Seized Injectors - Need Ideas to Remove!

[shakey doug]

Not suggesting you bash hell out of the chamber but give the nozzle holder body a touch up.

[Wotname]

Many suggestions for heat. How much heat and where, what are the ramifications of using heat of the head. Currently head is looking pretty good (for a 40 year old marine engine. No warps and gaskets surfaces in very good condition - I don't want to make more problems.

I can raise the whole head to 250 C in the oven.
I can make a bed of hot coals and support the head just a move it and monitor temperature with IR thermometer.
I can spot heat with MAPP gas.
I can apply freezer spray to the valve nut (the bit that is stuck).

What is the potential for damage to the head?

[Wotname]

Originally Posted by jimbunyard

Perseverance.


If you haven't, clamp or bolt the head to something immovable while you're slide-hammering.
Yep, clamped to heavy steel bench.

Heat cycling may help. Use acetylene, carefully, if you have it.
I have MAPP gas and can maybe get acetylene. Where is best spot to apply?


Your slide hammer looks big enough, but pictures can be deceiving. Is the slide at least 4-5 lbs?

Just on 4 lbs.
If you can get a helper, have them try and turn the injector while you slide hammer.


Fabricate a puller, put as much tension as you dare on it, and leave it overnight.
Might have to try this soon!!!

It will eventually pop free.

Thanks

[Wotname]

Has anyone used an electrolysis bath to remove rust?

Is this a useful idea or is there any known downside to sticking the whole head to an electrolysis bath????

[Wotname]

Originally Posted by Ex-Calif

This is pretty much how I would proceed with a couple of modifications

- I would spray with PB Blaster
- Use a propane torch to heat the head - Don't be scared to get it hot, like close to glowing red. It will take a lot of heat to get the metal hot. The PB Blaster will smoke and may even catch fire - don't panic - LOL...
- Use a turkey baster to then douse the injector housing with ice water
- Repeat a couple of times, reapplying the PB Blaster
- I would "gingerly" zap it with an impact gun between heat cycles - the vibration should help in breaking the bond

- I am very partial to PB Blaster. I restore classic MGBs and this stuff worked a treat on 40 year old suspension joints that were totally rusted together. In 40 years of twisting wrenches it has turned out to be the best for me.

- If it hasn't broken free by now I would try the breaker bar again.
- If all that didn't work I would try the impact more aggressively but I'd be careful at this stage before surrendering and taking it to a machine shop.

Thanks Ex-C, again I must ask, will this amount of heat damage the head?

I guess you won't recommend it otherwise but I feel I should double check with you first

[Wotname]

Originally Posted by shakey doug

Not suggesting you bash hell out of the chamber but give the nozzle holder body a touch up.

OK, I understand - thanks.

[Wotname]

For those suggesting taking to a machine shop, I have to ask - what method would a shop use???

[Wotname]

Originally Posted by sailah

Using a breaker bar without impact seems like a great way to snap something off. You need some type of thermal cycling to break the rust bond.

I've used my gas grill to heat things up my wife would find objectionable in the oven.

I'd try heating the entire assembly up by putting it on a tray so flames aren't licking the metal. Get it proper warm. Then use a piece of ice or dry ice on the injector body to shrink it. It doesn't take much to break the rust bond. Try doing this a few cycles. I'd also apply a good penetrant like Kroil, not sure what you are using but Kroil is my absolute favorite for things where I have one shot. Apply penetrant after you've iced the injector body.

After I had heat cycled the head, I'd modify an impact socket to fit those flats. Then hit it with a real impact. I use an 18V Makita 1/2" impact which will spin off anything, has more power than my largest pneumatic Ingersoll Rand.

If all those options fail, I'd set up the head on a milling machine and bore out the injector using carbide endmill and punch out the pieces. Or take to a machine shop and have them EDM it with a tap remover.

Thanks for the suggestions. What does EDM mean?

[shakey doug]

where abouts in Tassie are you?

[Wotname]

Originally Posted by shakey doug

where abouts in Tassie are you?

Huon valley (near Port Huon).

[boden36]

I like the idea of heating and cooling a few times in an oven. Not localised heat. I don't like the idea of hammering.
A good machine shop should be able to make up a dolly to press on the combustion chamber end of the injector, whilst properly supporting the head. A decent sized press should make short work of it. Be prepared to throw the injector away!



Regards,
Richard.

[shakey doug]

I have sent you a message

[Olddan1943]

Some times it is best to give up early, before you do additional damage.
Pull the head, take it to a GOOD machine shop.
Throw away ALL the injectors.
They MAY let you watch the magic or maybe not. If they dont let you watch and they are successful, be thankful you didn't have to buy a new head.

[captlloyd]

I would be very careful about heating cast iron and then quenching with something very cold. Cast iron can crack. Using something like WD 40 is ok to quench with or PB Blaster.

[roland stockham]

Dry ice. If you cool the insert it may shrink enough to break the seal. They sell kits for plumbers to freeze seal waterpipes.