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-   -   Rocker contacting top of retainer on vortec heads (http://www.hotrodders.com/forum/rocker-contacting-top-retainer-vortec-heads-227704.html)

flyingputz 12-29-2012 02:15 PM

Rocker contacting top of retainer on vortec heads
 
I don't mean to beat a dead horse, but here's my dilemma. I thought I had this ALL figured out. I've got the #906 vortec heads, Comp 26918 springs(recommended installed height 1.80") 787 retainers and +.050 locks. This gave me my necessary height and retainer to seal clearance, with NO machining. I don't like the idea of taking away that much material from the guides and seat, especially since the guide is ALSO the spring locator. I don't even know if ANY material can be taken away from seat to increase installed height? Now my rockers are contacting on many of the retainers. If I put the standard locks in place plenty of valve tip is available, however, that takes away my retainer to seal clearance AND increases my seat pressure to approx. 144 lbs. I feel my only option is +.100 longer valves. I will take up any extra height with -.050 locks OR shims. I know I'll have to keep the geometry correct at final assembly via pushrods. BTW, cam is 222-230 dur. .509/.528 lift @ .050 with 1.5 rockers. I'll be using Comp 1.52 rollers(self aligning). Screw in studs are already in place. As stated, I already have ALL these parts. Any thoughts or suggestions greatly appreciated.

ap72 12-29-2012 02:32 PM

try lash caps?

Are you SURE you currently have the correct pushrods? with an aftermarket cam you will likely need longer ones, and that may give you the clearance you need.

flyingputz 12-29-2012 03:11 PM

Lash caps crossed my mind, AFTER iI already pulled the heads back off of the engine. I hadn't yet used a marker/dykem to see roller sweep across valve tip, but even if I do need longer pushrods, the clearance is nil. I can actually spin the roller tip on one valve stem with rocker installed. Rocker RAIL is resting on the retainer, roller isn't even contacting valve. I WILL use lash caps or Manley LocCaps if I can. The 787 retainers are 7*. Are super 7 locks compatible? I have no lash cap experience, so if this is truly an option someone please let me know. Thanks.

BOBCRMAN@aol.com 12-29-2012 03:25 PM

Super & locks are actually 8 degree. Will not work correctly on any thing but super 7 retainers.

If your rockers are the self guided rail type. Lash caps won't work. They increase the valve tip diameter to 3/8". Rocker will be too narrow between rails.

Cheapest way out is to go with a +.050 pushrod and lightly trim the rocker rails for clearance. As long as the roller remains fairly centered on the valve you will be ok.

flyingputz 12-29-2012 04:21 PM

I didn't think lash caps & rail rockers would go together, no clearance there. I was just looking at them & realized that. I'm kinda leary about shaving down the rails. I sure don't want to turn 'em into paperweights. Could I switch to guideplates if I remove the rails, or muck 'em up trying to shave 'em down? I certainly don't need any extra expense (new valves) if not absolutely necessary. Thanks for your input.

MouseFink 12-29-2012 04:28 PM

What valves are you using?

Vortec valves have a .290" valve tip for self aligning rocker arms. Standard SB Chevy valves have .250" valve tips. If you use standard SB Chevy valves, self aligning rocker arms will contact the keepers.

I had to use Manley 11863-1 (E) 1.600" and 11860-1 (I) 1.940" valves and self aligning rocker arms. Ferrea does not have SB Chevy valves with a .290" tip. You must use Ferrea valves for a 351-C Ford.

Do not machine the Vortec valve spring pockets. They are too thin, use +.050" keepers to gain valve spring height. My heads have exhaust valve spring rotators which presents a special problem on the exhaust valves. I had to use .075" shims and + .050" locks " on the exhaust valve springs to get 1.750" assembled height. No problem with standard locks on the intake valve springs.

I am also using Comp Cams 26918 beehive valve springs. I enlarged the stock spring seat diameter from 1.250" to 1.320" in order to fit the Comp Cams beehive valve springs. I was even nervous about doing that.

flyingputz 12-29-2012 04:51 PM

Were you able to widen the spring pockets without taking the guide dia. down? I'd also like to widen the pockets a bit as the spring is quite tight/binding in pocket as it sits. The Comp tool takes down the guide (spring locator) as it opens the pocket if I remember correctly. I don't want to do that. Thanks for info. I bought the heads off c-list so I don't know if valves are original. I will measure the groove to tip distance in a bit. I THINK Trick Flow has valves with longer groove to tip?

GMC boogie 12-29-2012 07:40 PM

I would have used the 26981 springs and reduced the guide height with the Comp part #4726 cutter for .530 seals. Not alot has to be taken off to give the required retainer to seal clearance.

flyingputz 12-30-2012 12:56 AM

Mousefink,
I pulled a couple of valves, did some measuring, and found some discrepancy. The valve with actual CONTACT with the rocker rail measured .25" groove to tip. The valve WITHOUT contact, but very close measures .29". I don't know if the previous owner swapped some valves or ground the tip down. It looks as if some grinding was done. Tip of valve has machine marks on it. Do I file off rocker rails & install guide plates, or buy new/ longer valves?

cobalt327 12-30-2012 02:04 AM

Quote:

Originally Posted by flyingputz (Post 1628559)
Mousefink,
I pulled a couple of valves, did some measuring, and found some discrepancy. The valve with actual CONTACT with the rocker rail measured .25" groove to tip. The valve WITHOUT contact, but very close measures .29". I don't know if the previous owner swapped some valves or ground the tip down. It looks as if some grinding was done. Tip of valve has machine marks on it. Do I file off rocker rails & install guide plates, or buy new/ longer valves?

Do the valves w/the 0.250" tips have the 30 degree backcut like used on the Vortec valves? If not, it will likely be cheaper- and might run a tic better- by using Vortec valves to replace the non Vortec valves.

MouseFink 12-30-2012 08:12 AM

My machinist used a Comp Cams 4716 cutter to enlarge the valve spring seats for the beehive valve springs and reduced the O.D. of the inner spring locator boss. The tool cuts 1.320" O.D. valve seat x .630" valve guide boss. The Comp Cams 26918 valve springs are 1.310" O.D. x .885" I.D. at the base. The engine builder may have used Goodson tools but they cut the same dimensions as the Comp Cams cutters. I talked to the machinist about reducing the O.D. of the inner spring locator boss and he seemed to think reducing it to .630" O.D. for the .885" I.D. valve springs would not create a problem. The cutter provides spring clearances of .005" outer x .128" inner in order to register the valve spring properly on the head. That stabilizes the valve spring and prevent "dancing" (oscillation).

The valve guide itself was cut for Comp Cams 518 Viton metal body seals for 11/32" stems (.530" guide x .575" O.D. seal) using a Comp Cams 4726 guide cutter. I think the machinist removed about .150" guide height for .060" minimum retainer to seal clearance. He used the Comp Cams Viton metal body seals on the intake and exhaust valves. The Comp Cams seals are .575" O.D. and were pushed down on the .530" guides. That places the seals .060" from the ledge of the .630" O.D. guide boss.

IMO, there is no way to avoid cutting the inner guide boss when machining the spring pockets for larger O.D. valve springs.

As I recall, the machinist may not have used the Comp Cams 614 +.050" valve locks on the exhaust valves. I gave him a set to use if he needed them after eliminating the exhaust valve rotators. I recorded most of the engine assembly data on my computer for future reference in case my memory fails me.

MouseFink 12-30-2012 08:49 AM

Quote:

Originally Posted by flyingputz (Post 1628559)
Mousefink,
I pulled a couple of valves, did some measuring, and found some discrepancy. The valve with actual CONTACT with the rocker rail measured .25" groove to tip. The valve WITHOUT contact, but very close measures .29". I don't know if the previous owner swapped some valves or ground the tip down. It looks as if some grinding was done. Tip of valve has machine marks on it. Do I file off rocker rails & install guide plates, or buy new/ longer valves?

Your valves with the .290" tips may be stock GM Vortec valves. The previous owner may have replaced some of the valves and used standard SB Chevy valves that have .250" tips.

Manley Budget Series valves have .250" tips (exhaust) and .290" tips (intake).
Manley Race Master Series valves that I used have .290" tips (intake and exhaust) and all are machined with a 45* face and a 30* back angle.

Manley Race Master Series valves cost twice as much as Ferrea 5000 Series valves. However, you must buy Ferrea 5000 Series valves for a Ford 351W with .395" tips (corrected from my previous post) . I started to buy the Ferrea 5000 Series Ford 351W valves but I did not like .395" tip length.

ssmonty 12-30-2012 11:34 AM

1 Attachment(s)
flyingputz,
It may make some food for thought, but I don't think it will solve your problem.
I noticed that the top of the seven degree retainer seems to be higher than the top of the seven degree locks(on the left in the pic), vrs the same dimension using the ten degree locks/retainers on the right.
However it also seems that the 10* locks are closer to the tip of the valve like the +0.050" standard locks do, so no benefit.
You might look at the locks that have the recess for lash caps(pn611,or614). They might help? I don't know if you can run them without the caps? Probably not a good idea.
Personally I would use the standard 7* locks, and machine the top of the guides down about .070", and live with the increased seat load(130lbs@1.8" vrs 146lbs@1.75" installed height). I assume your using the roller cam/lifters the springs are designed for. If you consider that the conventional springs for roller cams typically use more force to control the valvetrain(seat load and over the nose) than behives do, your not hurting the valves, lifters, or cam IMO. Also if you may consider that many people install 1.6:1 rockers which increase the load on the valvetrain similar to increased spring pressure, but use the same springs as if they were 1.5:1 rockers, and have no detrimental effects. JMHO
FWIW,
ssmonty

MouseFink 12-30-2012 02:47 PM

I suggested Comp Cams 10* Super Locks for lash caps to gain a little clearance for the self adjusting rocker rails. I bought a set of those locks and trial fitted them with a rocker arm, valve and 10* retainer and did not gain enough clearance, even with the 10* locks and retainers which are wider than the 7* locks and retainers. I decided to purchase, prepare and install a set of Manley valves with .290" tips, even though they are about twice the cost of Ferrea valves. BTW, my engine builder used Comp Cams 795 10* retainers and Comp Cams 613 10* locks. I called him at home and he said he did not use the +.050" locks. He said he shimmed the exhaust valve springs enough to eliminate the valve rotators without using +.050" locks. All valves have 1.750" height and the train works perfect.

Parts:
Comp Cams 26918 beehive springs
Comp Cams 795 retainers 10*
Comp Cams 613 locks, 10*
Scorpion 1073BL rocker arms, 1.5:1 self self aligning, narrow body.
ARP 134-7104 rocker studs, 3/8"-24 x 7/16"-14 with Time Serts.
Alex's Parts shims, 1.255" O.D. x .875" I.D. hardened
Comp Cams 7940 push rods, 7.200" chromemoly, .080" wall
Comp Cams 15850 hyd. roller lifters, REM finish, short travel, .005" pre-load.

When I was trying to determine what valves to use, I finally called Ferrea and their representative suggested using the Ferrea Ford 351W valves with .395" tips. I am sure those would provide more rocker arm clearance than necessary but I thought the extra long tips may cause a problem with the rocker arm, rocker stud and push rod geometry. I purchased Manley Vortec valves with .290" tips. I believe those valves were designed with self-aligning rocker arms in mind.

flyingputz 12-31-2012 01:23 AM

SSMonty,
I used Crane machined steel +.050 locks (look a bit beefier than the stockers) and most are flush with the retainer. A couple locks are even a tad higher than the retainer( probably not even measurable). I just remembered I have a set of bad vortecs(cracked) laying around. I'll see if I can use the valves from the bad set. They have about 240,000 miles on 'em, but mavbe they'll clean up. I'll measure the rest of my valve tips and make sure that's the issue. I appreciate all the input guys.


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