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Kaderdak
GenIII
 
4/13/2005
18:38:45
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 Subject: 1.7 RR for a 5.2 magnum
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I'm looking for some 1.7 rocker for my '97 5.2 (I assume you probably had that figured out from the subject.) Anyhow, I've been looking around and it seems the three companies to look at are crower, crane, and harland sharp. Anyone have any experience with rockers from any of these companies? Will I need new guideplates and pushrods with any of them or would they be a direct bolt on? Lastly, will they fit under the stock valve covers or not, I've heard both yet and no. If anyone knows a good place to get some at a decent price that'd be great also. Thanks.
** '97 Dakota 5.2L 4x4 w/3.55(my best ebay purchase yet) **
** Homebrew CIA, Dynomax Catback, March Underdrive Pulleys, Transgo Kit **
** Borg Warner Brass Cap/Rotor to Taylor 8mm wires to NGK plugs **
** Homebrew dual electric fan setup with 180* thermostat **
** Sitting on BFG 31 x 10.50's **
** Tons more once I'm not a poor college student :) **
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rocker
Dodge Dakota
JOIN HERE
4/13/2005
18:53:23
| RE: 1.7 RR for a 5.2 magnum
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they will not fit with stock valve covers, without a little persuasion applied to the baffles for clearance.
sams got some good prices on crowers
www.socaldakota.com
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Mr RR
Dodge Dakota
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4/13/2005
19:18:40
| RE: 1.7 RR for a 5.2 magnum
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here ya go. scroll down for your motor. 1.7's non adjustable, fits under my stock valve covers, $300 shipped to my door. cant beat that.
http://www.harlandsharp.com/bolton3.htm
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rocker
Dodge Dakota
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4/13/2005
19:47:50
| RE: 1.7 RR for a 5.2 magnum
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if HS didnt suck.. that'd be a good deal
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dude
Dodge Dakota
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4/13/2005
21:25:50
| RE: 1.7 RR for a 5.2 magnum
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You wanna back that statement up, biggun?
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Kaderdak
GenIII
4/13/2005
23:40:59
| RE: 1.7 RR for a 5.2 magnum
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I was checking our krcperformance too, and saw they have aluminum comp cams 1.7 rockers for 375. Anyone have any experiences with these? Is aluminum a good decision, I think I've heard they have a tendency to not hold up as well.
** '97 Dakota 5.2L 4x4 w/3.55(my best ebay purchase yet) **
** Homebrew CIA, Dynomax Catback, March Underdrive Pulleys, Transgo Kit **
** Borg Warner Brass Cap/Rotor to Taylor 8mm wires to NGK plugs **
** Homebrew dual electric fan setup with 180* thermostat **
** Sitting on BFG 31 x 10.50's **
** Tons more once I'm not a poor college student :) **
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ScojoDak
Dodge Dakota
JOIN HERE
4/14/2005
09:37:47
| RE: 1.7 RR for a 5.2 magnum
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All three makes are good products. They all have their good and bad points. Just do your research before buying. Be advised that if you intend on reving above 5500 rpm, you'll be needing pushrod guide plates. Good luck!
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Mikes99Dakota
GenIII
4/14/2005
10:22:48
| RE: 1.7 RR for a 5.2 magnum
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I would get Crower...stainless steal RRs and Sam sells them. They are great. I will get some for my 318....but depending what cam I wil get too. Aluminum is good but like you said, wont hold up as well!
1999 RC Auto 5.2L
Bulet Glasspack, K&N FIPK, Viper Electric Fan Kit
Track Times: 60' - 2.223
1/8 - 9.78 @70.37 mph
1/4 -15.33 @ 88.16 mph
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.boB
Dodge Dakota
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4/14/2005
12:05:50
| RE: 1.7 RR for a 5.2 magnum
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Alum rockers will last a long time, probably longer than the rest of the engine, so don't worry about that.
Making things out of alum makes them lighter, and that allows them to change direction faster at high speeds. Less valve float with a lghter spring.
The down side of that is that alum rockers are bigger and bulkier, and therefore may not fit under the valve covers without mods to either the cover or the rocvker arm.
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gen1dak
Dodge Dakota
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4/14/2005
13:35:49
| RE: 1.7 RR for a 5.2 magnum
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Aluminum rockers have to be bigger to deal with the fact that aluminum loses half its strength at 400 degrees farenheit. Stainless, while still lightweight is not as light as aluminum. Aluminum has a fatigue factor to consider. Steel does not fatigue. Granted, in everyday life, on a street engine, aluminum rockers will last quite a long time, but, depending on the setup, and the way the engine is run, they are more prone to failure than steel. Stainless give the strength of steel, with most of the weight savings of aluminum....and they are, naturally, more expensive.
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another mark
Dodge Dakota
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4/14/2005
19:01:31
| RE: 1.7 RR for a 5.2 magnum
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Rocker I got nothing against anyone who says something sucks, but you need to tell us why you think the Harland Sharps suck. I got them on my 3.9. Had them on for a year now and no problem. They were an easy bolt on item with no other needed parts. Other than the allen wrench socket for my torque wrench. I hear since they are made of aluminum I can expect them to stretch over time or otherwise go bad???
Back up your comments.
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gen1dak
Dodge Dakota
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4/14/2005
23:49:17
| RE: 1.7 RR for a 5.2 magnum
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I was kinda wonderin' about that comment too. I mean, Harland Sharp has only been in the Performance business, like, forever. I think he knows what he's doing.
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N56629
Dodge Dakota
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4/15/2005
06:55:54
| RE: 1.7 RR for a 5.2 magnum
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"Stainless give the strength of steel, with most of the weight savings of aluminum.."
Generally stainless is not as strong as most steels. It is usually softer, but with better wear and corrosion characteristics. It also tends to be slightly heavier than carbon steel because it contains considerable nickle and chromium, both of which are heavier than steel. I would be glad to look up the specific gravities on each if you like.
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thisguy
Dodge Dakota
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4/15/2005
08:04:11
| RE: 1.7 RR for a 5.2 magnum
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whoever said metal does not fatigue should really think about what they are talking about before they say it. Also stainless is very hard not soft and stainless is alot stronger then normal metals too. Stainless is very heavy which u said. Aluminum will last in you rockers, its not like crane cams or any other manufacturer is goin to use low grade aluminum. Just think they make whole engines and even cars,planes etc out of aluminum so strength and fatigue of aluminum should not be of worry
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N56629
Dodge Dakota
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4/15/2005
11:40:25
| RE: 1.7 RR for a 5.2 magnum
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"Also stainless is very hard not soft and stainless is alot stronger then normal metals too."
Wrong again. Stainless is very tough and should not be confused with being very strong. Even the most exotic stainless alloys barely match carbon steel alloys. Try to find a single person that wants stainless steel axels in their vehicles.
I can provide all the information on tensil strength, shear strength, weights, etc. but not right now.
Start of with - Stainless IS heavier
Stainless plate 1" 42.67 lbs. per sq ft
Carbon steel plate 1" 40.84 lbs. per sq ft
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Mikes99Dakota
GenIII
4/15/2005
11:49:43
| RE: 1.7 RR for a 5.2 magnum
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We are talking about RRs not airplanes and rear-ends....geez
1999 RC Auto 5.2L
Bulet Glasspack, K&N FIPK, Viper Electric Fan Kit
Track Times: 60' - 2.223
1/8 - 9.78 @70.37 mph
1/4 -15.33 @ 88.16 mph
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thisguy
Dodge Dakota
JOIN HERE
4/15/2005
12:12:04
| RE: 1.7 RR for a 5.2 magnum
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If you would actually read the quote you took from my post you would have seen that I said stainless is stronger then most normal metals. Not carbon steel, which yes is a alloy too like stainless. Also you wouldnt want high carbon steel axles too cause most metals and aloys with very Hard surfaces are very brittle and can break easier, anywhoo back on the post, stainless RR are not the best solution for street engines, maily because you are trying to take weight off your valve train not add it. and any good quality aluminum RR will be stronger and outlast any stock stamped rocker that your vehicle comes with and you get weight savings which is where alot of the upper RPM HP increases are found simple stuff, less weight less resistance to movement and the easier something moves the more effient it becomes.
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thisguy
Dodge Dakota
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4/15/2005
12:17:10
| RE: 1.7 RR for a 5.2 magnum
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oh ya... if you got the cash and want probably the best rockers you can find get a set of titanium ones. they have superior strengh and great weight savings, not as much as aluminum but way better then and steels
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gen1dak
Dodge Dakota
JOIN HERE
4/15/2005
12:24:59
| RE: 1.7 RR for a 5.2 magnum
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Hate to break it to you, but where weight is the number one issue (aircraft), and steel strength is needed, they don't use carbon steel. They use stainless. And if aircraft examples aren't important, why do they advertise "aircraft quality"? Nobody wants stainless axles because of the cost. Why use it when milder non-stainless works fine? Now, I'm not disputing the usefulness of aluminum rockers, especially if an aluminum alloy, which improves strength and durability, is used. Obviously, stainless is heavier than aluminum, but it is also roughly 5 times stronger, and does not lose strength until a much higher temperature is experienced. Now, for someone who doesn't understand fatigue life, under normal load and operating tolerances, aircraft aluminum will STRESS FATIGUE to failure at approximately 50,000 hrs. This is why airliners, made of "aircraft quality aluminum" are completely stripped at 30,000 hr intervals and inspected for signs of stress fatigue. These areas are reinforced or replaced as necessary, and the aircraft are typically written off at 100,000 hrs. It's all about the numbers. It's strong enough to do the job, where weight is the number one consideration. Stainless, as wih other steels, does not stress fatigue. Neither does wood, for that matter. ANY material will fail when overstressed, but aluminum will fail under normal loads at approx. 50k hrs, even without overstress. Understand this. We're not talking about un-stressed sheet aluminum, like siding. The most dramatic example of this is the last shuttle disaster. The aluminum structure of the wing failed from the heat. Where superior strength, durability, and heat tolerances are needed, stainless or titanium are used, not aluminum. Now, in an engine, sure, it works fine. My initial reply was simply to explain why aluminum rockers are so much bulkier, (added bulk to achieve adequate strength) and why some use stainless over aluminum. I've seen failed (stress fatigued) aluminum rockers, but not stainless, or even stock stamped steel for that matter. I believe it's CompCams that even shows one in an ad.
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N56629
Dodge Dakota
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4/15/2005
13:21:23
| RE: 1.7 RR for a 5.2 magnum
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"Hate to break it to you, but where weight is the number one issue (aircraft), and steel strength is needed, they don't use carbon steel. They use stainless."
What kinds of planes do you own/fly? Should I be concerned that my landing gear struts are not made of stainless? I know that I do have many stainless steel screws on my planes
I'm wondering about the Gulfstream steering gear, Part 1159CM40208, that I have in front of me right now shouldn't be made from stainless.
It looks like you did a little research on aircraft at lest. You should also noted that it make a great deal of difference if the aircraft are presurrized or not.
" And if aircraft examples aren't important, why do they advertise "aircraft quality"?"
Most all aluminum commonly used in manufacturing parts are made from so-called aircraft quality. It's a great advertising gimmick in some cases. It's something like advertising "billet aluminum." Care to tell me what the hell "billet aluminum" is? I jokingly asked one of our buyers to get me some "billet aluminum" and he didn't know what the heck I was talking about. He called around to a number of suppliers one of them told him that it was nothing but ordinary bar or plate.
"The most dramatic example of this is the last shuttle disaster. The aluminum structure of the wing failed from the heat."
I thought it was the ceramic tiles that came off and exposed the aluminum. I don't think the aluminum was ever intended to be exposed to the heat. Even if it had been stainless, it would have failed at those temperatures.
BTW, I wasn't disagreeing with your statement that stainless RR are superior to aluminum, only erroneous comments on the material.
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Kaderdak
GenIII
4/15/2005
13:22:44
| RE: 1.7 RR for a 5.2 magnum
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Geez, maybe I should have got a degree in mechanical engineering instead! You guys is crazy! But no, thanks for all the input fellas. I'm thinking that since my 318 isn't currently and never will be a race engine aluminum rockers would be just fine. I can't spend much money on anything right now either, so I'll probably have to go the cheap route. Is it pretty much a concensus however that if I go with aluminum rockers then I'll have to get some aftermarket valve covers for extra cleanance?
** '97 Dakota 5.2L 4x4 w/3.55(my best ebay purchase yet) **
** Homebrew CIA, Dynomax Catback, March Underdrive Pulleys, Transgo Kit **
** Borg Warner Brass Cap/Rotor to Taylor 8mm wires to NGK plugs **
** Homebrew dual electric fan setup with 180* thermostat **
** Sitting on BFG 31 x 10.50's **
** Tons more once I'm not a poor college student :) **
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