pinning cracked heads

[robertson5347]

I have a 88 d-50 2.6 with a cracked head between the valve seats. Has anyone pinned or welded similar cracks? What are the procedure and success rate?

[pennyman1]

all depends on the skill of the shop doing the work - you are much better off just buying a new clearwater or odessa head and putting your valve train on it - no jet valves and a better casting

[robertson5347]

Can you plug the jet valves on the stock head?

[pennyman1]

yes - get a set of jet valve eliminators - they screw into the holes where the jet valves were

[Andy 2]

Sometimes even the most experienced shops can't weld a cracked aluminum head successfully. It has a lot to do with the casting itself. Cast aluminum is very porous and difficult to weld. Add to that the contamination that may be deep inside the crack and it becomes more difficult. I think when you add it all up, with the machining cost, if you do get it to weld successfully, you might as well buy a new head. I think Clearwater sells them for around $400 with valve train installed. Ready to bolt on, with a warranty.

[robertson5347]

Can you just plug up the jet valve with jb weld? Do you need to remove the jet valve cover that is on the inside of the head? How does it come out?

[camoit]

Can you just plug up the jet valve with jb weld? Do you need to remove the jet valve cover that is on the inside of the head? How does it come out?


NO JB WELD. There is a kit that eliminates them. You unscrew the stock ones and in goes in the eliminator kit.

[robertson5347]

Any comments on the next 2 questions. Do you need to remove and how the jet valve cover that is on the inside of the head?

[mitchi]

Not wanting to threadjack.......I have a question.

What is the benefit of eliminating the jet valves?

Where might you purchase these eliminating kits?

[Andy 2]

Are you speaking of the little bump with the hole in it on the inside of the combustion chamber? You do not have to remove that. Do not use JB Weld on you cylinder head.

[robertson5347]

Yes, Many people seems to think the heat from this bulb type cover is what causes the heads to crack. Your thoughts.

[camoit]

Not wanting to threadjack.......I have a question.

What is the benefit of eliminating the jet valves?

Where might you purchase these eliminating kits?


They expand and contract at a different rate then the head, they also get stuck open or burnt and can lean out the cylinder. It's worth removing them to remove the problems they can create. It was a bad idea then and now. It was to make the engine spin the gas as it enters to clean up smog. Thats all. By eliminating them with the kit the head can expand at the same rate because there solid and not a hollow straw.


http://www.silver-seal.com/product/6644/Jet-Valve-Eliminator-Kit-ChryslerMitsubishi-20-26L---Short.html


http://www.racetep.com/starhead.html

[Andy 2]

It's not the little nozzle dome that causes the heads to crack. The jet valve assembly that screws into the head like a spark plug might ,but if that were true there would be a lot more cracked heads out there. They are made of steel while the head is cast aluminum. Steel heats up and expands slower than aluminum. It also cools and contracts slower than aluminum. When things that are fastened together expand and contract at different rates, things get stressed that's true.The little dome is aluminum and part of the casting so no real problem there. As Camoit said, the valves can stick open which can affect compression and mixture. The jet valve head also has a little passageway in it to supply the jet valve with its mixture from the carb. If you're going to replace the head I would use a non-jet valve head myself. I believe the biggest reason the heads crack is from overheating the engine. Cast iron block and aluminum head. Usually between the valves where the casting is thin on #2 or #3 cylinder.

[robertson5347]

Another question along these same lines with jet valves. On the #2 cyl. exhaust valve port, there is a hole. What is its purpose and does it need to be close off as well?

[robertson5347]

On the 2.6 g54b head. There is a passage from inside of the exhaust valve on the #2 cyl. which goes to the intake side. Does this needs to be closed if closing the jet valves? What purpose does it serve?

[Andy 2]

I believe that is the EGR port. It does not need to be blocked off. You could clean it out if you wanted. If you have to pass an emissions test to get your registration you don't want that clogged up.

[robertson5347]

Thanks for the info. One other question, I need to use a head shim spacer .02" copper. Does it make any difference whether it's between the head and the head gasket or gasket and block? What do you use as a sealer on the shim and do you put the sealer next to the gasket side? I'm using a felpro blue stripe gasket.

[Acuta73]

Thanks for the info. One other question, I need to use a head shim spacer .02" copper. Does it make any difference whether it's between the head and the head gasket or gasket and block? What do you use as a sealer on the shim and do you put the sealer next to the gasket side? I'm using a felpro blue stripe gasket.

May I suggest having a look at SCE gaskets? They make machined copper head gaskets for the G54B, but you have to have some patience as they are special order. You can get them in any thickness you need and they are reusable. They also aren't "cheap", but like a K&N filter, the extra you pay is because you probably won't be buying another.

Their website has gone wonky, call and ask about them.

[gordiray]

My '82 2.6 liter Ram 50, close to 190,000 miles , has been overheating/losing power when hot, such that I turn on the heater full blast, open the windows, and slow down from about 65 to 40 or even lower, when climbing to 6000 ft east of San Diego, in the late after noon in late spring or once in June, for recreations , abut once a month.

When starting cold , seems that at least one cylinder is missing, (vibration) for 3 or 4 seconds, then smooths out with some more throttle.

Muffler (?) rattle in reverse. Smog inspection coming up in August. Passed OK two years ago, with a new lower catalytic converter. I put replacement exhaust manifold on it about 3 or 4 years ago. Old one was cracked. Also cleaned off deposits on the upper cat ( or maybe I just removed the upper cat core).

The head was resurfaced in Ensenada about 4 years ago. But later, the crank bearings scuffed when I overrevved for several minutes , via absentmindedly failing to go from second to drive on a long downhill.
an obvious overheat. Crank and rod bearings fixed. Maybe I warped the head , again.

Before that, mechanic in Ensenada said that valve clearances were correct. I have not set or checked the valve clearances myself for years.
Maybe head bolts should have been retorqued after 1,000 miles , after the head resurfacing? But a bicycle collision complicated my life, and I did not drive for at least two years.

Oil is full, coolant full, radiator should be healthy, with no rust or oil noted in coolant, which was regularly changed in years past. Have not checked the fan clutch

[gordiray]

Somehow, I prematurely posted. Continuing:
In the event that head /valve problems are diagnosed, have shopped online to see what a replacement head costs.
Several sources list Taiwan replacement heads, said to be CAST IRON ????
Is that an erroneous listing? Or, are there actually cast iron replacements for the original aluminum heads?

If I plug the jet valve holes, when is going to be the effect on smog test? On performance? On mileage? Overheating Or, what might be some other effect, if any?

On the flats, near the ocean, temperatures are normal for routine grocery shopping or other 5-15 mile trips. Thermostat was replaced about ten years ago. Have not tested the current one. Drove from 40, 000 to about 120, 000 (?) with a stuck or defective thermostat. With only VW experience, plus some Ford Escort misadventure ( bad module, a common problem with Escorts, before Ford began buying/ jointed with Mazda, which were much better, from experience until my sister crashed hers), I drove the D-50 and wondered why it ran so cool. A mechanic said " count your blessings". Maybe that contributed to the dirty condition noted in Tijuana when the Mikuni carb was cleaned at Carburadores Rodriguez, for a very low price by US comparison ( if a shop can be found yet who will do a cleaning and know Mikuni/Solex and are willing) .
The powerful solvents used in Tijuana are hazardous to the workers, and probably banned in California.

[Andy 2]

I would be suspect of the fan clutch for the overheating. Either way its an easy place to start and not expensive. Here's a bit of info on the jet valves....https://en.wikipedia.org/wiki/Mitsubishi_MCA

[lush90]

Recently read about an overheat caused by a partially clogged fuel filter, poster explained truck ran at normal temp up to about 50 mph but at higher speeds, engine overheated and died when speed was reduced. fuel filter replacement solved problem, idea being clogged filter caused lean condition. When was yours changed last?

[robertson5347]

Check water pump. I bought my truck with a overheating problem. No circulating. After checking for blockages. Removed water pump and found the propellers were missing (rusted off).



QUOTE=gordiray;41791]Somehow, I prematurely posted. Continuing:
In the event that head /valve problems are diagnosed, have shopped online to see what a replacement head costs.
Several sources list Taiwan replacement heads, said to be CAST IRON ????
Is that an erroneous listing? Or, are there actually cast iron replacements for the original aluminum heads?

If I plug the jet valve holes, when is going to be the effect on smog test? On performance? On mileage? Overheating Or, what might be some other effect, if any?

On the flats, near the ocean, temperatures are normal for routine grocery shopping or other 5-15 mile trips. Thermostat was replaced about ten years ago. Have not tested the current one. Drove from 40, 000 to about 120, 000 (?) with a stuck or defective thermostat. With only VW experience, plus some Ford Escort misadventure ( bad module, a common problem with Escorts, before Ford began buying/ jointed with Mazda, which were much better, from experience until my sister crashed hers), I drove the D-50 and wondered why it ran so cool. A mechanic said " count your blessings". Maybe that contributed to the dirty condition noted in Tijuana when the Mikuni carb was cleaned at Carburadores Rodriguez, for a very low price by US comparison ( if a shop can be found yet who will do a cleaning and know Mikuni/Solex and are willing) .
The powerful solvents used in Tijuana are hazardous to the workers, and probably banned in California.[/QUOTE]

[gordiray]

I had water pump problems repeatedly, in decades past. It was the bearings . Repeatedly self-installed the Auto Zone "lifetime warranty" replacements. They were the lowest cost ones from Auto Zone, "reconditioned", as I recall. Finally, spent more as an increment to a higher quality replacement . No problems of which I know since that event, about ten years ago. I doubt that there is bad corrosion, unless the inhibitors listed in any decent coolant brand are not adequate.

[Andy 2]

If the overheating is when you are going up long steep hills, perhaps dropping it into 2nd and getting the rpm's up will help.

[gordiray]

Yes. Been there, done that.

Nobody has commented on jet valve absence in replacement cylinder heads, such as California smog inspection effects, if any, to be expected?
What about the dubious(?) "cast iron" D-50 replacement heads with no jet valves, listed and found via an online search?

[camoit]

Put in the eliminator kit.
The SMOG inspection will not be a problem.

[noahwins]

There is no way for the smog guy to know if the head or block has been modified in any way.