Excellent video. I was recently having a discussion with a friend and fellow old car nut about roller rockers vs stamped steel rockers. Your video taught me things about rocker arms that I didn't previously know and also corrected a couple of misconceptions I had regarding their performance. Thanks for furthering my understanding of engine design.
@alleyoop1234 Жыл бұрын
David Vizard also has a good video on rocker arms
@goldsgarage8236 Жыл бұрын
Thanks for the information. I think I have watched it. AG
@johnj24968 ай бұрын
david vizard has a great video on dang near anything go faster run better auto he probably has forgotten more automotive knowledge than i can hope to gain and i would be happy knowing that much
@hotrodray68024 ай бұрын
You should have included the ratio at .150-.200" lifter lift. Some rockers are a better off-the-seat ratio giving more area under the curve. Back to back dyno tests show 12-20 hp better.
@goldsgarage82364 ай бұрын
Thanks for the question Ray. i have another video where I compare lifts every 10 degrees through the entire lift range if you want to check it out. AG
@alleyoop1234 Жыл бұрын
Pretty sure the dark gold rocker arm is a Harland Sharp brand. Always known for quality!
@greenmirror5555 Жыл бұрын
At 10:03 you can see both are stamped CRANE. You are correct that Harland sharps are that Orange gold anodized color and a little more square shaped.
@woodydavis8287 Жыл бұрын
Thank you for the time and diligence to document these parts
@goldsgarage8236 Жыл бұрын
Thanks Alley, GREEN is correct, they are CRANE. AG
@goldsgarage8236 Жыл бұрын
Thanks GREEN, you are correct. AG
@goldsgarage8236 Жыл бұрын
Thanks Woody. Thanks for watching and commenting. AG
@user-zu2ed6ye5w4 ай бұрын
Last week i tested 2 sets of. 1.6 rockers from 2 different companys and one companys gave. O24 thou. More lift !! Got to check everything !
@goldsgarage82364 ай бұрын
Good point, that was the inspiration for this video. AG
@Kissmyass247 Жыл бұрын
Great info! I really appreciate your scientific testing and comparison.
@goldsgarage8236 Жыл бұрын
Thanks Kiss, glad you appreciate it. AG
@drussell_ Жыл бұрын
The effective ratio actually changes as the valve opens due to geometry changes as the contact area on the valve moves, etc. It would be even more interesting to see the results taken at, say 5-6 different points along the valve lift cycle, then show a graph of them overlaid for additional insight on the analysis.
@goldsgarage8236 Жыл бұрын
Thanks for the suggestion drussell. I will need a second dial indicator so I can measure cam lift and valve lift at the same time, or just record cam lift at incremental points, document that, then record valve lift at the same points. It will be easier and more accurate with the crankshaft in the engine so I can use my degree wheel to record the points. As soon as I receive the crankshaft I will try to mock it up so look for a follow up video.
@drussell_ Жыл бұрын
@@goldsgarage8236 Yeah, it is probably simplest to just measure the lobe lifts at incremental points using a degree wheel, then measure the actual lift at the valve at those same points. This is one of those things where the overall geometry matters, and it is significantly more complex than it appears at first glance. For example, for those of us with shaft-mounted rockers on our Mopars, you can even change the effective ratio just by using longer pushrods and shimming the rocker shafts up a bit so that the face of the stamped steel rocker contacts the valve stem tip "further out" on the rocker. This is one situation where the difference between the shaped tip of a classic stamped rocker vs. roller makes a difference too, the stamped one slides across the valve more and can change effective ratio wildly depending on the shape of that tip and where it is in that part of the rocking-motion. The guys that run in various "stock parts" classes have been exploiting things like this for decades. It's all very interesting. 😀
@goldsgarage8236 Жыл бұрын
Thanks for your input. I will do the test as soon as I get a crankshaft in the engine. Watch for it.
@earlbrown5 ай бұрын
I know this is old, but you're right about the varying ratio as the rocker goes through it's lift. ....kinda. What you said is true IF you have improper rocker arm geometry from the wrong length pushrods. Usually when people use pushrods that are too short to put the contact patch in the middle. (or a stock shoe type rocker where the rockers contact point moves to the outside as the rocker opens the valve). That includes using that plastic tool that has no idea how many degrees of rotation the rocker is going to see (I.E. the amount of lift the valve will see) If you set up a roller tip rocker with correct geometry, the contact area pushes almost straight down through the entire lift/close cycle. (and it is straight down at the middle of the lift). Don't that will make the witness mark as thin as a needle. ...and if it's not in the middle, you have the wrong rockers. Not the wrong length pushrods. I'm really curious how close those varying amounts of ratio would have been on that test if they were set up with correct mid-lift geometry.
@craighightower4736 Жыл бұрын
Great information. I think manufacturers should have to include test results with their ads and catalog descriptions.
@goldsgarage8236 Жыл бұрын
Great point! thanks Craig
@johncalhoun801111 ай бұрын
I think so too
@The_forgotton_one9 ай бұрын
I've gone with yella Terra 1.7 adjustable shaft roller rockers as I'm from Oz and will always buy local before anywhere else, so I know the quality is as good as it gets for my ls 427 cost 5 times more than the trunnion upgrade but I'm expecting to Rev my engine hard into 8k + zone
@goldsgarage82369 ай бұрын
Thanks for your comment Chevy. AG
@theguy9234 Жыл бұрын
Yes Interesting tests. Thanks.
@goldsgarage8236 Жыл бұрын
Thank you!
@racerd966910 ай бұрын
You do not mention the rocker stud size, but it looks like it is 3/8, if so you need to change to the 7/16 studs. It will change the valve lift and stabilize the valve train. Another common mistake I see all the time on stud mounted rocker systems is the length of the shank on the rocker stud. The rocker trunnion should NOT run on the threads of the studs. As you can see the threads have shinny spots where the rocker trunnion is slapping against the studs, that can change you valve lift also. Another note if you are looking for Max power, you need to adjust the push rod length so the contact patch favors the ex side of the valve. Great vids as always.
@goldsgarage823610 ай бұрын
Thanks as always for your input and information Racer. AG
@Twogreenfeet4 ай бұрын
Why the exhaust side and not the middle where less valve guide wear (friction) happens?
@richardwalling9695 Жыл бұрын
Our car owner sent our GM 604 crate engine to McGunegil in Muncie Indiana with 1.6 Chevy rockers and they checked out at 1.65. Which were illegal and we had to buy rockers that checked out a 1.6.
@goldsgarage8236 Жыл бұрын
Very interesting, I have never checked out any that were more than advertised.
@richardwalling9695 Жыл бұрын
@@goldsgarage8236 do you use Chevie's jig to check them?
@goldsgarage8236 Жыл бұрын
First I use a dial indicator to measure the lobe lift, then I use a dial indicator right on the valve. Then do the math. In Pro Late Model racing the tech guys use a go-no go gauge as per the GM circle track manual. I am working on a video where I measure the lift from off the seat to max lift at 10 degree increments of crankshaft rotation, then calculate the average ratio.
@patrickmoore10177 ай бұрын
Very informative and great video.
@goldsgarage82367 ай бұрын
Glad it was helpful! AG
@4speed3pedals Жыл бұрын
I like PRW prices but there is a caveat, China. I have vowed not to purchase things for my engine that are made in China. I have been on the short end of the stick too often. Blue Scorpion is produced in Florida.
@goldsgarage8236 Жыл бұрын
Thanks Stovebolt. Good to hear from you and sorry I missed this comment until now. Blue Scorpions are great. They need a lot of room under the valve cover. I agree about china but it is getting even harder to build anything without something from there. AG
@gearhead7896 Жыл бұрын
Do you know the story of Jesel that launched that business? I think you would find it very interesting. Also, that is a great idea with bolting the carb lift plate to the head for a surface to put the mag base to.
@goldsgarage8236 Жыл бұрын
Thanks for your comment Gearhead. I will look into the Jessel story. AG
@samh8164 Жыл бұрын
Good info !
@goldsgarage8236 Жыл бұрын
Thanks Sam, glad it was helpful. I am still planning a follow up to demonstrate ratio over the full cam cycle from lifting the valve off the seat to full lift.
@samh8164 Жыл бұрын
@@goldsgarage8236 Insightful :)
@maldo72 Жыл бұрын
great info
@goldsgarage8236 Жыл бұрын
Thanks for your kind words maldo72. Please keep watching my channel. AG
@maldo72 Жыл бұрын
@@goldsgarage8236 will do keep it coming
@larryperry2094 Жыл бұрын
Nice to see accurate numbers. Advertised ratings give me a headache.
@goldsgarage8236 Жыл бұрын
Thanks for your comment Larry
@johncalhoun801111 ай бұрын
Nice
@goldsgarage823611 ай бұрын
Thanks for watching my channel and commenting John. AG
@johncalhoun801111 ай бұрын
@@goldsgarage8236 Absolutely! I Love your Chanel. Maybe I can get you to build me a good street Engine one day? Or recommend someone to me.
@RonaldLewis-py6yt9 күн бұрын
Question would you use 1.65 on the intake and 1.60 on the exhaust or ir it reverse, like your content! I'm in a 383 build soon and want max power for my 4wd no mud just highway!!
@goldsgarage82369 күн бұрын
Good question Ronald. It is hard to say without testing. It depends on how efficient the intake side of your induction system is compared tot the exhaust. If you have a good exhaust side, headers etc. It is possible to over scavenge and send good unspent fuel out the exhaust. I would start with the 1.65 on the intake side. AG
@RonaldLewis-py6yt8 күн бұрын
@goldsgarage8236 Yes sir Air Gap with 383 and hydraulic roller for 4wd extreme 202 and 160 ported to felpro 1206 I will run 750 down legged boosters and msd ignition 6al I wish I could afford dyno tuning too!
@RonaldLewis-py6yt8 күн бұрын
Ole yeah 15/8 headers and no restrictions flow master exhaust
@amiabledave50 Жыл бұрын
What do you consider to be the best rocker arms for marine/circle track where RPMs are high (6500) for long periods of time?
@goldsgarage8236 Жыл бұрын
Thanks for the question amiable, and I am sorry that I missed it until now. I think they all are up to the task. From my experience in Pro Late Model Racing, the GM performance (the aluminum colored ones) are the standard in all CT400 race engines. The mandated max RPM is 6400 and we run on the chip every lap. I have never seen one fail. I also have them in my Z28 Camaro. Hope this helps. AG
@amiabledave50 Жыл бұрын
Thank you for the reply
@Allthrashedout. Жыл бұрын
great vid whats the blue tool called ?
@goldsgarage8236 Жыл бұрын
Thanks for the question Punter, the blue tool is a Proform 66789 Push Rod length checker. You can buy it on Amazon for $23.96 $CAN or about $18 USD
@Allthrashedout. Жыл бұрын
@@goldsgarage8236 thanks very much
@NBSeventyseven11 ай бұрын
Hello, I would like to change the rocker ratio on my 92 Firebird from 1.5 (original rocker) to 1.6 (Comp Cams roller tip rocker). Would the engine control unit get this regulated because of the every 2 year exhaust gas test that we have to do here in Germany? My car is a 3.1 V6 but I like it a lot and want a little more power without making it complicated. Thanks in advance.
@goldsgarage823611 ай бұрын
Good question NBS. In my opinion, I think you will be OK. If you were increasing the duration it might be a problem because it would make the engine less efficient at idle, however by changing rocker arm ratio from 1.5 to 1.6. you are only increasing lift just less than 7% with a negligible increase in duration. Hope this helps. AG
@Twogreenfeet4 ай бұрын
@@goldsgarage8236 Put a degree wheel on and prove that duration is 100% not affected
@jamesmedina20629 ай бұрын
How old are those Crane rockers? They look nothing like my gold Crane rockers made in the late 90's.
@goldsgarage82369 ай бұрын
Thanks James. Not sure how old they are. I inherited them from a previous video. AG
@jamesmedina20629 ай бұрын
@@goldsgarage8236 Crane was the goto quality rocker but they say Crane went downhill and Scorpion is the good one now
@bengibson8778 Жыл бұрын
Is 110 octane unleaded race gas good enough for 13 to 1 in a SBC
@goldsgarage8236 Жыл бұрын
Tough question Ben. IT depends on many other factors, ignition timing, cam timing, intake valve close ABDC, dynamic compression, cranking pressure PSI, aluminum vs. steel heads. If you have lots of compression, you need a cam with lots of duration and vice versa. Another factor is how the car is driven. Lugging the engine at low rpm with high volumetric efficiency is always dangerous. All that said, 13:1 is a lot, I think I would play it safe and use a higher octane to start. Read your spark plugs, they are a good indication of what is going on. Using a colder range spark plug and back off the timing advance to start. Hope this helps.
@Aph873 ай бұрын
Stock rockers are trash
@richardburns-uz7of Жыл бұрын
I thought that was Nick's Garage guy. must be his brother
@goldsgarage8236 Жыл бұрын
Thanks for the compliment.
@brianholcomb64993 ай бұрын
Just use good name brand parts! Those PRW steel roller tip have never shown any performance, usually the opposite! Valve float much earlier! You also don’t want to use the smaller studs! (Unless it’s a low rpm pickup truck engine!) If you are building a performance engine & buying rockers, get the bigger studs! American made stuff! Overseas garbage makes more problems than they are worth! On lower power circle track spec type engines, the difference from the stamped steel, (stock stuff) & the Chevrolet roller rockers were very little! 1.5 to 1.5 it was only a few horsepower!