Has anyone ever done a budget camshaft install for a basically stock 318? Well i've been getting a bit bored and really want to look into the part costs associated with doing such a thing. After "searching" for previous threads, I ran across KRC cam's, Comp Cams etc. Everyone seems to have a different build up / variations so it is hard to figure out which direction I should be heading. I have also seen a few people convert to HS 1.7's recently. After reviewing indy's buildup, he did an amazing job, and converted from the 5/16 to the 3/8 stud size. All I basically want is some decent lope. Nothing too drastic.Truck is basically stock, and is not used for racing.I'm not going to swap my heads etc. WhatI want to know is themost costeffective way of doing a cam. Looking at the KRC, I would probably go with the KRC210. HS makes 1.6 RR which I ran across here. Do we have a pedestal mount? Someone who's been here before, just tell me the minimum required so I can get an idea of the $$$.

Also Reference here

Thanks in advance,
pcfixerpro

 

Budget camshaft build = 1.7 Roller Rockers

 

Yep, what CPTA said. 1.6 is the same size as stock, so that wont do any good. You don't want to use the 1.7 roller rockers and a cam at the same time because you can run into valve clearance problems, and problems with the stock retainers and springs.

 

There are plenty of people hop'n on the 1.7 band wagon, so this summer im gonna invest in that instead of a level kit. I have looked over aim's thread a few time already. I know silver_dodge has them as well. What constitutes the 1.7's as a a budget cam? Just answer me this question. If I went with a cam, would I need the adjustable 1.6's or could i use the non-adjustables? If the answer is that I do need the adjustables, then I will infact choose to do the non adjustable 1.7's and call it done. Thanks guys as always!

 

a 1.7 roller ratio is as a budget cam as you can get...cant use a 210 from KRC unless you do a computer upgrade , might as well stay with the 206 thats a computer friendly cam but not much bigger then stock hell 1.7 roller rocker with stock cam will give yea a slight bigger lift.. even with the 206x cam you will need a PCM upgrade... down the road if you want a bigger cam they can custom grind to work with the 1.7 roller rocker.....rember 1.7 roller rocker is a poor mans cam..which i just ordered...LOL.


stock cam specs
Valve Lift (Intake):.413" with 1.6 ratio
Valve Lift (Exhaust):.430" with 1.6 ratio

stock cam with 1.7 ratio:
valve lift (intake) :.438
valve lift (exhaust):.457
now go compare the 1.7 intake/exhaust with the performance cams and see what you get...

 

Well I was plannin on a B&G later down the road, but I did not want to dump money into 1.7's and then later say... oh i want a cam. It's good to know that they can custom grind a cam to work with the 1.7's. Haha, and as far as being the "poor mans cam".... sounds like a perfect fit for me... Haha, so would a 206 w/ 1.6's equal close to stock with 1.7's? Just wonderin where that line is at. Thanks PA

 

your welcome , i just edit my post had to do some math so here are some #s for you..
stock cam with 1.7 ratio:
valve lift (intake) :.438
valve lift (exhaust):.457
now go compare the 1.7 intake/exhaust with the performance cams and see what you get...

The ratio of a rocker arm is determined by the distance between the centerline of the pivot point to the centerline of the roller tip (or area of contact with the valve stem), divided by the centerline of the pushrod to the centerline of the pivot point (X). Most aftermarket roller rockers have the ratio stamped on them.
To determine the change in lift when changing rocker arm ratios, divide the lift of the cam by the original rocker ratio (which gives you the lobe lift), then multiply this number by the new rocker ratio. For example, the stock Mustang 5.0L HO cam has .444� at the valve. Divide this number by the stock rocker ratio of 1.6 to get the lobe lift, .2775� and multiply by the new rocker ratio 1.72, to get the new lift of .477�.

 

Thanks PA once again. I'm def going 1.7's over the summer and calling that portion done for now. I found the stock numbers, but the numbers with the 1.7's really helped. Basically throwing this cam in herewould be the same as throwing the 1.7's in without so much hassel. Comparing the specs to the krc 206 you talked about earlier.... the 1.7's are basically 1/3 of the cam. Since I wasn't looking for amazing things to begin with, I bet these rr will do the trick. Thanks for the imput guys.

I was reading around and it seems that the 1.7's may cause more pushrod wear or something. They recomended swaping the pushrods for hardened pushrods? How hard is it to replace the pushrods? The rr seem to be a DIY I can handle, but are the pushrods necessary? There was also a discussion that you should need hardened rods over 5500 RPM. My truck rarely ever gets beyond 2500 rpm unless im gun'n it where it may tach out and shift at 5 grand. What are your thoughts on that.

Finally, my last question for this morn... Do I need new valve covers? Silver_Dodge has his mopar valve covers, but aim has his stockers it looks like. I read somewhere else that you need to knock the baffels out for it too work with stock covers. After I hear all that, I think that about takes care of it for me.

Thanks in advance,
pcfixerpro

 

swapping pushrods is as easy as swapping the roller rockers. Just pull them out and slide them back in. Think of it like putting straws into 16 bottles of coca cola...except the bottlenect is basically the samediameter as the pushrod. Easy. And you really won't need hardened pushrods unless you are spinning 6-6500 for long periods of time like racing at the strip when you are passing the finish line in 3rd gear going 105MPH.

Regular driving with acceleration periods within a couple seconds in the red won't warrant the need for hardened pushrods. The only reason you would need hardened pushrods is when you are running dual valvesprings. Harder valvesprings and hiher lift would warrant the hardened pushrods. In that scenario it would be like washing your armpits but not your crotch.

 

be cautious about assuming that the stock Magnum rockers are actually 1.6 ratio even though the specification tables list them as that

If you put a dial indicatior on the valve stem,
and another dial indicator on the spot above the pushrod tip
you can measure the 'real world' ratio of the stock rockers
and you will usually find it is in the 1.66 to 1.74 range

archived posts:
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Jesse Lackman
Moparts Member
Posts: 395
From: Center, ND 58530
Registered: Jan 2000
posted 07-13-2002 05:16 PM
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how about 1.74?
Just measured one with a dial indicator. lobe lift at the rocker pushrod
socket = .345"

valve lift at retainer = .600"

Did it about four times to make sure

Jesse Lackman
Moparts Member
Posts: 395
From: Center, ND 58530
Registered: Jan 2000
posted 07-13-2002 10:52 PM
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I did check another one came up with a little less but still over 1.7.
Hughes has lots of roller cams for the magnum engines.


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boxcar
Moparts Member
Posts: 151
From: Mason MI USA
Registered: Mar 2001
posted 07-13-2002 10:07 PM
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Yeah, suprize! When I was degreeing in the cam in a magnum engine I got to
checking things and the ratio I got was around 1.69.

Made a cam lobe that was 270* seat, 218* @ .050 at the pushrod check at 224* @
.050 at the retainer. Makes you want to run out and spend $400.00 on some
heavily marketed roller rockers, NOT.