nail barely catches. So getting a machine shop to bore our .75mm so these oversized pistons fit looks like the way to go. 

[Stoffregen Motorsports]

Don't you have a thread going about this already?

 

I gave you my thoughts about the scratches there.

 

New pistons can be purchased from any local machine shop. Buying through them will kill many birds with one stone. First, when you bring them to block to bore they can determine the size piston required for the job. Second, some shops will not use parts they don't supply. Third, some shops have preferred parts to use based on experience. Lastly, they will be thankful for the purchase and be happier to see you in the future. You'll build a relationship with the local guys.

[Stoffregen Motorsports]

41 minutes ago, Richie said:

It took me a minute to understand but yea I seriously don’t think the scratches are that deep. My finger nail barely catches. So getting a machine shop to bore our .75mm so these oversized pistons fit looks like the way to go. 

I always go max bore when buying pistons. Why not? It's not likely you will have to bore it again in the future, unless you burn it down. At that point you can either get another block or have it sleeved. I would go .040" over and call it done.

 

No replacement for displacement.

[Crashtd420]

44 minutes ago, Richie said:

It took me a minute to understand but yea I seriously don’t think the scratches are that deep. My finger nail barely catches. So getting a machine shop to bore our .75mm so these oversized pistons fit looks like the way to go. 

 

Also do you know if block has ever been bored did you check that it is still 83mm...

I definitely think you should listen to stroffgren.... let the machine shop tell you what size to go... make sure you bring them your rods also... those need to get setup properly too...

 

[datzenmike]

6 minutes ago, Stoffregen Motorsports said:

Don't you have a thread going about this already?

 

 

 

I've merged the earlier post to the beginning of this one as it's similar and has pictures. Richie... this was done to avoid a duplication of questions and answers on two similar topics by members not aware they might have already been answered elsewhere.. 

 

4 minutes ago, Stoffregen Motorsports said:

 

 

No replacement for displacement.

 

Thank you Carol.

[Richie]

44 minutes ago, datzenmike said:

 

I've merged the earlier post to the beginning of this one as it's similar and has pictures. Richie... this was done to avoid a duplication of questions and answers on two similar topics by members not aware they might have already been answered elsewhere.. 

 

 

Thank you Carol.

Yea I do. But I can’t access it anymore dude to invalid url. Sorry for the confusion 

[Richie]

58 minutes ago, Stoffregen Motorsports said:

Don't you have a thread going about this already?

 

I gave you my thoughts about the scratches there.

 

New pistons can be purchased from any local machine shop. Buying through them will kill many birds with one stone. First, when you bring them to block to bore they can determine the size piston required for the job. Second, some shops will not use parts they don't supply. Third, some shops have preferred parts to use based on experience. Lastly, they will be thankful for the purchase and be happier to see you in the future. You'll build a relationship with the local guys.

ok sounds good. I’ll do those steps and have them through the recommendations for me. Thank you guys for the help!

[Stoffregen Motorsports]

Where are you in CA? I can probably help point you to a reputable machine shop.

[Richie]

13 minutes ago, Stoffregen Motorsports said:

Where are you in CA? I can probably help point you to a reputable machine shop.

Long Beach 

[Richie]

https://imgur.com/a/bT3603X
 

here is the damage 

[Stoffregen Motorsports]

That looks like overheating damage.

 

I don't have experience with any machine shops in Long Beach, but I just googled "long beach engine machine shop: and came up with about 20 results. Some of them are pretty huge, like Keith Black. TG's looks promising for what you need.

[Richie]

3 minutes ago, Stoffregen Motorsports said:

That looks like overheating damage.

 

I don't have experience with any machine shops in Long Beach, but I just googled "long beach engine machine shop: and came up with about 20 results. Some of them are pretty huge, like Keith Black. TG's looks promising for what you need.

Yea I called like 5 shops here in LB but I didn’t see those ones. I’ll give them a call. So by looking at the picture how do you know that’s overheating damage? And would you get it bored? Also I think you’re correct about overheating because the coolant ports on the block and head were corroded and orange until I cleaned them. 

[Stoffregen Motorsports]

Overheating causes the piston and cylinder wall to squeeze together and the piston starts to fuse to the cylinder wall. The dark scratches are low enough in the bore to be the piston skirt, not the rings.

 

I could be wrong, but it looks like overheating to me.

 

The scratches could also be from a broken ring, but as I said, they look low in the bore.

[Richie]

1 hour ago, Stoffregen Motorsports said:

Overheating causes the piston and cylinder wall to squeeze together and the piston starts to fuse to the cylinder wall. The dark scratches are low enough in the bore to be the piston skirt, not the rings.

 

I could be wrong, but it looks like overheating to me.

 

The scratches could also be from a broken ring, but as I said, they look low in the bore.

Thanks. I’m just trying to learn. Ok so I’ll look at those machine shops you find and start removing the block. Thank you

[datzenmike]

 

It's also parallel to the piston pin or 90 to the crankshaft. The major thrust side is the opposite wall. This side only gets secondary thrust on the compression and exhaust stroke. Piston slap?

 

 

 

How the hell are these pistons so clean????

 

 

 

[Richie]

Hey guys happy New Year’s Eve. 

On 12/29/2020 at 12:20 PM, datzenmike said:

 

It's also parallel to the piston pin or 90 to the crankshaft. The major thrust side is the opposite wall. This side only gets secondary thrust on the compression and exhaust stroke. Piston slap?

 

 

 

How the hell are these pistons so clean????

 

 

 

I cleaned them with soap and water. So I finally got the block out of the car. Just saying they should really put in the manual remove the tie rod first haha. But any ideas on where to start taking the block apart so I can clean it and bore it? Any books or tools I am going to need? 

[Stoffregen Motorsports]

First engine rebuild? Defintely buy the https://www.amazon.com/Rebuild-Your-Nissan-Datsun-Engine/dp/1931128030  book.

 

Put the motor at TDC and take some pics before you commence. Pics of the distributor rotor, the distributor drive location (once you remove the dist), the position of the timing chain guides (once you get the front cover off). Just take a ton of pics.

 

Gotta remove the flywheel and front cover, oil pump, distributor drive, crank pulley, oil pan, etc.

 

Then stamp all the rod caps and main caps with numbers so they don't get mixed up.

 

I usually measure the crank thrust before I take the crank out.

 

Your first rebuild. Good luck.

 

 

[Richie]

So I got all that off it’s literally just the block and piston 1 was at TDC but it moved a little. I am going to put oversized pistons in like you guys recommend before, would the stock piston rods be ok with that? And bearings? And yea first build kinda nervous haha. 

[Stoffregen Motorsports]

If you want to bump the compression with new pistons, either get yourself a cheap burette and google how to do some engine math so you can figure out the new compression ratio, or have the machine shop figure it out for you and have them choose the piston. 10:1 CR is fine for a well tuned street engine. Well tuned meaning the distributor should be re-curved and the carb tune needs to be right.

 

Stock rods are fine.

 

The best bearings are "tri-metal". If you can only find aluminum bearings, ask your machine shop or call one of the Datsun parts guys like Troy Ermish or Rebello Racing for good bearings. Again, your machine shop should be able to guide you on the bearings. If they try to tell you that aluminum bearings are just fine, tell them you want tri-metal anyway. One other thing, the machine shop will probably tell you to have the crank ground. If it doesn't need it, DON"T DO IT! Standard cranks are always better than undersized. Just have them "mag and polish" the crank.

 

Do you plan on running this engine hard?

[Richie]

35 minutes ago, Stoffregen Motorsports said:

If you want to bump the compression with new pistons, either get yourself a cheap burette and google how to do some engine math so you can figure out the new compression ratio, or have the machine shop figure it out for you and have them choose the piston. 10:1 CR is fine for a well tuned street engine. Well tuned meaning the distributor should be re-curved and the carb tune needs to be right.

 

Stock rods are fine.

 

The best bearings are "tri-metal". If you can only find aluminum bearings, ask your machine shop or call one of the Datsun parts guys like Troy Ermish or Rebello Racing for good bearings. Again, your machine shop should be able to guide you on the bearings. If they try to tell you that aluminum bearings are just fine, tell them you want tri-metal anyway. One other thing, the machine shop will probably tell you to have the crank ground. If it doesn't need it, DON"T DO IT! Standard cranks are always better than undersized. Just have them "mag and polish" the crank.

 

Do you plan on running this engine hard?

Wow thank you. And no I don’t. I just want to run right with a weber just something to cruise in. 

[Richie]

making progress 

 

https://imgur.com/a/6kljhk6

[datzenmike]

 

L16's 210 head should be around 38.5cc.

[Richie]

Hey guys. So I am going to buy the new pistons and did a part number search on google to see if these are legit and Datsun pops up in every link. Do these seem legit because they look different from the ones that were originally in the engine. Thank you for the help I just want to make sure I’m not getting scammed, I never bought off of eBay. 
 

https://www.ebay.com/i/132423426828?chn=ps&norover=1&mkevt=1&mkrid=711-117182-37290-0&mkcid=2&itemid=132423426828&targetid=1068323860310&device=m&mktype=pla&googleloc=9031090&poi=&campaignid=11758056140&mkgroupid=112020220737&rlsatarget=pla-1068323860310&abcId=9300462&merchantid=101677530&gclid=Cj0KCQiAoab_BRCxARIsANMx4S6YZ-MgKPp-qxo4r1dNVhYu4oy48vtuuLtc0JdVu8CSnzPJzccd3akaAgjvEALw_wcB&watchItemId=132423426828&opid=2385738&pageci=ricad-8090

[datzenmike]

You sure 0.75mm will remove the scuffing on the wall? 

 

What rings are those? If over boring you can use chrome rings rather than cast iron.

 

If you are good with that, buy first and discuss this with the machinist. Send with block to the machine shop. The machinist should measure them and confirm their size and then bore the block to match them and get the proper 0.001 to 0.002" piston to wall clearance. There will be variation in actual size and even the machine shop won't bore absolutely perfect. Nissan factory pistons range from 82.985mm to 83.035mm. As you can see the smallest piston won't fit a perfect 83.0mm bore. This allows under size pistons to fit a bore that isn't exactly correct and this saves throwing them away.

 

Have the machine shop hone the bores for you also.

[Richie]

See I’m kinda stuck in the middle. If I buy the pistons without getting pre bored, what are the chances the scratches are deeper than .75. But the correct step is to have it pre bored to measure, the machine shops wants the new pistons. Let say the new pistons don’t fit then I’m out $200 from buying pistons 🙃