Bent Valves due to timing belt failure, can I replace the valves with used ones?

[dx92beater]

Hey,

I have a Focus SVT with bent valves due to a defective brand new OEM timing belt tensioner when doing a timing belt change. This particular engine is the interference version of the ZTEC. The failure happened at idle and I still bent about 12 valves.

It is super hard to find a used head and all I have are some used, known good valves that I removed from another head. The community and support for these engines is very slow moving.

Could I lap the valves and stick them in the head? Does it need to go to a machine shop? My local machine shop is very pricey and run by an idiot. The valves are like $35 each. I checked the head for warp and there is very little...falls nicely within Ford's spec.

Thanks.

 

[maxdustington]

Some dude just swapped valves without even lapping them in a recent thread so I would say yes. I also read about it in a magazine like 15 years ago and it seemed easy.

 

[bdcardinal]

Yes you should be able to swap them, lap them, and as long as they seal you should be good to go.

 

[Imp4]

Originally Posted by maxdustington
Some dude just swapped valves without even lapping them in a recent thread so I would say yes. I also read about it in a magazine like 15 years ago and it seemed easy.

Well if that's not a ringing endorsement...

 

[UncleDave]

Better make sure the guides arent trashed.

 

[demarpaint]

Originally Posted by UncleDave
Better make sure the guides arent trashed.


+1 I would go over that head real good before tossing valves in it.

 

[dx92beater]

Thanks everyone. My eyes aren't the best anymore. Is there something that I need to look for on the guides? Cracking etc.? Also guessing that with the sheer amount of bent valves one of them is going to be trashed.

 

[maxdustington]

Originally Posted by dx92beater
Thanks everyone. My eyes aren't the best anymore. Is there something that I need to look for on the guides? Cracking etc.? Also guessing that with the sheer amount of bent valves one of them is going to be trashed.

Magnaflux and check the guides for wear I guess.

 

[FlyNavyP3]

Once the old valves are out it will be pretty obvious if the guides are broken. If the valves were a light tap you might be okay. If they're very bent chances are good you'll have several broken guides. They break on the portion of the guide that extends past the head into the bowl of the port. If guides are bent a trip to the machine shop is in order. If not lap in the new valves and let it ride.

 

[dx92beater]

Thanks for making it easy guys!

 

[Chris142]

Every valve and seat wear together. Taking parts from one head and using them on another head with out the proper machine work is asking for a redo in the near future.

You hand lap valves back where they were or new valves into old seats. Never used valves into used seats. There has to be a competent machine shop somewhere near the OP that can cut the seats and valves.

 

[BrocLuno]

All engines are used as soon as you drive them a few thousand miles. You can swap used parts to your hearts content. Careful scrutiny is advised. Slide the used valves in and out and rotate as you do so to look for any binding, etc. If smooth and reasonably tight, run what you got. Lapping in a good measure. Is it race engine clean room good - no ... Is it it good enough for the street - you bet

 

[Linctex]

Originally Posted by Chris142
Every valve and seat wear together.


not as much as you would think, anymore.

Originally Posted by Chris142

Never used valves into used seats.


This is becoming an old wive's tale as time goes by.
new materials and processes really negate this to a large degree, anymore.

Swap in the used valves and run it - you'll be fine.

 

[Shannow]

Having been in similar situations, I agree with both Chris142 and BrocLuno.

If you were doing this for a customer, then do it "right"
If you are doing it for yourself, then choose how good you want to do it.

Put the valves in the head. slide them in and out, rock them up down and sideways with the head in approximately the full lift location, then put your finger over the guide, pull the valves out and see if the suction creates a nice "pop".

Form your own opinion as to where you are and proceed as you wish to...your risk profile, your budget, and your reputation, which as you are the customer is not in question.

I've been in those sorts of situations.

One, a Holden 6, I noticed the intertia ring on the balancer had started sliding forward...a sign of incipient leg out of the bed on #2 or #5. That was Sunday afternoon tuning.
Got a short block kit (bored honed, hyper eutectic pistons, and cleaned up rods) delivered to parent's place during that week's commute. Ordered the cam I wanted (28/58, 24/64), and convinced the speed shop to press on the alloy timing gear.
Picked it up on the way home from work Friday arv and ripped in...in a carport, on a rainy weekend.
Broke it in sunday arv, and drove it 40 miles to work on Monday...nothing huge, very satisfying, and wouldn't suit my Professional role, and Dad with kids modern day reality.

 

[Audios]

Not worth the gamble IMO, are you really going to want to go back in there if only one fails or doesnt seat right. Are you going to only replace that one when you go back in or do it all? Id find a comeptent machine shop, even if you have to ship the head, and have them deck it, pressure test it and go over everything. Slap it back on and never think about it again.
Car-part has a ton of heads for sale also, between 2-400, super cheap!
http://car-part.com/cgi-bin/search.cgi

 

[CT8]

Pour solvent into the heads combustion chambers and see if the valves leak.

 

[dx92beater]

Wow, I am glad that I came back to review. It seems that everything that I have read on the internet has been consolidated into this thread.

Could I not pour water on top of the valves as a variation CT8 to see if they leak when done? https://www.youtube.com/watch?v=CcF16RAJtic

I have used this test to find all types of things.

If no leak, do I even have to lap. I have folks telling me that they even get away without lapping. One of you guys mentioned that here.

Thanks so far. Thinking about it all.

 

[BrocLuno]

How many of you'all have done this?

Like Shannow and others, I have more then once to get things running when the budget is tight. Worked every time

All depends on the condition of the guides, and if any seats go nicked ...

Machine shop will cut new seats by indexing on your existing guides ... Just like lapping them in by hand, only more expensive. A lapped valve will actually seal very well, and run a long time

There is no magic at the machine shop. If the cutters are worn they'll chatter and leave a wavy seat. If their guide spindle is not checked regularly for wear and run-out, they be off center. You can pay good money and not be any better off. A lapped valve is now a matched pair. Often times better than fresh cut seats, especially on a mediocre job ...

 

[FlyNavyP3]

Originally Posted by BrocLuno
How many of you'all have done this?

Like Shannow and others, I have more then once to get things running when the budget is tight. Worked every time

All depends on the condition of the guides, and if any seats go nicked ...

Machine shop will cut new seats by indexing on your existing guides ... Just like lapping them in by hand, only more expensive. A lapped valve will actually seal very well, and run a long time

There is no magic at the machine shop. If the cutters are worn they'll chatter and leave a wavy seat. If their guide spindle is not checked regularly for wear and run-out, they be off center. You can pay good money and not be any better off. A lapped valve is now a matched pair. Often times better than fresh cut seats, especially on a mediocre job ...


I've done what the OP is asking about and way way worse in a bind. I once broke the glaze on a cylinder with 220 DA sandpaper working in cross cross patterns across the bore to make a cross hatch. Couldn't afford a home at the time. Put the engine back together with new cast rings bearings and gaskets. No longer own the vehicle but it's still running strong a decade later. By some miracle it doesn't even use oil. I'm not even willing to admit to some of the other mechanical atrocities I've committed that turned out fine. Suffice it to say you can get away with A LOT!