It's alive! Finally.

Post by **jeepxj3** » July 4th, 2015, 10:28 am

That sounds like valvetrain noise. Pull the oil fill cap and listen there.
Check to see if any valve lash (pushrods too short) then check preload.

Worst case- you flattened a cam lobe, collapsed a lifter or got a bad lifter out of the box.

Post by **optmaxx** » July 5th, 2015, 3:05 am

I took it to a mechanic to take a listen and he told me that the noise didn't sound bad to him, and that it's possible to still have some air bubbles in the lifters. He didn't seemed concerned, but maybe the videos are amplifying the sound? I still took off the valve cover because I wanted to measure the pushrods, and they seem to be stock length at somewhere in between 9 5/8 and 9 11/16. I haven't measured the preload yet, but I'll have to find out how to do that.

I have a few videos. One that shows it running with the valve cover off, but it's kind of shaky because the rpms were high and I tried to close up the vacuum hose that was causing it to rev high while filming. https://www.youtube.com/watch?v=q93eaZE2pik

This one is under the Jeep. https://www.youtube.com/watch?v=jDerYt38oKE

And it's probably useless, but in this one I put the camera mic against the screw driver while it laid against the valve cover, (before removing the valve cover).https://www.youtube.com/watch?v=Tr76zkQ_AUY

I'll check the preload and if it doesn't seem off, I'm just going to drive it.

Post by **jeepxj3** » July 5th, 2015, 9:44 am

Cool Video with the valve cover off. I always wanted to do that. Made a bloody mess.

Post by **SilverXJ** » July 5th, 2015, 2:27 pm

I am not hearing anything abnormal in the videos. Unfortunately, sound don't come through that well. I would just drive it and see if it gets any worse or better.

Post by **6TIME** » July 5th, 2015, 7:48 pm

jeepxj3 wrote:Cool Video with the valve cover off. I always wanted to do that. Made a bloody mess.

Lol a mess for sure.. A better thing to do is take a spare cover and cut the top out then you can at least catch most of the oil trying to drain back.

Post by **jeepxj3** » July 6th, 2015, 3:03 am

The sound seemed less with the cover off. Whatever that means.

Post by **optmaxx** » July 6th, 2015, 3:52 am

jeepxj3 wrote:The sound seemed less with the cover off. Whatever that means.

You know, I thought the same thing when I was filming, but I just figured it was just me. I've been meaning to look up info on rockers hitting valve covers too, and I've been wondering if some 4.0 valve covers are taller; right now I have a 1995 valve cover.

Post by **optmaxx** » July 6th, 2015, 4:37 am

So, I came across these info while looking up valve cover stuff, and it says that the 1996 head use lighter pressure valve springs. I built my stroker from a 1996 block so I reused the cam because it was still in good shape (I had it looked at), but I used a 1995 rebuilt 7120 head. I'm just curious if my 7120 stock head valve springs will have a negative effect on my 1996 cam? http://www.enginebuildermag.com/2004/10 ... der-heads/

Post by **jeepxj3** » July 6th, 2015, 5:16 pm

Interesting point on the valve cover. That might be it, the rockers are hitting the inside of the valve cover, baffling or ribbing inside the VC? Did you check the inside of the VC for damage? Make a mess again and lower the VC onto the running engine and listen. IDK.

Post by **jsawduste** » July 6th, 2015, 6:11 pm

If I am not mistaken the OP used a stock 96 cam. Doubt the rockers would be hitting the VC as there is simply not enough lift in that cam.

Post by **SilverXJ** » July 7th, 2015, 4:38 am

No interference issue with the stock rockers and valve cover.

Post by **6TIME** » July 7th, 2015, 8:19 am

What springs are you running btw? I had a set of springs that were fairly large dia.. 1.47"? Can't quite remember. They were rubbing the inside of the valve cover. Take a peek and see if there's any evidence of rubbing on the inside of the cover just to rule that out.

Post by **optmaxx** » July 8th, 2015, 4:31 am

I'm assuming they are stock valve springs on a rebuilt 7120 head. I got it from Machine Shop Pros on ebay, no mods, just a rebuilt head.

I didn't see anything unusual inside the valve cover, maybe it amplifies the sound somehow? I'm just going to run it because I've had a few people hear it in person, and said that the engine didn't sound unusual to them. They were both engine builders that admitted some engine builds tend to be noisy for some time, while others are quiet from the start. My engine didn't sound like a collapsed lifter to them and they just suggested to keep driving it, we'll see. I did change the oil and it looked clean with no metal, I did make sure to add a bottle of Lucas zinc additive and changed the oil filter.

I got a pre test smog today and the NOX was a little high as they put it, it seems normal for strokers to have high NOX though. The O2 sensor was about a year old, and it's been out of service for 8+ months, plus it probably took some abuse during the break in so I bought a new one. I have 24 lb injectors and a full tank of 91 octane, but I'm running Champions RC12s...should I switch to a lower heat range plug? Which ones do you guys recommend? Anything else I should do to improve my chances to pass smog?

I got my MIL light to work and it gave me code 31 with the three key turns, I guess I should check my hoses to my evap canister? I don't have an evap solenoid, I never did, and I never got that code from my old pcm; I swapped it out for a JY PCM when I wasn't getting spark. Did all 4.0s have that evap solenoid, and if not, were some PCMs programmed to detect it?

Post by **optmaxx** » July 13th, 2015, 8:13 pm

So, I'm not sure if I should start another thread, but I'll post it here. Ok, I'm not passing emissions, and the only trouble I'm having is passing the 25 mph NOX, it seems to stay in the 1000s, well today it did anyways. It seems to do fine in all of the other ranges, it did pass the 15 mph NOX, and the guy doing the test commented that it's a clean running engine especially at idle.

The things I did so far is replace the plugs with NGK BKR6E-11, it cross referenced with the RC9s and the FR7s weren't available, and I replaced the fuel pressure regulator too. I'm not sure if going another step colder would help. Another thing I'm looking into is advancing the timing through the Hesco adjustable CPS? I believe I have to advance it to lower NOX right? Right now I have the CPS spaced with the felt spacer which is the recompensed gap I think. I had 91 shell gas during the test, but I went and filled up with 10 gal of chevron 91 gas today since I was running low. I asked if I should put any additives in the gas, but the tester advised against it cause it would mess up other readings? Idk.

He told me to go ahead and adjust the CPS and see what happens, he doesn't believe that it'll help though, he's beginning to think that it's the higher compression of the stroker. He feels that CAT and fuel delivery is doing it's job, but he'll do more tests to find what's going on tomorrow.

Post by **optmaxx** » July 14th, 2015, 3:19 am

I forget how to adjust the timing on the relocated Hesco CPS.

Do I move it closer to the balancer, or away from it?

Or do I place a washer under the CPS to advance it?

I forgot to mention that I do have a new O2 sensor, it's a Bosch. Also, the colder plugs and new fuel regulator did help, but only on the 15 mph NOX, it was cut in half compared to the first test, I think it went from 900s to 400s. The 25mph NOX stayed in the 1000s, but I remember that on the second test it settled at around 800s, on this test (third test) it went back up to the 1000s the same as the the first test.

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