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  #1  
Old 02-09-2002, 01:46 AM
Brian Mills Brian Mills is offline
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Default Rb Rockers

Just trying to stay ahead of the early mods for this spring.

I am wondering if I should stay with factory rockers or get true 1-5's in a roller version.

It is a 1978 440-3 in my motorhome, 30,000 miles. I am instaling Mopar cam #P4286675, duration 260/260, overlap 34, centerline 113, lift 430/430, I am using the recomended spring #P4286811, with retainers #P4452033, and locks #P4120618, 2 sets, single groove, 8*. These parts are here waiting.

I had the heads off 1,000 miles ago to fix a broken stud and a bad thread in a spark plug hole. I had the heads hot tanked and magnafluxed, they are in great shape, seats and valves are in real good shape.

I was just reminded that factory stamped rockers are not quite 1-5 ratio. The reason I ask is that I would like to get full performance from these parts.

Now I see some rockers with thicker cross sectional material,#P4529743, 1-5 ratio. Also cast iron/ ductile mechanical rocker arm packages, #P4120974 as well as the race aluminum roller rockers.

I have a degree wheel and a set of off-set bushings. This will be the first time I've done my own cam, and I want the best set up to last the years. I have paid $650.00 Canadian for these parts I now have, and I am not afraid to spend a little more to do it right.

Currently this engine is listed as having 360 lbs/ft of tourque @ 3200 RPM. The speed secrets book says the 1967 413 with 7-1 comp had 409 lbs/ft @2000 and this cam produces more. I have 8-1 and 440 ci. I am looking for 425-450 lbs/ft somewhere between 2000- 3000 RPM.

Only other mods to this motor are the orange box and distributer ignition update kit and a set of Heddman Elite ceramic coated double thick headers with a 2 1/2" set of duals with crossover.

The only nagging doubt I have is that these springs are good for .400-.430 lift, and is that with factory rockers or real 1-5's??????

Any help is greatly appreciated, I will be listening carefully.

Brian
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  #2  
Old 02-09-2002, 03:37 AM
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JVMopar JVMopar is offline
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A place called Aerohead racing has a set of roller rockers available in 1.5 or 1.6 including spacers and shafts for $339. Lifetime warranty. They are good for 15 hp, maybe more. If I had the money I would definately spend some to get the roller rockers. I can't tell you how much torque your gonna gain but if you gain HP you gain torque.
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  #3  
Old 02-09-2002, 03:38 AM
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JVMopar JVMopar is offline
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I suppose I should atleast give you the phone number to that place. (312)-862-0224.
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Old 02-09-2002, 02:40 PM
jelsr jelsr is offline
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Collapse one of your springs and measure it then subtract that figure from the installed height. The difference between coil bind and installed height minus a safety factor of .060 or so will give you the operating range of the spring. If it will run too close to coil bind to suit you go to the next spring. The lift figures are theoretical at a true 1.5.
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Old 02-10-2002, 12:11 AM
Brian Mills Brian Mills is offline
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Smile Rockers

Thank you for the reply's. I will definately give the Aeroheads a call, kind of like to stay with Mopar Performance though.

JV MOPAR, what size camper you got? I just went from a 72 360 class C to a 30' Pace Arrow, need room for all the kids now. Loved the class C though!

jelsr, sounds like good advice, would I be looking for spring travel that equals .430 times 5? I believe 2.15

Brian
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  #6  
Old 02-10-2002, 01:09 AM
jelsr jelsr is offline
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Brian,
The advertised lift of .430 would be the cam lobe of .2867 X 1.5. That's the actual cam lobe multiplied by the rocker ratio of 1.5. The actual ratio is usually slightly less then blueprint spec. I would say an operating range of around .500 would be good. That would give you about .070 for safety. In other words if you had a 2" installed height you would want a spring that would coil bind at 1.5" or less.
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Old 02-10-2002, 03:22 AM
Brian Mills Brian Mills is offline
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Right on! Now it all makes sense! Thanks for the info jeslr. I don't suppose you have any info on the various rockers I mentioned. I am going to make a few calls on monday and see what the people who sell them say about their respective products. They are just salesmen though.

Brian
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Old 02-10-2002, 12:21 PM
jelsr jelsr is offline
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Brian,
I have shied away from the aluminum roller rockers due to the short life stories I've heard. The Aerohead setup sounds good if the warranty is for the life of the arms (seems to be the weak spot) from wearing out at the pivot point. The price is right in there with the rest of them. The Harland Sharps are supposed to be very good but are pricey.
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  #9  
Old 02-10-2002, 10:04 PM
wedge440 wedge440 is offline
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Default rockers

The stamped rockers aren`t a ture 1.5.. They vary from 1.3 to 1.4 at best..
The ductile irons are closer to 1.5 and work good... Rollers are closest to being 1.5 then all but they do have a short life. (around 30,000 to 50,000 miles)

Use the irons for year round driving.
Use rollers for weekend crusing/racing.

I would stay away from aerohead, they are a part of Indy cyc. head.
I live about 5 miles from them and they are the biggest bunch of liers out there.
Visit mancini`s web site(www.manciniracing.com) or summit or jegs...You`ll find the best prices there...
Good luck
Joe
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Old 02-10-2002, 11:27 PM
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Acually I've got a 3/4 ton pickup, Camper special is the options package.
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  #11  
Old 02-11-2002, 12:33 AM
Brian Mills Brian Mills is offline
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Well that is certainly some good info. I kinda wondered about the aluminum rockers for durability. Guess I'll check what Mopar has to say about the extra thick stamped and the ductile iron. I want this thing hassel free.

jelsr and wedge 440 I really appreciate the responses.

JV Mopar, I should have caught that, guess I missed the "D".

Brian
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Old 02-12-2002, 12:58 PM
Brian Mills Brian Mills is offline
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Default Aluminum Rollers

Well I called the tech line. They claim that aluminum roller rockers only fail in a .600 lift cam app. with very high spring pressure. They say in my .430 app., the aluminum rollers should last as long as any others.

So the rocker set with shafts is $539.00, the cupped pushrods will be needed, and they are $142.00, and I thought I might as well look at the special hold downs, $114.00, total $795.00 Canadian.

Any one have an oppinion, I'm listening. Specifically any comments on value for the buck over factory rockers, or alternatives.

Brian

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  #13  
Old 02-12-2002, 10:27 PM
jelsr jelsr is offline
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Muscle Motors sells Crane Cams rockers with shafts for around the $300 mark. Summit has the Crane Cams pushrods for $79.95. Not recommending any brand names, just quoting prices.
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Old 02-13-2002, 12:30 PM
Brian Mills Brian Mills is offline
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I appreciate the info jelsr, but on conversion, that is pretty much the same price.

I probably shouldn't have quoted prices, what I am really trying to figure out is how much performance difference is there between stock rockers and rollers at the low end. If it is the kind of difference that is measureable, and more importantly enjoyable from a driveability standpoint, then I'll get them.

Picture me starting up the first incline going into the Rockie Mountains. I'm travelling at highway speed, 2800 rpm, the front tires start up the toe of the hill, as the load increases I give it some more throttle. When I crack the secondaries as the full 14,500 lbs. is being felt by the big block, am I happy I went the distance on this, or could I even really notice.

Don't get the wrong idea, I've had vehicles with aftermarket cams before. I just never thought the use of more pieces than just cam and lifters was a big deal. I'm wondering if I've short changed myself all those times.

Brian
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Old 02-13-2002, 05:13 PM
Doug Wilson Doug Wilson is offline
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Hi, I read an article a couple of years ago comparing roller rockers to stock ones in a street application, in standard ratios, and the conclusion was that the rockers gave a miniscule improvement in power - like 2 or 3 horsepower. One thing they did do - and this may make it all worth while for an RV application - was lower the oil temp by 15 to 30 degrees, depending on the rocker.

I'm going to put the Comp Cams Pro Magnum steel roller rockers on the 440/452 tow engine for the Ramcharger for that reason.
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  #16  
Old 02-14-2002, 12:01 PM
Brian Mills Brian Mills is offline
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Hey, that's some good info Doug. The first thing I am going to do this afternoon is check out the comp cam web site. I might even stop by the local engine builder and check out the price, he likes Comp. Steel rockers sound appealing as well.

When you read that article. Do you recall if they touched on the power gains in having 1-5 ratio versus the factory dodge ones which are not as accurate on the ratio?

Brian
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Old 02-14-2002, 06:48 PM
Doug Wilson Doug Wilson is offline
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My recollection is that they did cheeck factory ones and that ittty bitty HP gain was because of that. Note that I'm not saying "Don't do it!", just that you should consider cost/benefit. I think it would be a different story with a race engine and non-stock ratios. Well... I know it would.
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  #18  
Old 02-14-2002, 08:40 PM
Brian Mills Brian Mills is offline
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O.K. That is a very good point Doug, and a point made by another friend of mine over breakfast this morning. Funny how two Dougs so far apart can agree on the same thing.

For the amount of money, it is not worth it in my opinion. This idea is scrapped. I may go with the heavy duty stamped ones, P4529743, my parts guy is checking the price.

Brian
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Old 02-15-2002, 01:43 PM
Doug Wilson Doug Wilson is offline
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Isn't there some way of blueprinting stock rockers? I'm pretty sure there is, I just don't remember how!

Ah... the wonderful, golden years.
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