Hot LZ23

[john510]

1 hour ago, Bastard_510 said:

read, trained, and certified...where is your fancy paper? stoffregen see this is why i dont give out my piston info here. someone will throw them in and listen to mike because hes alllllways right and bow up their engine. 🙄 mike you want the book so you can be an "expert" ? ill even pay for it 🤣

johnny boy while i appreciate your try to insult me i would appreciate it even more if you could comment about either the build or a topic brought up instead of shit comments that gets no one nowhere. good advice hahaha i gave out good advice and i get a "Whatever man" or corrected with the wrong info by mike.

Fancy paper ? never mind.

[Bastard_510]

1 hour ago, john510 said:

Fancy paper ? never mind.

shit comment johnny boy. dont come here saying stupid shit and say nevermind like a fucking fool. 

 

[bananahamuck]

[datzenmike]

On 7/3/2019 at 5:51 PM, Bastard_510 said:

i do share (you now have a pattern available at a gasket shop for any bore...you’re welcome) here and there but its usually when i find some info thats wrong thats worth bringing up.  like how i just read that effective compression ratio is only at low engine speeds. you know who you are ill send you that text book if you want 🙂 guess mine will be 13:1 at 6,500 🙄the intake stroke at 5,000 rpm only lasts about 5ms (.005 of a second) peak VE does not happen at peake HP it happens at peak torque. 100 VE is only NA by tuned engines...tuned intake and exhaust...so full out race engine and a lot of money.

 

The intake is open for about 248 degrees on a stock L20B. That's about 68.8% of one revolution. There are 41.66 intake strokes at 5,000 RPMs so about 0.025 0.024 of a second per revolution but as the intake is only open about 68% of that it would be closer to 0.017  0.016 seconds or over 3  times what you say. Only goes higher on a cam with more duration. An L20B intake open for only .005 second would have to be revving 16,000 + RPMs... give or take.

 

As your VE % increases from it's low point at starting or idle so will your compression ratio. How could it not? I did not say it maxed out with HP only at higher RPMs. To increase the VE% typically a cam with more duration and lift is used and the RPM range increased. Peak torque and HP will now be at a much higher RPM range. 100% VE is possible with proper equipment and tuning but I doubt it's possible at 3,000 RPMs, the air is just not moving fast enough and valves closed too long.

                             

[scooter]

Back to what matters....

 

does it fucking haul ass yet?

[Bastard_510]

this is where we will leave it mike

 

On 7/4/2019 at 5:21 PM, datzenmike said:

 

The intake is open for about 248 degrees on a stock L20B. That's about 68.8% of one revolution. There are 41.66 intake strokes at 5,000 RPMs so about 0.025 of a second per revolution but as the intake is only open about 68% of that it would be closer to 0.017 seconds or between 3 and 4 times what you say. Only goes higher on a cam with more duration.                             

 

ok so 5,000rpm right? thats 10,000 strokes per min now divide that by 60 and youll get 166.66666 strokes per second. now divide 1 second by 166.66666 and you will get .006 seconds per stroke correct me if im wrong but thats only .001 off. an l20 with a 248 dur cam has a 2.8" effective stroke

 

 

13 hours ago, scooter said:

Back to what matters....

 

does it fucking haul ass yet?

 

yes lets get back to it....no im actually very pissed off. remember when i said the quality of work sucks here? well i line honed the block, got it all nice and clean, oiled so it wont rust. i go to put the crank in and it stops 1/8 above the bearings. wtf so its the thrust bearing i took it out and the crank sat down just fine and spun. so i took the set of lead bearings they send with the crank and they fit a little better...it sat down on the bearings but even with the nuts hand tight the crank would not turn by hand. the shop must have not bumped the sides enough for the thrust bearing. so my crank was bent , ground to the bottom of spec (i wanted it at the top), and no bearing will fit it. 🤬

Edited July 6, 2019 by Bastard_510

[datzenmike]

8 hours ago, Bastard_510 said:

this is where we will leave it mike

 

 

ok so 5,000rpm right? thats 10,000 strokes per min now divide that by 60 and youll get 166.66666 strokes per second. now divide 1 second by 166.66666 and you will get .006 seconds per stroke correct me if im wrong but thats only .001 off. an l20 with a 248 dur cam has a 2.8" effective stroke

 

 

 

 

 

Can't leave now, just when I'm learning something from the master.

 

5,000 RPMs Has 2500 intake and compressions and 2500 expansion and exhaust strokes. 2500/60 =  41.666 intake compressions per second or very close to.024 second per revolution of which 68.8% (248 out of 360) of that revolution the intake valve is open. 0.024 X .688 = 0.016 sec the valve is open.

[Bastard_510]

24 minutes ago, datzenmike said:

 

Can't leave now, just when I'm learning something from the master.

 

5,000 RPMs Has 2500 intake and compressions and 2500 expansion and exhaust strokes. 2500/60 =  41.666 intake compressions per second or very close to.024 second per revolution of which 68.8% (248 out of 360) of that revolution the intake valve is open. 0.024 X .688 = 0.016 sec the valve is open.

 

Ok we can continue 

 

i know why you think it’s right but you can’t divide 1 second by something that is only happening ¼ of the time. So if you wanted to use 2500 you would divide by a ¼ of 60 because the total strokes that happen in a minute is 4 times 2500. So 2500/15(a quarter of 60 to match the quarter amount of strokes) give you 166.666 now you can divide 1/166.666= .006

[datzenmike]

 

248 is slightly over 1/4 the time, about .344. Got it to work out to a hair over 0.008.

[Bastard_510]

1 hour ago, datzenmike said:

 

248 is slightly over 1/4 the time, about .344. Got it to work out to a hair over 0.008.

No no no not a ¼ of the duration we already figured that it’s really using 2.8” of stroke. It’s ¼ of 60. You’re using 2500 as your base. At 5,000rpm there are 10,000 strokes (one up and one down making 1 revolution)you miscalculated it as 2500 for intake compression and 2500 for power and exhaust when it is 2500  intake strokes, 2500compression, 2500exhaust and 2500 exhaust strokes. That adds up to 10,000 strokes and adds up to .006 for actual stroke time. 

 

 

[datzenmike]

Yeah one stroke is 180 degrees. Roughly intake 180, compression 180,  power 180 and exhaust 180 for two complete revolutions. In reality the valve timing is much different. The intake is open for 248 or well above just the 180 degree down stroke from TDC to BDC

[Stoffregen Motorsports]

11 hours ago, Bastard_510 said:

 well i line honed the block, got it all nice and clean, oiled so it wont rust. i go to put the crank in and it stops 1/8 above the bearings. wtf so its the thrust bearing i took it out and the crank sat down just fine and spun. so i took the set of lead bearings they send with the crank and they fit a little better...it sat down on the bearings but even with the nuts hand tight the crank would not turn by hand. the shop must have not bumped the sides enough for the thrust bearing. so my crank was bent , ground to the bottom of spec (i wanted it at the top), and no bearing will fit it. 🤬

You may need to sand the thrust bearing. Hit them on a belt sander until you have about .006" thrust end play. Be sure to sand down only the front side of the thrust bearing, not the back.

 

This is just part of the mock up process.

[Bastard_510]

8 minutes ago, Stoffregen Motorsports said:

You may need to sand the thrust bearing. Hit them on a belt sander until you have about .006" thrust end play. Be sure to sand down only the front side of the thrust bearing, not the back.

 

This is just part of the mock up process.

See i would’nt have a problem with that if it wasn’t for the fact it won’t sit down without some pressure. Also it really shouldn’t have to be done. I’ve had 5 cranks ground by this shop and it’s been getting worse and worse over the past 5 years. My l20 was ground and it fits any bearing with the right end play out of the box. Same shop 5 years apart. 

[Bastard_510]

new problem. did the z20 have 2 different rod bearing options? i went top put my bearings in and the tang is a lot larger then the rods slot . 

 

 

 

Edited July 6, 2019 by Bastard_510

[datzenmike]

 All L13/14/16/18/ L20B/ Z20/22/24 engines should have the same bearing for the rods. 12111-73400

 

Probably wrong ones.

 

[Bastard_510]

29 minutes ago, datzenmike said:

 All L13/14/16/18/ L20B/ Z20/22/24 engines should have the same bearing for the rods. 12111-73400

 

Probably wrong ones.

 

no these are the same ones listed but its a fat tab that extends to the end and the rods are smaller and dont touch the edge. what engine was in the 85 200sx? thats the only diffrent bearing number i can find for a 2 liter from the 80's and it looks right

 

[datzenmike]

The '84-'88 S12 200sx had the CA18ET and CA20E engine family, totally different. From '86.5 on there was an optional VG30E engine.

'89 on was the S13 with KA engines....

 

The '80-'81 A10 and the '83-'86.5 720 had the Z20S (carb) and the '80-'81 S110 200sx had the Z20E (EFI)

 

 

 

Either the rods are wrong or bearings wrong.

[Bastard_510]

4 minutes ago, datzenmike said:

The '84-'88 S12 200sx had the CA18ET and CA20E engine family, totally different. From '86.5 on there was an optional VG30E engine.

'89 on was the S13 with KA engines....

 

The '80-'81 A10 and the '83-'86.5 720 had the Z20S (carb) and the '80-'81 S110 200sx had the Z20E (EFI)

 

 

 

Either the rods are wrong or bearings wrong.

i just checked. the bearing is absolutely the right one for a z20. the rod area where the bearing sits is maybe 1/8" thiner so they must have their own bearing number for it. the rods are right z20 152.45 6.002" rods

[docbainey]

Bastard, shame on you for not knowing your crank was bent to begin with. You should have basic EQ at your disposal to figure that out before sending it out for rework. You're putting trust in somebody to follow verbal instructions? The very least, the job should have some basic engineering drawings to eliminate tolerance stacking and such and in you case, thrust bearing clearance. In your instance, the drawing would have shown the nominal dimension with tolerance and some perpendicularity sht for the thrust flat relative to the journal. If it's bent, your connecting rod side clearance is jacked also, since they couldn't figure out the thrust bearing dimension, and, nothing good typically happens when increasing rod side clearance on Datsun motors. Stoff could probably add to that.

[Bastard_510]

34 minutes ago, docbainey said:

Bastard, shame on you for not knowing your crank was bent to begin with. You should have basic EQ at your disposal to figure that out before sending it out for rework. You're putting trust in somebody to follow verbal instructions? The very least, the job should have some basic engineering drawings to eliminate tolerance stacking and such and in you case, thrust bearing clearance. In your instance, the drawing would have shown the nominal dimension with tolerance and some perpendicularity sht for the thrust flat relative to the journal. If it's bent, your connecting rod side clearance is jacked also, since they couldn't figure out the thrust bearing dimension, and, nothing good typically happens when increasing rod side clearance on Datsun motors. Stoff could probably add to that.

 

Listen, this has been the same conversation the same write up every single time. “Leave Mains at top of spec (given spec) rod journals middle (given tolerance)”. I took the crank out and it was bent. I put it on a v block and made it straight then took it to the shop. When i got it back it was bent and under what i wanted. It was bent after grinding and i know that because if it was bent when they started it would be straight after. Some one slammed it or dropped it. I had to take 3lb hammer to it to get it straight again. It was bent it’s straight as an arrow now. 

[scooter]

7 hours ago, Stoffregen Motorsports said:

You may need to sand the thrust bearing. Hit them on a belt sander until you have about .006" thrust end play. Be sure to sand down only the front side of the thrust bearing, not the back.

 

This is just part of the mock up process.

Did you get an undersized thrust? Ive caused this issue mostly on 302’s after a line hone due to the shitty flat sides on their caps. On dattos though the caps machined pretty nice so its hard to not fuck up grinding the thrust cap. 

 

Or is this issue with just the block side? In that case thats really strange. All i can really say there is make sure you have the right bearings.

 

3 hours ago, Bastard_510 said:

new problem. did the z20 have 2 different rod bearing options? i went top put my bearings in and the tang is a lot larger then the rods slot . 

 

 

 

 

I agree with the other posters someone probibly gave u ca20 bearings

 

i also have a hard time believing your crank is bent unless youve run it in v-blocks. Nissan makes awesome crankshafts!

 

as for size wise my line hone is on the high side of spec and my crank is a few tenths under the min and i still ended up with 2.2-2.5 thou for main clearance. This is ok!

im still running standard size bearings lol

[scooter]

22 minutes ago, Bastard_510 said:

 

Listen, this has been the same conversation the same write up every single time. “Leave Mains at top of spec (given spec) rod journals middle (given tolerance)”. I took the crank out and it was bent. I put it on a v block and made it straight then took it to the shop. When i got it back it was bent and under what i wanted. It was bent after grinding and i know that because if it was bent when they started it would be straight after. Some one slammed it or dropped it. I had to take 3lb hammer to it to get it straight again. It was bent it’s straight as an arrow now. 

 

Shitty that it got dropped 😞

 

What is your crank ground to now?

Edited July 7, 2019 by scooter

[scooter]

Was the crank you used go through a blow up? Cause i have a couple used z22 cranks and they both are zero runout

 

if its just a rod tang issue then maybe file the tangs out? Thats also weird my pauter rods were fine.

 

sounds like your getting all the curveballs thrown at cha just keep on truckin and drown out the flaming with sidedraft noise

Edited July 7, 2019 by scooter

[scooter]

This time around im even using aluminum rod bearings and not tri metals which makes me cringe but ill post pics if/when something goes wrong.

[Bastard_510]

41 minutes ago, scooter said:

 

Shitty that it got dropped 😞

 

What is your crank ground to now?

2.3500 one is 2.3494. The crank probably went through some shit before i got it. It’s not hard to bend them .0005” which this one was. 

 

The bearing numbers match mahle’s catalog for a z20. The rods are thinner and the tang is deeper. I sent them a email so we will see. 

 

I run aluminum in everything. My l had 0 oil pressure at idle for months and when i went in to fix it the bearings were hardly touched.