Cylinder wall scoring... Time to use spare motor?

[toshts]

Trucks running like garbage right now after swapping on the stock thickness w58 on my z22 block. Can't get it to idle under 1000 on all cylinders and it doesn't hit on all cylinders until it's warmed up. Lots of white smoke out the exhaust, thinking it's leaking coolant in the intake. Think the head gaskets holding fine and valves are good, it's got 180psi on all cylinders. Thought it was the issue with the distributor cap but doesn't seem like it. In the process of trying to figure out what's going on I stuck a boroscope down the cylinders and found this. 

 

 

Cylinder 4 here has some rough looking scoring down it and the crosshatch has been wiped clean on the side, I assume the other side has the same wiping but I can't get my boroscope to see it. 

 

 

Cylinder 1 has similar wash on it but no scoring. 

 

Here's a vid of cylinder 4 while turning the crank, sorry the quality got a lot worse when it uploaded but still can see it okay. 

https://drive.google.com/drive/folders/1uc8MYiwc82_zEBK5eIY0xLeyGSje3OTa?usp=sharing

 

This thing has been a nightmare, I thought switching to a stock thickness head to lower the compression would help along with non married intake and exhaust but I'm wondering if it's worth it to keep trying to figure this out with how these cylinder walls are looking. 

 

Other option - I have an l20b sitting in the bed of my truck right now. It's bored 50 over and was ran for about a week after being fully rebuilt before the truck it was in was totaled. It's been sitting for a while, I think since the 90s and the cooling system has a good bit of rust in it. But the crosshatch looks fantastic, block is perfectly level with no pitting and seems like it'd run great if I just go through it. Thinking about putting it back together, putting it in my truck for the meantime and eventually boring the z22 out to match the z24 pistons I've got laying around maybe fit the z24 crank too. If the l20b is a better option than trying to get my lz22 running better right now, would the u67 that's been milled 0.050 be alright to put on to bump up the compression or would that be too much?

 

Also to note - both the u67 and w58 have u20 casting cams that seem to have been reground. w58 cam measures 30mm at the base and 38mm lobe and u67 is 31mm and 39mm. 

[datzenmike]

IDLE:

Check the idle cut solenoid on the carburetor is working and has 12v to it. Turn ignition on off on off... you shoud hear soft clicking sound at rear of carburetor.

 

 

Forget the cylinder walls. If they were that bad the compression wouldn't be 180!! Valves are good too holding in 180s.

 

It's cooler now so steamy exhaust is normal. If using coolant then the radiator will be low and need topping up regularly. Does it need coolant topping up? You swapped the head so you must have put a new intake/exhaust gasket on. Check the bottom row of nuts are tight. 

 

Base circle on the L20B cam is 33.25mm or there about so yes reground. 8mm lobe lift is about a 0.472" valve lift. Stock is 0.413"

 

 

[toshts]

10 minutes ago, datzenmike said:

IDLE:

Check the idle cut solenoid on the carburetor is working and has 12v to it. Turn ignition on off on off... you shoud hear soft clicking sound at rear of carburetor.

 

 

Forget the cylinder walls. If they were that bad the compression wouldn't be 180!! Valves are good too holding in 180s.

 

It's cooler now so steamy exhaust is normal. If using coolant then the radiator will be low and need topping up regularly. Does it need coolant topping up? You swapped the head so you must have put a new intake/exhaust gasket on. Check the bottom row of nuts are tight. 

 

Base circle on the L20B cam is 33.25mm or there about so yes reground. 8mm lobe lift is about a 0.472" valve lift. Stock is 0.413"

 

 

Carbs a 32/36 and doesn't have an idle cut solenoid but it does feel like it's a carb issue. Pulls 15 mmhg, don't think it's a vacuum leak I smoke tested to be sure and there was nothing but the throttle shafts, carbs not even a year old so I doubt they could be worn bad already. All the manifold bolts are right around 10ft/lb, got em all hand tight then torqued the ones I could reach with a torque wrench, took note of the degrees I turned to reach the torque and hit the bottom ones with the same degree. That being said, the rusty headers that came with the engine are badly warped so I wouldn't be surprised if the intake didn't seal great and I'm thinking coolant getting in is probably an issue. If I'm gonna pursue the lz22 still I'll pull the manifolds off and bring the headers to the machine shop to get them level again. Only ran it a few times, radiator hasn't lost coolant but the expansion tank has gone down 

Edited October 28 by toshts

[ggzilla]

15 mmhg is low for a Datsun. I would expect 18 or more

 

Are you saying smoke is sucked into the throttle shafts?

[toshts]

1 minute ago, ggzilla said:

15 mmhg is low for a Datsun. I would expect 18 or more

 

Are you saying smoke is sucked into the throttle shafts?

Agreed - I was only getting 17 with the u67 which was one of the main reasons I swapped it, I got 22 with the stock z22. Hell I got 21 out of a z24 that had a blown head gasket with only 70psi in the back two cylinders.

 

I got a smoke tester since I used to work on a lot of BMW's - blow smoke into the manifold, plug everything, see where smoke come out. Only came out of the throttle shafts. 

[datzenmike]

15Hg is very low. Check idle mixture setting with a vacuum gauge. Set to highest reading at idle, around 750. Set Ignition timing and valve lash. Should idle 18-over 20 Hg.

 

The bottom studs have a 'cone' washer under the nut and each spreads the clamping force to hold the intake and the exhaust manifolds. The problem is the intake flange is 1/2" thick and the header is usually not, so force is not even and header won't tighten down properly. 

 

You would have to remove the rocker shafts on the intake side to close all the intake valves to have any chance of building any pressure blowing smoke into the intake. I assume smoke is blown into the intake through the throttle plate? There's not much clearance on the throttle shaft so how much smoke it too much? 

[toshts]

1 hour ago, datzenmike said:

15Hg is very low. Check idle mixture setting with a vacuum gauge. Set to highest reading at idle, around 750. Set Ignition timing and valve lash. Should idle 18-over 20 Hg.

 

The bottom studs have a 'cone' washer under the nut and each spreads the clamping force to hold the intake and the exhaust manifolds. The problem is the intake flange is 1/2" thick and the header is usually not, so force is not even and header won't tighten down properly. 

 

You would have to remove the rocker shafts on the intake side to close all the intake valves to have any chance of building any pressure blowing smoke into the intake. I assume smoke is blown into the intake through the throttle plate? There's not much clearance on the throttle shaft so how much smoke it too much? 

That is the max vaccuum I could get with initial timing at a very rough 900rpm, won't run any lower, at 12 degrees, 14 or 16. With or without vac advance. Valve lash is set. Those timing variations along with trying just about everything in-between 1.5-3 turns on the idle mix (best around 2) and it wants to die if I go under half a turn of curb idle which puts it right at/above 1k rpm. 

Smoke is blown down into manifold through brake booster vacuum hose with a plate/gasket sealing the top of the carb. Done it many times on webers and other carbs and the volume of smoke it creates makes it work good even at a low pressure but just about every carb I've done has leaked at the throttle shaft.

 

This header has spacers welded to the backing plate where the cone washers go so i assume it was made to be the same thickness before it got warped, I'll end up making step washers after I get it milled flat

[banzai510(hainz)]

i would throw the married intake/ex manifolds away. If idles has good comp. Adjust the idle mixture. Speed screw and timing.what is timimg w/ light? Is it clocked all to one side of timimg plate.try disconnect vac .or plug it. I have 20/30yr old webers and dont have major proplems.cracked weber adapters yes but one gets no idle. Shit maybe choke plate closed. I never used a vac gauge. Maybe pvc set up wrong. If runs at 1k rpm your almost there

[toshts]

Just checked the fluids again and I'm down 1/2-3/4 of a quart of oil. I've taken the valve cover off a handful of times to check stuff but I doubt that much has leaked out and there's oil sitting on the plugs when I've pulled them after running multiple times along with them turning dark real fast after running. Radiators still full but expansion tanks lower again as well.

[toshts]

1 minute ago, banzai510(hainz) said:

i would throw the married intake/ex manifolds away. If idles has good comp. Adjust the idle mixture. Speed screw and timing.what is timimg w/ light? Is it clocked all to one side of timimg plate.try disconnect vac .or plug it. I have 20/30yr old webers and dont have major proplems.cracked weber adapters yes but one gets no idle. Shit maybe choke plate closed. I never used a vac gauge. Maybe pvc set up wrong. If runs at 1k rpm your almost there

It runs but runs bad at 1k. Tried setting timing to 12, 14 and 16 degrees initial, with each setting I adjusted the mixture to the point of highest vacuum or smoothest running, tried to bring the idle screw down as much as I could, readjusted the mixture screws until I got it as best and low as I could with each setting. Couldn't get any of them under 1k on all cylinders. And I wouldn't not say it's running good at 1k either just hitting on all 4 most of the time.

[toshts]

4 minutes ago, banzai510(hainz) said:

i would throw the married intake/ex manifolds away. If idles has good comp. Adjust the idle mixture. Speed screw and timing.what is timimg w/ light? Is it clocked all to one side of timimg plate.try disconnect vac .or plug it. I have 20/30yr old webers and dont have major proplems.cracked weber adapters yes but one gets no idle. Shit maybe choke plate closed. I never used a vac gauge. Maybe pvc set up wrong. If runs at 1k rpm your almost there

Distributor is clocked so I have adjustment between 5 and 25 degrees. Pcv is drilled/tapped into manifold where the emissions stuff used to go and connected to block breather. Adapter is a brand new transdapt one piece adapter, got tired of the stacks of adapters getting loose or not sealing.

[banzai510(hainz)]

cAn you try 10btdc and then adjust mixture. I always notice when u adv timing the idle goes up. Haij mary clean idle  in case ur adjusting for a plug jet but im just guessing

[ggzilla]

If it is a dual-plug engine (8 spark plug wires), the timing should be 5 degrees

[toshts]

8 minutes ago, ggzilla said:

If it is a dual-plug engine (8 spark plug wires), the timing should be 5 degrees

Single plug w58 head. Doesn't seem like a timing issue it doesn't wanna run much at all under 12 (with vac advanced disconnected and at 900rpm, most likely less than 12 at what the idle should be). 

Gonna throw my spare carb on and see if that changes anything

[datzenmike]

Turn idle down to 700 and set advance. When the idle is that high mechanical (centrifugal) advance creeps in. 

[toshts]

5 minutes ago, datzenmike said:

Turn idle down to 700 and set advance. When the idle is that high mechanical (centrifugal) advance creeps in. 

It won't go down to 700 without dying 

[ggzilla]

17 hours ago, toshts said:

Can't get it to idle under 1000 on all cylinders and it doesn't hit on all cylinders until it's warmed up.

Have you check the spark plug gap? Maybe one of two of the plugs are fouled

[toshts]

Just now, ggzilla said:

Have you check the spark plug gap? Maybe one of two of the plugs are fouled

Plugs get fouled pretty much every time I run it. Tried 0.034, 36 and 40. Not much difference between them. I clean the plugs before each time I run it. 

[ggzilla]

If they are oil-fouled, cleaning won't help much

 

If they are fuel-fouled, yeh i would swap carbs if you have a good working spare

[datzenmike]

Plugs are self cleaning so maybe running too rich. Choke on or flooding. Float set too high. Fuel pressure too high? 

 

Check that the secondary has fully closed. If sticking, it's idling on extra air from the secondary. Secondary must be closed. This would explain the low intake vacuum also.

 

 

[toshts]

8 minutes ago, datzenmike said:

Plugs are self cleaning so maybe running too rich. Choke on or flooding. Float set too high. Fuel pressure too high? 

 

Check that the secondary has fully closed. If sticking, it's idling on extra air from the secondary. Secondary must be closed. This would explain the low intake vacuum also.

 

 

Good chance it's very rich, spare carb was even worse it's flooding out pretty bad when trying to run but not when the fuel pumps on by itself. My Mr gasket fuel pressure gauge reads about 4. Don't think that's accurate, I've got the facet pump that everyone recommends and haven't had an issue with it for the past year. 

[datzenmike]

A good Weber will handle 4 PSI but if you have an adjustable regulator turn down to 2 or 3 PSI. 

[toshts]

Here's some videos to run through everything, the longer one has most things we've discussed and the shorter one's on the carb settings

 

https://drive.google.com/drive/folders/1QGT1MkrBVl2a4tifSzpOrIXU9W_vklXw?usp=sharing

 

Didn't wanna run much at all on the spare carb, would fire a couple times on a single cylinder then die even with the choke on it was flooding pretty bad. Foot to the floor it started right up but would die if I let off it. Another thing to note is with the first carb when it was warming up if I opened the choke flaps with my hand it smoothed out a good bit, gonna pull the idle mix screw out and see if I somehow mushroomed the tip of it. 

[toshts]

37 minutes ago, toshts said:

Here's some videos to run through everything, the longer one has most things we've discussed and the shorter one's on the carb settings

 

https://drive.google.com/drive/folders/1QGT1MkrBVl2a4tifSzpOrIXU9W_vklXw?usp=sharing

 

Didn't wanna run much at all on the spare carb, would fire a couple times on a single cylinder then die even with the choke on it was flooding pretty bad. Foot to the floor it started right up but would die if I let off it. Another thing to note is with the first carb when it was warming up if I opened the choke flaps with my hand it smoothed out a good bit, gonna pull the idle mix screw out and see if I somehow mushroomed the tip of it. 

Added another video of it running cold. Got it down to a very rough 750 rpm, mixture screw adjustment had practically no difference, tip of the screw was perfectly fine. Also adjusted timing while running in the video, I'm sure the qualities gonna be too bad to see much but you should be able to hear the engine while I say what timing it's at. When it's warm the idle comes up to 900-1000 and smooths out to about what it was with the high idle on

Edited October 28 by toshts

[ggzilla]

Running when cold ... should not be 750 rpm, that's what it should be when fully warm. When cold it should run faster because of the fast idle cam from the choke. So perhaps your choke is not adjusted correctly. When the engine is completely cold, does the choke close 100%? If not it needs adjustment. First adjust choke to close 100% when cold. Thereafter when fully warm, adjust curb idle speed and mixture