Need help guys !!!!

[Lambo]

I know its not a Toyota but i need help, my Mitzi GTO tt 6g72 was using water so i pulled the heads to discover cracks in both heads on 4 out of 6 cylinders, and someone has been there before in japan and welded it up , but 8 years later it leaks.
I have found a Diamonte 3.0r at a upullit yard and the head looks and measures the same from the outside it is non turbo, is it possable that the head is the same, cams will be different, but could be swapped over,maybe valve sizes would be different ,could it be only the pistons on the Twin turbo will be different to lower the compression.I think the turbo runs about 8.5 and im picking the non turbo would be about 10.1
Is it possible the head would be the same or would they need to mod the area around the valves for the turbo, any help appriecated, i can't buy a pair of turbo heads and so car is now off the road.

Best Regards
Lambo

 

[Peewee]

If its like Toyota then there is rarely any difference between NA and turbo heads.

Besides the cams as you said, and the turbo heads usually have an oil feed for the turbo. (but not always, 7MGTE has it off the block, not the head)

 

[Lambo]

Thanks peewee for the help, i took the plunge and removed the heads at the upullit today, and your were correct they are the same profile in the heads around the valves, so tonight i started stripping them down, after i gave them a bath in engine cleaner, but now i have one more question or two, or three ,the lifter as shown below is from the original heads the top section can be pushed down and there is a spring pushing back at you but this only happens on 5 of the 24 the others are jammed solid, although you can turn the top section around while holding the base, but you can't compress them even tried gently in the vice still no movement.
The engine has not run for 8 months so i doubt there will still be any oil pressure inside the lifters.
With the upullit heads the lifters look exactly the same and the top section travels in and out of the base but not one of them has a spring action you can push it in but have to pull it out again. There is a crimped ring at the top which looks like it retains the top to the bottom, i suspect they are not repairable, but us poor kiwis don't give up without a fight, so what do you think the chances of carefully opening them up and fixing them would be, i did dissasemble some others years ago but these are quite different, I also saw an add in a hotrod mag for new ones that claimed to have a bigger hole on the side to allow better oil flow to stop the ticking i sometimes get, so i figured maybe if i am going to open them up maybe i could enlarge the oil holes ???? sorry for the long post guys hope i make sense, its getting late.
Best regards
Lambo

 

[cribbj]

Graeme, try giving those lifters an extended bath in carburetor cleaner - maybe that'll free them up. Also, I don't think that "all" hydraulic lifters have springs in them.

It's been a looooong time since I worked on a hydraulic lifter based motor, but I seem to remember that some used springs to reduce the lash on startup, while others didn't, and just suffered a noisy valve train until the lifters "pumped" up. Regardless, all lifters that have sat for an extended time ought to be given an extended parts cleaner bath - if you have access to an ultrasonic parts cleaner that would be even better.

 

[Muzza_NZ]

Hi Lambo,
I replaced all of my ticking lifters in a lancer I had some years back, and had a go at reconditioning some of the worn ones before buying them new.

The best way I found to clean them out (especially after a dodgy car salesman had put promar in with the oil to quiet it down) was to put each one in a vice (with soft jaws of course) and apply a little pressure. I used CRC contact cleaner to spray in to the inlet and outlet holes to dilute the oil and get the gunge out. Then I just sat them in some fresh oil and let them take it up.

A couple of things with the mitsi hydraulic lifters (really just from my experiences with them): they have a non return ball in the internal cusp of the plunger, which is spring loaded to seal the oil in. Over time this, and the plunger to cylinder tolerance, wears and the sealing ability deteriorates, so they still fill up with oil eventually, but tick until they get enough oil in them when cold as the oil gets squeezed out by cam pressure when turned off (plunger bottoming out). With the mitsi engines as well, if you replace the lifter, you really need to replace the cam follower, as this is used to seal the lifter for part of the cam rotation to allow oil to pressurise it, and over time the follower wears to the lifter lobe shape, so when you put new ones in, they don't always seal that well.

So, I'm betting that the 'solid' ones you've found, are actually the good ones, but to really see if they're good, you need to apply a little more than hand pressure.

Sorry for that long winded ramble, it's more just a muddled brain dump than a well thought out reply.

"I didn’t have time to write a short letter, so I wrote a long one instead" — Mark Twain