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procomp cams, rocker alignment

7K views 20 replies 6 participants last post by  StraubTech 
#1 ·
Hey guys. Finally got my pushrods in. I set up one cylinder, I have isky adjustable guide plates and I've run out of adjustment trying to center the rollers over the valve tips, seems as though both rockers have to be set towards each other so the plates have no more movement . Not sure if I should cut the plates and have them welded or if there are any other solutions? Pushrods clear the intake runners no problem. Wont be using these heads on any other builds every, have had nothing but problems. thanks for all the help
 

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#5 ·
yeah i think I may grind the tabs down that lock the two plates together so that I can move the plates in towards each other more and then tack weld them. The heads have been a big pain but according to my machinist who ported them he said I was actually lucky, that i ended up with the better casting.
 
#6 ·
the pattern it self is good. when i used the checker pushrod i had an old sbc guide plate thats the same thickness of the isky ones and i cut it in half to get the rockers centered on the valve tip. Was just surprised that i couldn't get the isky ones to center up without having to modify them.
 
#7 ·
The Pro Cpmps have improved in quality somewhat.They are still just a budget head tho & will likely need some tweaking.The only advantages they have over a set of Vortecs is that they are aluminum & they are cheap.The Vortecs will actually outflow the ProComps at under .500 valve lift.The best way to buy them is to buy them bare & use your own hardware & have them ckd & assembled by a reputable source.Skip White is about the only dealer I would buy an assembled head from & I think even he is getting away from the ProComps.
 
#9 ·
This issue is very common across a wide swath of differnt brand heads and including factory heads.

If you're not set up to blue print the engine by correcting these dimensional variations in this case possibily fill the rocker stud holes and redrill and tap them so the lifter, stud, and valve stem are in line (which can get also get you into moving the lifter or valve to get alignment) then the best alternative is to use a self guiding rocker. That will pivot the rocker so the valve end lines up with the stem. The cost will be an angle introduced to the push rod which causes inspection and possible relief of the hole where it enters the head. The additional angle does cost some information transfer between lobe and valve to be lost which of course the preservation of which is why the extensive effort and cost goes into blue printing. If you're not an in-the-money or are striving to be an in-the- money racer the effort of blue printing at this level is a lot of cost for very small gains.

Bogie
 
#10 ·
Haven't been able to get on in a while. I enlarged the guide plates and that worked out fine. Installed and adjusted the valves on one head. I'm running a solid cam. I noticed when I adjusted cylinder 5 that it was harder to turn over. So I figured just because I have more spring pressure. So after adjusting number 7 I noticed that it still feels a little harder when turned on number 5 exhaust valve opening. I'm not sure what that could be. Engine was blue printed on the bottom end. I felt the guides before the springs where installed and they all felt the same ex and In. being just a tad tighter. Any ideas what it could be? Tight spring? Even though they were shimmed properly. Bottom end turned perfectly fine before number 5 vales adjusted, doesn't feel like anything is hitting anywhere either. Really don't want to tear the head back off. It's also possible that it just me being paranoid. Thanks again for all the help.
 
#13 ·
Even with everything swapped it still wants to bind. And with the valve spring removed I can pull the valve up and down by hand with no effort at all. The only time the engine wants to feel like it will bind up is when valve lash is set. Everything is all oiled up. #7 ex valve starts to open just as #5 is just about to come back down. If I lose the rocker on #7 now, it feels easier to turn, as in doesn't want to bind. Only possible thing I can think of is the dampners may be causing the issue so I'll remove them. If that doesn't do it I'm not sure where else to look except maybe cam lobe issue. Valves are brand new.
 
#17 ·
Or the piston and valve are interfering with each other reasons could be the cam isn't timed with the crank, or the lift is enough to generate interferance.

It could be considered that spring or retainer is binding or a valve is bent. I that was a stem it would probably stick once open however a bent head could get into the piston.

Actually 40 for pounds to rotate the shaft of a newly built engine isn't out of line it's the binding that appears to be linked to a valve position that is cause for concern and needs to be checked out.

Once running the engine won't require so much torque to rotate because the oil films are different in a running engine, hand rotation doesn't build any hydro wedges between parts so much of what is felt is both showing run in time is needed to mate the parts which will reduce rotational resistance.

Bogie
 
#16 ·
No.. it doesn't because every time a lifter is rising another is falling. The friction to turn the cam should increase some but not dramatically with just one valve lash adjustment. You might verify that one spring is the same as all the rest of them. You could even swap lifters, pushrods and rockers and springs with another hole for testing purposes. I've don't several FT cam with just the outer spring and dampers left in so I find this whole thing very strange.
 
#18 ·
It doesn't take a constant 40 ft lbs, the most it takes is 40 ft lbs when valves are opening. I talked to a very well know engine builder today and he said to definitely take the dampner springs out. He said since it's a duel spring, the inner spring is what keeps the dampner centered. He's seen people leave them in and tear apart valve seals, bind up and do other damage during break in. So I'll take them out tonight and post my results when I get a chance. Thanks again.
 
#19 ·
Well I removed the dampners. Seemed to turn over much better.....I'm at a total loss, I can turn it by hand let's say 20 times and then randomly it will feel like it's binding. I'm not sure what else to check. Doesn't sound like a ring is broken unless one is. It always seems to be when #5 ex is just about full open and then it will bind when ever it wants to. I loosen that rocker and spins no problem. I even loosened the corresponding intake rocker (i think it was Cy 3) that starts to open when #5 ex is almost coming back down and it will spin no problem. Intake is not on so I got in there with a light doesn't seem like intake valve is hitting anything and also doesn't seem like exhaust valves are hitting anything. Bottom end was fully blue printed, bored, non file rings. Not sure where else to look except for tearing the motor all down again. I don't get why it does it randomly. Or am I just driving myself crazy and possibly because it's not all seated in yet. At a loss now.
 
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