4BD1 Knocking

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Originally Posted by Vern

So whilst we are all waiting for mikes outcome, what needs to be done to an engine to say handle 30psi and 700egts all day long. Good head gasket, pistons, head studs etc....?????

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Factory 4BD1T, no problem at all.
A true 700C sustained should be no problem for a 4BD1+T, but you will need alfin pistons to handle the cylinder pressures of 30psi.
Given that some cylinders can run hotter or colder than others, I would suggest 650C as a sustained maximum if you are also running high boost.
As boost rises, the intake air gets hotter and the average cylinder temperature rises even if the EGT remains the same.

650C EGT at 30psi is a hotter cylinder than 650C EGT at 15psi.

The only head gasket worth using is the factory multi-layer steel. Head studs aren't needed at those boost levels.

Thanks dougal, reason I ask is I have a spare 4bd1 in the shed that could make a good rainy day project, just wondering if its worth doing all the mods to it.:)

Damn Mike, sorry to hear there are more dramas :(



I had a clatter on mine once that sounded bad but it was just a bracket bolted to the block that had come loose. I'd recently thrown a timing belt on an other car so was hyper vigilant and panicked when I heard it. Hope it is something simple !!

Just out of curiosity... If oil comes out of the dipstick pipe (albeit small but constant amounts) is this a possible/ likely symptom of having a possible cracked or holed piston? Or rather worn rings/ smoothed sleeve?

Also how long can these engines run for with a failed piston (as described above) before complete/ catastrophic engine failure occurs?

Cheers

JP

Quote:

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Originally Posted by 110Landy86

Just out of curiosity... If oil comes out of the dipstick pipe (albeit small but constant amounts) is this a possible/ likely symptom of having a possible cracked or holed piston? Or rather worn rings/ smoothed sleeve?

Also how long can these engines run for with a failed piston (as described above) before complete/ catastrophic engine failure occurs?

Cheers

JP

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yes both holed and failed seal at rings and engine failure is imminent if you have a holed piston.

My engine started to make a engine noise about 18 months ago, it sounded just like a faulty injector, at approx 100k's later en route to having it looked at it stopped in a whoosh n bang, the top of No1 piston came off with disastrous results, $9,800 later all was well, I love my Isuzu but they do occasionally come to grief.
Just for info It was and still is N/A 4BD1, well after all it was 28.5 years old at the time, it will be 30 in Nov 2014, hopefully It will see me out, cheers Dennis:angel:

30psi and 700*c sustained all day long :eek: speed limits will be the limiting factor...30psi and 700*c when accelerating for short periods is no worries I've hit 900*c and over 30psi those settings lead to the speedo sitting on the stop :angel:

Can someone edit my post to say "quite frequently" instead of "all day long". Would have thought people would have known what I meant:(:D.
Anyway anyone heard from mike?

Nope i thought he may have responded to my last post with the offer of help but ive had no reply .:D

No news is good news? Hope so..