Hot LZ23

[datzenmike]

 

Fully counter weighted is always better. With a weight only on one side of the piston and rod the crank vibrates from an induced wobble. Both can be perfectly balanced, that's not a problem. It's when the cylinder fires and pushes down.

[Bastard_510]

you are mistaken. when balancing a crank for a 4 or inline 6 the crank is spun up alone. 4 cylinders do have secondary vibration that can only be fixed by balance shafts or a harmonic balancer. 

[datzenmike]

Whatever man. Already said they can be balanced perfectly alone. The vibration is from having a counter weight only on one side when the cylinder fires not from the actual balance. Still would rather have fully counter weighted crank. Balance shafts are more effective on longer stroke 4 cylinder engines. No Datsun engine uses a balance shaft because... not needed. The larger Z24 and maybe the Z22 do have a harmonic balancer. 

 

The L20B is very smooth revving past it's 7K red line. Smaller stroke L16/18 rev much higher without problems. Longer stroke Z 22/24 have a lower red line so vibration isn't much of an issue.

[Bastard_510]

14 hours ago, datzenmike said:

Whatever man. 

 

Chill out. do you like baseball?

 

14 hours ago, datzenmike said:

Already said they can be balanced perfectly alone. The vibration is from having a counter weight only on one side when the cylinder fires not from the actual balance. Still would rather have fully counter weighted crank. Balance shafts are more effective on longer stroke 4 cylinder engines.

 

swing...strike one. the placement of the weights does not matter. left, right, or both. i can see why you would think that but there is a lot more to it. 

 

15 hours ago, datzenmike said:

The vibration is from having a counter weight only on one side when the cylinder fires not from the actual balance.

swing and a miss. strike two. the vibration is from the acceleration of the pistons going to and leaving TDC compared to  the pistons at BDC. that force is called secondary forces. the top pistons are moving faster than the bottom ones to make it easy. if the second counterweight was there for the firing event then the engine would be out of balance for the other 3 strokes.

 

15 hours ago, datzenmike said:

Still would rather have fully counter weighted crank. No Datsun engine uses a balance shaft because... not needed. The larger Z24 and maybe the Z22 do have a harmonic balancer. 

 

 

ball....no one cares about your butt dyno. datsun didn't use a balancing shaft because balancing shafts started coming out in the late 70's to late 80's cars. so how would they use something that was just coming out in an engine that was set to be in production in 79???? it takes time to engineer engines. also balancing shafts have to rotate in opposite directions to cancel out side-to-side forces a single shaft or "fully counterweighted crank" could create.

 

15 hours ago, datzenmike said:

The L20B is very smooth revving past it's 7K red line. Smaller stroke L16/18 rev much higher without problems. Longer stroke Z 22/24 have a lower red line so vibration isn't much of an issue.

again...butt dyno. have you taken a physics class? they are very interesting especially when paired with a mechanisms class. anyways one of the other ways to reduce this secondary force is to reduce the reciprocating weight. so even with the redline being 7,000  on a z22 (l18 is 7800 at around 4000ft/min piston speed)the vibrations from the weight of the longer rods would play with the secondary force. the rods from a l18 are 22mm shorter than z20 rods and 35mm shorter than the ka. don't get me started on the larger pistons. that is a lot of weight. force= mass x acceleration. so ya the secondary force is still a major part of the lower redline ka, z series or l series. all of them have reciprocating weight....and the lower rpm engines have even more. sorry bud..strike three....you’re out.

 

 

Here are a few passages from the AERA text book on balancing inline 4 cylinders 

 

 

[Bastard_510]

here are some photos.

 

[datzenmike]

   Balance shafts have zero to do with Datsun engines, you brought them up. Somehow they struggled by. All Datsun engine parts are balanced before assembly including the flywheel and font pulley and run very well as they are. Counter weight placement is very important and splitting the weight to both sides on the rod is smoother than only one side, like a tire weight on a rim. Fully counter weighted is better but are expensive and in most cases a single is good enough. Your secondary vibration is more a problem as the stroke increases. It may be there in shorter stroke Datsun engines but so what? You're splitting hairs and making an issue of a non issue.

 

I never used the term 'butt dyno' and was expressing an opinion. By definition an opinion is NEVER wrong.

I have no opinion on baseball one way or the other. I'm ambivalent. I never watch or play it so perhaps there must be some bias towards it.

The redline on a Z22 is 6,500 not 7,000 RPMs to remain below the 4,000 FPM piston speed. Red line limits are not dictated by your 'secondary vibration' but a theoretical strength of the materials used and the acceleration g forces imposed on them. Engine stroke limits the engine red line. 

[john510]

Sounds like this guy has it figured out and just wants to argue with the good advice he's been getting.

[Bastard_510]

Mike i brought up balancing shafts to say that is the only way to cancel the vibrations you’re talking about. I’m can see my 4 engines don’t have a balancing shaft so you can stop repeating that. 

 

 

Yes all parts are balanced from the factory we got that 

 

“fully counterweights is better” can you tell me why? Your theory of engine operation is a little off and i have showed evidence of that. Maybe if you said “the weight is more evenly spaced across the crank giving it more inertia and keeping it running true like a heavy top” that would be on the track to being right. 

But you’re stating that the extra weight is to offset a firing piston...ok again if that were true you turned your vertical force to a horizontal force and created an balancing problem because 4 cylinder cranks are spun up alone. If that weight was used for what you are arguing, the crank would jump out of the v blocks when i balance them. Just accept that you are wrong or please don’t comment on the thread. 

Im a certified engine builder. I went to college for this. I have contacted the author of the text book to hear his opinion. I’ll post his reply when i get one. I started this just to keep my build logged somewhere and ask for seats so i didn’t have to cut my head for larger ones. 

 

John it started off as a correction. I was not looking to argue and i have seen mike give out great info but “half balanced cranks” and giving out engine ideas that leave the piston .060 below the deck are not one. 

[datzenmike]

 

 

You brought up secondary vibration and balance shafts, not me. I said fully counter weighted cranks were smoother running than not. Somehow Nissan struggled by.

 

Not 'extra weight' the weight split to both sides of the rod. 

 

 The extra counter weight positions don't seem to bother the L20B and Z20 cranks.

 

 

... and still mistaken about the Z22 red line.

[Bastard_510]

1 hour ago, datzenmike said:

 

 

You brought up secondary vibration and balance shafts, not me. I said fully counter weighted cranks were smoother running than not. Somehow Nissan struggled by.

 

Not 'extra weight' the weight split to both sides of the rod. 

 

 The extra counter weight positions don't seem to bother the L20B and Z20 cranks.

 

 

... and still mistaken about the Z22 red line.

i brought up that i kept seeing you and others say "half balanced balanced crankshafts". yup i forgot to correct myself 6,700 is just at 4,000fpm. the readline is still only 1k apart from the 18 but you have pistons 3-5mm bigger, rods that are 20-35mm longer and that all adds up to reciprocating weight. read the text again it says to help lower secondary forces reduce reciprocating weight. you have stated that the larger stroke engines with the larger rods and pistons had less vibration because of a 1k lower rpm readline...WRONG.

 

On 5/27/2019 at 8:31 PM, datzenmike said:

 

 

With a weight only on one side of the piston and rod the crank vibrates from an induced wobble. Both can be perfectly balanced, that's not a problem. It's when the cylinder fires and pushes down.

 

On 5/28/2019 at 5:53 AM, datzenmike said:

The vibration is from having a counter weight only on one side when the cylinder fires not from the actual balance.

both of those statements are dead WRONG. there is no argument you are wrong. the extra counterweight as in the 2nd mass is part of the CRANK balancing for the l20b and only to offset the pin. it doesn't matter the location left, right or on both sides of the rod. read a book. spreading out the  weight is like having a heavy gyroscope it wants to stay where it is and is more stable. 

 

[Stoffregen Motorsports]

11 hours ago, Bastard_510 said:

 

Chill out. do you like baseball?

 

swing...strike one. the placement of the weights does not matter. left, right, or both. i can see why you would think that but there is a lot more to it. 

 

swing and a miss. strike two. the vibration is from the acceleration of the pistons going to and leaving TDC compared to  the pistons at BDC. that force is called secondary forces. the top pistons are moving faster than the bottom ones to make it easy. if the second counterweight was there for the firing event then the engine would be out of balance for the other 3 strokes.

 

ball....no one cares about your butt dyno. datsun didn't use a balancing shaft because balancing shafts started coming out in the late 70's to late 80's cars. so how would they use something that was just coming out in an engine that was set to be in production in 79???? it takes time to engineer engines. also balancing shafts have to rotate in opposite directions to cancel out side-to-side forces a single shaft or "fully counterweighted crank" could create.

 

again...butt dyno. have you taken a physics class? they are very interesting especially when paired with a mechanisms class. anyways one of the other ways to reduce this secondary force is to reduce the reciprocating weight. so even with the redline being 7,000  on a z22 (l18 is 7800 at around 4000ft/min piston speed)the vibrations from the weight of the longer rods would play with the secondary force. the rods from a l18 are 22mm shorter than z20 rods and 35mm shorter than the ka. don't get me started on the larger pistons. that is a lot of weight. force= mass x acceleration. so ya the secondary force is still a major part of the lower redline ka, z series or l series. all of them have reciprocating weight....and the lower rpm engines have even more. sorry bud..strike three....you’re out.

 

 

Here are a few passages from the AERA text book on balancing inline 4 cylinders 

 

 

 

Hey Bastard, Mike's not wrong. You aren't wrong either but science isn't going to explain everything.

 

Questions - How long have you been in the Datsun game? Have you ever driven a Datsun with this engine combo? Have you ever built one of these long stroke L4s?

 

Facts - They do vibrate and a counterweighted crank does in fact help with those vibrations. Whether it is enough to warrant welding on custom counterweights, now that's debatable.

 

As far as that crack in the block, I wish I would have know about that earlier. I have repaired those a few times during my years building engines for Rebello Racing, and there is a simpler method. Your approach is good too.

[docbainey]

Stoff, Too funny, I forgot the dudes screen name is bastard_510!!!!!!!

 

 

[Bastard_510]

He’s wrong on the theory and where the source of the vibration comes from and what is actually helping reduce. As a dude who is constantly telling others what to do he should at least have the right information. I understand what he’s talking about and what he feels and i have explained why it’s smoother.  in the response from the author and someone he asked i am correct when saying the weight being spread evenly across the crank is a “stabilizer” as it’s acting like a gyroscope and making it “smoother”. The more mass the crank has the better gyroscope it is. That hides the vibration a little but they are still there. And yes I’ve driven/ been in 4 cylinders with a large stroke long rods. I understand the feeling. 

 

Science is the explanation of everything. 

 

About 10 years I’ve built mostly L series, normal Lz22s a lz20 and a few ka’s.

 

the crack in the black was repaired before i started this thread. I didn’t get the picture of the lock-n-stitch pin posted but i like the product. I actually saw the crack close up before the head snapped off. On the other side of the crack i had a problem. The drill bit kicked out the side and there wasn’t enough to tap. I was planning on scraping the block but i gave spray welding a shot. It didn’t stick well because i was trying not to heat the deck too much. I ended up drilling and taping a 9/16th bolt into the coolant hole. I cut it off and drilled a hole through the bolt. Then after all of that i was able to fit a pin on the edge of the bolt where there wasn’t enough threads to begin with. I’ll post a picture later. 

[Stoffregen Motorsports]

So having built L motors before, you do understand then. Cool.

 

Arguing the point is not going to change the fact that a counterweighted crank does help reduce engine harmonics. Science is a bitch because it doesn't always translate to real world application. That was my point in asking the questions I asked. I meant no disrespect and wasn't trying to pull rank.

 

 

[john510]

2 hours ago, Bastard_510 said:

He’s wrong on the theory and where the source of the vibration comes from and what is actually helping reduce. As a dude who is constantly telling others what to do he should at least have the right information. I understand what he’s talking about and what he feels and i have explained why it’s smoother.  in the response from the author and someone he asked i am correct when saying the weight being spread evenly across the crank is a “stabilizer” as it’s acting like a gyroscope and making it “smoother”. The more mass the crank has the better gyroscope it is. That hides the vibration a little but they are still there. And yes I’ve driven/ been in 4 cylinders with a large stroke long rods. I understand the feeling. 

 

Science is the explanation of everything. 

 

About 10 years I’ve built mostly L series, normal Lz22s a lz20 and a few ka’s.

 

the crack in the black was repaired before i started this thread. I didn’t get the picture of the lock-n-stitch pin posted but i like the product. I actually saw the crack close up before the head snapped off. On the other side of the crack i had a problem. The drill bit kicked out the side and there wasn’t enough to tap. I was planning on scraping the block but i gave spray welding a shot. It didn’t stick well because i was trying not to heat the deck too much. I ended up drilling and taping a 9/16th bolt into the coolant hole. I cut it off and drilled a hole through the bolt. Then after all of that i was able to fit a pin on the edge of the bolt where there wasn’t enough threads to begin with. I’ll post a picture later. 

Why are you even here asking for advice ? you seem to know it all already.And that counterweight argument you're making ? my L-16 didn't run or rev nearly as smooth as my L-20b with a fully counterweighted crank.I doubt Nissan put that extra steel on there because they had some to waste.

[Bastard_510]

35 minutes ago, john510 said:

Why are you even here asking for advice ? you seem to know it all already.And that counterweight argument you're making ? I doubt Nissan put that extra steel on there because they had some to waste.

again i originally wanted to find out if anyone new the factory size of a seat, to confirm a build and stoff was kind enough to say there was a 6 in rod. it was easy to find h beam z20 rods. also i wanted to have my build posted somewhere. other than that i havent asked for advice.i dont think.... anyways i dont like the reputation forums get for having the wrong information. i am educated in the field and wanted to correct it. its on every post where lz22 comes up along with ka pistons. Conversation over

 

 

the staking was to keep the bolt locked in place after drilling for the pin. i tried a crack pin paste but after a week of waiting for it to dry i staked it. since the threads where wallered out i staked the threads on the bolt before i installed it.

 

 

 

[Stoffregen Motorsports]

Are Z22 blocks getting that hard to find?

[Stoffregen Motorsports]

BTW - if you're going to use a header on that motor, you will need to cut that boss off the block, the one that Z22 is stamped on. Careful not to cut too deep, or you'll go into water. Ask me how I know...😒

[Bastard_510]

9 hours ago, Stoffregen Motorsports said:

Are Z22 blocks getting that hard to find?

 I had a listing on a few sites $250 to anyone that brought me a z22 block. No one had one near me. 

 

The old headers i have cleared when i mocked it up on the stand. But thank you. 

[wayno]

I put a L head on a Z22 block and used a header on my work truck, I cut/ground the header flange instead of the block.

[hang_510]

13 hours ago, Stoffregen Motorsports said:

Are Z22 blocks getting that hard to find?

good blocks are very hard to find.

 

I went with a Z22 after 3 unusable l20b 

It still had 1 small crack.

 

[scooter]

How much meat did you have left at the diagonal steam hole at 90mm? Did you offset bore it? 

 

I approve this rotating assembly, you will be just fine. If you run a stock flywheel, balance it. Out of all my parts i balanced the flywheel was by far the worst.

 

as for the crank, its not even a balance thing really, its a harmonics thing as well as a bending moment being put on the crankshaft from only having a counterweight on one side of the crank. This has not proven a problem with z22 cranks though. Not a bad idea to run the z22 front pulley or go aftermarket. 

 

If you have access to a flow bench, spend as much time as you can on it with that head. Take the wall side of the chamber beside the valve out to the gasket as discussed before.

[Bastard_510]

12 hours ago, scooter said:

How much meat did you have left at the diagonal steam hole at 90mm? Did you offset bore it? 

 

 

That photo is old. On the bottom minor thrust side on cylinder 2 is the thinnest. I didn’t believe it so i checked again and my tester was off  So it’s really .120” thick after boring in the thinnest spot. 

 

 

I don’t have a flow brench table that has a 90mm bore (500 to have one made and I’m not going to use it much) so the test would not show real numbers. 

[Stoffregen Motorsports]

When boring a Z22 block, one trick I learned is to have the machine shop spread the bores to avoid the steam holes. Add extra spacing between #1 and #2, then between #3 and #4. 

 

Z20 blocks don't have this problem.

[Bastard_510]

I’m going to turn my flywheel down to 13 lbs. i have a set of arp flywheel and pressure plate bolts but i haven’t picked a clutch yet. I have a Fs5c63a#2 trans I’m planing on using. That should hold the power right? Anyone know what this engine should make?