waynos 521 work truck

[wayno]

Both these engines were basically the same, both have L20b cams, I tried the RV cam on my L20b and was very unhappy from the start, it had no torque, when one has 6000+ pounds to move I need torque, so I built my first LZ23 and the cam was timed wrong, I drove it that way for around 5/6 years and never had an issue after putting in a head stud kit, then I found out the cam was timed wrong and I fixed it, it had a little more power but it became the knock/ping monster, I expect that is when the head damage started, I had it timed at 0 degrees until I re-curved the distributor, then I think I had it around 6 degrees BTDC, but it would start knocking again, the engine started bucking when I got off the freeway and was stopped at a light(engine temps were up higher than normal but it idled fine), the bucking would go away once I got moving and stayed moving, I thought it was my SU bowls boiling from the heat, I now suspect that was when that fire ring was disintegrating and the bucking was actually knocking/pinging in overdrive because of the fire ring having sharp edges, this truck was so much better with the cam timed wrong.

[Stoffregen Motorsports]

That feeling of rushing power can be misleading. A cam that's overly retarded can feel that way, but actually make more power properly advanced. It won't give you that rush of power, but a steady building of torque.

[wayno]

I do not recall having any rush of power in this truck unless I disconnected from the trailer, then it is like a different truck, I hardly use any pedal at all when I do not have the trailer, this is about torque and being able to go down the freeway at 60mph basically on close to level ground without without having to drop a gear or completely floor it.

 

The way it is looking if things do not improve I am likely going to put the repaired head on my old block and put it back in the truck, if this is all about a few degrees on cam timing I do not see this working out, my old engine had more power timed at 0 degrees running regular pump gas with the cam a complete tooth off with the groove way to the right of the notch.

[Stoffregen Motorsports]

I'm not stuck on cam timing, I'm just wondering if the two engines are so identical that they can actually be compared as equal. Don't throw the baby out with the bathwater. You might still have a great engine, but it may simply need some tuning.

[wayno]

I drove it to a job this morning and it was better with the timing at 10 degrees BTDC, but I messed with the cam timing after I got home, I cannot get it the way it is in Mikes photo, so I removed the gear and took it off the chain and moved the chain to the side, I put the gear on it in all 3 positions and it just got uglier so #1 dowel hole was the best with the groove slightly left of the center of the notch, so then I put the gear on the chain one link over, turned the cam till the gear settled, then I removed the chain from the gear and tried it in all 3 positions and #3 dowel hole appeared to be the best which had the groove mostly right of the notch, there is no happy place, BUT this was without the chain on the gear, things will and do move around a little to get the cam gear to drop onto the dowel hole, but the groove did not move an 1/8" to the left, I did not take a photo but it basically looked like this photo below, but I had not even moved the engine.

 

I drove this truck for years with that groove another groove width to the right, it was not even close to that notch and I had no issues after putting a head stud kit in it for a very long time.

 

I test drove it and I could not tell any difference from the drive this morning after I had been re-timed yesterday, it did not knock/ping on either drive and the torque is a lot better, that complete dead spot where I thought it was going to die after letting out the clutch appears to be gone, maybe it was timing, but the day before yesterday when I let out the clutch at a signal it just kept bogging down to the point the truck was going to quit moving and die if I did not press in the clutch to get the engine revving again, it seemed like anything below 2000rpms was worthless.

 

I am getting tired of messing with this engine, the only thing different between the two engines is one was a Z22E block and the other was a Z22S block, and this head has larger intake valves by a couple mm, oh and this one I am setting the valve lash at the lash pad, while the other engine was initially set at the cam lobe, but from then on(years) I just felt them to make sure they were not tight, they were not even close to 12 thousands as that seemed tight to me and that engine ran better, but this one is a lot quieter.

 

I will drive it this way for a while and decide if I am going to put the other engine back into this work truck, the head has been repaired and I see no reason to not put it back together, it is a great engine.

[wayno]

I forgot to mention, when I pulled the plugs yesterday to do the compression check and looked at them I was slightly puzzled, #1 was black except around the tip where it was tan, #2 and #3 were just black, and #4 was like #1, black except around the tip(to the curve) where it was tan, I have dual SUs, #1 and #2 are on the front carb and #3 and #4 are on the back carb, how can #2 and #3 be completely black, I can see the front two cylinders being tan and the back 2 being black(rich), but the two middle cylinders puzzles me.

[Stoffregen Motorsports]

So virtually the same except one has big valves and you were using a different valve lash setting on the one engine.
 

You say the blocks are different. Some people call everything that's inside the block a "block" so do you mean the rods and pistons are different too? Or literally just the block is different?

 

Didn't you say that one of them had an "RV" cam?

Edited June 6, 2021 by Stoffregen Motorsports

[wayno]

OK, one block was a Z22E block, when it was bought it had the fuel injection intake manifold on it which I sold, the other block was a Z22S block, it had that intake manifold on it also, I do not recall what pistons the Z22E block had but I had both bored out to 89mm to except the stock Z24 pistons, the machine shop did not tell me there were any hiccups so I assumed both the blocks excepted these stock Z24 pistons so to me that means both blocks/cranks/rods were the same meaning the pistons had the same pin height.

 

The heads are both modified, both are W53 castings(closed chamber), the old engine(Z22E block) has the head with the 280Z valves(42mm intakes???), both heads had the intake runners ported to match the dual SU intake manifold(1.5"), the exhaust ports were not touched on either head, the W53 head on the Z22S block which is in the truck right now was fitted with 44mm intake valves, I just looked at both casting numbers on the heads and it appears the space between the bottom of the letters/numbers(W53) and the face of the head is about the same, this does not mean they are the same but they appear to be about the same to me.

 

Both engines used the same intake/exhaust, the only difference in break in was the oil, the Z22E block had 20/50 used to break it in, this Z22S block had 10/30 oil used to break it in, and the Z22S block I spun the engine over(without spark plugs) to soak everything with oil before starting it as this engine sat in my back room in my house assembled for 6 years??, I also squirted oil in each cylinder before I turned it over and covered the cam with assembly lube as the old stuff had dried out, the Z22E block had just been assembled so I just started that one without these extra things I did as it had not sat for years, both had the oil pump filled with oil(primed) before installing.

 

I thought about how this Z22S block had sat all them years inside my house(climate controlled) and wondered if this could be the reason one is a better engine than the other.

 

As for the valve clearances, as I already mentioned this new engine was set 12 thousands at the lash pad, the old engine was set by feel which I can tell you right now was way looser, it was likely 15 thousands or greater at the lobe, this made that engine a little noisier, but I had had them get tight before so I kept them loose.

 

The RV cam happened a long time ago on an L20b block, that engine had no torque with that cam, I regretted having that head done afterwards, it was a waste of money, my thinking was defective, I thought if the valves stayed open longer or had a higher lift it could breath better on the freeway with stock valves and hardened seats, was I wrong about that, it had no torque and it was worse than my old wore out engine on the freeway(4 quarts of oil per tank of gas), 5th gear was not used as it would not maintain freeway speeds in that gear except down hill, that is when I built my first LZ23 to replace that engine, that engine went into my 520, since then I found a 219 head and that is on that engine now, the W53 head with the RV cam is on that Z20E block I have(flat top pistons) that likely has a 10.8 to 1 compression ratio, I have had that engine running on a stand, but it has never been in a vehicle, it would likely need race fuel to run properly, I should sell that engine.

 

And let me repeat, my work truck now weighs 3900 pounds empty with me in it (which it is never empty), I am pretty sure with all my equipment in it the trailer weighs over 2000 pounds(has electric brakes), I ask a lot of these engines, they get a workout every time I drive them, I used to have a ton or more in the flatbed all the time(wet moss weighs a lot), this is why I had 1990 Nissan hardbody V6 dual piston vented rotor disc brakes on this truck, I do not pressure wash tile roofs anymore so I don't have wet moss in my truck anymore, back then I was rolling around over 8000 pounds all the time and it took that LZ23 to move the truck/trailer/wet moss and good brakes to stop it, this is why I am always talking about torque as I notice when I have less power.

 

4 hours ago, Stoffregen Motorsports said:

So virtually the same except one has big valves and you were using a different valve lash setting on the one engine.
 

You say the blocks are different. Some people call everything that's inside the block a "block" so do you mean the rods and pistons are different too? Or literally just the block is different?

 

Didn't you say that one of them had an "RV" cam?

 

Edited June 6, 2021 by wayno

[datzenmike]

 

 

2 hours ago, wayno said:

OK, one block was a Z22E block, when it was bought it had the fuel injection intake manifold on it which I sold, the other block was a Z22S block, it had that intake manifold on it also, I do not recall what pistons the Z22E block had but I had both bored out to 89mm to except the stock Z24 pistons, the machine shop did not tell me there were any hiccups so I assumed both the blocks excepted these stock Z24 pistons so to me that means both blocks/cranks/rods were the same meaning the pistons had the same pin height.

 

 

 

Z22E (E for EFI) and Z22S (S for carburetor) couldn't have had the same intake manifold on them.

 

wayno is there any chance the machine shop milled the tops of 4 of those pistons? Maybe 1 to 1.5 mm???

 

The later Z22E blocks used a longer rod / shorter pin height so if a Z24 piston is put on them they would rise above the deck by about 2mm of which 1mm would be in the gap provided by the head gasket. You could easily sand the thicker raised outer rim down by hand this amount. The 15cc dish would be lessened, I calculate about 12cc removed, making it very close to a flattop. The compression with a closed chamber head could be around 11 to 1. If this was your first engine it would go pretty damn GOOD!!!!!! Your second engine, probably with the shorter rod would have been closer to 8.8 compression and would have been noticeably sluggish in comparison.

 

 

 

Did the first engine ping excessively????? or did you have to retard the advance a lot????

 

If YOU assembled the engine you would have noticed right away that the pistons sat too high. If the machine shop did this they may have trimmed them to fit. This is not impossible and it would explain the difference in power/torque.

[Stoffregen Motorsports]

5 hours ago, datzenmike said:

If YOU assembled the engine you would have noticed right away that the pistons sat too high. If the machine shop did this they may have trimmed them to fit. This is not impossible and it would explain the difference in power/torque.

Thank you Mike for distilling it down. That's what I was getting at. Are all things really equal? Or are some things not really equal?

[wayno]

Geez guys, both them engines had the pistons about 1mm below the top of the deck, they both looked exactly the same without the head on them, this is the first LZ23 engine made with the Z22E block, the pistons do not look milled to me, the little dot is still there and if they had taken 3mm off them pistons that dot would not be there anymore.

 

 

If you read this thread Mike you would remember me talking about knocking/pinging constantly after I timed the cam properly but not before that, before that it did not knock/ping, that is likely why the head had to be repaired, but this block did not have the pistons milled as I would have mentioned that way back then, that would have been something I remembered and been charged for, I certainly would have talked about it.

 

 

[datzenmike]

OK wayno it was just a 'what if?'.

[Stoffregen Motorsports]

Yep. My angle here is to find out if the two engines you are comparing are actually identical, or if there are enough small differences to account for the difference in power between the two.

[Charlie69]

Here this might help in comparison.

 

Z22E

 

Z22S

[datzenmike]

Z22E was used on the '82-'83 S110 200sx. Not used on 200sx in 81. That was the Z20E still. Ignition timing was 6 degrees California and 8 everywhere else

 

Z22S was only used in the '81-'82 720. In the '80 720, the L20B was still being used.

 

 

So the Z22S is 86 hp but the Z22E is 103?????? They use the same block, head, valves and cam but EFI adds 17 HP?????? How is that believable?

[wayno]

It does not want to die now when I let out the clutch, that appears to be the timing that fixed it, before it was at 5 degrees BTDC, now it is at 10 degrees BTDC, then I changed the cam timing to where the groove is just on the right side of the notch and that changed nothing, it is not knocking so I may advance it even more if I get brave, it still turns over like crazy but I can keep it moving at 60mph in 5th gear on level ground without flooring it so it will work for now, I will likely clean up the old block and put the head back on it as i think that engine has more power, that engine will likely go back into the work truck and if everything goes well this engine may go in the 520 if I start driving it more, I put insurance on it recently so I will likely start driving it.