Roller Rockers/1.6 Rockers/Roller tip rockers

Installed the 1.6 Crane long slot stamped steel rockers. Seems like everything works good except I can "hear" the valve train now unlike before with the 1.5's.(and that's over the flowmasters :) ) Not one particular spot, just the whole thing.

Clearances checked out fine (very mild cam) except it was hard to measure rocker to valve stem contact with the stamped rockers to determine if I need different length pushrods.

Has anybody done this swap and is more valvetrain noise normal or would you buy one roller rocker and try and check pushrod length?

Thanks for listening to my rambling. :)

Did you readjust the valves properly? Did you double check? Triple check? The majority of valve train noise that I've experienced has been from poorly adjusted lifters. I pull up and down on the pushrod until all of the play has been removed, then I go a little past half a turn for lifter preload. Seems to be just about perfect.

Kev

Did you readjust the valves properly? Did you double check? Triple check? The majority of valve train noise that I've experienced has been from poorly adjusted lifters. I pull up and down on the pushrod until all of the play has been removed, then I go a little past half a turn for lifter preload. Seems to be just about perfect.

Kev

I double checked them before firing it up, I'm gonna triple check them after they sit for a while. Just thought I'd see if anyone else had done this swap while I'm waiting. :)

I always set at 1/4 turn preload. I heard the less you can get away with the better. Maybe I'll try the 1/2 turn.

Are the push rods binding in the push rod sots?

Are the push rods binding in the push rod sots?


Is that what the louis tool is for (I think that is what it is called) to lengthen the pushrod slot a bit?

Are the push rods binding in the push rod sots?

I'm assuming you mean the casting holes in the heads? I don't have guide plates. I was gonna check again for binding also. I didn't see any the first time around. If I still have that much noise I think I'll just swap back. For the very small gains I've heard about(if any) it's not worth the hassle.

Is that what the louis tool is for (I think that is what it is called) to lengthen the pushrod slot a bit?

I've heard about one of those, but know nothing about them. Wouldn't they get metal shavings in you motor? Dumb question?

I'm assuming you mean the casting holes in the heads? I don't have guide plates. I was gonna check again for binding also. I didn't see any the first time around. If I still have that much noise I think I'll just swap back. For the very small gains I've heard about(if any) it's not worth the hassle.

Just pull out a couple of the push rods if they are binding I would suspect it should put a mark on it somewhere. The net gain in lift is somewhere in the area of 6.7% when you switch from 1.5 to 1.6 ratio rockers.

I'm assuming you mean the casting holes in the heads? I don't have guide plates. I was gonna check again for binding also. I didn't see any the first time around. If I still have that much noise I think I'll just swap back. For the very small gains I've heard about(if any) it's not worth the hassle.


Not sure if that kinda thing can be done with the heads on the car but if it can I would think that getting metal in the motor might be an issue also.

Sure enough, it looks like the pushrods are rubbing against the casting holes. There are no marks on them, I don't think they are binding, but very close. With the 1.5 rockers they are about perfectly centered in the holes; with the 1.6 I have less than .020". I guess that means I need shorter rods or bigger holes. :rolleyes:

Anybody want to take any educated guess on how much shorter I need to go? I would have to order them tonight if I want them here by this weekend for the drags.

I know there's probably too many variables for a guess. If I can't find an adjustable one locally for some tests, I'll just have to wait for another day. Thanks. :)

Ahhh, didn't I suggest to check for pushrod clearance.... :rolleyes:

Ahhh, didn't I suggest to check for pushrod clearance.... :rolleyes:

Okay...Okay...you were right. ;) It least I did all the checking though. Now do ya have a guess for me? I think I'm gonna order a set along with an adjustable rod, check the length and if I'm right, I'll be good to go this weekend, if not I'll send them back unopened and get the right ones for another day. :cool:

A friend called today and we have a gang of people going out there including one guy who has a newer mustang cobra that turned a 13.3 a few weeks ago. I can't let him embarass me. :D

I think some guys from this site are heading out there too. :)

Not to beat this to death, but it's bugging me. I assumed the push rod slots you are talking about are the holes in the head the pushrods go through? If you can see in the pic, the left is the 1.6 and right 1.5; the 1.6 rod sits very close to the bottom edge of the hole. 1) This hole is very smooth, I don't see how it could "bind" in there unless something was really bent, also I don't see how a shorter or longer pushrod would make any difference in "centering" the pushrod in the hole. 2) The only way it seems to fix it would be to enlarge the hole? Once again just trying to learn, thanks for the input.

I've been thinking about this all night. I hope this what you guys were talking about or I'm really starting to sound like an idiot. :D http://img319.imageshack.us/img319/9231/pushrods6aj.th.jpg (http://img319.imageshack.us/my.php?image=pushrods6aj.jpg)

Here is a link for the tool needed to lengthen the push rod slot in the head. It looks like you will need to remove the head to do this. Maybe others will chim in and confirm that.

http://www.powerandperformancenews.com/store/merchant.mvc?Screen=PROD&Store_Code=PH&Product_Code=POW351305&Category_Code=PUSHROD

BTW other compaines do make this tool too this was just the first one that came up when I did a search for a louis tool

Yes, it appears in this case that you need to enlongate the pushrod holes in the heads. Personally, I would just run the 1.5 rockers for now and wait until you remove the heads on down the road to elongate the pushrod holes.

Also, a shorter or longer pushrod won't make any difference in "centering" the pushrod in the hole. The 1.6 rockers are shorter behind the pivot point, which changes the pushrod angle through the head and caused the interference problem.

Yes, it appears in this case that you need to enlongate the pushrod holes in the heads. Personally, I would just run the 1.5 rockers for now and wait until you remove the heads on down the road to elongate the pushrod holes.


Ya me too, if I had the heads off anyway it would be worth it to me to do the work involed to get the extra 6.7% increase in lift. BUT if I was not removing the heads anyway then it is a LOT of extra work for such a little increase. Just my 2 cents. :)

I had the same problem several years ago and the easy solution was to run a longer pushrod. I went from stock to .100 over and the engine got considerably quieter.

I had the same problem several years ago and the easy solution was to run a longer pushrod. I went from stock to .100 over and the engine got considerably quieter.

Was the noisier engine a result from less-than-ideal valvetrain geometry (pushrods a little bit too short)?

Also, a shorter or longer pushrod won't make any difference in "centering" the pushrod in the hole. The 1.6 rockers are shorter behind the pivot point, which changes the pushrod angle through the head and caused the interference problem.

After thinking about it last night that's all I could come up with also. Thanks for confirming it. :)

Yea, no way am I taking the heads off for this; if they ever do come off before I swap out engines I'll just go with a new cam. Maybe use some of those secret specs. ;)

Thanks for the help guys.

Anyone use Lash Caps while were on the subject?

This has been discussed before. You would have saved yourself some trouble and expense if you had
read this topic (http://stevesnovasite.com/forums/showthread.php?t=19951&highlight=louis+tool). I may merge these threads into one and put in FAQ section.

This has been discussed before. You would have saved yourself some trouble and expense if you had
read this topic (http://stevesnovasite.com/forums/showthread.php?t=19951&highlight=louis+tool). I may merge these threads into one and put in FAQ section.

Ya know I did a search before starting this and never even saw this one. :mad:

Got an adjustable pushrod with my latest summit order. Seemed like a good thing to have in the tool box either way. From one quick check I think Mike Goble was right, a plus 100 might be enough to give the clearence needed. Its buttoned up with the 1.5's for this weekend now. Maybe I'll do some more checking next week.

Was the noisier engine a result from less-than-ideal valvetrain geometry (pushrods a little bit too short)?

Having a pushrod that is .100" too short won't cause any added noise if there is sufficient clearance around all the parts. The noise was from the pushrods hitting the heads where they come through the slots. These were SportsmanII heads and Harlan Sharpe rockers. I stopped at Vic Hubbards in San Leandro and asked about a Louis tool. The machinist there suggested trying .100" longer pushrods first, and the change in geometry was just enough to keep the pushrods from contacting the head.

:eek: I ran into this problem awhile back. I had Vortec heads w/ 1.6 rockers. At the time, I was young and inexperienced with the necessary actions to take with this set up. I agree that pushrods which are 0.01" too short will not be a reason for noise. If they are adjusted properly, they should be snug against the rocker and lifter regardless... One day, I noticed when my valve cover was off, that my pushrod was ridiculously close to the hole in the head. Did a little research, and it turns out that one must enlarge the hole to ensure proper pushrod clearance. My pushrods actually had rubbing marks on them, not scratches... The tool to guide the drill bit to enlarge the diameter of the hole is nice, but not completely necessary. With the heads off, hold the drill at an angle perfectly dead on straight to the existing hole. If you have extra $, buy the tool. This must be done with the heads off of course, for metal shaving issues. In your case, I would suggest sticking with the 1.5's until you have the heads off, b/c it is not worth all the work to get a few extra horses. Think about having a machine shop clean the heads thouroughly after you have drilled them. I didn't do this, and clean them to the best of my ability, although that isn't the best idea...

My 383 runs a mild hydraulic flat tappet 276/282 advertised duration, 0.476/0.486" lift with 1.50 rockers. Spring pressures are 125 seat and about 275 open. I'm currently running Summit's house brand 1.6 ratio stamped steel rockers. I'm swapping the stock pushrods with a set of stiff 0.080" wall chromemoly pushrods. I also have a set of 1.52 ratio Comp Cams roller tip rockers I could install.

What would you guys use? The existing stamped steel 1.6 or roller tip 1.52's?

Are the rollers full rollers? Or tips only? Personally, I'd sell both and switch to full roller rockers. Big name's are big money, but I bought into a set of Scorpian Full Roller Rockers that were cheaper without sacrificing quality and my engine thanks me every time it starts and runs! But with these, my choice would be roller tip 1.52's.

I've run Scorpions too, got em on ebay real cheap--never had a problem with 600lb+ springs.

I run Scorpion's also.
Mike

It seems like your worried about the roller tip more than the fact that the 1.5 will reduce the valve opening. I'd use whatever ratio the motor wants then worry about the steel verses roller part. Are you having problems with the steel ones? RM

What do you guys think of these? Super cheap!!

http://cgi.ebay.com/ebaymotors/NEW-HEAVY-DUTY-ROLLER-ROCKERS-SB-CHEVY-1-6-HOT-ROD-RAT_W0QQcmdZViewItemQQcategoryZ107063QQihZ003QQite mZ130014938171QQrdZ1

I wouldn't trust those China made rockers.

The Scorpions are your best bet! Got mine for under $200 shipped.

http://www.jeselonline.com/index.php?categoryid=61


how's 'bout these, too TOO pricey ???

I heard the full roller stainless rockers were more suited for the street while the aluminums are more geared for racing. But I hear lots of things.

http://images.amazon.com/images/P/B00062YDH8.01-A36276C8ZCAUKC._SCMZZZZZZZ_.jpg

I've done extensive testing on the subject.
Roller tips won't make any noticeable difference in performance or guide wear.
The bulk of the friction is at the fulcrum.
Putting a roller tip on a steel rocker just adds more weight over the valve. Roller tip steel rockers are at least $100 plus shipping and handling so it has to be the worst bang for the buck you can buy. If you engine makes more power with the extra lift from the 1.6 ratio then stick with those, or buy full rollers.

I've done extensive testing on the subject.
Roller tips won't make any noticeable difference in performance or guide wear.
The bulk of the friction is at the fulcrum.
Putting a roller tip on a steel rocker just adds more weight over the valve. Roller tip steel rockers are at least $100 plus shipping and handling so it has to be the worst bang for the buck you can buy. If you engine makes more power with the extra lift from the 1.6 ratio then stick with those, or buy full rollers.

I would have to agree with this 100%. Changed from cheap stamped steel to Comp roller tips and gained absolutely nothing.:( Mine did make some more power from changing the lift.

I should have asked Paul about this before, could have invested the money in something better.:p

I would have to agree with this 100%. Changed from cheap stamped steel to Comp roller tips and gained absolutely nothing.:( Mine did make some more power from changing the lift.

I should have asked Paul about this before, could have invested the money in something better.:p

Actually, this question comes up a lot. I know I've been giving the same answer over and over but everybody seems to zoom in on those $100 roller tips in the Summit catalog because it looks like an easy upgrade. Even though they don't do squat, I'll bet they make a fortune off 'em. I know they got my money. I have a set in my wagon. I'll tell you what is a better investment of that same $100, especially if you go to 1.6 rockers. A good set of pushrods! Stockers are way too flexible for anything other than stock springs and low lifts.

Paul,

In your testing, which is more flexible: stock stamped rockers, or stock pushrods? I've heard lots of folks claim that the stock rockers flex too much, costing lift at the valve. True or False (assuming a spring suitable with a street hyd cam - something like Comp 981)?

Paul - we've all read how inaccurate the actual ratio of the stamped steel rockers can be. Have you done any testing to substantiate this? I don't expect the true ratio of the Summit stamped 1.6's would be any less than the 1.52 Comps. Perhaps I'll set up the dial indicator tonight and try both.

Also, in a street flat tappet application such as mine (275 lbs spring pressure, less than 6,000 rpm), are the gains with a roller fulcrum that significant?

Stock GM rockers are pretty good for stiffness but are subject to fulcrum wear and breakage. Ratio is often less than 1.5 (like 1.45) so that's why people sometimes see power gains with 1.52 rockers.

I've seen testing that shows gains from the rollers can be measured in watts up to significant hp. There are lot's of rollers out there and I haven't tested them all. Don't assume that the only difference is the price.

Friction reduction is free HP but the gains at the flywheel often are measured in watts not gross HP. In fact sometimes the only evidence of friction reduction is lower oil temps.

If I had to prioritize, I'd say valve train stability is more important than friction reduction. It's not glamorous but it does make a difference. The farther you get from stock the more important it becomes and the more money you have to spend.

A winning professional race team wouldn't think twice about spending a grand or more for something that nets less than 5hp.
A 1-2 hp gain is not something you can really notice in the seat of your pants, but get 10 of these together and you have something.
My advice to all the street guys is to go for the big gains first.
All too often I see someone willing to spend $800 in $50-$100 increments on crap but won't spend $800 on a set of heads.

My advice to all the street guys is to go for the big gains first.
All too often I see someone willing to spend $800 in $50-$100 increments on crap but won't spend $800 on a set of heads.

Great advice.

Always remember the K.I.S.S. rule when building a budget street motor.

I running these full roller rockers from Crane. Got a good deal on 'em ;)

http://static.summitracing.com/global/images/prod/large/crn-10751-12_w.jpg

I am also running the crane gold rockers in my 468. The shop that assembled the engine said they were a good bang for the buck.

I hear lots of good stuff about Harland Sharps and they are pretty darn cheap. Not ebay china cheap but cheap

Thank you very much everone. I truly appreciate the input.

I do like the roller fulcrum rockers. One reason I've stayed away from them is concerns about clearance problems with my internal valve cover breathers. Yeah, I could purchase different valve covers, but that just drives the cost up that much more.

My application is only slightly milder than stock; hydraulic flat tappet, 275 pounds open spring pressure and sub 6,000 rpm. I've found a lot of opinions out there that with these operating conditions, no roller rocker will provide noticable gains over the stock stamped steel ones.

I broke out the mag base dial indicator in an effort to determine the true ratio of the Summit house brand 1.6 stamped ratios. Using the true lobe lift and subtracting pushrod deflection, I came up with about 1.58:1.

I was wondering ir switching to roller rockers from my stamped rockers would really make that much of a difference? I would think that the heat loss in the valve train would be noticable but would it be noticed in the pedal?

You won't notice a whole lot in the pedal. It is a far-better set-up though as far as reliability and precision goes.

Best of Tech has a merged thread on 1.6/roller rocker questions (http://www.stevesnovasite.com/forums/showthread.php?t=21628)

There are a couple advantages to running the aftermarket roller-tipped rockers over stock stamped rockers. One thing is the aftermarket cast rockers are a lot beefier and stronger, but it's not gonna make it go any faster. The ratios are more precise and the tolerances are tighter on the aftermarket rockers, again not a whole lot of bang there but it's something.

The main feature I like about the aftermarket roller-tipped rockers like the Comp Magnums is that they have a hardened pushrod cup insert. This allows you to run moly pushrods without wearing clear through the rocker like happens with stamped rockers.

A guy at work has a very nice 1970 Vette. He had a moderate performance cam installed and he kept wearing the pushrods through the stamped rockers after a while even after lubing them and taking extra care during installation. I had a used set of Magnums laying around and gave them to him. We installed them in the parking lot (slapped them in) after work one night and after 4 years, he hasn't had any issues at all. Mission accomplished.

If I had to choose between the cheesey stamped stock rockers and the roller-tipped, I'd pick the roller-tipped every time. They're significantly stronger. Are they worth $100? Maybe, it depends. If you're not having any problem with the stock rockers I probably wouldn't bother.

I run the Crower stainless "Enduro" full roller rockers on my 406. I have never had a problem with them and they hold the lash very well with a solid cam. They cost about $400 per set.

Has anybody noticed the LS engines have roller rockers without roller tips?
The end is a radius that "rolls" over the tip without sliding. No reason to use a heavy roller that only uses 1/4 of the circle diameter. Reduces the weight with no drawback in performance.

Has anybody noticed the LS engines have roller rockers without roller tips?
The end is a radius that "rolls" over the tip without sliding. No reason to use a heavy roller that only uses 1/4 of the circle diameter. Reduces the weight with no drawback in performance.

Crane is now making these in the aftermarket. RADI ARCS Rockers

http://static.summitracing.com/global/images/prod/large/crn-11782-16.jpg

Three different ratios built into a single set of Crane Radi-Arc rocker arms!
Crane Cams' Radi-Arc rocker arms feature a unique new "Radius-Pad" rocker tip plus three different ratios built into a single set of rockers. These rockers deliver the dyno-proven, friction-fighting, horsepower-adding benefits of the exclusive Crane needle-bearing, fully rollerized fulcrum. The unique Radius-Pad is the first new rocker arm innovation offered to the racing world in decades. It offers a sizeable increase in valve stem tip contact area, minimizes concentrated stress, eliminates most valvetrain geometry problems, and has no moving parts at the rocker's tip! The Crane Radi-Arc rocker arms' Radius-Pad is precision-manufactured from the highest quality alloy steel, heat-treated for durability, and permanently secured to the rocker arm's main body.

The radius tip isn't new but I guess the secret is now out. R*ush engines had shaft rockers with radius tips long before this and I'm pretty sure Crane didn't invent it. We did testing a few years back and found the roller tip doesn't really roll it moves in an arc. Adding a roller tip is just additional weight so there is no benefit. It's the fulcrum that needs the bearing. I've been saying that here for years but nobody wanted to listen because it went against conventional wisdom.

I'm looking for some 7/16" full roller rockers...DriveWFO just picked up some Summit house brand ones, which he says are Scorpion brand, and I'm also looking at some Harland Sharp.

Any good/bad experiences with these?

My cousin bought the Summit ones, and they are extremely noisy. I am running the Harland Sharp and they are great!

I have Jegs brand on mine and love them.

cant beat Scorpion for the price

I don't have the Summit/Scorpion rockers installed yet, but they look nicer than the Crane Gold's I ran last season. Scorpion told me their rockers have a lifetime warranty. I also want to add, mine clear up to 1.625" springs.

Scorpions here Pat. 7/16-1.6
Mike

I have summits for the last 4 years...no complaints

i dont know about the summit ones but we had some harland start to split next to the small roller
we ran the scorpion on 3 or 4 motors now and no complaint yet

I run Crower. Indestructable, but expensive.

Ive heard very little bad about Harlands that s one reason I got mine. Also they are local to me so I dont mind tossing a few bucks into the local economy.

As for the summits being scorpions? What part number. The summits i looked at where the same as Por-comps. Imported and sloppy.

I was going to go with Jegs brand for the price but they were out at the time and the sales rep talked me into the Harlands. No complaints;)

Hmm...guess I'm leaning towards the Scorpions... Thanks everyone!

Ive heard very little bad about Harlands that s one reason I got mine. Also they are local to me so I dont mind tossing a few bucks into the local economy.

As for the summits being scorpions? What part number. The summits i looked at where the same as Por-comps. Imported and sloppy.

Summit now sells the Scorpion Performance Race rockers under the Summit brand. Like I said in another post, Scorpion Performance told me this directly while on the phone with them.

This is the Scorpion Race rocker:
http://www.scorpionperformance.com/Nimages/scorppic.gif

and this is the Summit rocker. Same rocker, just without the Scorpion logo:
http://static.summitracing.com/global/images/prod/large/sum-g6910.jpg

Anyone tried the ones from PRW?I was looking at the stainless ones.

The web site is www.performaceracingwarehouse.com

scorpions are the way to go....nothing but good about them...they have an oversized roller tip and big roller pivot

Summit now sells the Scorpion Performance Race rockers under the Summit brand. Like I said in another post, Scorpion Performance told me this directly while on the phone with them.

This is the Scorpion Race rocker:
http://www.scorpionperformance.com/Nimages/scorppic.gif

and this is the Summit rocker. Same rocker, just without the Scorpion logo:
http://static.summitracing.com/global/images/prod/large/sum-g6910.jpg

Good Info. I was skeptical of the summit brand for fear they were Proforms junk.

scorpions are the way to go....nothing but good about them...they have an oversized roller tip and big roller pivot

Roller tip doesnt matter. Over sized means Over wieght, They dont even roll when in operation.

Roller tip doesnt matter. Over sized means Over wieght, They dont even roll when in operation.

What doesn't roll? The roller tip? Yikes! :eek:

they Rock!!!!!!!!!!!! :eek:

I have these from miller engineering, it is there precision mid lift roller rocker.

http://i177.photobucket.com/albums/w235/nabit/PA4570-1.jpg

Nobody likes Crane Gold rockers?:(

Nobody likes Crane Gold rockers?:(

Scooter, I really liked the Crane Golds (which you have now). Never had a problem with them. They were THE choice for a high-end, narrow body, self-aligning full roller rocker. They fit under those stock-height valve covers too :)

I have these from miller engineering, it is there precision mid lift roller rocker.

http://i177.photobucket.com/albums/w235/nabit/PA4570-1.jpg

I have millers on my 385. I have crane gold on the 67 chevelle 468. however I built that motor in 1980. and cranes were the only ones to have then.

I just bought new heads for my SBC, RPM Performer Edelbrocks with a RPM manifold. The cam I have is a 270 Magnum Comp Cam 0.470 int./0.470 exh. lift, Duration at 050 inch Lift: 224 int./224 exh. Instead of getting 1.5 roller rockers, what would the 1.6 give me over the 1.5. would this make it a 480 lift instead of a 470 lift. Can someone fill me in on this. Also I know there is a thread before this one which roller rockers to buy. I was thinking on buying Comp Cam roller rockers. But if I can save a few buck on a different brand and end up with the same result I'm in there. Any thoughts.

If you select the cam grind you want from the get-go, there is no need to go with different rocker ratios.

The Scorpions look like a rip-off of the Crower aluminum roller rocker design. Crower had that style rocker before I ever heard of "Scorpion". Buy Crower. Made in the U.S.A.

Most of the Summit brand stuff is Chinese. I try to limit the amount of oriental parts on my Nova. Not that they're no-good. It's just a principal I have. I like America better.

Am I wrong? Where are the "Scorpions" made?

If you have numbers of .470 int./0.470 exh. lift your "gross cam lift" numbers would be .313 int/.313 exh. Take your gross cam lift numbers and multiply that by 1.6 (instead of the 1.5) which would equal .500 int/.500 exh :D
Gets you a little more cam in case you need it.

I have had that cam in that motor for 8 years now, I did not see the light then, I'm just working with what I have.;)

Buy the best part for the least money. Welcome to the global economy.

Kev

PS Paul picked up Erson 1.6 full rollers for my blue light special. Absolutely no complaints.

I believe the edelbrock rpm heads would benefit with the added lift. I'd go 1.6 if you have the means.

Kev

The Scorpions are a rip-off of the Crower aluminum design. Crower had that style rocker before "Scorpion" ever had them. Buy Crower. Made in the U.S.A.

I try to limit the amount of oriental parts on my Nova. Not that they're no-good. It's just a principal I have. Most of the Summit brand stuff is Chinese.

Am I wrong? Where are the "Scorpions" made?

"Scorpions" Made in the :usa:

OK, what brand of rocker do you gents recommend.

OK, what brand of rocker do you gents recommend.

look here all the brands are covered and such.

I know I am going to open a can of worms here: going to 1.6 also increases 0.050 duration at the valve. the actual amount has to be measured at the valve not the cam lobe.
When going to 1.6 rockers be sure to watch for binding at the lower part of the head next to the block. you may have to do some clearencing.

http://www.stevesnovasite.com/forums/showthread.php?t=56765

The Scorpions look like a rip-off of the Crower aluminum roller rocker design. Crower had that style rocker before I even heard of "Scorpion". Buy Crower. Made in the U.S.A.

Most of the Summit brand stuff is Chinese. I try to limit the amount of oriental parts on my Nova. Not that they're no-good. It's just a principal I have.

Am I wrong? Where are the "Scorpions" made?

They're made here in the USA. :) I made sure before I bought my set.

http://www.scorpionperformance.org/spo/scorpion-performance-about.cfm

Scorpion Performance is the world's most trusted brand of high quality engine parts. Currently manufacturing Scorpion branded high-performance parts and private labeled parts for qualified warehouses.

Scorpion Performance manufactures the following items under the scorpion label.We also offer a private label program for qualified warehouses. Unlike some of our competitors Scorpion Performance prides itself as being 100% made in the U.S.A. This is why when it comes to quality control and maintaining critical tolerances Scorpion can't be beat.

They still look like a rip-off of the Crower design. The patent must have run out.

So? Good products get immitated. Doesn't mean they're inferior. Companies just have to change with the times.

Kev

Never said they were inferior. Obviously if they imitate one of the best they can't be too inferior.

Scorpions were originally manufactured in Australia. As with many other's here on the site, I've had them for some time now, and have had no issues. I'm wondering if Summit has the same warranty (lifetime) on the rockers as what Scorpion offered their customers(?) It would be nice to know they do still offer it.

Scorpions were originally manufactured in Australia. As with many other's here on the site, I've had them for some time now, and have had no issues. I'm wondering if Summit has the same warranty (lifetime) on the rockers as what Scorpion offered their customers(?) It would be nice to know they do still offer it.

Scorpion told me they will offer the same warranty since it's their rockers that Summit is selling.

Anyone use Comp Cams "PRO MAGNUM" roller rockers? I have them on my 383
but I was wondering if their a bad rocker since nobody else has them.:(

Anyone use Comp Cams "PRO MAGNUM" roller rockers? I have them on my 383
but I was wondering if their a bad rocker since nobody else has them.:(

I've got a set, they are the best rocker you can get, IMO ;).

Thanks for the reply I thought I was the only one with these rockers!:cool:

OK, now this is bizarre...I go to look at the scorpion rockers at Summit...and they're not there. The Summit house brand is, but not Scorpion brand. I could have SWORN the Scorpion brand ones were there a couple of days ago. Not at Jeg's either. :confused: :confused: :confused:

OK, now this is bizarre...I go to look at the scorpion rockers at Summit...and they're not there. The Summit house brand is, but not Scorpion brand. I could have SWORN the Scorpion brand ones were there a couple of days ago. Not at Jeg's either. :confused: :confused: :confused:

You won't find them listed under Scorpion. Scorpion doesn't show up if you search by vendor either. I can give you some detailed pics if you'd like. BTW, I'm not trying to convince anybody that they should use these rockers, but rather just stating the results of my research into the Summit brand rockers.

I'an sure Summit has them but not listed.You could look here also.

http://www.scorpionperformance.com/

I have the 7/16", 1.52s pro magnums also. No complaints. :cool:

You won't find them listed under Scorpion. Scorpion doesn't show up if you search by vendor either. I can give you some detailed pics if you'd like. BTW, I'm not trying to convince anybody that they should use these rockers, but rather just stating the results of my research into the Summit brand rockers.

No, it's not that...I believe you, it's just that I SWEAR they were listed at Jeg's or Summit not two days ago. No biggie, guess I'm losing it... :o

Joe Sherman claims he never sees any benefit to 1.6's on the exhaust side, but yes on the intakes. I have them on both sides in the junk 350 because it's only got .454 lift with 1.5's. Must be working o.k., running 6.60's in 1/8.

Be sure you have piston to valve clearance if you go with the 1.6 ratio. Make sure you have no spring coil bind and the retainer doesn't hit the top of the stem seal or valve guide. Last thought is check the rocker ball doesn't run off the top of the valve stem. RM

Anyone tried the ones from PRW?I was looking at the stainless ones.

The web site is www.performaceracingwarehouse.com

I just pick a set of these up for my 406 i'm currently building. They look like a real nice piece.

Anyone use Comp Cams "PRO MAGNUM" roller rockers? I have them on my 383
but I was wondering if their a bad rocker since nobody else has them.:(


I use the Crower stainless steel Enduro rockers on my engine. They are very similar to the pro magnums. Stainless rockers don't add that much weight and are a lot stronger. They usually cost more though. Aluminum rockers are lighter though which is a slight performance advantage but won't take as much abuse.

The Crower Enduro aluminum rockers are the ones that look like the Scorpions.

I like the stainless rockers better for a street/strip car because they hold-up longer. For an all-out strip car you can get a couple more ponies from aluminum rockers (not sure how much though). Stainless rockers are usually better for circle track cars since they are more rugged for the longer race periods although I know a lot of guys that use aluminum in circle track racing too.