Roller rocker valvetrain noise

Folks - maybe you recall one or more of my posts mentioning excessive valvetrain noise.

Well:

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13 of rockers showed at least some sign of contact with the valve retainers. That one was probably the worst of the bunch. The retainer doesn't look much happier.

I didn't check the valve stem height. Honestly I didn't even think of doing that- but I assume that after several rebuilds the valve stem was resurfaced enough to now not have enough clearance.

Yes there are many ways to fix this problem, but I figured since the rockers are now damaged, the cheapest and fastest thing to do was to apply this method:

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With the self-aligning ears ground down enough to no longer peen the top of the valve keepers, the engine is now much quieter. I'm not sure if it's safe to run the engine at higher RPMs though. I'm concerned that the roller tip might float off the top of the valve and go sideways on me.

Hopefully this is something to remember to check. Just one more thing to add to the "learning" list.

Roller rockers are not self centering. You need pushrod guides to keep the rockers centered over the valve stem.

I can't speak for full roller rockers, but the PRW roller tip Sportsman rocker as self guiding if you want them that way. I used them on my recent build and they were very well made and have worked fine to this point. Having a roller on the valve stem is a big deal in reducing valve guide wear.

Lamune may want to consider a sway as the Sportsman rockers are not all that expensive.

These are most certainly self-aligning roller rockers. Comp Cams 1617-16 if you'd like to take a closer look.

booster oddly I have a set of the PRW roller-tips in my stash of stuff, but they're not the self-aligning variant and I don't have the guide plates.

Off the top of my head the ways I could think of to fix it were

1: grind down the alignment ears
2: get guide plates and replace the rockers
3: pull the heads and get new valves installed
4: replace the heads with new ones

lamune's rockers do not look like they are self centering. The valve ends have witness marks on them to show that they moved side to side, and contacted the valve stem.

Fred Kiehl wrote:

lamune's rockers do not look like they are self centering. The valve ends have witness marks on them to show that they moved side to side, and contacted the valve stem.

Sorry Fred, no, they are self-aligning rockers. From [You must be registered and logged in to see this link.]

Code:

Chevy V8 265-400 cid (SBC) - 1988 and later w/ Self Aligning Rockers - 3/8" Stud - 1.52 Ratio

I mean, if I took them to a belt sander, what did I sand away? The roller? [You must be registered and logged in to see this image.]

Depending on your installed heights- spring pressures -etcetera, maybe a set of - .050 keepers would have been an option.
Their grooves are .050 higher moving the retainer + top of keeper down from the valve tip.
They, of coarse, change your spring installed height and you would have to go through all that.

The racing engine shop that did the heads for my mild build made a strong case for changing to LS beehive springs and retainers. They said they did that conversion on nearly all the gen 1 GM stuff as they just plain are better in all ways, from stability to valve stem wear plus better spring rate capabilities for getting on seat and compressed spring rates. They used my existing valves with them and the PRW Sportsman rockers worked very well with them. So far very quiet and running well.

At the risk of being rude, which I do not intend, the rockers you show are not self-aligning. Attached, hopefully, is a set of rockers that are self-aligning. Look at the valve end roller on each and you should be able to tell the difference. The easy way, imo, to fix your problem would be to install the correct rockers and try to sell what you have to someone that isn't afraid of a little damage. And while you have the valve train apart, it would be a good time to double check your pushrod length, unless you are positive that they are the correct length for the changes that you've made.

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68scott385 wrote:

At the risk of being rude, which I do not intend, the rockers you show are not self-aligning. Attached, hopefully, is a set of rockers that are self-aligning. Look at the valve end roller on each and you should be able to tell the difference. The easy way, imo, to fix your problem would be to install the correct rockers and try to sell what you have to someone that isn't afraid of a little damage. And while you have the valve train apart, it would be a good time to double check your pushrod length, unless you are positive that they are the correct length for the changes that you've made.

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I think they are self aligning based on pic in the first post.  I can plainly see the where the casting is extended with the ears for the aligning where it comes off the diameter of the rest of the end of casting at the roller.  The ears are narrower than the rest of the diameter there so stand out in the pic.  

You can also go to the link furnished later that has more pix at better angles to see the ears.

The link you have doesn't show the end of the rockers with the ears, they are on the bottom and out of sight, or maybe the rollers are showing a flange or washer on the ends full diameter.

PRW like I have in mine are done the same way as the original post shows, with the casting doing the guiding.

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Dudes. I know I'm a novice first-time-engine-rebuilder guy, but I know the difference between a self-aligning rocker arm and a non-self-aligning rocker arm. You'll have to trust me on this one.

Even if they are self aligning, using guide plates would have avoided the damage to the rockers.

If the rocker guide ears where contacting the valve retainers as mentioned in the first post, I don't see how guide plates would have made any difference. Longer valves about the retainer or offset keeper grooves which were mentioned earlier would still be needed, I think.

Fred Kiehl wrote:

Even if they are self aligning, using guide plates would have avoided the damage to the rockers.

Nope. Would have made no difference. The "guide ears" were taller than the distance between the valve stem and the retainers.

Using the -.050 retainers would probably have been sufficient to solve the problem, but sanding the ears down was a zero-dollar test. The rockers were already damaged anyway.

booster wrote:

If the rocker guide ears where contacting the valve retainers as mentioned in the first post, I don't see how guide plates would have made any difference.  Longer valves about the retainer or offset keeper grooves which were mentioned earlier would still be needed, I think.

I believe they moved side to side to get the wear on the ends of the arm. The valve head should be smaller than the roller width.

Fred Kiehl wrote:

booster wrote:

If the rocker guide ears where contacting the valve retainers as mentioned in the first post, I don't see how guide plates would have made any difference.  Longer valves about the retainer or offset keeper grooves which were mentioned earlier would still be needed, I think.

I believe they moved side to side to get the wear on the ends of the arm. The valve head should be smaller than the roller width.

In the pic in the first post, the wear is showing as a pocket, so it couldn't be moving side to side and had to be hitting something. Side to side would give a relatively flat scuffed wear point.

I think the most correct way to explain it is that the self-aligning ears were peening the valve retainers. Like a hammer.

I'm not sure what the confusion here is, but I did just notice that Comp's page for those rockers shows a picture of the pushrod-aligned version and not the self-aligned version. In fact I can't find a picture online that shows it. But I did take pictures during engine assembly:

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lamune wrote:

I think the most correct way to explain it is that the self-aligning ears were peening the valve retainers. Like a hammer.

I'm not sure what the confusion here is, but I did just notice that Comp's page for those rockers shows a picture of the pushrod-aligned version and not the self-aligned version. In fact I can't find a picture online that shows it. But I did take pictures during engine assembly:

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Yeah, peening is a good way to describe it, and on top of that is also gets dragging under pressure from the rotation which drags out material too.

You had mentioned some time ago, I think, that these rockers have a bit of a reputation for being noisy. I wonder if others may have had the same issues as you do.

You should set up a rocker and just remove the play, then see if it will wiggle side to side on the valve stem to the point where the arm frame touches the valve stem. If it does move side to side enough to touch the end of the frame, they are not self centering. I have aluminum rockers on my 454. They have the same type of geometry, use the same type of adjusters, and are not self centering.

BTW, when you tighten the adjusting nut, after tightening the hex locking set screw, turn the nut a little to snug it up (about 1/10 of a turn). If you do not do the final step, the adjuster nut can still back off. I found that out the hard way and had to pull the valve covers to readjust the valves to keep them from backing off. A friend of mine learned that the same way I did.

I looked at the rockers that 68scott385 posted a link to, and they have a flange on each end of the roller to keep the roller on top of the valve stem. If yours have a flange on the frame to center it, the valves may have floated, or the rocker was not adjusted correctly at some point, allowing it to hit the valve stem off of the roller, and damaging it. It does not look like it hit anything else. I would like to see a pic from the roller end of the rocker on the valve with it pushed to one side then the other.

Hey Fred, let me take a step back here because maybe I'm not explaining what I found. I simply don't understand the confusion for what I feel is a very straightforward issue. Let me explain how I found it.

I had the valve cover off, intending to readjust the valves and try and isolate where the loud ticking noise was coming from. I had started the engine with the cover off, it was clacking really bad and I shut it down after a few seconds. I happened to run my finger across one of the roller tips, and it spun freely. Not only that, it spun freely on a valve that was open which I thought was really weird. I called my buddy and asked him just to make sure I wasn't insane. The roller should be in contact with the top of the valve stem at all times, and should not spin freely. Yet I'm looking at a valve that's open and the roller is turning. Something other than the roller tip is holding this valve open... so he told me to take the rocker off and take a look at the underside, and that's when I saw the damage. The self-aligning ears, which are molded into the body of the rocker, were pushing the valve retainers down to open the valve instead of the roller tip pushing down on the top of the valve stem like it's supposed to.

There are only two choices here - the rockers are self aligning or they are not. These obviously must be because I don't have guide plates, and I can't imagine a SBC would run for more than a few seconds (if it even survives cranking) if you accidentally installed non-aligning rockers without the guide plates. I've been driving this car like this for months now.

Now to answer your question, the alignment ears have maybe a few thousanths of play side-to-side against the side of the valve stem. Enough that when the valve is closed it'll make a little click but no more than that. A non-self aligning rocker's roller would slide off the top of the stem. And again take a look at the picture I posted of the side-profile of the rocker. There's an alignment casting below the main rocker body that's obscuring the top of the valve stem from view. I put that against the belt sander and ground some of it away. Noise gone.

Comp makes the two versions of that rocker. 1617 is self-aligning, 1601 is not. I have 1617's and I sincerely doubt the engine would even start with 1601's installed without the guideplates.

And yes, thanks, I did see that trick of turning both the polylock and the nut together a smidge to make sure they really stay locked together. That seems to work really well.

Booster by the way I did find a number of complaints of valvetrain noise with those particular lifters, not so much the rockers. Though really isolating that is pretty hard as that sound is hard to localize. I'm also not really clear as to why the roller rockers make any noise at all given all the bearings.

Ah- I should have posted a picture of what the top of the valve looked like, maybe that'll help. Valve on right is the one that matches the rocker picture above. (#1 intake)


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Maybe a closer look would really drive it home. The damage to the rocker underside (right side in image) matches the damage to valve retainers (left side) where the two attempted to clearance against each other. Also looks like it jammed the valve in that alignment and preventing it from rotating since the wear pattern is obvious.

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I hope that clears up any confusion. 13 of the 16 rockers exhibited at least some evidence of contact with the valve retainers. 4 of them were bad enough to spin freely even under open valve spring tension.

Is the groove worn in the keeper in the last pic the same width as guide section of the rocker or is that from something else. It also looks like there might be some scarring on the valve stem itself, but the may just be the roller occasionally hitting compared to the one next to it.

Do you still have the old iron heads to grab the valves out of? It looks like you probably will need them as even offset keepers might still hit.

I can't speak for the GM stuff for certain, but on the shaft mount Mopar stuff I used to work with a lot (no guides) there was a very specific clearance that you wanted between the rockers themselves and the shaft supports so the could move side to side some. These were either stamped bathtubs or cast adjustables and if they didn't have enough clearance they would bind or if they had to much clearance they would loose too much oil out of the tub. Oil came into the tub from the shaft not from the pushrod. No rollers on the tips back then so they were hard on valve guides with big lift non roller cams and stiff springs.

When I assembled mine with the PRW rockers, I did movement pattern on every rocker to get a look at the roller contact patch through the full range of motion when moving. I got in that habit to determine pushrod lengths long ago because of the rather large tolerance variations in the machining and parts. It was not uncommon to have to use several different pushrod lengths on the non adjustable bathtub rockers in the same engine.

The PRW rockers did have noticeable side to side movement when they were off the valve during zero lash setting, which I found to be useful in determining first contact the pushrod and more consistent than turning the pushrod to tell. I did not measure the side to side movement at the tip, but I would guess it was in the .003" range of clearance.

I can see the issue, and I think the rockers are ones I would never use. Using the end of the rocker to self centering can cause issues of this nature. I like the ones listed by 68scott385 better because they would use the valve stem for centering, and not have the clearance issue with the sides of the frame extending beyond the roller.

Fred Kiehl wrote:

I can see the issue, and I think the rockers are ones I would never use. Using the end of the rocker to self centering can cause issues of this nature. I like the ones listed by 68scott385 better because they would use the valve stem for centering, and not have the clearance issue with the sides of the frame extending beyond the roller.

I don't understand this as the flanges on the roller look like they would extend down just as far as the frame does on lamune's rockers, so it would hit the keeps also.

Is it possible that the valve stems are either not machined correctly, or not designed for a roller rocker.

Fred Kiehl wrote:

Is it possible that the valve stems are either not machined correctly, or not designed for a roller rocker.

The assumptive cause of this problem is the unknown number of rebuilds done on these heads. Twice that I know of, but possibly more. Multiple resurfacing events on the valve stem ends probably shortened them, some more than others, leading to this issue.

New valves would be in order. You must measure things, and if they are out of spec, you get new ones, or correct ones.

having the valves replaced is not economical Fred. I can't get a machine shop to do that in the next 6 months. And no I'm not going to do it myself either.

The only way to fix the problem of the valves being messed up in a reasonable timeframe would be get new heads, which I'm not opposed to, in all honesty. The Edelbrocks have a stock 170cc intake runner volume which I like for the low-end responsiveness. I'd probably go that route if I decided to replace the heads entirely. There are some really excellent heads out there so there are plenty of options.

I forgot to post this earlier by the way. Not sure why the design of the Crower is really any better than this one. In my mind they work exactly the same way with regard to staying centered on the valve stem.

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If you are staying with the quest for low end responsiveness, as I did also, and under low 300s for hp, the iron heads are probably the best heads by quite a bit for the application.

All the data I was able to find when researching indicated that to be true. Only real downside is the weight.

Possibly better materials or better bearings in the Crower.

Buickman1 wrote:

Possibly better materials or better bearings in the Crower.

Stainless steel - yup. I do like that. Adds quite a bit to the price though.

At this point I'd be curious to see if anyone ranks roller rockers by amount of noise output. The ones I have are pretty noisy, but some of the bearings are notably damaged (tips don't spin very freely) probably from the repeated hammering onto the tops of the valve stems.

Been doing a little poking around to try and understand where the noise comes from. Nothing definitive. The theory that the self-aligning rockers are shifting side-to-side during their cycle and slapping the sides of the valve stem as a noise source seems plausible, but not conclusive. If that were the case, going "guideless" and using the guide plates instead would make them quieter but I haven't found proof of that so far.

Booster - I have sitting in the shed a pair of NOS iron LT1 heads. All things being equal what I've seen is that there's no difference in terms of power output between the iron and aluminum heads. Big difference is that the aluminum ones come in 58cc chamber variants and the irons all appear to be 62cc. I think I'd rather go with the F/Y body 10.8:1 vs the B/D 10.5:1 for a little extra zip. Also the aluminum ones do conduct heat away faster, so that's probably a plus.

lamune wrote:

Buickman1 wrote:

Possibly better materials or better bearings in the Crower.

Stainless steel - yup. I do like that. Adds quite a bit to the price though.

At this point I'd be curious to see if anyone ranks roller rockers by amount of noise output. The ones I have are pretty noisy, but some of the bearings are notably damaged (tips don't spin very freely) probably from the repeated hammering onto the tops of the valve stems.

Been doing a little poking around to try and understand where the noise comes from. Nothing definitive. The theory that the self-aligning rockers are shifting side-to-side during their cycle and slapping the sides of the valve stem as a noise source seems plausible, but not conclusive. If that were the case, going "guideless" and using the guide plates instead would make them quieter but I haven't found proof of that so far.

Booster - I have sitting in the shed a pair of NOS iron LT1 heads. All things being equal what I've seen is that there's no difference in terms of power output between the iron and aluminum heads. Big difference is that the aluminum ones come in 58cc chamber variants and the irons all appear to be 62cc. I think I'd rather go with the F/Y body 10.8:1 vs the B/D 10.5:1 for a little extra zip. Also the aluminum ones do conduct heat away faster, so that's probably a plus.

IMO, a lot of the information out there on aluminum vs iron heads is not well thought out. Aluminum will give you the capability of using a one point higher compression ratio without detonation, but I have never seen a side by side that showed the extra point made more power. It is very possible, probably likely, that the colder running aluminum lost as much energy to the water as it gained from possible better combustion. The factory rated compression ratios are never right in the first place. I measured and calculated the ratio in the Buick engine when I disassembled it. Not the the rated 10.5, but only 9.8. Of the stock engines I have measured all were under rated ratio by at least a half a point.

In my rebuild I did get a true 10.5 ratio with the iron heads. My heads ended up at about 62cc after angle cutting the head surface to even out the CC readings. I had the block taken down to zero deck which required about .020 or a bit more to get to for my Keith Black flattops set at zero height. With the Felpro hi perf head gasket it gives right on 10.5 with .039 quench for very fast burning combustion.

The smaller 58cc chambers mainly, I think, only compensated for having the pistons too far down the hole. Better to have bit bigger chamber and tight quench with flatops for best combustion, IMO.

The iron heads are said to have the best intake runners of any of the LT1 factory heads and they make the same hp as the bigger port aluminums but without the weaker low rpm. Iron holds more heat in the combustion chamber and heat is energy and also a big help in vaporizing the incoming charge without creating any dropout areas.

If you have the iron heads already, and are building a street car of 350hp of so or less, it would seem to me that the iron ones would be a good way to go.

I have roller rockers on my 454, and they are absolutely quiet. They require guide plates. You need screw in rocker posts to use the guide plates.

I was listening to an Engine Masters show, and there is a static compression and dynamic compression ratio. There is a formula to figure it out. It references the cam advance/retard.

Aluminum heads allow you to use higher compression with the same octane fuel, and not detonate. It may be 1 point, but could be up to 2. You can adjust the advance/retard to increase/reduce your effective compression ratio. I think I remember that they had a 13:1 static compression engine that would run on 87 octane without detonating.

If the rollers do not move smoothly, they are not rollers anymore. My roller rockers are free rolling after 10K miles. I have a .512 lift cam, hydraulic lifters, a 1.73 rocker ratio, and absolutely no noise. Another Engine Masters show swapped the standard rockers for aluminum rollers, and saw about a 6 HP increase. If you removed the aligning lobes, you no longer have self aligning rockers, and are risking damaging other parts, so I would not run the engine with them, and no guide plates.

There are calculators for dynamic and static compression ratio. Dynamic compression ratio is a good example that relates to why static compression ratio is a bad way to evaluate an engine

Dynamic compression simulates what the actual compression ratio is in a running engine so it accurately determines running compression pressures in the chamber, and that compression pressure is one of the main determiners of power and detonation. The calculations try to determine just how much of the compression stroke is lost to valve timing/duration and leakage so they know how much of the displacement to use for the dynamic compression ratio calc. Since they use valve timing it is obvious that a long duration cam will generate lower dynamic compression than a low short duration cam would, even on the same engine and same static compression. IIRC most high perf stuff will be in the 7-8 for dynamic compression. The engine I built for my Buick has very little overlap and is short duration, and at 10.5 static came in at, I think, 9.3 or so. Even the race shop that did the machining was bit surprised at that. The intake closing point is the critical point, it appears.

The extra point for aluminum heads in static compression is because the heads suck heat out of the chamber faster and cooler mixture loses pressure and dynamic compression by some amount.

So it is kind of useless to compare engines of the same static compression ratio because the rest of the engine counts a lot in the dynamic compression ratio, which is the one that counts.

There is a quite good dynamic and static compression calculator in lamune's engine building thread.

I saw part of an Engine Masters episode last night, and they had a problem with a hot spot on a set of iron heads that would cause it to diesel when the engine was hot, and they closed the butterflies. They had no problem with the aluminum heads.

Absolutely, you can get hot spots in iron heads and there are ways to reduce, but not eliminate them completely, too. That is because the iron heads retain more heat, but remember that is not a bad thing as it can make them more efficient and give better charge atomization. My guess would be, but have never seen any data on it, is that an iron head would have significantly different optimized EFI programming compared to aluminum for any engine, like ours, that is programmed to use wet intake runners (puddle) because the intake runner is going to be hotter in the iron head version. Normally, in the side by side tests I have seen the aluminum and iron heads had somewhat different designs as the two materials don't cast in the same way. I think to get a really valid test you would need CNC cut chambers, ports, and cooling passages.

As I mentioned earlier, the "extra" point of compression you can get with aluminum is because of lower heat retention so isn't a free bonus as it has costs in efficiency and power.

I think we all have seen the comparisons of the LT1 engines with iron heads vs aluminum and the iron heads almost always come out on top until you get quite high in cam/hp area compared to stock.

It is also my opinion that dynamic compression is more of reliably predictor of detonation, although at higher rpm you also start to have volumetric efficiency coming into play on induction/exhaust tuned engines designed to run at a specific rpm range primarily.

Big cams will drop dynamic compression so you can put more static into a big cam engine without detonation, you also wind up with lots of EGR but that is not a good bonus from a power standpoint while it also will slightly suppress detonation.

Also my opinion, is that the better way to reduce detonation while keeping higher compression is to make the engine with very tight quench. Under .040" quench in a closed chamber head will normally give at least one, but often more, safe compression. In my past Mopar small block twin turbo, with open chamber iron heads and 8 to one compression and essentially no quench pads it would detonate at 6-7psi boost. With closed chamber heads and 9 to one compression I could got to 12-14 psi without detonation on the same gas. A big bonus with tight quench is that it speeds up the combustion process a lot so the engines like to have less timing in all ranges. Tight quench engines will tend to like closer to 30* compared to closer to 35* for non tight engines from what I have seen.

I still need to do a few more data logs on my engine at true 10.5 to 1 static and iron heads, tight quench, but the preliminary stuff I have gotten is not showed any knock counts either at WOT, light cruise, or in the transitions on and off the throttle. Having access to knock sensor data is a wonderful thing as most of the time you probably won't even hear the light detonation.

Fred - I did not completely remove those aligning tabs or whatever we want to call them, I just shortened them. So far they haven't fallen off, which is good. What you said about your rockers on the BB being quiet does lend support to my theory that the ticking is caused by the aligning tabs slapping the sides of the stem during the valve operation cycle. Like I mentioned before they all have a slight amount of slop and when loose enough to move by hand, like when the valve is closed, you can make them "tick" by moving them side to side.

A new set of rockers is needed at this point anyway, so I'll get a set of guide plates and the appropriate rockers so I can do an A-to-B comparison.

The iron/aluminum head discussion is interesting. Seeing as how my Vette heads have messed up valve stems, and that I have a set of new B body heads sitting around, another A-to-B seems to be in order. I'll get the current state of things sorted out, take it to the dyno, then swap the heads and do it again. If the aluminum heads prove to be superior in some way aside from looking nicer, I can get a set or repair the ones I have now.

I remember the thread about whether an engineer could build an engine. I guess the answer is yes, but he can not leave it alone once he has assembled it.

Fred Kiehl wrote:

I remember the thread about whether an engineer could build an engine. I guess the answer is yes, but he can not leave it alone once he has assembled it.

Fred, that's a different problem statement entirely!

Fred Kiehl wrote:

I remember the thread about whether an engineer could build an engine. I guess the answer is yes, but he can not leave it alone once he has assembled it.

Said Fred, the non engineer, who also can't seem to leave stuff together and is constantly tinkering. [You must be registered and logged in to see this image.]

I am not tinkering, I had an engine failure, and am rebuilding. In the process, I am making some upgrades, and fixing things that were not done right by somebody else. Tinkering is when you can not leave anything alone, even when it is right. I wish all I am doing was just tinkering.

Everyone gets to define their own definitions, as they say. But to me, with all the changes you are making during the engine failure repair sure look like tweeks to me.....

Maybe you are a non practicing engineer!

Since I had to replace the engine, I decided to upgrade some aspects rather than put it together the same as it was. Other than the engine, and other peoples mistakes, there are no "tweaky" changes. If I was tweaking, or tinkering, it would be in running condition, and I would be making small unnecessary changes, just for the sake of making changes.

This sounds an awful lot like the axiom "the only difference between screwing around and science is writing it down" - so clearly what I am doing here is science.

I dragged the iron heads out of the shed. One I disassembled and have all the parts in labeled bags, I was inspecting it and planning on reassembling with better springs. The other is still together so I took a shot of the valve stem area and wow even just visually the difference in the "height" is obvious compared to the heads I have on the car now. Also I need to swap out the rocker studs if I want to go guideplates on this.

Well, I learned a lesson at least for next time.

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That pic certainly says it all, and shows how badly somebody messed up those other valves.

Since you are going to get guideplates, are you planning on using the PRW roller tipped rockers you have or give full rolllers another shot?

On edit. I wonder is somebody put tall keepers in the heads to try to get correct installed spring heights without cutting spring pockets. If so, removing them might give you enough room.

Such entertainment,.. blind leading blind etc,..

95 wagon correctly diagnosed the problem,. there's not enough valve stem above the keepers,. change the keepers,. perhaps for all you uninformed, you should pay close attention to gerry's posts,. his full time job is caretaker fabricator engine builder for a stable of race cars,. not to mention his dry sump LS7 t56 wagon with porsche 959 radial caliper brakes etc,.
Fred in my opinion you talents are strong in removing jumkyard parts,. but suspect in engine assembly,.

I have built 4 engines, and I check to make sure everything fits correctly before installing it, and starting the engine. I have never entertained using self aligning roller rockers, and had not looked for or heard of them until this thread came up. I suspect that you do not know me well enough to comment on my abilities.

Whoa! Ok, well, at some point- these heads are coming off. And when they do I will measure and inspect and let everyone know what I discover the root cause of this failure to be.

Fred Kiehl wrote:

I have built 4 engines, and I check to make sure everything fits correctly before installing it, and starting the engine. I have never entertained using self aligning roller rockers, and had not looked for or heard of them until this thread came up. I suspect that you do not know me well enough to comment on my abilities.

Fred, after reading about your exploits for many years, i do feel i can comment on your engine assembly skills. your fabrication skills. I suspect you have little to no experience with gen 2 sbc's

lamune wrote:

Whoa! Ok, well, at some point- these heads are coming off. And when they do I will measure and inspect and let everyone know what I discover the root cause of this failure to be.

Root cause has already been established,?

phantom 309 wrote:

Fred Kiehl wrote:

I have built 4 engines, and I check to make sure everything fits correctly before installing it, and starting the engine. I have never entertained using self aligning roller rockers, and had not looked for or heard of them until this thread came up. I suspect that you do not know me well enough to comment on my abilities.

Fred, after reading about your exploits for many years, i do feel i can comment on your engine assembly skills. your fabrication skills. I suspect you have little to no experience with gen 2 sbc's

Two of them are LO5s, and most controllable things in building engines transfers across all GM engines. I do not know if you know much more than I do about building engines.