Tune & Log. Gen VI CBB 1999 Vortec 7400

Ok and the adjustable studs...roller tips checked to be right across the center of the valve tip? Permanent marker trick? Other than that I'm not sure. I wouldn't be running it up that high with that much valve train noise. If you can hear clickety clack over the roar of a BBC then there's a problem. Might be like you're saying though. Maybe the rollers are loud? Idk about that.

Really intelligent decision on those rockers. When I hear "roller rockers" I shake my head because that usually means the aluminum kind. Those things typically break in short order. People don't understand that yeah they may have the strength, but aluminum has poor fatigue life.

Also how much preload on the lifters?

Here's a fun calculator. Data taken from Log 7:
Attachment 134512

Quote:

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Originally Posted by SiriusC1024

Ok and the adjustable studs...roller tips checked to be right across the center of the valve tip? Permanent marker trick? Other than that I'm not sure. I wouldn't be running it up that high with that much valve train noise. If you can hear clickety clack over the roar of a BBC then there's a problem. Might be like you're saying though. Maybe the rollers are loud? Idk about that.

Really intelligent decision on those rockers. When I hear "roller rockers" I shake my head because that usually means the aluminum kind. Those things typically break in short order. People don't understand that yeah they may have the strength, but aluminum has poor fatigue life.

Also how much preload on the lifters?

Here's a fun calculator. Data taken from Log 7:
Attachment 134512

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WTH? 300HP??? It had more than that stock! :) It definitely feels better than when I got it, does that estimator do torque? That count the larger injectors too? 36lb/hr vs. 19lb/hr?

I will pull the covers and look at the contact point, not sure I checked that. I did get info from Comp cams who determined that those lifters should have 1 - 1-1/2 turn of preload past zero lash.

I still plan to do a real, running valve adjustment as I bought some stamped covers to cut open to use as oil splash shields.

ake it with a grain of salt it's just an estimator. It does torque implicitly from airflow and volume. That's how it gets hp from rpm. It doesn't account for actual torque production from spark or how efficient the exhaust side is (except at overlap). Plus the gains from a cam are typically geared for top end airflow. You didn't lose torque down low anyway. I bet if you ran it up you'd see a difference. It's kind of a good thing.

A good way to check gains is to look at the VE table. Cylinder fill and torque are very closely related. Compare when we started to where we are. Pretty decent gains, man.

You should have checked contact pattern. May be able to get enough adjustment at the rockers, but worse case is different length pushrods.

Quote:

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Originally Posted by SiriusC1024

ake it with a grain of salt it's just an estimator. It does torque implicitly from airflow and volume. That's how it gets hp from rpm. It doesn't account for actual torque production from spark or how efficient the exhaust side is (except at overlap). Plus the gains from a cam are typically geared for top end airflow. You didn't lose torque down low anyway. I bet if you ran it up you'd see a difference. It's kind of a good thing.

A good way to check gains is to look at the VE table. Cylinder fill and torque are very closely related. Compare when we started to where we are. Pretty decent gains, man.

You should have checked contact pattern. May be able to get enough adjustment at the rockers, but worse case is different length pushrods.

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The Comp Cams Kit came with the springs and new pushrods. I added on the roller tips and the adjustable studs. I still have the stamped stuff and may throw them back on just to see if the noise goes away! It sounds like a really loud sewing machine, not like knocking or rapping hard to describe.. almost like if you take an old time reel mower and push it really fast??? :)

Ok so actual worse case scenario is valves hitting the pistons. What kind of piston to valve clearance are we talking with that cam? High RPMs things stretch out. Piston comes out of the hole a few thousandths more, exhaust valve lengthens from heat, etc.

Check on all that stuff I mentioned. I'd be worried about high rpm noise, too.

Way over required clearance, I measured with original lifter that I had converted to a solid lifter and then I mounted the head and ran crank to squish putty inside cylinder, over 0.100" clearance. I had originally almost freaked out when measuring it because I had put too much putty in there and I thought I had pistons hitting the head due to the 0.010" decking, then I breathed a sigh of relief until the thing locked up solid when turning by hand! Turned out to be oil pan rail hitting crank (vice versa actually) due to the stroker crank, but a little percussive persuasion fixed that... I took off the pan and widened the mounting holes and widened the rails a bit. Not hit the crank! :)

Ok that's good. Valve train check it is then. So what's your thinking on doing a running lash adjustment? That's for solid lifters. With hydraulics there would be no way to tell if preload is correct by just sound. Could be almost bottoming out or just barely compressing the lifter. The comp spec should be right.

Btw still waiting on a log to get spark right. Are you wanting to wait until the IAT situation is figured out?

Or maybe it's just simply an oiling issue. Diesel oil has very poor film strength. Try some of that Q-state Synthetic 5w-30 (5w-40 Euro would work fine, especially the extra clearance bearings. Plus, 5w-40 is recommended by GM in HD applications) or Mobil 1 0w-40 FS. Oil probably needs a change anyway. ZDDP is old tech. Boron is used now, and the film strength of modern oils is much higher. On the other side, modern diesel oils really cut down on ZDDP.

Have to make sure it's a good oil though. Wouldn't run white bottle Valvoline or anything like that. Film strength around 100ksi, regular changes, and it'll last forever.

I originally had 5w-30 in it. Oil pressure was 60PSI at cold start at idle and after getting it HOT by driving 15miles in 93 temps and stop and go traffic it went to about 15- 20 at idle and still had the sewing machine sound with a bit more of a clack... I had driven it to the racing engine guy who assisted with the machine shop work and such. He said, "Don't run that 5W-30 stuff, get Rotella 15W-40 diesel oil that has zinc in it". That is why I put that in it. I had read extensively that you don't want to run synthetic until the cylinder walls are broken in and up to about 200-300 miles. I am doing one more change on the dino oil, then switching over to the synthetic. At least that was my plan. Film strength sounds intriguing as it seems like it would help keep the pressure higher all around if I am understanding correctly? I kept telling him that this isn't a drag Suburban and that it shouldn't see north of 5K RPMs so not sure how much of the 'old style drag racer' info/tricks apply. One thing that did bite me was that apparently he (or his guys) put in a drilled oil galley plug behind the timing chain, unbeknownst to me. I coated the engine in Cosmoline and packed it away for the winter. In the spring I took out all the plugs, cleaned everything out and then put it all together with the drilled plug at the back of the motor! F! Still have an oil stain trail across the driveway... Oil never ran out, oil pressure never went low so I definitely didn't hurt it from that. Did pee a quart or so all over the bottom of the truck and driveway though! So I am pretty sure it's not a low pressure problem because after I changed to the 15W-40 Rotella it sounded and acted the same pressure wise... maybe 1-2 PSI higher at hot idle. I plan to wrap the intake tube and run it tomorrow. I have tune 10 loaded and the LTFTs cleared. At the very least I will get a log even if I don't get to the IAT stuff just yet.

I've had similar experience with various 5w-30 oils. The Xw-X0 rating is all over the place viscosity-wise. Have to look up the actual data sheet to see true viscosity at 40C and 100C.
https://www.shell-livedocs.com/data/...0d7017f8b7.pdf
https://www.shell-livedocs.com/data/...c6216b24de.pdf
https://shell-livedocs.com/data/publ...d17f3428b0.pdf

The QS is a little lighter, but it offers far better protection. Diesel oil is meant for diesels. Low RPM and oversized load surfaces.
QS 5w-30 Full Synthetic - 133,302 psi
Rotella T4 15w-40 - 72,022 psi
Rotella T6 (synthetic) - 67,804 psi

Film strength is the true indicator of oil protection ability. If the film breaks down to where it's metal on metal then that's where additives like ZDDP come into play.

https://540ratblog.wordpress.com/
My oil pressure gauge and drain plug magnet agree.

Drain it if it doesn't work. Might be quieter valves, but if it's like you're saying then maybe not. I won't bother you about it again lol. Just a little advice.

I was born and raised on import cars. First Mitsubishi, then Honda and finally Toyota before I got out of the dealer 'mechanic' spectrum and went to all manufacturer's electrical systems. Had an auto electrical shop for a bunch of years and then hurt myself and got to doing only my own cars. Everything I had put together (probably 20 or so motors) was all stock with a notable exception of taking a stock Mitsu Short block and mating it with a stock Mitsu Sapporo car head. This resulted in cranking compression of 260PSI on the gauge and requiring running a 12 gallon tank of gas with 2 cans of 'octane booster' and 0 degree timing. BUT it had freaking torque for a 2.6L 4 banger! Blew head gaskets every couple trips to Philly's Front Street, but I was able to change head gaskets over lunch at the dealer and it never left me stranded. I just puff, puff, puffed my way home! This is my first foray into mix and match parts, so I am open to any advice, and I appreciate the time and consideration! Back in my day there wasn't 'synthetic' or at least not for under $40/quart! I have zero problem with the noise as long as I am confident it is not an indicator of a problem and is just how it works. I will pull apart the valve covers/rockers and take a look at the valve tops after getting an eye on the operation to make sure stuff doesn't look 'off'.

QS 5w-30 Full Synthetic is the recommendation?

https://www.amazon.com/Quaker-State-550046194-3PK-Durability-Synthetic/dp/B00RRI64BC/ref=sr_1_1?crid=38A9HESAWMFAC&keywords=Quaker+Stat e+5w-30+Full+Synthetic&qid=1689390063&sprefix=quaker+st ate+5w-30+full+synthetic%2Caps%2C70&sr=8-1&ufe=app_do%3Aamzn1.fos.006c50ae-5d4c-4777-9bc0-4513d670b6bc

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the laptop went to sleep in the middle of the second log. I didn't wrap the intake tube yet... Too hot! My own IATs are high today.

QS 5w-40 Euro in my opinion. I'm running it in my LS right now and it's holding up great to the summer heat.

I kinda miss tuner cars. The muscle car trend kicked off by the revived mustangs, challengers, camaros is awesome, but why can't we have both? What have we got now? Supra? Don't get me started on that rebadged BMW wannabe. I kinda started with tuners, too. 1991 Taurus SHO was my first "fast" car. Yamaha V6, Mazda 5 speed. Beat a paper plates 350Z. The poor kid driving it looked like his heart broke. I think I had more fun in "The Big SHO" than the HCIE TA that I daily now.

I'm down in Daytona for the week. Didn't bring my laptop :(

Quote:

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Originally Posted by SiriusC1024

QS 5w-40 Euro in my opinion. I'm running it in my LS right now and it's holding up great to the summer heat.

I kinda miss tuner cars. The muscle car trend kicked off by the revived mustangs, challengers, camaros is awesome, but why can't we have both? What have we got now? Supra? Don't get me started on that rebadged BMW wannabe. I kinda started with tuners, too. 1991 Taurus SHO was my first "fast" car. Yamaha V6, Mazda 5 speed. Beat a paper plates 350Z. The poor kid driving it looked like his heart broke. I think I had more fun in "The Big SHO" than the HCIE TA that I daily now.

I'm down in Daytona for the week. Didn't bring my laptop :(

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I am a bit older than that even. Back when 'Front Street' in Philly was a place for street racing, but before the track cars were showing up. This was when you raced your daily driver! :) Have fun in Daytona. I think I may have gotten a bit of a handle on the IATs by doing that wrap thing. Not exactly 'cold air intake' territory, but at least it does cool off after I drive it after idling for a bit now. Before the IAT would just go up and stay there, now it moves around a bit more. The last couple of tunes seem a little less peppy? or I may just be getting used to it. I got a couple of logs today with the airtube wrapped. I also plugged some holes in the area that has the intake tube stuffed into the fender with grommets and Ultra Black.
Attachment 134560
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Less peppy because spark was removed. IAT spark chopped everything down. I'll get it setup better when I get back. There was a lot of knock before, just about anywhere above 65 kPa, and it's best to be safe.

I like what you did with the wrap. Still don't get why it's so hot in the first place on a factory intake. Is hot air being sucked into the air box somehow?

That makes sense with the spark. I had noticed that with the knock sensor when it went bad, just seemed lethargic. I am wondering if it is real knock or valvetrain noise, exhaust noise?

I dropped it off for inspection tonight and it always terrifies me when someone else is driving my cars! Last time I dropped off one last month they called and said "you need a front axle for inspection because yours broke.". Ummm,,, OK. I had just rebuilt the front end and as I was putting it together I was like "should I replace the axles while I am in here???" and decided to skimp on the $120. Wrong choice.

I will give it another look after I get it back (pass or fail) and see if there is some other way engine bay air is getting in there. I saw a bunch of holes in the inner fender so I plugged them with grommets and RTV, I also saw the lower airbox had expanded and there were some openings that could let it air in. I did a quick and dirty RTV fix, but will revisit in more detail with some gasket material. Heck, I may just pull the grille/bumper out again and just plumb it myself to behind the headlight area and insulate it better to make sure. I have been looking for some documentation to see if there were some inside the fender parts that were missing, but being so old I couldn't find any so far. The good'ish news is that the air temp does come down after idling while driving it where before it would just climb and climb without coming down as air flowed, so I at least slowed the heat transfer and headed in the right direction. I hope you can see that in the C and D logs for 10.

The good news is that the inspection guy will have a less angry motor to test! :)

Yay! Got stickers.

Just put in the QS Euro synthetic. Will be driving it possibly tomorrow but am going away Thursday thru next Monday. If I don't get a chance to run it before then I will definitely after I get back. Is it possible the valve train noise is showing as knock? Just curious. Thanks!

It's possible. I can desensitize the knock sensors if you'd like. I figured it was real knock due to increase in displacement with stock heads. I can run the DCR numbers and do a bit more when I get back.

I run high octane exclusively, basically 92+. The calculations I did, with the head gaskets, the decking, the cylinder head cc and the pistons had it come out to 9.0 - 9.5:1. I had read that this is ok for normal 'pump gas' but I always run the 'high test' (yeah, grandpa term...). I haven't heard what I would consider ping, like from the old 80s K-cars or anything like that and the power only seemed to fall off after tune 8 I think. I am still digging into the IATs and plan to insulate and seal the little duct that takes the air from in front of the radiator support, as well as where it enters the fender. I also plugged the holes that were there that don't make much sense if it is supposed to suck fresh air... Thanks for checking in and enjoy the rest of your trip!

another question. Is there a way to compare the data from the first log and then the data from the 10th log to see if there is less air being pumped thru the motor for a certain RPM? maybe indicative of a cam being wiped or something? I am not liking the noise. I am wondering if there is a restriction of the lifter galley or something from the galley plugs. It's a gen VI 454.