That's interesting. I've looked at shaft rockers in the past and was dumbfounded by the cost. Why the .200 offset? What kind of valve covers do you have?Originally Posted by spfautsch
To test this on my car, I have some roller tipped stamped steel rockers in a box somewhere from days gone by. Can I leave my guide plates in for a test? I am thinking not.
Thanks. Here's a crappy video showing some of the necessary mods. [link] (81mb)
I was also initially dumbfounded by the cost, until I owned two sets of very expensive stud mount roller rockers, two sets of custom length pushrods, three sets of adjustable guideplates, and all the time I wasted trying to make it all work. Hindsight is what it is.
Stock valve covers but some of the supports had to be trimmed to clear the shaft mount bases. Slightly modified 3/8" thick perimeter bolt standoff spacers were glued to the heads with rtv to give necessary clearance. Longer center studs were custom fabricated by a guy with a tig welder and lathe who needed an excuse to (use them / get away from his wife). Getting the stud height correct (the seals want about 0.040" crush) was the toughest part. The 0.200" offset corrects the difference between lifter bore centerlines and valvestem centerlines so there's no lateral deflection. Added bonus here is there was some seat of pants increase to be felt with the shaft mount setup due to eliminating all valvetrain deflection.
If I had it to do over again I would have spent more time milling the 3/8" standoffs so the valvecovers would have fit better.
I doubt your roller tipped stamped rockers are self-aligning, and even if so the guideplates themselves are a possible source of noise. Without the 0.200" offset there is no way to get stud mounted rockers to align with the valve stems without having the pushrods non-parallel, which causes sideways deflection. The rocker arm tip is pushing down on the valvestem, while the spring load causes the rocker arm to want to sweep away from the cylinder bore center, loading the pushrod against the guideplate.
Last edited by spfautsch; 07-14-2020 at 06:06 AM.
Thanks for making that video. It's very informative and you have done a really nice job there.
When I first read the post, I read it as you getting .040 crush on the valve stem seal. I'm thinking, how in the hell am I ever going to figure that out. lol
I have a set of tall valve covers I can use while I'm trying to figure out doing it the way you did or maybe an alternative method.
Do you have to shim the mounting surface to get the proper rocker arm sweep on the valve stem? Is the preload and final adjustment done with the adjuster?
Do you just bolt them down and set your lash?
Thanks
Edit: was your knock similar to what shows in my graph?
Last edited by A95Y; 07-16-2020 at 07:00 AM.
These look promising.Jesel-Premium-Stud-Rockers-Head.jpghttps://www.jesel.com/premium-stud-rockers
Yeah, no. The valve cover mounting studs I made had a 1/4x20 base thread so I left the nuts that lock against the head bosses loose. Adjusting the heights on these so the valve cover seals were "good" was quite a chore. At least a quart of Mobil 1 0W-40 was sacrificed in finding the right amount of seal compression. If I could've found a source for 304L stainless bar stock of the right diameter I would have just turned them to a pre-determined height and been done. But I'm not quite equipped with the tooling to do that efficiently. It's quite a redneck operation I run here, and I'm not ashamed to say so.
I couldn't find anything pre-fabricated that I was comfortable paying (ridiculous amounts of money) for, so I did this, and I love the "sleeper" look. Bear in mind I already had a set of coil brackets for my coil-near-plug setup fabricated that wouldn't fit a F / B body (stamped steel) valve cover design, and didn't want to toss them in the scrap bin.
Yes, and sort of. If you go to something like this you'll want to buy an adjustable length pushrod and get accustomed to spending hours hunched over your front tires (or just do what I did and yank the engine for the fifth time in 2 years). See my next comment about final adjustment / lash.
My lifters are solid, so after finding a shim height that gives a good sweep pattern and have the bases torqued down I set my lash "the old fashioned way" with a feeler gauge. But with hydraulic lifters you can probably set them once and be done. The manufacturer says you should only go to 3/4 of a turn from bottomed out for lash adjustment, so in my case I was contemplating 7.250" pushrods to give me roughly 0.040" preload with the Melling LS[x] hydraulic lifters. Once you get your preload set you can just treat them like LS lifters and run each cylinder pair down until the shaft seats on the pedestal, and you're done forever.
Bear in mind that the 7.250" pushrod length is dependent on your valve stem length, head gasket thickness, and how much your head decks have been milled. You don't (or I've apologetically overlooked if you have) specify any modifications, but Lloyd likes to put +0.100" stem valves in when he works on a pair of heads.
Not entirely. The knock pattern that you're seeing running along the RPM axis - left to right - is probably all or at least mostly false knock.
On the other hand, the knock pattern you're seeing running along the MAP axis - top to bottom - is probably not. You should look at your timing tables and see if something seems to match up.
Neat info on the Jesel LS type lifters "for legacy applications". I'm sure they're priced $$$$$$$ accordingly. On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
You have no idea. I have a piece of rope, a divining rod and a hammer.
I bought some cheap aluminum valve covers. They were around $100 a few years ago. I had to modify them a little with some brute force. I also had a smaller alternator made by a local shop to lose some weight for drag racing. I like the sleeper look as well. I wouldn't want to keep those valve covers on forever, when i make the change. It's good to know I have something ready to go.I couldn't find anything pre-fabricated that I was comfortable paying (ridiculous amounts of money) for, so I did this, and I love the "sleeper" look.
I have 2 sets of heads. Currently, GM LT4 castings built and ported by Lingenfelter. Nothing on the receipt indicates any alteration in valve stem length. My other set are the stock heads, again built and ported by Lingenfelter. Both sets have the same components, the flow numbers are about the same. I should have stayed with the OE heads and saved a couple grand. My block has been decked.[/QUOTE]Bear in mind that the 7.250" pushrod length is dependent on your valve stem length, head gasket thickness, and how much your head decks have been milled. You don't (or I've apologetically overlooked if you have) specify any modifications, but Lloyd likes to put +0.100" stem valves in when he works on a pair of heads.
Yea, they look like the optimum setup to me. I just got an email back from Jesel and.......wait for it..................$1550. I thought they'd be cheaper for some reason. I almost pulled the trigger on the Scorpions today. I'm still sleeping on it.Neat info on the Jesel LS type lifters "for legacy applications". I'm sure they're priced $$$$$$$ accordingly. On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
Last edited by A95Y; 07-17-2020 at 09:02 PM.
Boy, the guy at Jesel did not like it when I asked him if Scorpion made their shaft rockers and I asked him for help on pricing. He said they make their own parts in the USA. He said you can’t compare Scorpion to Jesel, they are two completely different companies and he was already giving me a discount on the premium studs. He didn't think he could help me and good luck. The old saying "It doesn't hurt to ask" did not apply in this case. Oh well.On a side tangent, I bought the Scorpion setup because I've read on numerous places on the interwebs that Scorpion manufactures the shaft mount setups for all these "name brand" vendors (Jesel, Comp Cams, Crane, Lunati, etc.).
These performance parts companies are pretty much all like this. The lifters I bought are branded Lunati, but they look identical to Morel branded lifters that normally sell for slightly less (when Jegs isn't offering a $100 discount). I'm relatively sure all the LSX lifters on the market are made by Melling and possibly one other company.
Before you go dumping a bunch of money I feel compelled to ask if you've looked for all other possible causes of false knock. Such as:
* exhaust hitting the body
* a cracked piece of exhaust equipment (cracked welds on my exhaust tips set the sensors off like nobody's business)
* single mass flywheel + rough clutch engagement
* loose motor mounts
* <I'm sure I'm forgetting 15 other things>
I am going to have to put some SA rockers on and remove the guide plates and re evaluate. I have an A4. I will check for the obvious.
Tried getting lucky with the exhaust. Spfautsch had mentioned this as well.
no exhaust.jpg
There are some short pipes still attached that go down the start of the tunnel. I woke the whole county.
Well, my W10 laptop lost it's display and I lost my enthusiasm for a while. I have W10 dual booted on my Mac, it's a PITA to get the USB loaded with the Thunderbolt ports. The resolution of the Retina display screenshot is impressive. The green knock looks like it is on the Y-axis or that may be where the data points hit to make it look that way. I was mostly driving around in 3rd. I did one smoker.
What I did since the last post was reinstall my exhaust and install the slotted 1.5 stamped rockers with no guide plates. spfaugsch was kind enough to lend me a set to hack up. I did nothing with the tune.
1.5.jpg
I'm not sure what to make of that, maybe someone else has some ideas. The "raindrop" alignment on the MAP axis seems really unusual. Normally MAP numbers generate purely random patterns.
Glad you were able to make use of the stamped rockers - hopefully it wasn't a waste of time.
I got someting similar for no reason, just by the preload on the lifters. Anything over a 1/4 or 1/3 of a turn made the knock sensor go crazy.
Not a waste at all. Thank you. Another thing that happened is my car idles better and turning on the A/C at an idle doesn't kill it. I wonder if I should put 1.5's in it? Is the 1.6 ratio changing my duration undesirably since my cam is spec'd with 1.5 ratio rocker arms?
.
Did you get rid of it by adjusting the preload? I'm not going to try and address it with these rockers, just curious.
I have another question. Will that mysterious knock affect my 1/4 mile E.T.? At WOT will the sensors hit that area, if that makes sense?
Thanks
That's baffling. See my request at the end of post.
Knowing you're shooting for better ETs, I would have to say no. Off the top of my head, the only things I can fathom might cause the car to idle better with the stamped SA rockers is:
1) lack of knock retard due to less valvetrain noise
2) less valve overlap due to less duration
#2 seems like a stretch since the decrease in duration / overlap is doubtful to be enough to make a discernible difference with idle quality.
At any rate, knowing you're aiming to lower your ET I would personally be shooting for more lift rather than less.
If you have logs that you wouldn't mind sharing - both of a 1320 pass, and then of idle before and after going back to stock rockers it would be easier to answer. If you're seeing any knock retard in the load cells in question then the answer is most likely. But we don't know your tune - for all we know your knock retard tables are bone stock, or completely zeroed out.
BTW, since I'm sitting on the balcony watching a storm roll in on the beach I just re-read the entire thread a bit more carefully. If you still haven't been able to find your original knock module, I'd be happy to trade you for my LT-1 module for a few days / weeks if you wanted to test that.
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