Disaster....Carb Stud Sucked Into #7
 

Im not really looking for much in the way of advice, Im just venting. Freak occurrence. I guess Im lucky it seemed to occur on startup rather than driving.

After Thanksgiving dinner I decided to load up the dog and take a holiday ride. Got in the FIrebird, didnt want to start. Which is strange. After a couple failed attempts I got out and started poking around. Thought maybe a vacuum hose or something had some loose the way it was acting.

Went to remove the air cleaner, the wingnut was sitting on top, but I could see there was no stud and my heart dropped. Removed all the plugs and none were damaged. After looking with my borescope I finally found it wedged into the #7 intake valve.

Stupid. I have a very short stud because of low hood clearance. And it must have worked its way out. I guess ill start loctighting in air cleaner studs.

I *think* that initially it wasnt in the valve but was holding the butterflies open before it worked its way lower. The fact that it never fired off might have saved me from total catastrophe. I can see where it just barely kissed the piston but I dont see any evidence the valve hit the piston. Still, thats my big concern at this point, the valve being bent and or the valve seat being damaged. Im not overly concerned about the small mark in the piston. I would obviously prefer the piston to not have been hit at all, but I dont think it warrants blowing the engine apart.

Long story short I removed the intake and driver valve cover. I was able to rotate the engine until the #7 intake opened further than it was wedged and pulled out the stud with a magnet.

Of course nobody has RA-IV size intake gaskets in stock locally so I had to order a set. I think the plan is to bang it back together, and then do a leakdown and or compression test in the cylinder. If it tests fine Im just going to send it. The valve seems to open and close normally from a visual standpoint.

Silver lining, with the intake off Im going to separate the water passage. Ive wanted to do that forever but didnt want to take the intake off just for that.

Whats the best cutting tool to get that done? Jigsaw? Its an aluminum RPM.

Oh man that sucks, but hopefully it didn't bend the valve

On ocassion when i use all'thread cut to length for a air cleaner stud i will run a nylon loc'nut down against the carb top.

make sure the top of the piston didn't take a hit above a ring pinching a ring, should be easy to tell

good luck nows a chance to make it better than before

Yes you got lucky!
Before you potentially waste time in bolting the intake back on I would bring 7 to TDC and pour some engine oil at room temp down that intake runner and see if it leaks into the chamber .
If it does then it’s time to pull that head.

Oh gosh, mine is super loose...thanks for bringing this up and hopefully she is ok

I just did that. Nothing immediately leaking but Ill let it sit while I go run errands. Easy idea to try. Thanks

Hard to consider myself lucky when such a bad thing happened, but I guess it could have been worse.

I’m probably going to do that. But I don’t own one. So the oil test was convenient until I go buy a tool.

if you have compressed air you can usually use a hose from a compression tester connected to shop air pressurizing the cylinder without rocker arms to see if anything major is going on

Slap it back together, and compression check it. If it's building compression, and you don't hear air leaking out thru the intake, run it.

heck with rocker arms on and no intake you can just crank engine over with starter and see if it pumps back into the port

Sorry to hear yes a jig saw will work rpm's are a bitch to cut off
I generally use a large hack saw w a pretty course blade and some wd40 then hit the edges w grinder and one of those layered 80 grit grinding discs

Yeah, it does look way harder than other intakes. But its still just aluminum so shouldnt be hard to cut. I may try the hacksaw before the power tool.

At times I have drilled a bunch of holes in hard to get at areas to use a saw on.
You drill the holes close enough and or big enough to just snap the crossover off once the other cuts are done.
Think of it like perforations.

Something similar happened to me. It was the washer under the wing nut that somehow got in. The engine was running slightly rougher, hard time idling, with some popping in the exhaust. I did a compression test. One cylinder was down to 170. All the rest were 175/180. I didn't expect that to be a concern. Anyhow I took the head off and found the intake valve was leaking slightly. Turned out the seat was damaged and required repair.

Yes, the stud was likely use plain 1025 steel which is not as hard as the valve itself, but the cast iron is a different story.

Sorry to hear this but what’s the best method of securing the carb stud so this doesn’t happen? I see one person mentioning the locking nut on the carb air horn but seems like the stud could still vibrate loose eventually?

It could always be worse.

Well, it’s officially leaking.

I had the thought that I have one of the air tools that let you change valve springs with the heads installed. So I put that on and pumped about 10 psi through it. That oil I put in there earlier started bubbling. The oil lever leaked so it must be small.

I’m so disgusted with the situation I want to light the whole car on fire. I always said i wanted to add more cam and a single plane if I pulled any of it apart. But this close to Christmas that would be a poor financial idea.

I called my local machine shop and they said they had the availability to help me. So I guess I’ll pull the head and drop it off with them on Monday. The repair itself won’t cost all that much but it’s a pain in the neck amount of work.

Terry Cummins who owns the machine shop and has been around forever tried to commiserate with me. He said they see it all the time where nuts and bolts go through the engine and he had done it himself.

Anyone have headgasket recommendations for the older bathtub style round port E Heads? FelPro 1016? Can I reuse my head bolts?

Carefully use a hacksaw to part it at the flange. Don’t cut it in the middle between the water port and intake port, stay closer to the water port. You can get the cuts nice and straight here if you’re patient.

Next I would follow Steve’s advice and drill a series of holes right next to each other.

Some heavy files and a lot of elbow grease will get you the rest of the way through it.

Honestly it’s a ton of work. I did this to a Torker II using a band saw. Once the crossover was separated I dove in with a series of cuts to remove all I could. Many hours of filing and sore hands finished it off most of the way, fine files and sanding finished it.

I also removed the exhaust crossover.

Never again. :)

Juice ain’t worth the squeeze unless you’re doing a super precise intake port alignment on a race engine where the intake gets removed frequently.

I’ve seen so many intakes where the flange was cut in the wrong place essentially ruining it. Also when it’s time to sell most people prefer uncut intakes.

It’s not really so bad as long as the cylinder did not get scratched in the area where the rings ride.
Once the head is in the hands of the shop it’s not even a hours worth of labor to freshen up the face of the intake valve and the seat in the head.

Your time wise it’s part of an after noon each to get it apart and then put it back together, so that’s really not bad.

A 1016 gasket works fine, heck I have used the lowly 8518 gasket in a pinch on a blown motor up to 6 psi of boost.

Re-using your head bolts is also fine, just make sure that each threads into the hole with just normal finger force.
If need be use a clean out tap .
I thin film of oil on the threads is all you need, no dripping oil should be seen, so no dipping the bolts in oil.

I like to wet a rag with oil to rub the threads with.

If you’re running at least a 1/2” spacer then do what a whole lot of racers do.
Sandwich aluminum window screen between two gaskets and this whole terrible issue will never happen again.

None of the head or intake bolts need to be sealed do they?

I'd have said "gasoline". Thinner, will leak past a poor valve seal easier/quicker.

Better yet...do a cylinder leakdown test on that cylinder BEFORE installing the intake manifold, and potentially wasting a gasket set.

No.


:)

That would have been my move if I owned a leak down test kit. But I pressurized the cylinder by different means and confirmed it leaks unfortunately. So the head is coming off. One more thing I might do is ask the machine shop to put helicoils into the header bolt holes for me.

I just worry this is like LS Cam bearings. They are fine if you dont look at them. Im concerned that I pull the head off and find the damage to the piston is worse than I thought, and then this just spirals out of control.

I took some pictures but I gotta take them off my camera tomorrow.

Finally a bit of good news. Removed the head. There is the small spot on the piston we knew was there. And there is a larger spot on the head in the combustion chamber that I’ll talk to the machine shop about any repair options. Obviously we likely have some damage to the valve seat. But that appears to be the extent of it.

No damage to the bore. All the other ones look fine too. I’ll take the head to the shop on Monday and probably reinstall it all next weekend.

The head gasket came off super clean too which is nice. I taped it all off with aircraft flash breaker tape to keep it clean and put a little wd40 in the bores

Sorry to hear this happened to your engine. I've never used any threaded rod on any carb. I use right stuff on the washer and seal it to the air cleaner cover so it never falls off, then I use a bolt down through the cover to the carb. I've have to custom length some of the bolts with different filters. I believe on my 76 T/A I used a ARP chrome valley pan bolt fit perfect with my cone style filter.
I've used a jigsaw to cut water cross-overs off. One thing is not to get the blade hot as the aluminum will clog up the blade.

Sorry to hear about your misfortune. I've had my share over the years. I always run a jam nut down on the air horn to prevent this.

Cutting the crossover loose is easy. Best to do on a bandsaw. But a Sawzall will work too. Use some light oil on the blade so it doesn't clog up with AL. Scribe a line and take your time. Clean up with a 36 grit flap-wheel on a 4-1/2" grinder. It's a cake walk.

A nick in the chamber is a non issue as long as there’s no sharp edge to it.
But that can be just lightly rolled over .

Glad your damage was minimal… I saw this on a YouTube video about 6months ago… guys stud made it to piston top,& broke top right off piston….cracked block… he lost his 455 …Golds Garage is the channel…was hard to watch

You were lucky. My carb stud came loose and destroyed my last 455. It windowed the block, broke the lifter valley, the cam was in three pieces, the rod snapped in half. destroyed the oil pump and windage tray and put a big hole in the pan. The head was not hurt at all.

Was that the dark amber Kapton tape or the blue Mylar tape ? ... Sometimes we had the thinner green Mylar tape, didnt like that as much

It’s blue. I think it’s Mylar but it’s thick. Only problem with it is it likes to tape to itself if you aren’t careful when you break a piece off. This is my last role that I liberated from an army UAV site that I helped close down.

The unit had left on a 12 month deployment.

The base Fire Marshal came in. Looks in all the Flam Cabinets and stuff. Says “This stuff can’t all stay here until the unit gets back. I’m not telling anyone to steal…….but I’m coming back tomorrow and any of this stuff here goes in the trash….”

Myself and a couple of greensuiters who didn’t deploy got the message and reaped the rewards.

haah...similar to the "EXPIRED" yellow tape I seem to keep being told to remove ;) Hoefully a little freshen up is all yours needs.

This thread prompted me to go make sure the air cleaner stud was loctited in on my car. As bad as it probably feels, I’ve seen much worse damage from much smaller parts. Good luck on the repairs.

I would use a bolt on the air cleaner instead of the stud. this way if it comes loose it stays on top instead of being sucked into the engine..

Hello Fellow Veteran track73

I was at Nha Trang in Vietnam, Helicopter Mechanic on 20th SOS Huey Helicopter Gunships 68-69

I was also at NKP Thailand, 21st SOS CH-53C Helicopters, Flight Engineer and Gunner on the Mini Guns,
I Flew Into LAOS for the CIA's Secret War 72-73 Got Shot at, but Never Wounded.

Those were The Days of our Youth, I was 26 and 29

Hope you Made it Home OK

Take Care

Dusty

Dropped the head off with the machine shop. Hoping to be able to pick it back up before the weekend.

I separated my RPM. It wasn’t too bad. Drilling holes in a line was a great tip. The jigsaw was very slow, especially through the thick flanges. Cleaned it up with a 36 grit sanding disc. Could spend some more time on it but I’m pretty happy with it as is. Now if. Decide to go to a victor or northwind later it will be a breeze.

You work on cars, you need a leakdown tester.

This is my suggestion. Includes "master orifice" for verifying the tester.

https://www.aircraftspruce.com/catal...rs_orifice.php

Tell 'em you want the 14mm adapter instead of (or in addition to) the 18mm it normally ships with.

That lip around the valves is horrendous!

Is that not how all the bathtub E heads look?

Engine made power above expectations so Ive never had any reason to question any of it. It certainly doesn't have enough of an effect for me to feel the need to pull the other head off and take it to the machine shop too. But its something Ill note if and when the engine needs a full overhaul one day.

And yeah I should buy a leak tester, but the couple of times Ive needed one I borrowed it from a friend. So there has always been something else higher on the list of things to spend money on. In this case I proved the leak by pressurizing the cylinder with a different tool.