427 s/o engine melt down?????? - Page 8

Cracker · #**141** (**permalink**) 07-15-2006, 04:47 AM

While not an authority on all-things-Shelby, I recall someone arguing that they were REAL ONES. I guess so...

What'saCobra? · #**142** (**permalink**) 07-15-2006, 08:59 AM

Don't be naughty...

HSSS427 · #**143** (**permalink**) 07-15-2006, 12:16 PM

Shipped the heads today back to Keith and he is going to send me a new set of Shelby heads that he's already ported and tested.

Here's a better view of the inside of the port where the failure occurred

Excaliber · #**144** (**permalink**) 07-15-2006, 02:32 PM

Is the problem with the heads a faulty casting or to much porting leaving them with thin walls?

I'd appreciate any additional information anyone can provide on fundamental details of Shelby heads. No ax to grind, just keeping up with market trends.

lineslinger · #**145** (**permalink**) 07-15-2006, 02:46 PM

Is that a scratch or is there a crack at the base of the valve guide..?

Jac Mac · #**146** (**permalink**) 07-15-2006, 05:05 PM

Appears to be an exposed portion of guide or K-liner. Smokey Yunick used to advise treating all alloy heads with ? sodium silicate? in the water jackets for heat barrier reasons. Would this also help seal porosity like this ? I know there are several ceramic sealers out there that can be used. But the best results are obtained when the casting is clean & uncontaminated .Perhap's a pressure test of any head prior to use would be cheap insurance & save a lot of grief down the track.

I know there are several times I have asked myself the same 'silent' Q.

Jac Mac.

Excaliber · #**147** (**permalink**) 07-15-2006, 05:12 PM

The heads WERE pressure tested! This sounds kind of like plugging one hole only to find another, and another. Perhaps the heads were 'stage 3' ported, leaving the wall thickness a tad to thin? Shelby only offers Stage 2 porting. What ever the heck Stage 2 and Stage 3 means!

Both Edelbrock and Shelby are made from the same material and hardness spec. A quick comparison indicates they are virtually the same in all critical deminsions (wall thickness, chamber sizes, etc.). The Ebrock heads can be machined to accept larger valves. With larger valves they will ONLY fit the 427 original iron or Shelby alloy blocks (that applies to both manufacturers). The cost difference is profound, which leaves me wondering if the Shelby heads are really worth the extra dough?

HSSS427 · #**148** (**permalink**) 07-28-2006, 01:04 PM

Well, at last, here it is back together with new Shelby Heads and Edelbrock Performer RPM intake from Keith Craft.

Just took a first short drive and it seems to be running fine. Only things of note: Oil had blown out the rear goose neck breather. I'm running that breather and a PVC coming out of the right front valve cover. Maybe this is why the originals had an oil recovery tank on the fire wall??

Also may have a small water leak at the surge tank. Getting some water drips from there. Need to see if it's the seal with the intake, or a hole in the solder connection on the bottom feed tube.

Got my fingers crossed that this is the end of this story....but I've posted that before in this thread

jimmymac · #**149** (**permalink**) 07-28-2006, 08:53 PM

I hsd a similar experience .got freaked out !Well do a pressure test on the cooling system .Listen to where the pressure is going. I supect you have blown a intake gasket at the front or rear of the engine .It let coolant into your crankcase and intake port when one of your cylinders filled You got hyd, lock .Light you may not have damaged it but if it doesnt run the same pull the oil pan and look ! an line up those pulleys or the belt will not stay put Check for signs of coolant in oil good luck

Carnut427 · #**150** (**permalink**) 07-29-2006, 12:16 AM

Quote:

Originally Posted by HSSS427

...Oil had blown out the rear goose neck breather. I'm running that breather and a PVC coming out of the right front valve cover. Maybe this is why the originals had an oil recovery tank on the fire wall?...

From my experience, there's too much oil flying around under the intake to use the rear breather. IMO you're better off closing that hole, using a breather on one valve cover and the PCV on the other if your intake is newer and doesn't have the filler on the front with breather. Been there, done that.
Just my 2 cents...
Dan

HSSS427 · #**151** (**permalink**) 07-29-2006, 07:25 AM

Carnut427,
Thanks - I can do that, just want to make sure my issue isn't a symptom of something else. I understand that FEs generally need a lot of "breathing." You appear to be saying that the oil may be getting thrown out vs blown out. Is there someway to measure how much pressure the blowby is creating and if that is out of norm?

Was thinking of intalling another PCV in the driver valve cover to match the passenger side, and leave the rear breather as the "intake" for fresh air. Alternatively, I could make the driver side breather the PCV system intake as is traditionally done, and seal off the rear breather. Just wondering if that will be enough venting.

Also wondering if I just need a better filtering system on that rear breather to keep the oil in the crankcase. The goose neck breather has some "steel wool" looking material in the bottom with a perforated steel cap to hold it in. But doesn't look to be very thick and obviously the oil isn't having much of a problem going through it.

Thanks!

Jerry Clayton · #**152** (**permalink**) 07-29-2006, 08:33 AM

Looks and sounds like you've been making progress---

Now, I would like to see you remove the braided AN hose on your PCV valve---where it goes near your starter solenoid is like a ticking time bomb--That can cause an instant electrical short and the current flows directly thru the carb since the valve cover end is insulated with a rubber grommet--

Altho braided fuel and brake lines look nice they are potential sourses of failure and around anything electric----

Jerry

Carnut427 · #**153** (**permalink**) 07-29-2006, 05:50 PM

Quote:

Originally Posted by HSSS427

Is there someway to measure how much pressure the blowby is creating and if that is out of norm?

An easy way to check is to cover the rear hole with a gasket (with the vent on top) and install a breather in the opposite valve cover.

Quote:

Originally Posted by HSSS427

Was thinking of intalling another PCV in the driver valve cover...

Forgetaboutit.

A PCV is a controlled air leak; one is plenty.

Quote:

Originally Posted by HSSS427

Also wondering if I just need a better filtering system on that rear breather to keep the oil in the crankcase...

I tried several types of filters in my rear vent; nothing worked for me. Gessford Machine (and others) sell and install the rear vent systems, so I'm sure they know how to make them work; it was just easier for me to use the valve cover.
Again, just my 2 cents...

Dan

HSSS427 · #**154** (**permalink**) 07-29-2006, 08:53 PM

Puttered around a little today and still seems to be running good. I didn't really run it hard and noticed I didn't have the blowby when I got back, but wasn't out very long.

Jerry, I think the picture is a little deceiving as there's a good bit of space between the PCV hose and the solenoid. However, good food for thought as I should consider what would happen if the breather cap came out of the valve cover and was bouncing around in there. Are there covers for the solenoid connections similar to battery terminal covers. Seems a good idea to cover those up regardless.

Carnut, I think what Gessford uses is a steel wool filled "basket" under the breather that provides more barrier for the oil to go through. Had one on the old intake that seemed to work. However, stupid me, when I drilled out the plate on the new Edelbrock, I drilled the hole to match the size of the opening on the breather bottom - not the standard size hole that the basket fits.

Well, looks like I'll have to take the hole saw to the other valve cover and stick a breather in there.

Is there any science to putting the breather on the front vs the rear of the cover? I was thinking it would at least look symetrical if it was on the front and matched the other cover, but then thought having it opposite (on the rear) the passenger cover would have more cross flow diagonally across the block. Suggestions?

Going down to Jekyll Island for the week and broke down and bought some street tires (Firestone Indy 500s) from Tire Rack, so will get those on when I return and then really give it a run. The left rear Goodyear is showing cords and I think is about to bite the dust.

BTW Dan, I used your tag line on my wife today because she was in that mode......she didn't seem to think it was nearly as funny as I did

Carnut427 · #**155** (**permalink**) 07-30-2006, 12:32 AM

Make sure you put the hole between a pair of cylinders so there isn't a valve under it. Ideally you should have a baffle (on both sides). I use these:

They're made for Chevies, fit in a 1 1/8" hole. The problem with them is the hole in the center of them is too big for a PCV valve; I find a grommet that fits a PCV (or breather) and has a long enough shank so that it will fit down in the Mr. Gasket #5425 baffle. The OD of the grommet doesn't matter, as I sand it down on the belt sander so that it fits snuggly in the baffle.
DSC Motorsports (and others) sell a plate that fits over the hole in the intake the rear breather goes over with different holes or no hole. You could buy one of those to cover the rear hole in your manifold and it would look factory. You could also drill a hole the correct size to fit your breather and sandwich it between the manifold and breather if you choose.
Sorry your wife doesn't have a sense of humor.

Dan

HSSS427 · #**156** (**permalink**) 08-04-2006, 05:23 PM

So far, so good. Put a new set of Firestone Indy 500 tires on it - what a difference from the Goodyear race tires. Almost like driving a street car with power steering. I was amazed at the difference.

Car ran great, put still getting oil out the rear breather. Put a PCV intake on the driver side rear valve cover and ran a line in to the side of the turkey pan for the intake source. Tried running it with the rear goose neck still attached to see if it made any difference - appears it did not. Alos got some blow by on the passenger valve cover where the PCV breather was mounter.

So, will seal off the rear breather and try it with just the closed PCV system alone. If that doesn't work may resort to full breathers on both valve covers.
Thanks!

Carnut427 · #**157** (**permalink**) 08-04-2006, 11:10 PM

Did you hook the PCV valve up to a full vacuum source, like the base of the carburetor or directly from the intake? Breathers alone aren't going to get the job done. Well, actually they would, but you'd have blowby coming out of them, and it's really best to suck that out of the motor and burn it, which is what the PCV system does.
Good Luck,

Dan

Excaliber · #**158** (**permalink**) 08-04-2006, 11:18 PM

PCV to the turkey pan won't do anything to speak off. GOT to ge attached to INTAKE manifold vacuum. One source for that is typically that BIG port on the lower part of the carb.

HSSS427 · #**159** (**permalink**) 08-05-2006, 09:43 AM

The cap on the front of the passenger side cover has a PCV valve inside it. Have one of those rubber baffled gromets installed. The -6 AN braided line is connected to the vacum port in the carb base.

The cap on the rear of the driver side has the PCV removed and the inside has a foam sponge filter in it. I've connected it to the turkey pan as a source of air. The rear gooseneck breather is still functional at this point, and that's where I'm getting lots of oil out of. I'm going to seal it off, but then worried that I won't have enough venting and will get blowby somewhere else - likely around the grommets holding the breather caps. Based on Carnut's posts, I'm still wondering how much of the oil coming out of that breather is blow-by vs "throw-by" from the hydraulic lifters slinging oil all over the place.

I've got a block off plate on order to seal off that rear breather, and some of the breather cap fasteners that give a better seal than just the rubber grommets. I guess it's just a matter of experimenting until hitting on the combination that works.

Engine has about 250 miles on it since rebuild - can I assume that the rings are fully seated and the blow-by isn't likely to decrease at this point?

Excaliber · #**160** (**permalink**) 08-05-2006, 10:14 AM

Yeah, thats a good setup for the PCV, should work fine. "Throw by"? Interesting thought, doesn't seem likely though. Rings seated? I would think so, at least for the most part, there not going to get a lot better.

Hmmmmmm...



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