Damaged cylinder head repair

Since I dropped a valve and damaged the head [Indy SEZ] the guide is split open for sure haven't pulled the head just intake. I'm weighing options here. Try to repair, it looks pretty bad. Replace the single head. Or buy a pr of Edelbrock E Streets and be done with it. With the economy taking a crap I want to be careful with $, but I also don't want it to sit for months not running. Thoughts?
The 446 is probably toast hint of water in the oil. I have another shortblock ready..512 with a smallish roller.
This happened yesterday, but I did make my quickest passes ever. 10.66@125.4 1.47/60 and picking up with each pass.

You won’t know till it’s taken apart and stripped but I’m betting it’s fixable. Jump on it and get it to a shop before everyone else. Winters coming. Indy may even fix it.

A head broke off a valve?
Intake or exhaust?

The most common reasons I see that are usually because there was something unhappy in the valvetrain, valve to piston contact, or in the case for exhaust valves, it can be a corrosion issue.

I would carefully inspect the cam & lifter that correspond to that valve, along with checking to see that the spring hasn’t given up.

Also, I’d look for witness marks in the heads near where the pushrods go.

It’s pretty rare that a valve breaks “for no reason”...... as in just fatigue.
With some detective work, you can usually find the reason.

Intake valve. Broke all the way off. Valve spring is not broke as far as I can tell.

The head broke off, or it broke up by the retainer?

The head of the valve. You can see it with intake off. The guide is split open.

It’s very rare for an intake valve to “just break”....... without some sort of help.

Look everything over carefully when you pull it apart.

The last broken intake valve I can think of was in a 452 head.
That motor was running an aggressive SFT cam with 1.6 rockers.

The actual failure that resulted in the broken valve was the tangs got sheered off the locks from the valve hammering shut repeatedly.
The locks had actually worked there way towards the top of the valve, and the roller wheel from the rocker had pounded a trough into the top of the locks.
When the tangs finally let go, the valve slid down the guide, the piston whacked it, and then the head of the valve snapped off.

The cause of the valve hammering shut and pounding the locks into oblivion was that the spring had died.
Only that one spring was dead........ down like 30-40lbs.
The other 15 tested within a few pounds of new.

Why that one spring died was the unanswered question on that failure.

The valve stem is still attached and the keeper still holding retainer. With the spring pulled tight. The head is off and there is a hole in the piston luckily it didn't scar up the cylinder. The head of the valve is wedged in the port and the guide is cracked, the exhaust valve looks to be bent also. The chamber and seat is scarred up.

Weak valve springs lead to death and destruction in high performance engines when driven aggressively

No arguments here. I'm just glad it ruin the block. Especially since it's a 65 year block.

My main point was, especially with regards to intake valves........ they very rarely break without a reason.

I understand. I didn't see any obvious, that point to any one thing. I need to drop the pan and check #5 rod bearing since it was that cylinder. There is a small witness mark on #7 piston. So it's possible the springs lost control of the valves. It happened at 1-2 shift [6400 rpms] a friend said he could hear the engine sound change.

If I was you, I have broken more than one valve while drag racing , I would replace all the valves now instead of later, when one breaks off others are sure to follow. The damage caused by over revving one affects all the rest of them

Here’s a few pictures.

A good machine shop or better yet a good shop that specializes in fixing broken heads can fix aluminum heads with no sweat
You might want to compare prices on fixing it compared to replacing with a new one

I’ve fixed way worse than that. That’s a relatively easy fix. As Cab said replace all the valves. And I would double check the spring load.

Its a "good" thing that the bowl caught that piece.

I've seen worse that were repaired successfully... but they weren't mine

Regardless, ouch!

Well, I see what’s 99% likely the cause of the failure.

Yep, & replace ALL the intake valves, new springs & double check PV clearance

As said EASY fix and by all means replace ALL the valves.

Yes, after further thought , ALL of the valves not just the intake

My guess is, it’s the #1 reason for broken intake valves.


On the plus side........ I’m liking the complete lack of carbon build up in that intake bowl.

Remember some broken pieces could have gone into other cylinders Even on the other side. My son had a 1/4 inch chunk of an Edelbrock intake valve in number three cylinder end up stuck in number 4 or 6 and pinch a ring.

Ok. Give me the good or bad news. The spring looks like new in that it was not moving around same for the keepers and retainer. No metal scuffing at all. I'm thinking the valve gave up. Or # 5 rod bearing went but it still had 60# oil pressure.

Don't know what the top of the piston w/ the broken valve looks like, but I'd be looking very closely at all of the piston tops for any indications of other valves possibly coming into contact, too.

It's bashed up and has a hole were the valve stem went thru it. The cylinder wall looks fine. #7 did,but when? Probably after #5 broke.

This pic tells the tale:

aha! i was wondering if you were referring the shiny and kinda marred edges of the other intake valve.

I have some BBC heads here now that have a few valves showing the same thing.

There’s really only one way to get that shiny ring.

A very intimate relationship resulting in a shiny ring. Then everything crumbles after too much hitting and abuse.

Sounds like a lifetime movie

The thing is, the fact that it’s showing contact for the full diameter means the valve is rotating, since nothing would touch all the way around otherwise.

So, the rotation means there is some degree of the stem flexing in different directions as the valve rotates around.
Like bending a coat hanger back and forth......... it can only flex so many times before the material is fatigued and breaks.

In my mind, the question as to why the valve broke has been answered.

Also, the contact is not the result of valvetrain control problems.
That’s not to say there couldn’t be some of that as well, but that won’t result in contact with an intake valve.
When you float an intake valve, even if it’s lagging way behind the cam....... at IVC, the piston is nowhere near TDC.
So, the only way to get the shiny ring on an intake valve is....... inadequate clearance during the IVO period.

It’s not all that uncommon for me to see this condition when I’m reconditioning heads.

Any suggestions who to send the head to get it fixed?

Hopefully it’s a quality casting. I sent my leaky W5 head to a guy in Iowa that had brought sprint car heads back from the dead. My head basically crumbled as he tried to weld it.

Indy would be my first call, considering they did lots of cylinder head repair work in the past. Whether the new owners do any of that, you'll only know by asking.

Indy still does repair work and it is second to none. I had a block fixed and if you didn't look real close you could not tell it was ever hurt. They also fixed my B1 heads last year and they look perfect.

It's an Indy head. So that's good to hear. Thanks.

Wow I suggested Indy 10-1-22. Lol 😂

We don’t listen to old guys! …..all kidding aside it’s a great time we live in when you can actually recommend Indy for something.

What about Brett Miller? He's within reasonable driving distance.

Who to use in central Texas area for head and block weld/repair?
I've been jacking around since March to get mine welded up after dropping a valve seat on the dyno..
It's been sitting in 2 different machine shops and all they done is walk around it.

Dave

Call Slawko, not in Texas by any means but can fix you up. Assume Indy is still doing this work but not sure....

Yes Indy is. I talked to Deanna. She said send repairs Attn to her.

This is what I'm talking about. Dropped valve seat did this on 4th dyno pull.

Dave

I'd say I got lucky compared to that. Hope you get it fixed.

Thanks Carnut, So far it has been in 2 different shops that promised to get it done. Stuff just sits in the floor while they walk around it to work o other stuff.
I bought another Indy block, but I'm going to use my B1 heads on it since I have them. Now I have to order a set of pistons for the B1. Wierd bore at 4.400.

Dave

Indy did the repair portion of this job, then I touched up the valve job and opened the ports to MW size.

Looks like they’ll be able to race another day......

Excellent as always! Yeah.