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Need help picking a inexpensive rockerarm..


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Hey guys, its time for me to spring for rocker arms and finish putting the beast together. I have found out that I only have around six months to slap this baby together and get her on the road! In order to do that I will need to save as much money as possible.

 

350 chevy 2 bolt mains W/ARP studs

Stock crank only needed polishing

Competition Cams Xtreme Energy solid lifter 256/268

Dart Iron Eagle 215 heads (home port cleanup job)

Jictor Jr. Intake

Holley 750 Vac secondary

Eagle forged rods

Hyperutectic pistons 9.3 - 1 compression ratio

 

Here is what I was thinking about in the way of rocker arm

 

Very Cheapest would be a regular stamped long slot rocker $47.69

http://store.summitracing.com/partdetail.asp?part=SUM%2DG6800

 

Next would be a steel rocker with a roller tip $98.95

http://store.summitracing.com/partdetail.asp?part=SUM%2D141506

 

Then would be a aluminum rocker that is a full roller $159.50

http://store.summitracing.com/partdetail.asp?part=SUM%2DG6905

 

I know that these are all pretty cheap compared to the best alternatives and I also know that the answer would be the best one I could afford. I am just curious how much it would hurt me to go with the regular stamped rocker and maybe upgrade sometime down the road? Also, if I were to go with the stamped arms would I still have to buy an adjustable pushrod to measure the needed length or could I just go with the stock length? I dont mind spending the money for that but would like to also save time.

 

Thanks for your help.

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Summit really has some cheap stuff. I was thinking about going with the summit brand pushrods also. They are not one peice but they do have welded tips and should be better than the stock replacements from autozone?

 

http://store.summitracing.com/partdetail.asp?part=SUM%2DG6400

 

Or maybe these from Comp Cams

 

http://store.summitracing.com/partdetail.asp?part=CCA%2D7812%2D16

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the true aluminum roller rockers will allow your engine so both run slightly cooler oil temps and make 15-20 peak hp more due to lower friction, all the choices work, but you should know that the roller tip rockers are basically wasted money as the amount of friction effort the roller tips gain is totally insignificant.

the differance between the stamped steel and roller rockers is about $100, thats not a bad deal even if you only got 10 hp from the lower friction

if your on a tight budget get the stamped steel and upgrade later

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the true aluminum roller rockers will allow your engine so both run slightly cooler oil temps and make 15-20 peak hp more due to lower friction' date=' all the choices work, but you should know that the roller tip rockers are basically wasted money as the amount of friction effort the roller tips gain is totally insignificant.

the differance between the stamped steel and roller rockers is about $100, thats not a bad deal even if you only got 10 hp from the lower friction

if your on a tight budget get the stamped steel and upgrade later[/quote']

 

Thanks, I'm a mechanical engineer and it really didn't make any sence to me that the roller tip would make a difference. There is MUCH less metal to metal contact area on the tip than on the fulcrum! What do you think about the pushrods?

 

Thanks for your help Grumpy!

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I used the Competition Cams roller tiped steel rocker arms before going to the full roller aluminum ones, and my impression of the steel roller tipped arms was very good. The machining for the main pivot socket was an excellent match for the "ball", and with the proper supply of oil was much much better than the OEM set-up, but again, not as good as the full roller bearing rocker.

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heres a simple way to get close to the correct length

BUY ONE OF THESE TO CHECK WITH! THAT ALONG WITH CHECKING CLEARANCES SHOULD BE ALL YOULL NEED TO GET A GOOD IDEA ON VALVE TRAIN GEOMETERY

66042132.jpg

400-200-PushrodDiagramA.jpg

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3567&prmenbr=361

 

after making sure the valve springs are correctly installed you drop the checker in place on the rocker stud and install your adjustable pushrod

adjust the length to fit and measure the resulting length if its within twenty thousands of the stock length its fine for most applications, if its more than 30 thousands long or short get the closest length set available

 

btw, if your one of the people that still does not own an adjustable push rod! you can easily make your own by cutting a stock pushrod in 1/2 (2 pieces), removeing 1 inch from the total length an then with about 2 " of a 4 inch section of 3/16 or 1/4" thread rod installed and (in one section epoxy it in place leaving about 2" sticking out thread two nuts onto the thread rod and slip on the other end of the cut pushrod,(no epoxy) use the two nuts to adjust to stock length and let the epoxy harded in the one section[/color] now you can easily measure and order custom push rods useing the pushrod checker and adjustable push rod as tools

AND YEAH IT ONLY WORKS WITH THE CYLINDER HEADS ON AND THE INTAKE REMOVED BECAUSE THE HOLE IN THE CYLINDER HEAD that GUIDEs THE PUSH ROD WON,T ALLOW THE NUTS ON THE ADJUSTABLE PUSHROD TO PASS THRU, UNLESS YOU PLACE THE CUT ABOUT 1" from the UPPER END OF THE ADJUSTABLE TEST PUSHROD [color:"red"] BUT I prefer to place the adjusting nuts centered as I like to watch for all clearances with the intake manifold removed while manually checking as I turn the engine over by hand durring assembly, and at that point, while checking all the clearances, I use test springs which apply very little load on the push rod

8928864.jpg

 

http://www.jegs.com/cgi-bin/ncommerce3/ProductDisplay?prrfnbr=3272&prmenbr=361

 

HERES OTHER TOOLS YOU MIGHT NEED

77866784.jpg

 

77866902.jpg

 

24947101.jpg

 

71062391.jpg

 

SOMETHING TO READ

http://www.compcams.com/information/Products/Pushrods/

 

CCA-7705 5.800 in. to 9.800 in. adjustment range, Master pushrod length checker 4 piece kit ... $78.69

 

here

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DO NOT BUY the Summit rocker arms! They are Junk!! :evil: They are made by a company called Proform and are aboulutely worthless. I can say this because I too tried to save a buck on these. Buy a name brand (Crane or Comp Cams) I had the summit ones and sent a pushrod right thru the end of one after it failed. I double checked my geometry and it was spot on. I now have a set of Crane full rollers and have not had one problem. They were $250.00 for the set but the piece of mind is priceless. What I've learned is not to save money on internal engine parts you get what you pay for. Rick

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Volman, I've got a set of Harlon Sharp full rollers, 1.5 ratio, 3/8 stud, that I don't need. They're in good condition except for marks where they have hit the retainers at some point. I don't have any nuts for them, but I'll take $125 shipped. If you're interested, I'll send some pics.

 

John

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Guest grinsha

I have been running ProForm roller rockers on one of my engines for 3 years with no problems.

Aftermarket stamped rockers are a better choice than stock ones. The ratio of stock rockers varies from 1.4-1 to 1.7-1 aftermarket rockers are much better.

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I will be running Comp Cams roller tipped rockers. I chose them not for any possible horsepower gain, but to limit the side loads applied to the tip of the valve stems. (The higher the lift, the more important this becomes). On a street engine roller tips should help the valve stems and guides live longer.

 

I'm avoiding aluminum rockers due to the fatigue factor: aluminum has a definite life span when stressed. (That's why they are always available used-- racers know of the fatigue problem and change them out as preventive maintenance).

Per David Vizard's How to Build Max Performance Chevy Small Blocks on a Budget (page 100) " ... remember that aluminum fatigues and is only good for about 2 to 4 million cycles (4 to 8 hours) under race conditions before breaks can start occurring. If used with springs typical of street engines, they can last as long as 75000 miles".

 

The key there is "as long as". I have a friend who ran aluminum rockers on his 427 Vette and broke them. He went back to steel.

 

Given an unlimited budget, I'd run full roller stainless... but that wasn't your question. :D

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