Fel-pro here also. As far as being warped, I bolted mine up to an old clean head with no gasket, tightened it up, and went around with a feeler gauge. There were spots were a .020" gauge went in loosely. Trip to the machine shop and $60 later and problem solved. The last time I pulled them off the gaskets were all evenly crushed with no leaks.

Great idea! I've got an old used set of cast iron LT1 heads in the garage, think I'll use them to try this same test - THANKS!!!

UPDATE ON LEAKY HEADERS - BAD WELDS!!!

This weekend I fabbed up an aluminum plate to fit over the header flange on my SLP Tri-Y headers. Wanted to do a water pressure test to see if the headers themselves had any leaks. Since my Fel-Pro 1404 gaskets won't be in until this afternoon, figured I'd check that out while I was waiting. Boy was I in for a surprise!

I never got to the point where I had a chance to apply the air pressure. Filled them up with water and watched the water level dropping about an inch a minute (or faster). You could actually see the water level dropping. The bolted on and RTV'ed plate was holding fine, but there were FOUR places where water was literally running out where the header tubes were welded into the collars that are welded onto the flange. I knew there were places where the welds between the collars and the tubes did not go all the way around the tube, but looking at the head side of the flange it was sealed. What I didn't realize was that only reflects the collar to the flange welds, not the tube to collar welds. So I have a set of headers with an extremely piss poor welding job from SLP. Not being a welder myself, and being on a Sunday, I decided to try some "cold weld" type stuff that is designed for sealing exhaust cracks, gaps, and joints. Haven't water tested it yet 'cause I had to let it set up yesterday, but I no longer have any visible gaps anywhere. If it won't hold water then I guess I'll be looking for a welding shop.

<rant mode on>
It's no wonder there was extra air in that header! I think I could probably go buy a cheapo welder and teach myself how to do a better job than these have in an hour or two.

Needless to say, I'm going to seal any gaps I see on the collector flanges and probably going to have to pull the passenger side header to check it as well. I can't believe these welds. No wonder I've not been able to find this problem for so long. You pay your hard earned cash for what is supposed to be a quality product and don't expect to be sold something a high school shop class could have done a 100% better job putting together. Obviously, there was never any quality control checks on these headers. Arrrrrggggghhhhh!!!!!

<rant mode off>

Congrats vern. I dont think I would use cold weld. I dont think it will hold. Since you have them out just bring them to someone who can weld.

You're probably right, but since I already have it on the driver's header, and since it's the easiest one to pull and install, I may go ahead and try it and see if it holds. If not, all I've lost is a few hours labor. Hopefully I haven't messed up the possibility of having them welded with the exhaust sealer I used already. I'll wait on pulling the passenger header until I see how this works out. It may be fine since it was reading so much richer than this known leaky header side was - sure hope so anyway!

I'm definitely thinking about learning to do some light welding. Been far too many times if I had my own I could do it quickly and fairly cheaply as opposed to finding some hack somewhere and losing time and money waiting on them....

Vern, I hear you on the SLP headers. The earlier ones were pretty good quality. The tri-y's I had were welded nice, but were close to the steering framerails and other stuff. When I recieved my 1 3/4 shorties I about threw them against the wall. They looked as if they were welded by a monkey on crack. I apologise if you any of you guys are monkeys. I ended up grinding on them and rewelding most of them myself. IF I lived closer I would do the same for you. It only took me about two hours. The sad part was I had to wire wheel off al the ceramic coating, which was not cheap. I called SLP and they were going to charge me a 20% restock fee and shipping both ways. When I explained they were new and unexceptable they said all their headers were like that and they have not had MANY complaints.

I am not one to bash companies, because I know how hard it is to run one, but I must say I was highly disappointed at the level of customer service and craftsmenship.

Yep, me too

I hate it when you spend good money for something and it turn out to be crap!
Same BS (but less $) when I got my 3rd oil dipstick from Mr Gasket.
Looks real nice and pretty except it is plated so heavily that it doesn't go into the block. My measurement shows at least 0.008 oversize.
the side that the dipstick goes into will fit the block, just not the side that is supposed to. Still fighting with that problem.
I would say if the JB Weld stuff doesn't look like it will hold up for a long time, just run them out and get a good weld job on them.
One thing for sure, you have the gone through everything and then some.
once the headers are fixed, the setup should be perfect for years to come.
Start driving that thing

Thanks for the encouragement, I appreciate it!

Actually, what I'm using is not JB Weld. It's a product that comes pre-mixed in a tube that you just squirt out and smear into the gap, crack, whatever. It's kind of a cream/off-white color. Made by Qualco, called "Exhaust Sealer". So it's supposed to stand up to the heat of an exhaust pipe (JB Weld isn't). So far the stuff I have put on has set up hard, they claim it's "weld hard", so we'll see if it works. After the first application, I did the water test again and had a spot between the #3 and #5 pipes that I had missed. So it's setting up now and I'll water test it again tomorrow. If it holds water, I'll add some air pressure and see what happens. If the sealer blows out I'll start looking for a welder.

Don’t waste your time, the stuff was pretty much only meant for emergency repair with some sort of backup (it usually comes in a kit with some strapping or something to wrap around it). It dries to a brittle, sandy ceramic like consistency which crumbles/flakes with any kind of strain applied to it.

Just get them welded.

WRT to the flange leaks… I’ve tried all sorts of things with good luck. Probably the simplest was to just double up gaskets with a set of the individual port metal shim gaskets at the ports that were leaking.

Running them over a big belt sander works (usually will take the ends down more then the middle, but that usually gets pulled flat as you bolt it down). A large mill file works the same way. Taking a welder and running beads around the ports and bolt holes and grinding them flat a la sanderson headers works well also…

For about 350 you can go to sears and get their mig set up with regulator. It cost just about as much as a good set of headers for our car, but you get more uses out of it.

It is an extremely durable welder and pretty easy to use. I would be glad to give you pointers and tips. You will need to spend another 75-100 for Gas, good wire, and a helmet. If you have a tractor supply or airgas they will have this stuff. I forget the gage nozzles that come with the craftsmen setup but if you get a mild steel grade wire for the middle gage nozzle (I think there are only three nozzles with the welder) and a 80 Argon 20 carbon dioxide gas mix, it is almost a matter of point and shoot.

Whatever you do don't use the flux core stuff on your SS headers, it will work, but they will be rusted in a matter of months due to contamination.

Mark - that was not exactly what I was hoping to hear, but I appreciate the info anyway. The stuff I used didn't come with the strapping or wrapping stuff, but from the sound of it it's probably the same stuff. Definitely a sandy colored ceramic like material. I'll check them out this evening and see if I can get it to crack or flake. I may still go and have them welded, just don't know any good welding shops around here. I'm sure there are some, just don't know who to trust trying to seal up ceramic coated stainless steel headers.

Dave - thanks for the info on the welding gear. I will probably still go that route eventually, just a little short on $$ to do it right now. So I'll have them welded if this stuff looks weak at all. Since the driver's side is the easiest to get on and off, it is definitely the side to experiment on. From looking under the car with a flashlight last night, I think I've probably got a couple of small places on the passenger's side as well with these crappy SLP welds <sigh>

Well, the good news is as of 7AM this morning it was holding water. Left it full of water when I came to work, we'll see if this sealer holds all day. If not, I'll be grinding it off and looking for a good welder. If still holding water tonight, will be putting it on and seeing if at least temporarily that corrects the split AFR issue. At least I'll know I found the problem. If/when the sealer gives out, I'll either swap/replace the headers or get them welded. Hopefully the sealer will hold long enough for it to get warmed up and in closed loop so I can compare the AFR on each bank of the motor. Will know tonight!!!

Good luck tonight....a header leak will definately cause you problems...had some do that to me as well but it was just a gasket leaking....trying to fit a square port gasket with a round tube header didn't work.

Thanks, I hope it does too - at least long enough to show me that's the end of the problem. Then I can get them welded if I need to. It's just going to feel good to have finally solved the issue after a year and a half (provided it does - keep your fingers crossed!!!

Yep, that’s the same stuff, usually available in a package with some backing as a "bandage" or in a tube. I think that permatex also sells a smaller ammount of it in a little squeeze out pouch. The stuff won’t hold unless you can absolutely keep the joint from flexing and back it with something…

Good luck on the testing…

Well, it doesn't look good....

Fired it up late last night, and I'm still .75 - 1.00 AFR richer on the passenger side per the WB's. I went ahead and changed the plugs on the passenger side to make sure there wasn't a misfire going on, plus I wanted to see if it was really running rich over there. The plugs I pulled were all sooty. I plan to change the other four this weekend.

So, now I'm lost, disturbed, p!ssed, frustrated, and about ready to throw a SR in the trash. Don't know what to try next. Dizzy cap and rotor? New distributor? Different motor <argh!>

I'm open to suggestions of any kind (except where to put the SR LOL) at this point. I have no idea what to try next......

Suggestions, anyone?

I feel your pain...I have been having isssues with my motor since day one. My problem is that the damn thing shakes at idle. It holds the rpms well but its not smooth. I have looked into everything you have done except the header issues. I too have SLP headers and was hoping that you had found your problem so I would have another plan of action. I have been following this thread since it started and wish you luck. Another thing to look at could be the collector gaskets.....

Replaced the collector gasket and sealed those welds when I did the rest of the driver's side header over the last two days.

Any other suggestions???

Well put me on the list of ghost in the machine problems. Only reason I had so many suggestions is because I have done them all on my car and have netted nothing. I have a 383 with pro topline vortec heads and SLP runners LTR setup heavily ported. The combo ran hard when it first went together a year and a half ago. For the last six months no matter what I replace or due it is down on power and misses and pops. I am on my third ignition, and I mean complete iginition. Dizzy(MSD), wires, coil, plug, wiring harnesses.

Had it on the dyno about a week ago, and I still cannot figure out what the results mean. 181 HP 367 TQ. I think my motor is reverting to a deisel. At any rate I would appreciate help, but not here on this thread as this is VERN's, and I have covered alot of ground that I just have not mentioned, much of it the same stuff vern has done or been told to do.

It makes it hard to keep the car and work on it. Chances are if I did not have about 4 time its book value sunk into it, It would probably have been out the door long ago.

DAMN - just spent 15 minutes thinking thru and typing a msg and lost it. BLAH!!!!

I know what you mean, Dave. Only difference is I'm probably closer to 7 or 10 times it's book value. No way I could ever afford to sell it even if I wanted to. But there may be an SR on the auction block before much longer.... <sigh>


Anyway, time to think out loud on this, hope nobody minds...

Alright, we need fuel, air, spark, and compression for combustion, right?

Currently left side is controlled by the ECM, and that WB says it's following stoich pretty well. So the fuel going to the left side matches the amount of air over there (which doesn't rule out an air/vacuum leak of some kind). Cranking compression with throttle body wide open was 234-247 (nice and consistent) on the driver's side, so on the left side there doesn't appear to be any mechanical problems causing this.

The injectors have been swapped side to side and the problem didn't move, so any fueling problem has to be being forced/called for by the ECM.

Two lines of thought that I can see (tell me of any others - Please!)

1 - there is some combustion problem on the RIGHT side where it is not able to burn all the gas it is getting and hence reads rich on that side. Possible causes would be bad compression in a cylinder (a bad lifter not letting valve open or close all the way, bad valve, broken or cracked ring, hole in piston) or a bad ignition (plugs have been replaced on that side, so would have to be dizzy, cap, rotor, or plug wire(s) ), I doubt the dizzy or MSD Digital 6 box would be likely since all four plugs were sooty when changed, but could be the cap or some wires. No wires were obviusly arc-ing late last night, but one could still be bad.

2. There is still (somehow) extra air getting into the left side of the motor. If that is happening that would explain having more fuel on the right side than can be burned. Not likely though, I've resealed the entire intake system more than once (all to no avail), but anything's possible.

Only thing I can think to do is pull the right side header (I suspect there's leaks there too, but thatould only increase the already too big WB differences. But at least I could do a compresentation test on the even cylinders and see if there's a problem in there.

Other than that, about all I can think of is:
- Testing and/or changing some plugs wires on the right side (altho this is the third set in 2 years on the car),
- Maybe try some new AIR backflow valves (maybe the driver's side is allowing in "free air"),
- New dizzy cap (current one is only 6 months old)
- Another dizzy (have a slightly used MSD I could put in)

Any other ideas or suggestions?

Vern,

I've not worked with the WB O2 sensors, so I have to ask HOW do you calibrate them? Maybe there is a resistance value difference in the leads between short/long sides (Pass/Driver) that isn't compensated for?

Vern can you try capping the air leads to the headers? Maybe you have an air injection malfunction of some sort.

On the book value thing, mine is a GTA so I was hoping that counted for something. (I am not being serious)

Good idea, I'll cap them off in the morning and see if that makes any difference.... Thanks, Dave!

Wheel Spin - every WB has a free air calibration procedure, bt it differs by brand.

I’m sure you’ve checked this already but on the off chance… did you make sure that the FPR diaphragm isn’t leaking dumping some fuel down one side of the manifold via it’s vacuum line?

vernw, the split AFR may be the nature of the beast. My 327 is the same way. The drivers side runs hotter then the passenger side. This is caused by the cooling system favoring the passenger side. On a stock engine it isn't such a big deal. On higher performance engines the discrepancy becomes larger.

I was going to put a WB on each side but decided not too. I don't want to know how bad the split is (seriously, I don't want to know).

If you have access to the Jenkin's book he has a whole chapter devoted to cooling on the SBC. He made quite a few changes to the water flow to help even out the cooling between the banks.

One last test that may be worthwhile: borrow, beg, or steal (Ok, maybe not steal) a single plane port injected manifold. Install it and try it. Then go from there.

RBob.

If you do that, you might as well put the super-ram for sale ad up right now!!

Crossfire - No, I haven't checked the AFPR for leaks. Guess I'll do that tomorrow. Excuse my ignorance, but how would I go about doing that? Just pull the vacuum line and see if I smell any gas in the line?

RBob - Chicken!!!! Don't want to know, eh?

Seriously, though, you may be right about it being the nature of the beast. Regardless of what LPE says, you might be right.

Wish I knew someone to borrow a single plane manifold from to test with. But I don't know anyone wth a MiniRam or LT1 available for borrowing, and the Stealth Ram won't fit under my hood (don't know any available ones of those either).

Lo-Tec - Be patient, I'm almost there...

And now an update with a little additional info - I did cap off the AIR tubes on the headers this morning. Didn't appear to make much, if any, difference though.

I have noticed one thing a little different though - The difference between the 2 WB readings is worst at idle and low kPa values. The readings seem to get closer together the greater the load (kPa value) on the engine. Under moderate to slightly heavy accelleration (but below PE) they are essentially the same (within +/- .1 - .3, and the richness is actually switching a little from side to side). At idle it's still 1.5 or so richer on the pass side.

Can anyone make sense of this kind of situation?

Usually it’s pretty obvious when you mess with it, at the very least you’ll have gas in the vacuum line, I had one adjustable one that was actually making a fine mist of gas out the threaded deal in the top for the adjusting screw.

Reversion from the cam??

OK - I'll check that out on the AFPR tomorrow, today is pretty tied up with my youngest graduating from hisgh school this afternoon. I don't have an adjustment screw on the top, I'm using a Holley AFPR, but will check the vac hose.

As far as cam reversion for the varying difference, why would it only show up on one side of the motor? Looks like I may have to check valve lift and see if all are lifting the same (possible wiped cam lobe?)....

Well this has really driven you nuts! Everytime something pops up that could cause it, its just not there.
The only thing left I can think of is the rail pressure being higher on the pass side. Don't know if those rails are like the stock TPI or not.
Having it batch fire, maybe the flow through the crossover tube is just making enough restriction to have a 1/2 psi drop in FP to the drivers side.
Pressure is going to drop anytime there is flow (slight as it may be it is there)
I forget where the test point is on those rails (before the crossover IIRC)
Its one of the few things that could be constant in all situations.
Maybe stick a gauge at the front or rear of the drivers rail if theres a plug there.
Probly not easy to flip the flow sequence around to try it but its all I got left for ya.
Possible to run a tee line into the other side in parallel with the crossover tube?

Hmmm.... have to think about that one JP, don't know if the fuel could be "T"-ed into both sides or not. As for the fuel rails - they are the factory TPI rails that you use on the SR. The FP check point is before the regulator which is in the crossover to the driver's side rail, so what you're saying could be possible....

Nope, don't want to know, I'd be crazy about it Did I ever mention the time when I noticed. . . . and spent untold hours chasing a . . . (not going there).

Anyway, with the issue being the AFR off at idle and matching under load (higher air flow), you have most likely fixed it. At idle the air and fuel flow is so low that the slightest difference will change the AFR. It could be something as simple as different deck heights between the 2 banks. Or a difference in head temperature from low coolant flow (low engine speed).

As you mention once under some load the side-to-side AFR evens out. I would drive it some more and if under a heavier load the AFR is still OK, then go with it. As long as the idle quality is decent, and traffic crawl and pulling out is OK, it isn't worth worrying about.

RBob.

I think that's exactly what I'm going to do for the next few days, Thanks RBob!

I sure hope you're right!!!!! Time will tell......

vernw, it sounds like you have one arm longer than the other in regards to the sides of your engine. You don't notice when it counts... just when sitting there!

Since your ECU can get things straight at WOT... I think you'll be okay.

Little things can be absolutely maddening. I chased down about four GM service bulletins in order to fix a belt alignment problem. I ended up replacing an alternator, both belts, a tensioner, a couple of idlers... and almost a power steering pump. Replacing all the other parts did the trick, seeing as my problem was a combination of service bulletins.

I have wondered if you have experienced a design issue in the superram itself that lends itself to problems if the scavenging isn't perfect. Low load... irregularities within airflow... manifesting in different cylinder readings. It is a shame you can't run an 02 sensor on each cylinder to watch the readings.

So, I was looking at the design...



Maybe your problem has to do with scavenging (exhaust leaks) and them compounded with the lean/rich combination due to the turbulence on the passenger side (more open) as opposed to the funneling on the driver's side (more directed). If your ECM uses batch fire, the system can't compensate completely like sequential would to drown out the differences.

I would think that the issues you have sound like scavenging and cylinder fill because the problem corrects at higher engine speed. Usually, scavenging is consistent with low speed differences in cylinder efficiency from back pressure problems ("escape holes" around welds of the Tri-Ys).

Hot exhaust behaves more like water (fluid) because it moves quickly, expands faster, and has a more active behavior as it pulls air in from behind it. So, if more escapes on one side... you'll have irregularities in readings from one side to the other... as the engine tries to scavenge for the next cycle.

I wouldn't worry unless it causes problems. Run it through the RPMs and see what the values are at 800, 1k, 1.5k, 2k, 2.5k, and etc. Your condition may not do squat to rob you of power if it evens out between 800-1k. Couple that with your stall speed and launch RPM and it may be meaningless.

Thanks for the thoughts and ideas. I'm going to try and do some testing over the next couple of days and see how close and when the WB's get close to each other. Will report back as soon as I know more. Again, thanks for everyone's help on this!!!

Vern do you still have your old TPI setup? Maybe you could re-install it to see for sure if it is the SR or sumthin' else!
Good luck....

Nope, Wulff, sold it a long time ago. All I have now are my SR and some unconverted LT1 intakes.

Now that the exhaust is sealed, I think you're seeing the some of the reasons that GM had to use AIR injection to get it to pass emissions. It's probably the reason they put the O2 on the driver's side as well (of course it's also much easier to change on that side, as opposed to digging through AC stuff).

When LT1s got dual 02s, the split BLMs came into the picture. Before that, almost no one outside of GM had much of a clue about it. I think you'd calm your nerves if you found a stock TPI car buddy, welded in some bungs for him, and tested on his car to see what it does at idle.

Looking at the tops of the installed plugs on the driver side, it looks like I may still have a small exhaust leak. Cylinder #3 is showing a very slight gray coloring from exhaust residue on the top of the plug (all three others look fine). So I guess I'll be checking header bolts again tonight.

What little testing I've been able to do so far, it's starting to look like the AFR's are abiut .2 to .3 apart under fairly heavy acceleration, and sometimes the driver side is the richest. There's no way I know of to data log both WB's at the same time unfortunately, so getting exact measurements is going to be hard (driving and watching the road as well as 2 WB displays and a tach while WOT and trying to shift and work the clutch all at the same time isn't very easy for this old phart LOL). Especially since one WB display is in the A pillar and the other above the right side of the stereo head unit.

I'd much rather find a buddy with a SuperRam (and I actually know of one) and add an extra bung for him and see what his SR does. Unfortunately he's fighting a drive line vibration problem and doesn't want to drive his car right now. Good idea though, I'll see what I can work out along these lines. Appreciate the reply!!!

Can you get someone to ride with you? Have them watch the WB's, or better yet, video tape the WB's along with the tach.

RBob.

That's going to have to be the plan, will be trying to find a guinea pig for that this weekend LOL

i wonder did you ever get those problems worked out? i've been looking to buy a superram myself, but am a little scared about the problems people have.

I think I've about got it resolved/figured out. Will post up more info by the weekend on what I've done, what worked and what didn't, things to watch for, etc.

sounds good, thanks

Well if your going to trash it. On your next trip up north I'll leave my trash can out for you when you stop by. I need another intake in my collection.....

Ha! Ha!

You're killing me, Scott!

Got a spare converted LT-1 welded up for Sportsman II heads (and maybe even ported) I can borrow for 3 or 4 weeks for some comparison testing?

Figure there's about the same chance

Seriously though, I hope to have it figured out. Got one last thing to do then I'll post up what I found. Just want to be certain before I go sounding off about something before I have all my facts straight...

I'd offer an LT1, but I don't have one welded up.
My Accel would fit, but the tard I ebayed it from cracked all the rail mount holes. And failed to mention it..... I'll get around to fixing it once I learn how to do AL. with the TIG welder I bought.
Hope you got it fixed. Although I'll miss checking on your progress....

Yeah, appreciate the offer since you don't have one that would work



Yep, I hope it is too....