Installing a Cam: How To...

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#106

12-14-2010, 09:05 PM

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I forgot to mention: If you do need rockers, new sets are all over ebay for about $50.

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#107

12-15-2010, 11:06 AM

AbandonedBronco

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I hadn't thought to look at Ebay for rocker arms. What's the thought on one of those $50 sets vs. say a $100 set from Shucks/Napa/Comp Cams since they're all about the same price from them?

I agree that I should have replaced the rocker arms when I did the full conversion, but I hadn't budgeted for it (hadn't thought of it), and after I got in there, I figured it was alright since they seemed to work fine on the previous cam and springs. If those were worn and old, I didn't think they'd have MORE slop on a new cam and springs. Guess I was wrong. =P

I'm certainly hoping that it's the lifters/pushrods. It'd make sense that if a lifter isn't giving full lift internally, that it'd cause running problems. When I inspected them visually, there didn't appear to be any issues with them, but who's to say what damage may have occurred inside. So, when a pushrod goes against it, it collapses much too easy.

I looked at the pushrods and they looked straight, but I haven't tried rolling them for trueness. For $20, it might just be more worthwhile to put 12 new ones in there.

I'm thinking, for the time being, I'm going to just get myself 12 new lifters, pushrods, and rocker arms, and try reinstalling them all correctly, unless someone has further advice or ideas of what else I should replace. I agree that if I was shimming it up with washers, something was quite worn out. I just figured it would work until next summer when I pull the head for a P&P and I'd replace all that stuff then (and it may have too if I had put the right size washers on there!!)

Thanks, hopefully it'll be running soon. Not for a few weeks though as money's tight. =/

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#108

12-15-2010, 11:23 AM

Rogue_Wulff

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I can't really add much to the advice already given, except to say that if you plan to pull the head for a PnP, have the rocker studs replaced with proper screw-in studs.
Those press in studs work ok on stock stuff, but when you step up to higher lift cams, and stronger valve springs, the strain can be a bit much for ~30 year old press fit parts.

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#109

12-15-2010, 11:29 AM

AbandonedBronco

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I was thinking that, and been planning on it. Is that something I can do myself? I've seen stud pullers for around $40 that also come with a guide for tapping new studs, but it's certainly not something I'd want to screw up.

Is a larger diameter stud going to require different rocker arms again? I assume they're going to be larger since the bore of the stock stud is larger than the threaded part. (ie. my washer jamming issue.)

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#110

12-15-2010, 11:36 AM

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The correct screw in studs will be capable of using the same rockers. They are made in varying sizes, some with a different size/pitch threads on the top and bottom, IE: 7/16 bottom & 5/16 top.
As for a DYI task, I don't know. Some heads/studs require milling down the top of the stud boss, to allow for the hex-head in the middle of the stud. If this is needed, I wouldn't reccomend a novice trying it.

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#111

12-15-2010, 11:43 AM

AbandonedBronco

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Makes sense. That's good to know on the studs.
I'm assuming that going this route will require me to set my lash and adjust my valves myself from now on? (No more stock torque-and-go).

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#112

12-15-2010, 11:46 AM

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Quote:

Originally Posted by AbandonedBronco

Makes sense. That's good to know on the studs.
I'm assuming that going this route will require me to set my lash and adjust my valves myself from now on? (No more stock torque-and-go).

Correct. The valve lash must be adjusted manually, the way god intended.....

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#113

12-15-2010, 11:51 AM

AbandonedBronco

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Sounds good to me.

My issue with the stock setup is once it wears out a tiny bit, there's no adjusting it.

Just called a shop. $350-ish for a mild P&P along with new screw in studs.

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#114

12-15-2010, 06:50 PM

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MAGNAFLUX that head!!! It may cost $30 or so, but is way cheaper than putting it back in to find it's cracked.

I know you'll probably throw a wrench at me for saying this ... but if you install 7/16" rocker studs, then you could buy a set of used bbc roller rockers on ebay for about $100. Of course that would bump your v.lift to around .480".

The $350 is a fair price. That is what I paid for p&p. Get clear with them regarding the runners: exhaust cleaned and polished, intake left slightly rough. It is real difficult for them to port match the DP intake, so they will most likely want to gasket match. While those valves are out, a 30 degree back cut on the intakes would be nice.

A note on porting:

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ontVertAlignInTxbx/> <w:Word11KerningPairs/> <w:CachedColBalance/> </w:Compatibility> <m:mathPr> <m:mathFont m:val="Cambria Math"/> <m:brkBin m:val="before"/> <m:brkBinSub m:val="--"/> <m:smallFrac m:val="off"/> <m:dispDef/> <m:lMargin m:val="0"/> <m:rMargin m:val="0"/> <m:defJc m:val="centerGroup"/> <m:wrapIndent m:val="1440"/> <m:intLim m:val="subSup"/> <m:naryLim m:val="undOvr"/> </m:mathPr></w:WordDocument> </xml><![endif]--><!--[if gte mso 10]> <style> /* Style Definitions */ table.MsoNormalTable {mso-style-name:"Table Normal"; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority

9; mso-style-qformat:yes; mso-style-parent:""; mso-padding-alt:0in 5.4pt 0in 5.4pt; mso-para-margin-top:0in; mso-para-margin-right:0in; mso-para-margin-bottom:10.0pt; mso-para-margin-left:0in; line-height:115%; mso-pagination:widow-orphan; font-size:11.0pt; font-family:"Calibri","sans-serif"; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:"Times New Roman"; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin;} </style> <![endif]--> The consensus among Buick engine builders/testers is that for anything short of a full-race drag engine, basic porting is good, polishing is bad.
Porting meaning basic stuff - cleaning up casting lines, the bowl area, reducing the enormous valve guide boss, making sure the port floor makes a nice smooth curving transition, and blending the valve cuts. Leave the intake walls rough and the exhaust reasonably smooth (100-120 grit).

Polishing anything but the exhaust side is seen as a waste of time/money, unless you're building a 7000-rpm screamer. Then you go nuts reshaping and polishing while your wallet gets significantly lighter.

In my limited street-engine-only experience, there's a really steep return-on-investment curve...basic port and bowl cleanup will make a real difference, but beyond that the gains go down pretty fast while the cost goes up as fast or faster.
Key areas to look at:
#1 is where the intake floor transitions down to the valve, it needs to be a nice smooth curve without bumps or lips to spoil flow. Most times you can lay this short side back and it'll help (but be careful you don't hit water)
#2 is the valve guide boss, most of these are enormous, and right in the middle of the way (especially on the exhaust side).
#3 is the bowl area where the valve seat cuts are. Make sure there's a smooth transition.
#4 Make sure the entrance to the intake ports aren't bigger than the intake manifold exits (not a problem on Ford integrated-manifold heads), and make sure that the exhaust manifold/heater passages aren't smaller than the heads exhaust passages. From carb to tailpipe everything can get bigger or stay equal, but not smaller.

I also like a good 3-angle valve job with back-cut valves.

<a href="http://s659.photobucket.com/albums/uu316/bobbyrogue/?action=view&current=3-angle-drawing.jpg" target="_blank"><img src="http://i659.photobucket.com/albums/uu316/bobbyrogue/3-angle-drawing.jpg" border="0" alt="Photobucket"></a>

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#115

12-16-2010, 01:20 PM

sedly

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Ive got new hardened push rods coming from Comp.
$30 for the set.

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#116

12-16-2010, 09:28 PM

Wyowanderer

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Quote:

Originally Posted by AbandonedBronco

Sounds good to me.

My issue with the stock setup is once it wears out a tiny bit, there's no adjusting it.

Just called a shop. $350-ish for a mild P&P along with new screw in studs.

Make sure you have them magnaflux the TOP of the head too. Pulling studs is risky business, and often a crack will appear around the stud hole. It's worth it to know.

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#117

12-18-2010, 10:25 AM

AbandonedBronco

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If I were to go the head rebuild route, it'd be at last resort at this point, and it'd be sitting for several months more before I would be able to afford it, unfortunately.

In the mean time though, I'm thinking of putting another set of new lifters in, and then getting some new rocker arms and pushrods to eliminate worn out parts.

Someone else I spoke to mentioned that my valves may be worn/damaged? Any thoughts on that?

Also, I was wondering, are these an inexpensive alternative for rocker arms? Ones that I could install now?

COMP Cams 1416-1 - COMP Cams Magnum Steel Roller Tip Rocker Arms - Overview - SummitRacing.com

They're a 1.6:1 ratio with a roller tip. Just a thought, and a lot less expensive than the $450 Comp wants for a set specifically for the 300.

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#118

12-18-2010, 07:22 PM

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No, those rockers will not work. Sbc will not work; only bbc will, but then the ratio is changed. I am running bbc crane rockers, for a 409 bb, with 3/8" stud. I found them still in the box at the auto swap meet for $100.

Harland Sharpe has new roller rockers for the 300, either 3/8" or 7/16" studs, for IIRC $260.

If I were you, AB, I'd pull the head and take the valves out and check them one at a time. If one is damaged replace one. Then I'd roll the p.rods on a sheet of glass, install new lifters, new studs, and run it.

The brunt of the force would have been absorbed by the weakest component --and most likely that would have been the p.rods or lifters.

Good luck.

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#119

12-18-2010, 08:02 PM

sedly

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Hey AB,I was re-reading this thread and I was particularly interested in the engine break in portion.Mybe F-250 can help me out on this.I am going to be at this stage on my rebuild soon and its all new to me.I have read a few different things on cam break in,my understanding is this'
-run the engine 20 mins at 2000 rpm or so with tranny in Neutral-a steady 20 min-
-then do the timing
-drive truck at variable speeds,put the engine under load but without high RPM

Im posting this because I wonder if the Cam was broke in proper and to learn this info for myself.
-

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#120

12-19-2010, 12:31 AM

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Always go by what the cam manufacturer says. Go on their site or contact them via phone. Use a good break-in oil or additive. You need two guys there, one to watch the engine, and one to watch the gauges. Set up a good fan to blow through the radiator to prevent over heating. Remember that on initial start up your temp gauge will probably go over 200--210 before the thermostat opens and you breathe a sigh of relief!

Run with pure water first time around, until you're sure all the hoses, etc. are water-tight, then drain rad. after a couple of days and add antifreeze. When you change the break in oil, keep the filter for a month after in case anything goes wrong. If it does, that filter will hold valuable clues as to what happened.

Pump/prime the oil system with a drill motor prior to start up, making sure you are getting oil to all rockers. Set engine at TDC before starting, and retard about 10 degrees. Mark distributor on block for a reference. If you're using a MSD or another high power ignition, hook your timing light to a seperate vehicle battery, stand on a piece of wood, and wear rubber gloves, unless you want to risk tasting the fillings in your teeth!! Believe me, it is no joke.

Good luck.

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