If saving a little money in one spot but cost you more for other parts to make it work isn’t a savings. Eric thanks for the information. Really enjoy your videos and can’t wait to see more.
It’s my findings that it always goes like that. My last build was a 427 stroker LS (I know, disgusting) it has new AFR 245’s and Jessel shaft mount rockers. And it took a lot of time during mock up to get everything “just right” and there were tight tolerances but nothing was rubbing. First off the rockers were so heavy that max power was at 5600 RPM where it should have been at least 6800. So I used it like that for the season and when I disassembled to inspect there were marks on most of the rocker arms where at some point they were rubbing the retainers. I have since removed the 1300 hundred dollar pain in the ass Jessel shaft mount rockers for the tried and true stock “style” LS rockers that 99% of the LS community uses. All better.
i was about to bite the bullet on a set of jesel pro comp series rockers for my 418 build solid roller... (4.125x3.850 stroke) but ive been leaning over to the texas speed OE style roller tip adjustable ones. i would like to do a nose weight test on both rockers
For solid roller I would only recommend shaft mounted rockers. It’s your lucky day because I have a set of beautiful Jessel shaft mount rockers, 1.75:1, that I would give you a great deal on 😁
I had them send me an assortment of shims, it allowed me to move each rocker to center over the valves, and forgot to mention yesterday, I spot faced the the head bolts on a mill to clear the stands. Neither of those things were mentioned in the instructions. It took me a few hours to mockup right, I engraved them to each cylinder number, and each stand to make sure it goes back on the head it was setup on. It really wasn't too bad, I do not have experience with jesel or T&D to know if installing their products would go any smoother.
I have used over 10 sets of shaft rockers from Scorpion... After the aforementioned alignment issues that are easy to correct with the lateral shim exchange , they have given many hard laps of service on high lift/high rev small blocks...I did have to notch the stand even with head bolts when the thin shims were needed...
I bought a set of T&D sportsman shaft rockers. I had the stands on and off more than a half dozen times grinding crazy amounts of for clearance for the head studs and nuts. Standard part number, standard Dart heads. Sometimes stuff happens. Have been on an oval track motor for three years running like a champ.
About two years ago, I had called Scorpion about their shaft rockers. They were just under a grand for the set, which was $3-400 cheaper than the T&Ds. Ultimately, I went with the T&Ds since I couldn't find much info about the Scorpion shafts. It's a shame that they have caused so many issues because, while they are cheaper, they still aren't cheap by any stretch.
Scorpion list shaft stand shims in their catalog. Just like Jesel do, Jesel’s tool is to obtain proper geometry on a .600” - .800” total valve lift application, on lower than .600” total valve lift applications Jesel recommend raising the stand height, and for higher than .800” total valve lift applications, Jesel recommend lowering the stand. Jesel also do no recommend machining the bottom of the rocker stand if the shaft is required to be lower (theoretically the exact situation to requiring increased clearance above the head bolt/stud) they recommend either machining the cylinder head, running lash caps or installing a longer valve. The theory on the minimal sweep pattern refers to the minimal sweep pattern from half to full lift, which is where the spring pressures are exponentially increasing and this increased load can cause the greatest guide wear. And Jesel also offer a 6 degree angle style body, which would be similar to the scorpion. T&D offer 5 different variants on their stand height gauges. .550” .650” .750” .850” and 1.000” designated lift and also stand shims. T&D only lack the angle body variant that Scorpion and Jesel do. The height checking method used by Scorpion for their shaft rockers is the same as what Yella Terra use. In any multi pivot system there are multiple variables that can be changed if geometry checks out undesirable to end up with the exact same correct geometry. The goal is the same for all rocker systems, regardless of the mounting style.
interesting comment on the minimum sweep during the half to full lift portion of the event, makes some sense. Also contradicts the midlift at 90* theory and reduces total lift some.
@@roberthollinshead2325 Simply just a note for future use: The degree symbol is created with Alt held and 0176 typed from number pad. Alt0176 90* is now 90°, 180* is 180°, 45* is 45°, 230* is 230°. Found that and saved it on a post-it note by the 'puter. ✌
I have the Scorpion 1.5 1.6 shaft rockers on Dart Platinum 215 heads with ARP studs no problems whatsoever everything fit perfectly after one and a half years I had the bearing go out and one rock her and Scorpion replace the whole set free of charge
I'd have to see for myself, but from what I can see, you could cut the one piece bridge bar Into 4 pieces so the rockers are in pairs. You could slot the bolt holes in a milling machine if it won't center over the valves. You may also find the bridge bar may have to be milled in height to allow the rockers to fit On some applications. So long as the roller tip covers the full width of the valve stem, you shouldn't have an issue. These things are what separates Engine assemblers from Engine builders, and those who may or may not call them selfs Engine builders. As engineering Toolmaker myself, if it won't fit, make it fit.
I think you missed the point. I shouldn’t have to modify machined parts to make them work. It’s not that I can’t make them work, it’s that I shouldn’t have too.
Hey bud.. don't worry about it. I'm glad you show the ups and downs of how it really works to build something from mixed companies and their parts. People need to see that it's not all rainbows and unicorn farts!
I know you have mentioned core shift in the raw casting before, do you think that the machining of heads could be out of spec far enough to cause the roller alignment issue that we saw when you mocked up the rockers the first time? Tolerance stack might be coming to play here as well.
Eric Weingartner, if you have a lathe, u can face off the ends of the head studs as long as u maintain a full nut. Also, are the locks set up for the sewer lid style lash caps? If so, would that buy u an adequate amount of clearance between rocker arm and retainer?
My friend assembles race engines and ran into same issues with scorpion shaft mounts on big block Chevy. Shimming, lash caps, special valve covers etc..took 2 months to be ready to order pushrods
A big design flaw I see in every shaft rocker system, no matter who manufacturers them. Is why does the axle shaft sit above the C/L of the saddle. This puts all the bending force on the hold down bolts. I re-machine the saddles so the shaft is even or slightly below the C/L of the shaft, this puts the bending force back on the stands not the bolts.
On SBF with Jessel rockers I have had to get the shaft mount/stand offset machined .050 toward the intake. A lot more time involved than most will ever know........
Eric a comment on that chevy that was making lots of hp but at too high a rpm for the usage (maybe he wanted some longevity) I think I said I'd have advanced the cam which U did later in the video. Another option would be to go with some really high ratio rockers and a shorter Jones cam ( with really strong pushrods) I think the low end would come up, hp would stay high but would drop off in the can't use it anyways range. On a street strip car I would just drop the ratio but evidently not the thing to do here Merry Christmas
Be interesting to see if you had more retainer clearance without the .2 shims. Try without head bolts. Maybe machine studs to correct height for this application. it's always something. Jesel. Thanks for sharing. Cheers!
I had to turn studs down on a lathe to make rocker stands clear... on everything too... BBF...BBC... SBF... SBC... FORD FE... 3 TO 4 studs per side.... put slot in top to help remove them with head on...
Any chance you are running a +0.050 retainer or lock? Could add some rocker body to retainer clearance with different retainers, locks or lash caps as others have mentioned. Changing the retainer or lock will of course change your spring installed heights. Assuming you have some wiggle room on installed height. Also agree on turning down the top part of the studs in a lathe to make them work.
On my 434 i was running t&d that shafferoff put on and notched out to fit the value springs and was all set up wrong and a couple broke and i could tell they were not going to take responsibility socalled t&d and they suggested me to use the chromoly rockers and to use a smaller diameter. After talking to to joe at sunset race engines. And finding out shafferoff had the wrong springs for this cam installed and had isky redzone lifters with out the offset we ordered the correct lifters and the right springs with smaller diameter and installed lash caps that should have been one to keep the value tips from mushrooming and help with the setup
Good Info. It's always something when trying out new combinations. Then there's a domino effect with the plan. Question, why no lash cap? For my stuff it saves the valve tip from wear. It would seem to help with your rocker clearance as well. Which i think is another reason I started using lash caps.
I can respect that philosophy. As an engine builder we all have to pick our compromises to make something work for what we want to achieve. A NASA engineer quote, “Cheaper, Better, Faster, you can only pick two”
I thought about that but you are adding more mass to the valve and you would have to buy more shims to get it right. In the end it would cost another $150 or so and give me less valvetrain control.
@@WeingartnerRacing I've ran into this several times. I cut the studs even with the top of the nut and cut a screwdriver slot on top of the stud with a cutoff wheel. Maybe lower the retainer with a .050 lock and re-shim springs to within .030-.040 from coil bind at max lift. (If springs allow)
Minor detail in spite of all the other problems you found, but it looks like you had the rocker with the larger pushrod offset on the exhaust side rather than the intake.
@@WeingartnerRacing I stand corrected. Just looked like the placement of the adjuster bolt hole was more centered on what you had as the intake rocker 🤷♂️
I was looking at Jessel and T&D catalog. Do the instructions state anywhere if you have to have 3/8 screw in studs or the upgrade 7/16 screw in studs. I think I saw the picture of the instructions in this video that said 7/16 bolts hold the shaft mount down. Did you use the Scorpion shaft rockers on the Pro Maxx heads also?
What would really be nice would to see the kit set up on the exact head it was made for. The set I purchased for my 420 SBC with AFR 227 heads fit perfect with .180 shim Heads have =180 valves with +.100 lock groove (1.950 install height) It has performed flawlessly for 6 years. The head studs fit fine. I operate it Only into the 7200 rpm range at .730 lift (Isky custom grind). I have never reached valve float but do have minor marks on the rockers from the springs moving around. I know the extra tip height works to my benefit. Would a lash cap not work the same in your application?
It's a lot of work,normally you would expect them close to what they are made for? probably be a lot of variables for a average person? hope you can sort it, all the best to you and your loved ones
I don’t get how on my sbc with AFR 220 heads with the little M block the jesel shaft rockers cleared my head studs. Yes it came with those special bolts with the torx flat heads on them but I didn’t have to run them. I got the jesel sportsman kit for the AFR 220 heads and was concerned but if memory serves me correctly I had around .030 of clearance after torquing everything down. I did have to cut the edges off a few cheap harbor freight feeler gauges to get it to fit in that tight spot but I was concerned that when heat got in the motor,that it might expand putting pressure on the shaft mount. I thought this cause aluminum heads with cast iron block an then steel mount,all the metals will expand at different rates. So clearly I was nervous but I haven’t had a single issue. Honestly the only real clearance issue I had was I had went with .120 wall 3/8 diameter pushrods and on the AFR heads they didn’t really clean up the casting edges all that well and in a few spots I had to take a die grinder to those casting edges to prevent the pushrods from rubbing. I really am puzzled by how much more your stud protrudes into that shaft mount compared with mine,it seems as if I have like 4 to 5 threads that just peek through the nut after it’s torqued. The stud kit is just the off the shelf ARP head stud kit that Dart recommends for there block and it’s the same one that AFR recommends for the use with their heads,so I know I don’t have anything specifically special. If you have a jesel kit laying around ya might wanna give that a shot and see if ya have the same issue. Sometimes spending a little extra money initially does end up saving you money in the end.
It’s unreasonable to expect parts manufacturers to account for every possible parts combination that people can come up with, especially for the SBC. Figuring out how to get around issues like this is what separates “engine builders” from mere “engine assemblers.”
Sorry the rockers aren’t working out. You never can tell if something is going to work with your specific application. You mentioned in your video you were still waiting on the rotating assembly. Have you ever tried Ohio Crankshaft? They are fellow racers too. I’ve heard a lot of good things about them. I unfortunately haven’t had a need to use them yet myself.
They'd be a big no from me dawg. Personally, I've never been a big fan of Scorpion products. For me, this just reiterates my opinion. I know the wait time from Jesel is a PIA, but for everything it appears you'll need to go through to get those Scorpions to work, I'd opt for the "right" way, bite the bullet and go Jesel. By the way, what kind of company produces a shaft mount rocker that really only works with head bolts. Most people who are the point of going with shaft mount have also likely stepped up to studs.
Just curious why no lash caps? that would increase your retainer clearance and probably require a stand height increase as well for possibly more stud clearance.
It solves the retainer to rocker issue for a very low cost. The added weight is very low. The height of the lash cap would also raise the stand, and clear the head stud better. Seems like a win win. I hit the LIKE button! Haha
Are the scorpion rockers a lot cheaper than jesel or t&d? With all the problems just to “make” it work and not getting 100% good feelings about it, me personally, wouldn’t run them. Valve train and lifters are the most common failure points, not a place in my opinion to take a chance. My ocd would always keep me thinking about that and on race day one less thing to think about the better. Just my two cents.
@@WeingartnerRacing The lash caps give you a wider foot print for the wheel on the rocker and protect valve tip plus you gain a bunch of clearace between rocker and retainer. As far as the stud versus bolt, I rarely use bolts and always shorten top of stud to clear rocker bar, especially on Jesel. T&D rocker bars are machined out more for clearance. This is common in building motors, rarely do you buy off the shelf parts and expect them to fit without some modifications.
What's your professional opinion on ebay's knock off jessel shaft rockers, are they worth using? Their alot cheaper, but im also concerned of the whole "you get what you pay for"?
You could machine one side and a shim on the other side of the rocker,? but why would you want to buy something you have to spend time machining, your time is money made or lost, they need someone who knows what their making, now you loose weeks machining fitting etc, all the best to yous and your loved ones
Each rocker has circlips that locate it on the shaft, they are shimmed side to side, I had to move shims around when I mocked up the scorpion shafts on afr 195 heads. The instructions don't mention it, but an email to their tech support and they overnight me extra shims and clips, plus 3 extra bearings in case you drop a needle bearing when you are doing setup. Pick your poison, pay 3-500 more for jesel/T&D with head bolts for under the stands, and a more plug and play experience, or spend a few hours doing mockup and save the money (enough to buy a cam and pushrods at the time I did mine) Sheldon Barrs also makes a great set of "sportsman" rockers for a good price.
Each rocker has circlips that locate it on the shaft, they are shimmed side to side, I had to move shims around when I mocked up the scorpion shafts on afr 195 heads. The instructions don't mention it, but an email to their tech support and they overnight me extra shims and clips, plus 3 extra bearings in case you drop a needle bearing when you are doing setup. Pick your poison, pay 3-500 more for jesel/T&D with head bolts for under the stands, and a more plug and play experience, or spend a few hours doing mockup and save the money (enough to buy a cam and pushrods at the time I did mine) Sheldon Barrs also makes a great set of "sportsman" rockers for a good price.
@@WeingartnerRacing Been running them for years now keep from beating up your valve stem everything is always a double edged sword now day's enjoy your video's.
A solid "nope" from me. I wouldn't even count on the casting of those rockers to withstand anything resembling racing. One or two dyno pulls maybe, but that's about it.
