Funny how something that makes gasoline less aggressive creates more power!Originally Posted by SiriusC1024
Funny how something that makes gasoline less aggressive creates more power!
Ok, added two cans (treat 25 gallons each) to my 42 gallon tank, idled for 12 minutes, let sit overnight and then ran it this afternoon out to the store and back.Funny how something that makes gasoline less aggressive creates more power!
Here are the logs.... I still see knock, but didn't look close enough to see if there is a difference or not.
No difference with the octane booster.
Well. Here's with knock sensors disabled. There's no sensitivity adjustment for the sensors. All you can do is adjust how much spark is removed when knock is detected. Might as well pull it all since who knows what's actual knock.
I'd assume the spark table safe if this was a regular 454. On one hand you've increased displacement through overbore, but on the other hand there is better quench. DCR decreased due to cam. Is that enough? Was hoping to find optimum through tuning.
I don't like doing it this way. If it were me I would have already put in the drilled gallery plugs, used Morel lifters, checked rocker contact, or whatever it took to get the noise to stop. I have doubts about the longevity of the engine.
Changes applied to tune 9. Logs from 9 have more accurate fuel trims. WOT shift RPM and PE adjusted also.
Last edited by SiriusC1024; 08-16-2023 at 04:54 AM.
Yeah, I haven't been driving it and the 'day job' which is also a night job gets in the way... Also, I don't have a garage, so the 90+ temps have been slowing me down a bit too. The noise has been constant and consistent. I will be pulling the valve covers and checking the valve contact shortly. I put a few miles on it for the beginning tunes, but have just really been driving it to get logs so that is the only real time on the motor so far. What I read is that the priority main motor (Gen VI) don't need the drilled plugs. The roller lifters aren't cheap and the ones in there right now are new from Comp that came with the kit. It is decked so maybe the contact is a little off and I may need to do something there. I should know in the next day or two. I may put the factory rockers on one side for a few seconds just to test the noise. Lucky for me I am a pack rat and haven't thrown anything away yet. Not even the OEM crank with all its damage. I have to put exhaust on my daily driver before I take this back down (Not available in an emergency) and once I get that done I can dig in.
Last edited by oldpartsnrust; 08-16-2023 at 05:04 PM.
wideAngle.jpg
number1.jpg
underside.jpg
ok, so I finally got the adjustable pushrod guides so dug in there. I did see a few that weren't perfectly centered. Can that make the noise I am hearing? I didn't know I would need to adjust that as the stock guides had very tight clearance on the holes and the guides don't adjust. Here are some pics of the valvetrain. I think it looks pretty good as far as i don't see any metal or discolored stuff. I do see some of the rollers are not perfectly in the middle of the valve so I am adjusting them and then will reset the preload tomorrow. I was going to put the stock rockers back in but the rocker balls have a larger diameter and they would flop around on the adjustable studs. If I can find the stock bolts I may still do that. Here are the pics of the valvetrain.
It could very well be contact between the pushrods and the guides causing the noise. It's reasonable to assume more deflection at higher rpm. Could always put some permanent marker on the pushrods then run it to see if any scrapes away. Easier than modifying the guides as a test.
The rocker is off-center, but not the way I was talking about. Contact pattern is normally a concern in the direction across the head, intake to exhaust, rather than along the head. I don't see from any of the pictures how the longitudinal offset shown in the picture can be adjusted. That misalignment will translate to the other side of the rocker, offsetting the pushrod and making contact with the guides even more likely.
Wait a minute. It's been a while since I've worked with this setup. Don't the pushrod guides maintain contact to keep the rocker centered?
Last edited by SiriusC1024; 08-19-2023 at 09:08 PM.
That is my understanding, the guides keep the pushrods in place to keep the rockers centered. I do understand the concern about the pushrod length causing the contact pattern in the other axis, but I didn't get there yet. I trusted the 'bolt on parts' and just slapped it together. I did find the OEM bolts and rockers so I can eliminate all but the lifters if the noise persists.
Last edited by oldpartsnrust; 08-19-2023 at 09:38 PM.
Only if the rockers are causing the problem.
I think I found something, with your guidance. Can this make the noise? AND does this uncover that the pushrods are too short? Using the OEM rockers and bolts I was able to align the pushrod guide plates and then swap out one at a time to the adjustable studs without the plate moving. The valve side to side looks much better, but the front to back is obviously sus (or the other way around if you are looking in relation to the engine).
Valve1.jpg
Valve2.jpg
Last edited by oldpartsnrust; 08-20-2023 at 06:47 PM.
First picture is contact pattern at zero lash then second picture is total contact pattern as valve moves? Second picture definitely shows that the contact pattern is way off.
So you can fix the side to side misalignment for all rockers? Was it just the position of the guides?
The pushrod would have to be shorter to center the roller tip contact pattern because the rocker fulcrum is below the valve tip in height. How much, .025 .050, can't say. Looks like you need an adjustable pushrod length checker and test spring. Be careful with the length checker because the test spring might not be strong enough to compress the lifter. If that's the case, factor in how much the lifter should compress vs turns it takes to go from zero lash to full.
Also in the second picture it looks like the pushrod on the right is touching the clearance hole in the head.
Last edited by SiriusC1024; 08-20-2023 at 07:22 PM.
The first and second are after removing the rocker having turned the engine over a few times. They appeared to show the same pattern when I eyeballed it.
I did seem able to adjust the side to side on all on the driver's side, so I am assuming I can do so on the passenger side as well. It seemed to be the position of the guides. I made the (incorrect) assumption that they would align when bolted down during original assembly.
I will look into measuring the correct length pushrods and such. I know this needs to be done regardless, but do you think that could be the noise I (and the knock sensor) are hearing?
The rocker in that pic is loose, so the pushrod is just leaning around, but I will double check when I get back in there for sure!
I think setting alignment and contact pattern will fix it.
Imagine the pushrod being misaligned horizontally. As it goes up what was once clearance will now be a touch point. That's why the guide plates are slotted. Only allow for misalignment in one direction - along rocker rotation. Not across.
Contact pattern could cause noise, too. Worse, it'll break off a piece of the valve tip and wear out the roller tip axles.
Last edited by SiriusC1024; 08-20-2023 at 07:41 PM.
I hope that is the issue. Reassuring to hear that this may be it. It will take me a bit to get this sorted because I don't have the tools for that yet! I was mostly an import mechanic and mostly stock factory stuff at that. Thanks again for all the help!
Also, the pushrods that came with the cam kit were about 1/16" longer than factory.... I figured they were just stronger due to the increase in valve spring pressure, but maybe that has something to do with the contact pattern. You mentioned that once I get a measurement for the one cylinder, it should be the same for the rest correct?
Last edited by oldpartsnrust; 08-20-2023 at 07:45 PM.
I'm just glad that I am able to help honestly. It was to the point of throwing guesses out there.
Do check clearance on the hole in the head. Account for deflection of the pushrod (bending) at higher rpm's. Needs to be a fair amount. Pretty sure those holes are typically machined slotted or clearanced with a die grinder for higher lift cams and bigger diameter pushrods.
Last edited by SiriusC1024; 08-20-2023 at 07:46 PM.
Well, from what I am reading, another benefit of having the proper geometry is additional lift!
Haha true!
Ok, so I don't think I can get much better than this:
Valve1a.jpg
Valve2a.jpg
I think I am the 'victim' of some dumb luck here... Just for the hell of it, I tried the original pushrods since the new cam kit came with longer ones (assuming due to the new smaller base circle) and I needed shorter ones. I guess the decking and the base circle cancelled each other out??? I'll take whatever small favors I can get!
Just waiting confirmation from here that what I think is correct then I can button her back up and see what we have!
Last edited by oldpartsnrust; 08-22-2023 at 05:46 PM.
That's a good pattern. Just make sure the pushrods are up to the task of handling the extra load. Could always order a set of stronger ones that are stock length. Might go .025" shorter than factory length to get it perfect.
Pay attention that the guide plates are sized for the pushrod diameter. Also, no contact at any point of travel on the bottom of the guide plates. Only side to side on those.
Double check that the ball end of the pushrod matches the cup of the rocker! Maybe I'm seeing it wrong, but it looks different between the two. How's that going to be in the lifter cup, too? That could've been making noise and affecting oil pressure, too.
Left to right good I take it? Clearance on pushrod holes in the head? Can't quite tell without being there.
Last edited by SiriusC1024; 08-22-2023 at 07:26 PM.
I have checkers and am going to shorten another 0.025 ( 7.600" and 8.550") and retest the pattern before ordering
The old and new along with the guide plates are all 3/8". I will double check clearance for plates and holes in heads.
The old and new pushrods were the same and I will check the bottom of the rockers when I get the checkers in there. Pretty sure it was the same.
I believe I was able to straighten out the left to right with the guide plates.
Sweet. I think this will be the fix.
Reply With Quote