Vortec head problem?

['69 Gmc]

First off, this is my first engine build. I recently bought a set of 062 vortec heads not cracked. They have the Alex parts 110# valve seat springs on them. Not machined but will supposedly clear up to .550 lift. (I plan on running the camp xe268 .480 lift). My question is with the valve tips. All are very mushroomed/ rounded to the point where if they where ground flat the rockers would hit the retainers. What would have caused this? And would y’all recommend all new valves? I’ve almost purchased Alex parts stainless valves set a couple times, but I’d hate to put a new set in and the same thing happen.
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[PGSigns]

Pull a rocker and less look at the bottom. Are the the correct vortec rocker?
Jimmy

[homemade87]

If I was to guess I would say the push rod length was to long or short . As the valve rotated the rocker hammered on the outside edge of the stem . Since they all are like this , its a good possibility .

I think new valves are in order . I would not run them

['69 Gmc]

Back story. It’s a ‘98 GM crate 350 with the vortec heads added. The PO bought an old Vette this engine was in, he said two lifters failed and bent two pushrods. He LS swapped as he intended to. I got it as is with no lifters or pushrods in it at all with the intake just sitting on it. He said he just threw them all away because they were cheap junk.


They are the vortec rockers. All the tips are rounded but not the same. Some are worse than others. Just want make sure i correct what caused the failure/ valve tip wear problem.
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[homemade87]

I also would put a dial on a lifter to check to see what lift it is . Who knows what is really in there or what had been done .

I still say push rod length was wrong making the rocker ride on the edge .

['69 Gmc]

The only valves I can find that have the .260 groove to tip like the Vortecs came with are stainless. Are the stainless the way to go? Can I use stainless with the same valve seals?
When I seen the under side of the rockers, that don’t look good. Do they need replaced as well?

Measure lifter? I don’t have any that were in the motor. I have my new ones that I got with my xe268 cam.

I did mic the cam that was in the motor. Seems to be the stock crate cam. Around .400 valve lift
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[homemade87]

I thought you were going to reuse that old cam . What I was referring to was measure the lift on that old cam when it was in the motor to get the lift . Any lifter would do that .

Being you are putting a new cam in , heres what I would do . Those rocker studs look to be screw in ones . I would remove them and add some guide plates for the push rods ( could be the rockers were walking sideways ) . The stainless valve are a good option . I have always run stainless valves . They are pretty durable . I also would replace the rockers . I feel if the old valves have damage so does the rockers ( those stamped steel are not the best ) . May even look into a roller tip rocker as well . By all means check push rod lenght and get the proper swipe pattern on the valve . This should get you running .

[PGSigns]

Were the pushrod holes drilled? Were the rockers worn out when they went on? They look like it.
Jimmy

['69 Gmc]

Originally Posted by PGSigns

Were the pushrod holes drilled? Were the rockers worn out when they went on? They look like it.
Jimmy

The pushrod holes are stock vortec 7/16” circle.
I haven’t ran this motor. It’s going together now. That’s how the rockers looked when I got the motor
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[PGSigns]

You are going to need to get the heads cut for guide plates and use regular rockers or get new rockers for the vortec head.
Jimmy

['69 Gmc]

I’m thinking about getting the Alex parts stainless valves. Then comp cams self aligning 1.52 magnum roller tip rockers, then measure for pushrods. Would the 1.52 roller tips be worth the $100 more than just getting replacements of what I have?

I almost got the xe274 cam at .490 lift. The 1.52 rockers would put me in between there at .486 with the xe268. Just not sure if that’s worth an extra $100
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[garyd1961]

There is no way a factory vortec head is going to work with a 550 lift cam unless the bosses have been machined. I doubt it would work with a 490 lift either. Why don't you have the bosses machined down while you have them off?

[Captainfab]

No machine work is needed if the correct springs, retainers and seals are used.

Originally Posted by garyd1961

There is no way a factory vortec head is going to work with a 550 lift cam unless the bosses have been machined. I doubt it would work with a 490 lift either. Why don't you have the bosses machined down while you have them off?

[Captainfab]

I'm wondering if the valves and or springs and retainers are not correct for self aligning rockers? For some reason the rockers were moving side to side and they are not supposed to. Sorry to say but you will need all new valves, rockers, springs and retainers.

Originally Posted by '69 Gmc

I’m thinking about getting the Alex parts stainless valves. Then comp cams self aligning 1.52 magnum roller tip rockers, then measure for pushrods. Would the 1.52 roller tips be worth the $100 more than just getting replacements of what I have?

I almost got the xe274 cam at .490 lift. The 1.52 rockers would put me in between there at .486 with the xe268. Just not sure if that’s worth an extra $100
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[PGSigns]

You may want to take them to a good engine machine shop and have them checked over to see what has been done in the past and the overall condition. Decide what the goal is for the entire engine build and get what you need to get to that goal. That will tell you if the roller tip rockers are worth the money and if they are even needed.
Jimmy

[mattfranklin]

Originally Posted by garyd1961

There is no way a factory vortec head is going to work with a 550 lift cam unless the bosses have been machined. I doubt it would work with a 490 lift either. Why don't you have the bosses machined down while you have them off?

x2

The guidance bounces around a little for Vortec heads, depending on stack up of manufacturing tolerances, but the top of the guide needs machining if you are putting in a cam. Especially a 0.550 lift cam. My eyes are as big as dinner plates right now.

If that's really the lift and those are really untouched heads I'm surprised more things were not bent at first startup. (EDIT: Oh. I just carefully read again that the PO bent a bunch of parts and blamed it on junk parts.)

CompCams and others make cheap DIY cutter tools for that if you're so inclined.

[mattfranklin]

Originally Posted by Captainfab

No machine work is needed if the correct springs, retainers and seals are used.

Interesting, so you're thinking +0.050 retainers or valve keepers/locks? I hadn't thought of that as a cure for this.

['69 Gmc]

The lift limit is definitely corrected without machining with the proper pieces. I’ve studied and measured the heads I have several times. The spring kit claims .550 lift, but as stated heads vary. All of mine will pull .600 before any contact. So even .550 lift leaves a .050 cushion. My cam I intend to run is .480 valve lift with 1.5 rockers. I ordered new stainless valves today. Just gotta decide what rockers to run.
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[mattfranklin]

1) Like a previous comment said, checking the push-rod length is a priority here.

2) The special retainer setup might change the geometry of how the rocker tip works on the top of the valve. Another thought was, do the stock rockers contact the retainers in any strange way through their range of motion? I didn't see any marks, so maybe not. Unless both the rockers and retainers have been changed since the PO had the problem.

3) I'm also wondering if these valves are new or if the PO beveled the tips to get rid of burrs and bad wear patterns. Clumsy hand beveling might explain that appearance. I've seen pros put on a bevel before grinding the valves, just to make sure the valve could be centered and straight in the grinder, but the bevel is normally minimal and very clean.

[mattfranklin]

Do you notice any odd wear on the push-rod holes where the push-rods might have contacted the sides of the hole? These guys recommend opening up the diameter to 1/2".

http://www.superchevy.com/how-to/148...ds-valve-lift/

EDIT: BTW, take their advice on spring seat machining with a grain of salt. They are switching to larger diameter dual springs and used the tool to do that. That work would ruin the spring locator boss for stock diameter springs.

[mattfranklin]

Originally Posted by '69 Gmc

The lift limit is definitely corrected without machining with the proper pieces. I’ve studied and measured the heads I have several times. The spring kit claims .550 lift, but as stated heads vary. All of mine will pull .600 before any contact. So even .550 lift leaves a .050 cushion. My cam I intend to run is .480 valve lift with 1.5 rockers. I ordered new stainless valves today. Just gotta decide what rockers to run.
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I see it now. Cool...
https://www.alexsparts.com/valve-spr...ssure-vsk4h50/

['69 Gmc]

Originally Posted by mattfranklin

Do you notice any odd wear on the push-rod holes where the push-rods might have contacted the sides of the hole? These guys recommend opening up the diameter to 1/2".

http://www.superchevy.com/how-to/148...ds-valve-lift/

EDIT: BTW, take their advice on spring seat machining with a grain of salt. They are switching to larger diameter dual springs and used the tool to do that. That work would ruin the spring locator boss for stock diameter springs.

I’ve have inspected the pushrod holes. No sign of wear/contact at all. I considered drilling them out to 1/2”. Seems most that do that is due to running 1.6 rockers. I don’t think I’m going to.

Maybe the reason the old valve tips look like they do is the stock rockers didn’t like the high spring pressure of those aftermarket springs? Or Im starting to think the cause is simply the PO just didn’t have the valves set right. Seems like they were loose and the rockers walked around a little
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['69 Gmc]

What’s yalls opinion on rockers? I’ve measured the stock ones that need replaced due to things I’ve read that they aren’t a true 1.5. All mine are close to 1.46. Anyway I’d like to do full roller, not for 5hp at 6k but just smoother/better operation. I feel the roller tip are a waste, and might as well stay stock. This motor will in no way be a race motor. Just restoring the old truck and want a healthy motor in it. I will have my foot in it a lot lol. It’s hard to spend $300+ on rockers for a cruise in truck. I have no problem paying for quality, just feel like some options are $150 higher for the brand. But I’m scared of the $100 full roller rockers on eBay. Thoughts?
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[mattfranklin]

I'm a fan of stock rockers, too.

Engine Masters (on Motor Trend On Demand and YouTube) did a nice video on rockers of various ratios and configurations. Freiburger offered opinions on quality of different brands of rockers in it. They compared stamped steel stock and rollers of 1.5 and 1.6. If I remember correctly, the stocks made plenty of power.

[mattfranklin]

Found the link for the Engine Masters roller rocker episode: https://www.youtube.com/watch?v=TvQHgt-tF7Y