Joining the 4BD1 turbo fitting group - some help please!

Quote:

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Originally Posted by rar110

The most popular Isuzu manifold is the one used on the 6x6, with 45 degree flange which I believe is a T3 flange. Many popular turbos have the smaller T2 flange. So an adaptor plate needs to be used.

The 6x6 used a T25 turbo so I assume they required an adaptor plate.

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No adapter plate on the 6x6 motor, the T25 turbo has a T3 intake flange.

Apparently the 4BD2T motors use a exhaust manifold with T2 flange.

When fitting a Turbo to the 4BD1 should the head bolts be re-torqued to turbo specs?
if so , should they be removed and lubed with moly or just cracked loose and tightened?
What specs and should it be the 2 stage method? I have read different opinions?
My memory is not what it used to be.
Thanks.
Keith

Quote:

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Originally Posted by 123rover50

When fitting a Turbo to the 4BD1 should the head bolts be re-torqued to turbo specs?
if so , should they be removed and lubed with moly or just cracked loose and tightened?
What specs and should it be the 2 stage method? I have read different opinions?
My memory is not what it used to be.
Thanks.
Keith

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When i fitted my Turbo kit there was no mention of re torquing the head bolts. I have had 24 months of trouble free driving including towing a trailer up to the cape twice. I would leave well enough alone. My opinion.

Quote:

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Originally Posted by 123rover50

When fitting a Turbo to the 4BD1 should the head bolts be re-torqued to turbo specs?
if so , should they be removed and lubed with moly or just cracked loose and tightened?
What specs and should it be the 2 stage method? I have read different opinions?
My memory is not what it used to be.
Thanks.
Keith

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Certainly wouldn't hurt to check them Keith. 2 stage + angular, I can't remember the figures but I can look them up for you later if you want.

I have done a fair few K,s already . Out to Birdsville and the Hay River track last winter and not worried about it. Its only recently I read that the turbo has different torque figs to the NA and the studs should be lubed with moly whereas the NA is lubed with engine oil.
Can the studs be used more than once or does that last turn stretch them and we need to use new ones?
Now its not NA anymore do we treat it like a turbo?
Back in the day lots of people were putting turbos on NA 4BD1 engines and I was wondering if they retorqued or just let things be.
I am inclined to just let it go as its going well just now.
See if I get any other replies.
Keith

I didn't re-torque mine and ended up with a gasket failure. It was odd, if I drove around off boost I didn't have any problems but if I used the turbo (about 18psi max and temps no greater than 550) it would pressurise the cooling system. I inspected and re-used the existing head bolts and two stage + angle torqued them and have no problems.

Out of interest - what’s the procedure for retorquing?

I’d guess you do one bolt at a time as loosening them all at the same time would probably break the seal on the gasket?

Steve