Thread: Cast Iron heads for 300TDi?

Just to let you know about another 2.5 diesel I own with similar issues.

Nissan YD25 which has a steel block and alloy head. These also do head-gaskets for similar reasons. The turbo is water-cooled and these water lines corrode first developing pin-hole leaks near the turbo. The resulting water loss is slow enough that it isn't noticed until the head-gasket goes.

The van I bought with this problem had already had the gasket done by the previous owners, but the muppets (truck workshop) hadn't cleaned the block so the new gasket wasn't any better.
I had the van up for sale, the gasket went when I was delivering it. Oops.

So the problem isn't just landrover engines, but it does seem to have a common cause, water loss going un-noticed.

FWIW I have a new head gasket/t/stat housing gasket and stem seals here ready to fit as mines had the heater let go a few months back although so far everythings ok........

JC recommended the composite gasket unless I had a freshly decked block and new head.

This is the latest emails from the chinese company that is looking into Cast iron heads. Can anyone work out what "stodd" wants to know re: the OEM number in the email below, Regards Frank.

Dear Frank,

Thank you , Someone told me that the 300TDI have the OEM number. Is that correct please ?

Stodd

----- Original Message -----
From: Frank stanton
To: China 4x4 Extreme
Sent: Monday, February 27, 2012 7:19 PM
Subject: Re: Cylinder heads,


Stodd, thank you, Regards Frank.

From: China 4x4 Extreme
Sent: Monday, February 27, 2012 6:39 PM
To: Frank stanton
Subject: Cylinder heads,




Dear Frank,

I have contacted some companies in China of the Cylinders Head and now we are waiting for some answer from them. We will come back to you some feedback as soon as we had them.

Best regards,

Stodd

From my understanding,intercooling has very little to do with EGT's.

EGT's are caused by over fueling, worn injectors or over compression (over boosting).

Comparing truck engines Tank to a domestic vehicle engine is like comparing Sydney harbour with your bath tub, both hold water but are far different in every other way.

Just the sheer amount of material in say a Cat truck head or in some cases heads can't be compared nore can they be compared in the work that they do.

The Commercial engines are designed for a specific purpose and meet a specific life span, once they hit that life span, the good operators would rip it out and recondition it so that it lasts that life span again.

If you say that a 300Tdi has a life span on average of 300,000kms then most of what your asking for an improvement to has already met what it is expected to (probably twice what the manufacturer expected) and everything else is a bonus.

Also Commercial engines are generally designed to be rebuilt, Domestic engines are not, yes they can be rebuilt but they will never be as good as they were when they were new unless you do a lot of work and improvements which would then make it better than new but may not may it last any longer.

Even though I'm disappointed in myself for killing my 300Tdi, I'm paying the penalty by having to drive a Falcon ute until I have the money to fix it but I can't fault the car, it gave me 65,000 kms more than what I expected it would and I've owned it since 185,000 kms so it's done me pretty well.

I have spent nearly half my life having to justify repairs to bean counters and the only thing that really matters in the end is if the product meets initial expectations, if it doesn't either buy another product from a different supplier or improve on what you have, neither of which is ever cheap.

Cheers Casper

Originally Posted by Casper

From my understanding,intercooling has very little to do with EGT's.

I get the impression isuzurover, Dougal et al will disagree.

I certainly do anyway.

Originally Posted by B92 8NW

I get the impression isuzurover, Dougal et al will disagree.

I certainly do anyway.

Actually the main bit I was going to say was wrong was this:

Originally Posted by Casper

...

EGT's are caused by ...(over boosting).

...

I posted recently how increasing boost lowers EGTs - quite a lot.

But yes - intercooling effectively increases boost by increasing air density.

Originally Posted by B92 8NW

I get the impression isuzurover, Dougal et al will disagree.

I certainly do anyway.

Yep.
More boost lowers EGT's. Intercooling makes a massive difference too.

My issue with the alloy vs iron head on something like a 300Tdi, is not overheating but the mechanical properties of the material. The lower elastic modulus of alloy and creep is the reason the head bolt tension reduces over time, thus lowering the clamping force on the gasket, leading to blown head gaskets, and in turn other problems.

It is cheaper to produce alloy heads.