Delica Canada | Mitsubishi Van Club

Aluminum cylinder heads have lots of advantages over cast iron heads, however not blowing head gaskets is not one of them.

On our little diesel motor we have a cast iron block and aluminum head combined with a compression ratio that is twice as high as a similar gas motor.

During warm up the the parts of the motors are expanding at very different rates.

What can you do?

Warm up your motor slowly...after start up drive light on the gas avoiding heavy loads until the temperature gauge is into the normal rate and the cooling system is warmed up.

Keep your cooling system in good repair and full (low on fluid? guess what part of the motor will have no fluid first....the head).

Lets keep our motors running and keep our heads on our blocks...

(these are rules I have run all my cars by.....even my old drag cars wait till it is warm and drive it like you rented it).

To prevent BHG (Blown Head Gasket) use ARP head studs and tighten following the correct installation procedures. Head studs are the first choice, but even just stronger head bolts that permit a higher torque would be good.

Also use either the stock head gasket or a good aftermarket gasket like Victor Reinz, etc. Fel-Pro is OK for normal applications, and would work in a pinch, but would be my last resort. And with Fel-Pro, use the Copper Coat brand spray sealer even though they say not to (Fel-Pro will tell you that you should not use any sealant), the Copper Coat will help seal it. Just get both sides of the gasket with about 3 good coats or so of sealer. You do not need to spray the block or head surfaces. I also like to use the Copper Coat spray on many other gaskets like manifolds, works very well!

Of course, some heads on some engines can warp if overheated even once, the Nissan L-series six cylinders come to mind. I think the 4 cylinder in-lines would be less prone to warp over something like an in-line six aluminum head.

Is it possible to use ARP head studs? I noticed they don't have a 4d56 engine listing. Where are you getting these studs?
Thx!

How are people cracking heads? I live in flat land so the van isn't under heavy loads very often, no overtaking on the highway really, cruising speed max 110. Usually 105. Any faster and I can tell it's working hard. But, I think even if I was back in BC, even going un The Cut I would be taking it slow and tuck in behind a rig. One thing I love about these is that it's useless being in a rush. I have a motorcycle for that!

Are there warning signs before hand?