[cgrey8]

Yep. Did all that. Shimmed to take up the "slack" in the lifters. It seems I shimmed too much. So, I'll be pulling about .060" out of each lifter so this doesn't happen again.

Here's the thread where pushrod length and shimming was discussed. I think I've learned a lesson. Don't overshim:
How to Size pushrods

[StangD]

I'm a little confused I guess. You said all the other lifters are tight as can be, but you are now pulling .060 out of the shim pack so no others will fly apart? .060 is a huge lash adjustment to a lifter that might not be loose. I think I would bring each lifter to base circle and evaluate individually.

[liljoe07]

I'm a little confused I guess. You said all the other lifters are tight as can be, but you are now pulling .060 out of the shim pack so no others will fly apart? .060 is a huge lash adjustment to a lifter that might not be loose. I think I would bring each lifter to base circle and evaluate individually.

Not only that, but most lifters are already pre loaded(not lashed) .020-.060. Not sure how much pre load Chris has, but either way that much more preload, could put the plunger in front of the oil feed. Blocking oil flow.

Reducing shim is not the fix here.

[cgrey8]

As stated in that other thread about sizing pushrods, I shimmed twice.

The first shimming was done to get near the smallest swipe across the valve stems. Minimal swipe was found around .250". So I shimmed the rockers up about .200". Then I sized the pushrod length plus some to make up for the plunger distance in the lifters. I'd have to go back to that thread, but it seems like that gave me a pushrod length somewhere around 6.500" or possibly 6.550". But what I found as I was installing each rod is some plungers plunged more than others. The ones that didn't plunge as much needed some shimming up of the lifter so the plunger wasn't bottomed out and thus holding the valve open all the time. So to be consistent, I shimmed all the rockers such that when they were tightened down, I could pull them back off the valve roughly .030-.060" with my hand. Before I installed the valve covers, I could pull back on each rocker to compress each lifter plunger to bottom which was roughly .030-.060". I'm thinking I shouldn't have done that and instead just sized pushrods to plunge ~.050" into its respective lifter and called it done ignoring that some lifter plungers would've plunged in way more than that and instead just accepted that oil pressure would hold the lifter tight.

When I pulled the cover off today, that .030-.060" plunge I used to be able to get out by pulling back on each rocker wasn't there and that was a good hour at least after the engine had been run. They were all tight as can be. Maybe it was because they were still full of oil? If they are holding oil that well for that long, I obviously didn't need to preload them in so deep. A preload of .050" would've been more than sufficient hence why I'm thinking I need to take some shims out and relieve the preload some.

But I admit this is an area of engine building I was brand new at. I asked the questions, explained the strategy above long before the engine got buttoned up in hopes there'd be someone to read it and tell me I was doing it right or tell me I was setting up for disaster. I never got any indication that I was doing something wrong, so I moved forward with what seemed reasonable at the time.

And BTW, yes I did use threadlocker on the threads and torqued them down using a torque wrench. If this happened because the bolt backed out, I guess it is possible I missed one. I called myself being very careful to make sure I didn't miss one and screw something up. But anything's possible.

[StangD]

I am pretty new around here. I didn't catch the pushrod thread. You have taught me alot on tuning. I hope to figure this out with you. Gotta start at the beinginning.

First of all, a lot of people just slam some pushrods in, get lucky a couple times in a row and deem the entire process unnecessary. At stock lift, with stock parts you can get by with MUCH more. (i.e Ford didn't use 50 different length rods for the same 93 5.0 or whatever. Your cam isn't radical, but nonetheless it isn't stock. I assume you have had a valve job at some point? Unless your machinist was damn meticulous, now you have different valve length heights. Anyway, the little tolerance changes may make it necessary to shim some rockers differently, or maybe not. It HAS to be real close to right or you are going to fight this. Think of an adjustable 7/16 fine thread rocker stud. There is zero lash, most run about 1/2 turn tighter. Another 1/2 turn and you have valves on the verge of not closing correctly, vacuum drops and the engine runs rough. We have to get the lash closer than .060 from rocker to rocker.

Can you post a link to the pushrod thread you refer to? I'll check out your procedure.

[cgrey8]

...I assume you have had a valve job at some point? Unless your machinist was damn meticulous, now you have different valve length heights...

Yes the heads did get a full valve job, right after the porting. Machinist did a back cut on the valves as well as grinding the tops of each stem to get them equal length. I even asked if certain valves needed to go with certain cylinders. He assured me that any intake valve could go into any intake location. Ditto for exhaust.

And yes, I knew I wouldn't be able to reuse my stock pushrods because my stock cam and the cam I'm running have 2 different base circles. I think the stock cam was 1.440" and my cam is 1.350" or something like that. Add to that the additional shimming I did to get the minimum swipe pattern, I needed a good bit longer rod than stock.

...There is zero lash, most run about 1/2 turn tighter. Another 1/2 turn and you have valves on the verge of not closing correctly, vacuum drops and the engine runs rough. We have to get the lash closer than .060 from rocker to rocker...

That sounds like what I'd expect for solid lifter, not hydraulic lifters. With solid lifters, you'd have a lash of slack between the rocker tip and valve stem. However with hydraulic lifters, you can set them up with a preload where the pushrod plunges into the lifter thus giving you zero lash at all times as long as the lifter plunger fills with oil and stays full.

But what you are describing sounds less like lash and more like preload to the point that the lifter plunger is bottomed out and is almost holding the valve open even when closed.

...Can you post a link to the pushrod thread you refer to? I'll check out your procedure.

I posted it above where I mentioned it. Here it is again:
How to Size pushrods

[StangD]

Yes, sorry about the misused terminology. We are talking lifter preload here. I am working on my own valvetrain tonight but promise to read the thread carefully and see what you did. Just a couple points in the meantime.

Don't get wrapped around tha axle on my statement about valve length. I am just making a point that tolerances have to be accounted for sometimes. Had it happen to me just last year when a machinist screwed up the valve height on a friend of mine's a non adjustable system. This one was drastically inconsistent. Yours likely isn't off that bad, but it helps to know what you are dealing with before you throw in "global" shim adjustments.

And the lifter may appear to have 1/4 inch or more of travel, but that is not what you have to work with regarding preload adjustment. Not even close.

[StangD]

I gave the thread a look. It appeared you were trying to determine rocker sweep without using "solid lifter". That is a term for making a lifter solid for testing, not using an actual mechanical "solid" lifter. If you measured using your hydraulic lifters without modification, your pushrod length calculation using sweep method is not valid. Doesn't mean the pushrods you have are not OK. But if they are, it's just luck.

In the event you end up back at that point, I have "solid" test lifters I can send you for free.

[cgrey8]

I got the replacement rocker on order from Summit Racing. In the meantime, I'll be pulling the other valve cover and intake to do a reshimming job. And yes, I was wrong, I didn't have enough shim. My thinking was backwards. With any luck, this will be just a matter of finding out how much more I need to shim by and that'll be it. Worst case scenario, the valve met the piston and I'll be looking at pulling that head to replace a valve. But before I jump to all that, I'll be doing a compression test of a few cylinders to compare to this cylinder.

So next Engine Build 101 question...how consistent should each cylinder be for pressure and what should i expect for pressure? I'm assuming a PSI above 150, but not above 200.

[85GT]

Engine Analyzer Pro will spit out cranking PSI and idle vacuum for your combo. You can give that a try. Is the cam installed per spec? Rod length?

Pedestals are a pain. Maybe you want to consider these:

http://www.summitracing.com/parts/crn-36655-16

For a mild set up, just might be the ticket. I have them in my 351C, though never really put that much mileage on them to speak for their longevity.

OR, by just using one of them, maybe you can buy that way, you would have a way to get the correct pushrod length. Then all you would have to do is find the correct shim pack that gets the rocker bolt to torque in 3/8 -1/2 a turn.

[cgrey8]

Given only 1 rocker failed, I'm not yet ready to give up on these rockers. I can deal with "a pain" to setup as long as it is possible to setup. I'm fairly sure I know what my problem was. I preloaded the lifters too much. So I need to shim the rockers up enough to get the pushrods out of the plunger. But something odd is going on in that I used to have some plunge slack on every rocker/lifter. But every one of the rockers are tight as can be. So I'm going to pull the intake just to make sure there's not something under there going on I should be aware of.

Where do I get Engine Analyzer Pro from? Is that a free thing or a pay-for software? I do have desktop dyno (an old version). I remember it indicates IMEP and a number of other numbers. But I don't recall that it estimates compression pressure. Maybe there's an online calculator I can google for that will claculate compression PSI. If there is, I'll edit this post with a link.

Edit:
This is the only one I found that was worth anything, and even it is not that great.
Not2Fast: Engine Cranking Pressure
It asks for cam duration info, but doesn't ask for anything more. I don't see how it can be accurate at all since it doesn't take into account intake lobe center (i.e. advance/retard). But it's at least something to get a number in the ballpark.

[decipha]

the secret to powah is to get the plunger fully depressed

dont be scared to put a half turn on she

while makin' powah in a drunken state i once exclaimed to the masses, if it taps it lacks, if its silent its violent

[85GT]

It's a good bit of coin, but use to be able to download and try for 30 days.

http://performancetrends.com/Engine-Analyzer-Pro.htm

Post cam details, rod length, stroke, bore, head gasket thickness, and I can probably get you a ball park number.

Was thinking you might be able to keep your rockers with that conversion. They look like regular ones, maybe just need to open the hole to 3/8ths if it's not.

[StangD]

Nothing wrong at all with those Scorpion rockers. They are US made, and a provider of rockers for several of the major players in the valvetrain industry. COMP Cams for one, and I am not talking about COMPs low end offerings either.

[StangD]

the secret to powah is to get the plunger fully depressed

dont be scared to put a half turn on she

while makin' powah in a drunken state i once exclaimed to the masses, if it taps it lacks, if its silent its violent

I think maybe you're posting in a drunken state too

If you need to overtighten your lifters to keep the valves open longer, perhaps we need more duration on our camshaft.

[decipha]

hung valve=no powah, see above^^

[StangD]

hung valve=no powah, see above^^

right, and adding more preload is not going to help. I may have misinterpretted your "give her another half turn" comment. It sounded like you were suggesting he take some more lifter plunger travel away. Anyway, he has pedestal rockers and another half turn will have him shopping at newbolts.com tonight. He has to adjust preload the hard way.

[markedforlife]

Chris i would do a cylinder leak down test on that cylinder that would tell you if that
valve got bent. Check another cylinder to see what the percentage of loss is and the
bad cylinder should be within a percent or two, if the valve is leaking when there is
air pressure within the cylinder you will hear the air leak thru the throttle body or
thru the exhaust tailpipe dependent on which rocker came off, also a proper compression
test requires all sparkplugs be removed with a fully charged battey and a wide open throttle
blade and the coil wire grounded.
I did a compression test on a brand new motor which was built by a quality machine
shop and it was a 12.5 to 1 motor and i recall 175 psi on the first stroke and a variation
of only 5 psi more after 5 strokes on all cylinders.
A cylinder leakdown should be between 3 to 8%.

Sorry to see these problems with your build i feel for you man...

[liljoe07]

the secret to powah is to get the plunger fully depressed

dont be scared to put a half turn on she

while makin' powah in a drunken state i once exclaimed to the masses, if it taps it lacks, if its silent its violent

You can't do that with all lifters. You'll block the oil feed hole.

Chris, my opnion is you need to start over with the push rod length. Go to Advanced and buy a $3 lifter and make it solid. Get the smallest swipe. Add for pre load. Shim accordingly. And be done with it. I'm not a fan of adding that much shim if I don't have to.

I would have expected you to be around 6.3-6.350 on the push rod length.

[StangD]

lil Joe

How far are you willing to shim to get minimum swipe? Most of my experience is admittedly on stud rockers because I always convert to them. I have heard from a number of people I trust that the stack can really get high chasing optimum swipe. I'm inclined to think that is not such a good idea if you aren't running an aggressive cam. The factory non-rollers certainly don't maximize anything good, and the valveguide service life is still quite good compared to other factory head designs.

My personal builds get a very thin swipe, 1/16" this time, but it is nothing like Chris' current build.

[85GT]

Approximate minimum swipe can be figured out from total lift and rocker pivot to tip distance.

Couple of before and after pics of swipe with stock rods and then a 6.400 or 6.450, forget which off hand.

P1010040a.JPG

Before

(72.87 KiB) Downloaded 513 times

P1010038a.JPG

After

(83.75 KiB) Downloaded 513 times

[StangD]

Couple of before and after pics of swipe with stock rods and then a 6.400 or 6.450, forget which off hand.

Looks just like mine, and that's why we gotta measure this stuff. I run 6.800s

[85GT]

So next Engine Build 101 question...how consistent should each cylinder be for pressure and what should i expect for pressure? I'm assuming a PSI above 150, but not above 200.

I get a theoretical 170 psi with 18.1 inches of vac using your components on a 331 shortblock.

I can say my combo showed it would have 183 and 16.0 and it was right on the mark.

[cgrey8]

Great.

Summit got my replacement rocker today. So I guess I'll get back to it tomorrow if life will allow. I already got crap going on Saturday so no time will be had then. MAYBE Sunday.

[StangD]

So next Engine Build 101 question...how consistent should each cylinder be for pressure and what should i expect for pressure? I'm assuming a PSI above 150, but not above 200.

I get a theoretical 170 psi with 18.1 inches of vac using your components on a 331 shortblock.

I can say my combo showed it would have 183 and 16.0 and it was right on the mark.

I'll address the consistency question. Right now, who really knows if you are broken in yet. That means everything regarding consistent cylinder pressures. Within reason don't be overly concerned now. After breakin hopefully they are all within 5 pounds or so. I picked up a solid ten pounds after I loaded it up a few times in 3rd gear. (My preferred method to seat moly rings, there are certainly other viable methods out there). My only rule I strictly adhere to is don't stress the engine until you have some confidence there are no strange noises, severe oil leaks etc. Then I take it through a few heat cycles. Then I subject it to some load.

[cgrey8]

Well, I got everything reshimmed as best as I could figure it. Most of the plunge is in tact now. I'm still dumbfounded how hydraulic lifters pump up and stay pumped up eliminating the spongy plunger action the lifters have when they aren't filled with oil. I always just assumed the lifter plunger quickly relieved the pressure when the engine stopped. But in the case of the stock Ford lifters I have, they don't bleed down easily. It took multiple manual roll-overs of the engine using a 1/2" breaker bar to get the valve springs to relieve the plunger pressure enough to restore the spongy plunger action.

Once I got the rockers reshimmed up, I just threw things back together without the HVAC to get the engine to run and verify that it will run before doing a complete reinstall of everything. The good news is the engine runs and drives 100x better than it did. It revs smooth, it doesn't have that obvious tick it did when the rocker bound the spring and threw itself sideways. Although even warmed up, there's a noticeable amount of valve noise. I'll be taking the valve covers off again, just to give everything a once-over before buttoning it all up and calling it good. As-is, it is a significant improvement. It was raining so I couldn't get on it hard, but just driving around the neighborhood, it drives much nicer and much more like I'd expect it to. The tune isn't dialed in at all so there are still some lean spots on transitions, but overall, not bad...not bad at all from a driveability standpoint.

I did try to test compression pressure, but my compression tester's adapter that screws into the sparkplug hole isn't long enough to reach the threads on the GT40p heads. They are just down in the hole too deep. So I tried the rubber-tip thingie and held it against the head as tight as I could while hitting the starter. I couldn't get a tight seal, but even with bleedoff, the suspect cylinder pushed the gauge over 150PSI. I'll need to get some threaded pipe from the hardware store to get an accurate measure. But I was pleased to see that even with a known bad seal, it was over 150. I just hate it that a piece of pipe and the hose length will reduce the crank pressure lower than it is with a sparkplug. But it will give me an idea of consistency which is all I wanted confirmation of in the 1st place. I'll try to get over there tomorrow to get what I need so I can get an accurate test before reassembling everything. Unfortunately, it won't be tonight.

A continued concern is the LAMBSEs are still not equal while at idle. On average, the DS is .05 lambdas higher than the PS. The 302 had the two banks dead-on. At first, I was going to blame this on the exhaust leak I discovered during the engine install. But then I realized an exhaust leak would make that bank seem leaner, not richer. The higher CL LAMBSE indicates the EEC is having to pull more fuel from that bank than it is the other. So, I'm not 100% sure what to make of this or if I need to be concerned about it. Otherwise, it doesn't seem to be causing a problem...yet.

The high idle is also still there. The thing idles with around 28-30kg/hr which the lowest idle RPM I can get is in the high 700s to 800s. If I completely block off the PVC, it'll get into the high 600s and the MAF drops to about 24-25kg/hr. The throttle plate is as closed as it can get. I'm wondering if the 2.9L V6 ISC is "bleeding" air past if vacuum gets too high...higher than the old 302 could produce at those loads. To test that, I'm considering sandwiching a piece of tin or aluminum between the TB and the ISC just to see if the ISC is where the additional air is coming from. If it is, I'll need to come up with some kind of flow limiter for it even if it is just a piece of tin with a smaller hole in it than what the TB and ISC have to reduce the flow a bit. I'd really like to be able to control the idle to a lower RPM than what I'm getting even if it means I have to sacrifice some idle RPM control via the ISC. Come to think of it, I think I might have another TPS that came from a Mustang 5.0L that I can mount on there and try. I can't imagine the tiny hole in the throttle blade is flowing enough air to run the idle that high. The high vacuum HAS to be pulling open the ISC valve...unless someone can tell me a compelling reason why that's not possible.

[decipha]

any chance of a vac leak on the other bank with the low lambse?

[cgrey8]

I guess it is possible. I'll take a peek closer and see what I can come up with. Although if it was a single cylinder that had a leak, I would expect the HEGO to kind of visually show that by bouncing at high speed between rich and lean as the fuel gets close to stoic. I'd expect that as the lean cylinder outputs a lean exhaust, but the other 3 cylinders output slightly rich. So the effect would be the HEGO showing rich, but every time the lean cylinder outputs, I'd see a spike lean. I'm not seeing that. The HEGOs are behaving very much like I'd expect them to. They are responsive and behaving like I would expect them to. When the shims were screwed up, they weren't behaving quite right. They do appear to be working right now.

[StangD]

Glad to hear you have progress Chris. If the valvetrain noise is light I wouldn't sweat it much for now. Getting some miles on the thing and some datalog time would pobably be a better investment of your time. Not saying lifter noise will cure itself in time, but it sure wouldn't be the first time it ever happened.

Regarding your comments about hydraulic lifters, they are pretty amazing little devices IMO. So seemingly simple in design, but they do at in a fairly complex manner when you consider the wide range they operate in.

[cgrey8]

I got everything buttoned up and got some drive-time on it. It still has a fairly loud and noticeable rattle or tick to it when it first cranks. But it does seems to smooth out once it gets warm. But even warm, it still has obvious valvetrain noise. There's one particular noise that if I had to guess what it is, it's the sound of a valve slapping the seat as it closes. But it cranks, idles, and revs just fine.

Taking it for another drive, I'm still amazed at how well the engine runs with 87 octane. If I got on it hard up into the RPMs, I could hear it starting to detonate so I backed off until I could fill the tank with 93. But I was amazed that it did as well as it did on the cheap stuff. Some of that could be my conservative timing table I'm using just for testing. But it is encouraging that once I get the CNG going, if I'm ever traveling a long distance and need to flip to gasoline just for highway driving that I can get away with the cheap stuff...I just can't WOT it high into the RPMs with it.

As for torque, it breaks the tires loose in 1st gear without too much trouble. I can't floor it in 1st at all or it's a sideways smoke show without popping the clutch at all. The 302 didn't do anything near that. I was a little disappointed that 2nd gear didn't break loose any. 2nd gear is just a little weaker than what 1st gear was with the 302.

There are some obvious things I need to work on:

• Lean spots and a little rough take off where the engine wants to conk out or rev really high if I open the throttle too fast from a dead-idle. Not good for easing out into moving traffic from a stop sign or a parking lot.
• The declutch rolling RPMs need to calm down too. It's holding the RPMs a bit high while in Open Loop idle strategy. No surprise attention is needed there. It's an easy fix, just trial-n-error to find values that work well for OL RPM Idle.
• Closed Loop cruising has the LAMBSEs in the mid to low .8 lambda range. So either injector parameters or the MAF curve will need some tweaking. That's probably my bad. I adjusted the tune based on info I was getting with the bad valve configuration. I should probably go back to my "starter" tune and start working it out from there which is basically my 302 tune with the CID, injector parameters of the new engine, conservative spark table, and MFA disabled.

The part that still has me minorly concerned is the LAMBSEs are still not even with each other. Although they seem to be a tad closer than they were. There's still a good .03 lambda difference between them. I don't know what that's about. But for now, I'll just keep an eye on it and see if it eventually works itself out. I know that's not normal, but at this point, there are other things I can fix and it doesn't seem to be causing any issues. If I turn Adaptive Learning on, that's well within its abilities to correct for so it might not be something I need to concern myself about...at least not right now. Thoughts on this one?