427 s/o engine melt down?????? - Page 7

Jac Mac · #**121** (**permalink**) 07-13-2006, 03:48 AM

We had problems years ago in NZ when the fuel companys were using 'toulene' to help boost fuel quality. Side effect that did not become obvious for some time was a carbon type residue that seemed to get into the port end of the bronze guide [literally into the pore's of the bronze ] and cause it to shrink on the valve stem.

Other than that , perhaps your valve stem seals are to efficient or perhaps you need a bit more oil up top, if you are using restrictors etc. I use stand pipes to raise the oil level up to the first coil of the valve spring when running if PC type seals are fitted to Intake & Exhaust.

Jac Mac

What'saCobra? · #**122** (**permalink**) 07-13-2006, 05:24 AM

You have been plagued with more than one thing going wrong at a time and still retain my sympathies. Life presents what it presents, ain't it grand?

But, i don't care much for that sticking valve. Perhaps the carburized excess oil from the now presumed leaky intake manifold gasket has fouled the guide, as you infer. Certainly it was sticking, and it might also have had a carburized build-up on the valve seat, rather than only or in addition to the guide.

Either one of these cases bothers me a bit. i would suggest removal of the rocker, locks and springs of that particular exhaust valve #6 and ensure that it has an easy smooth movement up and down, seats in the valve seat at the proper height (measure to some convenient reference point) and rotates smoothly in all open, closed and intermediary positions.

i have two concerns: one, that the guide is still fouled and may run dry, which would lead to premature failure. Use of some marvel mystery oil or a quality penetrant oil (not TOO much) may help free the rather narrow guide clearance, if it is reluctant to move very smoothly. Two, that the seat seal isn't clear and could lead to an eroded valve or seat prematurely. The valve depends on proper seating to cool it, of course, and when it doesn't seal properly, it overheats, frequently causing a stem failure or pit erosion along the valve edge. Mounted in the aly head, the seat rarely overheats, but it could still be mashed by the sharp edges of carburized oil leakage (though not likely).

If you are still disassembled, make sure you are happy with the easy movement of the valve and particularly that it closes easy to the sealed position and rotates smoothly while open and closed. Designed-in rotation of the valve during operation distributes the wear accross the stem face, where it is pushed down by the rocker surface or roller. If the valve doesn't rotate properly, because of a sticky guide, it will at least wear more quickly in one place and shorten that valves usable life.

It is no surprise that it is the exhaust that is sticking, because that valve carried away the leaked and partially burned excess oil from the upper oil valley under the intake manifold.

Frankly, if you feel any roughness in the rotation or when you rotate it while closed, i would recommend head removal, guide replacement and a touch-up of the valve edge and seat.

If it were an aircraft engine, you would do this to save lives and property. While you can always pull over and call a tow truck, it could be at least expensive.

If you want to calibrate your fingers to the proper 'feel' of the smooth rotation while the valve is both open and closed, remove the exhaust springs etc. from a different cylinder and do the same exercise and measurement.

Just a thought.

Cracker · #**123** (**permalink**) 07-13-2006, 06:03 AM

Scott - Although not likely on the PI intake, you might want to check the pushrod holes in the Edel. intake for clearance. Depending on how much higher lift your new cam was, it is possible (unlikely though) that at the extreme lift you have some pushrod clearance issues. This is not necessarily related to your valve issue but something else to "check off" since your are still in the engine.

With my Sidewinder intake with a .600 lift cam we had to greatly increase the holes for pushrod clearance. Thus the suggestion.

Regarding #6 - have you backed off the rockers completely and turned the motor over? If so, what was the reading? If not, it might tell you the best case scenario.

HSSS427 · #**124** (**permalink**) 07-13-2006, 08:13 AM

Tony - yeah I did that to try a compression test and did it for leak down. Since the valve was sticking I didn't get much of a reading. However, after tapping the valve I got an appropriate leak down test reading.

Couple of thoughts - the engine has been sitting, and there's little or no oil that's been pumped back up to the heads so maybe that caused the sticking since I've just been turning it over by hand. Will also check the clearance on the push rods.

WhatsaCobra - thanks for the detailed explanation - it helps to better understand what is going on. To my point above, do you think it could just be lack of oil on the valve at this point? Maybe I need to prime the oil system first via the distributor hole and a drill.

What'saCobra? · #**125** (**permalink**) 07-13-2006, 08:57 AM

Of course, 'staking' a valve, that is, tapping it to seat it, does work. But, you should be careful to know exactly why, which is why i brought up the issue of dry/fouled guide, or valve seat interface carbon.

Yes, normally, if an engine has not been run for quite a while, it isn't wrong to run the oil pump with a drill and see pressure for a few moments, perhaps less than a minute. But, if you will forgive me, the careful removal and replacement of the distributor opens up another can of worms, given your current skill and degree of precision, that you might not want to introduce this into the mix of currently uncontrolled variables.

Alternatively, a simple spray/dribble of oil on the valve stems & guides might suffice for these purposes. Either way, don't ignore certaining that the #6 ex valve is free and clear in the guide, and that it closes with ease. Don't force it too much if you find serious resistance, because you may score the stem (not likely) or seriously score the guide (more likely, since it is softer) and then it must be replaced for sure.

i'm gonna' wish it was a momentary glitch, so as to not require the head removal again. But, valve guide issues are potentially very serious indeed, so my wishfulness isn't in any way related to the reality of your valve guide/stem/valve/valve seat condition.

i've unfortunately seen aviation wrenches 'stake' valves with impunity and request a sign-off without a notation in the log about how the compression was achieved and on which valve. This MIGHT be reasonable on a 'self-maintained' low compression 65hp Piper Cub, which is rather easy to park somewhere if it fails. It is likely a necessary option on a radial-engined fighter with the Japanese hitting the field and we need to get up in the air, NOW. But, it is certainly NOT acceptable in a 350hp turbocharged twin-engined cabin-class altitude cruiser with 8 seats and big baggage used regularly between here and the Bahamas. Or on your precious Cobra engine, unless your budget has provision for learning by experiment.

If it sticks open too much, too deep, you are going to be buying at least one piston, valve and gasket set. Maybe lots more. Think about it. What little bit could possibly prevent your spring(s) from closing that valve? You DO recall how difficult they were to compress, right?

It is typically the hot exhaust valve/guide that sticks, not the MUCH cooler intake components, just as it is the ex valve that burns, erodes, over-heats, warps, etc. It took years of practical experience to learn just how to keep ex valves working, just how long was the minimum on the seat to cool, how to rotate, how to dampen, how to harden, etc... Exhaust valve operation is very tricky technology that looks disarmingly simple as we just buy the parts and install.

You get the idea...

HSSS427 · #**126** (**permalink**) 07-13-2006, 09:03 AM

Just got off the phone with Jeff at Keith Craft - lots of great insight! Here's some points as I recall:

1. When adjusting hydraulic lifters, when you initially adjust the lifter it may move the valve off the seat and the engine will have to make several rotations for the lifter to prime and the push rod to center on the lifter cup. Then the hydraulics will go into effect and the valve will close.

2. Based on above, I can't actually test compression while lashing the valves as the valves won't be seated. Thus, should only do a leak down test when the engine is warm.

3. To lash the valve, back off the adjusting nut until there is play (lash) in the rocker arm. Now spin the push rod with your fingers while tightening until you can feel that there is no lash - then go another 1/4 turn. I was tightening until I couldn't spin the push rod with my fingers and then going an additional 1/4 turn - too tight per Jeff. However, these lifters are for a 460 engine and have enough play to potentially go 1 - 2 turns past zero lash

4. Aluminim heads when cold may not be completely symetrical and need to be warm or the valve guides could be "sticky."

5. On aluminum heads when cold, carbon will stick to the valve seat and potentially keep the valve from seating. When I tapped the valve, I probably knocked some of that carbon loose and allowed the valve to seat

Yesterday, Keith said he was looking in to writing a book that is full of these types of tips. He said he's found - and I agree based on books I've seen - that most books tell you the theory and basic how tos, but don't give you the real life tips on how to deal with issues and fixes for all the types of things that seem to be coming up in a lot of threads here. I told Jeff he needs to make sure he gets co-author credit

Now, back to the garage to put the tips into action!

Wayne Maybury · #**127** (**permalink**) 07-13-2006, 11:02 AM

HSSS

I just read this whole thread and have to admit that you certainly have had more than your share of bad luck with this engine. I also note that you do not seem to be discouraged (except talking about a Vette at one point).

While I read the entire thread, I don't remember seeing it mentioned why the engine seized nor why the belts came off a couple of times. These two things signaled the beginning of the problems and the belt issue has to be addressed for sure.

I know that we all have 20/20 hindsight but as I was reading the first page or two of this thread, I kept thinking "why doesn't he pull the engine and send it back to the builder?". Of course, it is a bit late to consider that option now. FE's are not the easiest engines to work on and this one seems to have a special personality. KC has an excellent reputation and probably could have saved you a lot of time by getting everything back on track immediately. This is simply an observation, not a criticism.

I wish you the best of luck. You sure seem to be taking all of this in stride. I would be freeking out if I had half thess problems.

Regards,
Wayne

HSSS427 · #**128** (**permalink**) 07-13-2006, 02:32 PM

Wayne - glad there's at least some entertainment value here. Couple of reponses:
I have thought of pulling the engine, but it's such a pain and I was hoping to fix it myself. Keith has been there on the phone to help.

The belt came off because I hadn't aligned the water pump pulley. i think I left a spacer/washer off the shaft thus the pulley was to close to the engine vs the balancer and alternator.

The engine sieze I think was hydro-lock when the head got a pin hole in it and dumped coolant into the cylinder.

I just took it for a ride and the left side sounds and runs great. Still some missing with the right side and I smelled coolant coming out of the right side pipe after I stopped. However, it could be water that has remained in that pipe from prior issues as I haven't unhooked it and cleaned it out. I also think I may need to look at the valve lash one more time on the right side back - I hear some clicking and clacking under there.

Jerry Clayton · #**129** (**permalink**) 07-13-2006, 02:44 PM

Funny, I think FE are one of the easist engine to work on---first engine(OHV) with up front distributor, flat oil pan, light weight 10 bolt heads, iron manifold a little heavy, easy to change camshaft,

Jerry

HSSS427 · #**130** (**permalink**) 07-13-2006, 07:00 PM

No, this is not a picture of my irrigation system.........

Hole in the exhaust port of #3. I notice the water low when I got back from a short run, and then it was dripping from the side pipe. Topped off the surge tank and took the rug rats to the pool. When I got back there was water on the garage floor. Hmmmmm....

Checked the tank- empty - added more and here it came again out of the side pipe.

Pulled the headers, and started taking a shower when I un bolted #3. Snapped these pics and headed for the beer.....

Don't know what to say at this point.

Rick Parker · #**131** (**permalink**) 07-13-2006, 07:11 PM

These heads were reported to have been pressure tested? Maybe the pressure wasn't applied to the right place ........if you know what I mean????

blykins · #**132** (**permalink**) 07-14-2006, 04:04 AM

Well, at least you definitely know what the problem is at this point. This would probably cause every symptom that you've experienced thus far....too bad you've changed out 49 gaskets, a head, and an intake to find it.

Cracker · #**133** (**permalink**) 07-14-2006, 05:09 AM

Scott - my sympathies, in every since of the word! I'm down in your neck of the woods today, are you around so I may pick up my iron?

I've often heard of porosity plaguing blocks & heads (mostly Dove stuff though) but it appears you have a serious case of it. I wonder if overheating the heads can induce/expose these imperfections. I have an idea, give me a call on my cell this morning to discuss.

HSSS427 · #**134** (**permalink**) 07-14-2006, 06:46 AM

Called KC, but he is out of town at the moment. Tony there said they have had porosity problems with Shelby heads in the past and Keith has elected not to use them as they couldn't seem to get it resolved with the company.

Are others aware of similar problems with Shelby heads? What are thoughts on repair vs replace? I know the pin hole can be easily fixed, but am wondering if there is any way to test and assure the overall integrity of the head to keep this from happening again?

Thanks!

Excaliber · #**135** (**permalink**) 07-14-2006, 08:36 AM

I thought the Shelby heads were really Edelbrock heads with a Shelby name on them?

undy · #**136** (**permalink**) 07-14-2006, 08:57 AM

IMHO, the vendor that sold you the heads should bear the responsibility of replacing them, not another repair. Who knows if future head expansion and contraction might "uncover" another hole, even if a pressure test proves it's OK now (as it has before). In addition, I would think all gaskets and supportive materials should be a part of the restitution. Labor would be negotiable. I'm a small business owner myself and sometimes you have to dig deep to make it right for the customer, even if it wasn't the result of company negligence.

Another thought. Water running down cylinder walls has a tendency to "wash" off cylinder wall lubrication. I would want to inspect pistons, bearings (oil emulsification) cylinders and all journals prior to running it again, essentially a total tear down.

I'm sorry, I just think you're due much more that over-the-phone counseling and "mail order" spot repairs. If it were me I'd pull the whole motor, crate it, ship it up and let them know to ship it back when it's tested and 100% again.

What'saCobra? · #**137** (**permalink**) 07-14-2006, 01:11 PM

i am unfortunately in most agreement with undy's suggestion. This thing has got legs we cannot quite fathom at this distance.

There is a distinct risk that you might have at least once experienced a hydraulic lock on this motor when it might not have started for you at any time in the past. If that really happened and you have contaminated rings and bearings and a 'stressed' piston top, things aren't gonna' get good with just a replacement head. It might solve the proximate problem and run, but the life cycle could be zippo at high power and the failure might well be rather more expensive than a little pissy leaker.

Let a pro get up to his armpits in this mutha and have a eureka moment of his own. KC is fine folks and you might have to negotiate a solution that is cool with you both, but i would feel downright rotten to let you keep digging in this sand hole without suggesting caution at this point.

i wish it wasn't so.

Tony Radford · #**138** (**permalink**) 07-14-2006, 01:38 PM

Scott, call Bill at Southern and get a professional opinion. He knows this stuff awfully well. And he's REAL close!

Cracker · #**139** (**permalink**) 07-14-2006, 02:04 PM

Ernie - Edels & Shelby's are not the same - many differences.

Tony R. - Scott does not need to call Bill - Bill has contacted Scott.

Undy/Whatsa' - I doubt whoever originally sold the heads could be located much less warranteed at this point. Especially considering the circumstances. In my opinion, KC has agreed to a very fair arrangement for Scott.

Regarding all the suggestions to let professionals do it, I agree but becomes a somewhat mute point this far into the journey. Scott's insisted on trying to do the work himself - I commend him for his resilience but will have to live with the consequences of doing so.

Scott - if all else fails, I'll buy your motor and install my Bimmer motor in your ERA - at least it will run nearly every time.

Excaliber · #**140** (**permalink**) 07-14-2006, 11:15 PM

Well thats interesting on the Shelby vs Edelbrock head thing, I had wondered about that. Is Shelby using his own castings for the heads?



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