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Hello CSK,
Once top hat liners are fitted, be it a 3.9, 4.0 or 4.6 and assuming of course it has been done properly, then that is the end of any further problems as far as coolant leaking into the engine is concerned.
They don't make brand new blocks already fitted with top hat liners to my knowledge. You can of course buy a brand new block, say a 4.6 and then have top hats fitted before you use it.
Better option is to buy a seasoned block and have top hats fitted into that.
Ron.
Thanks for the info. What is a seasoned block?
CSK wrote,...A seasoned block is one that has already been used. In other words second hand.Quote:
Thanks for the info. What is a seasoned block?
Ron.
RoverP6B ,First of all what is the blocks composition ? A seasoned block is second hand ? been used ? No , No cigar for that !!
Scientifically ther are reasons a block can get the "seasoned" tag
First one , Number of heat cycles , second one , time stressed , third one stress relieved . by either High heat or Low heat ,
Number of heat cycles , how many times is the engine taken to full operating temp and returned to ambient temp . Number needed , in excess of 5000 (For cast iron)
(if you start and stop your engine 3 timeds a day thats 1500 days or 5 years )
Then theres time stressed , for how long was the engine run to full power and stressed to the same level , A 100 full power runs of 1 min will do the trick,
Then thers Heating or cooling .
Heating the whole block up to around 850C will do a good job of stress relieving , obviously not much good fpr a Alloy block !!!
Then thers the Low temp approach , common;y known as Cyrogenics , its also a method of strees relief .
To understand how these things work you have to some metallurgy knowledge , crystalline structure , carbon content.
400HPONGAS wrote,...That's fair enough. My understanding was based on a converstation with an engine builder some years ago, so although the reference that I made to a seasoned block being used, that may well be necessary but not sufficient in order to accurately describe such a block.Quote:
RoverP6B ,First of all what is the blocks composition ? A seasoned block is second hand ? been used ? No , No cigar for that !!
Scientifically ther are reasons a block can get the "seasoned" tag
First one , Number of heat cycles , second one , time stressed , third one stress relieved . by either High heat or Low heat ,
Number of heat cycles , how many times is the engine taken to full operating temp and returned to ambient temp . Number needed , in excess of 5000 (For cast iron)
(if you start and stop your engine 3 timeds a day thats 1500 days or 5 years )
Then theres time stressed , for how long was the engine run to full power and stressed to the same level , A 100 full power runs of 1 min will do the trick,
Then thers Heating or cooling .
Heating the whole block up to around 850C will do a good job of stress relieving , obviously not much good fpr a Alloy block !!!
Then thers the Low temp approach , common;y known as Cyrogenics , its also a method of strees relief .
To understand how these things work you have to some metallurgy knowledge , crystalline structure , carbon content.
Ron.
a seasoned block as I know it is a good condition second hand block that' s been rebuilt for performance.
the logic is that the block has been heat relieved through operation and is known not to have any defects. This only applies if the engine hasn't been abused or killed via over heating or mechanical damage.
In answer to the original question. Id go the 3.9 and either pin the liners OR do the top hat conversion.
I thought Seasoned meant used
Stress relief is completely different its an actual process carried out on any block new or old as described above:)
true enough but you can get a brand new block, go through a specific stress relief process lets just say a good heat soak at 850 degrees with an appropriate cool down only to build an engine out of it and find that due to a casting defect one of the support webs (an example only) has a bubble in it that will lead to a fracture when placed under the duress of use.
its an old school thing and with modern casting techniques, metalurgy and non invasive/destructive testing techniques is more or less obsolete.
Quote:
Originally Posted by Blknight.aus
If the liner has slipped due to cracked block, will pinning the liners be just as good as the top hat conversion. Also, I bought this thing for 3k and has quite a few electrical woes, body is good and no oil leaks but it still doesn't seem worth it. thats why I was considering getting a used 3.5 efi and just doing a quick motor exchange. The 3.9 to me is evil because of this common flaw of liner issue. Looks like good 3.5efi runners are going for around $1200-$1500. Only going to be used for weekend/camping trips. It all comes down to money. I'm nearly thinking of buying another Rangie with good motor to use as spare parts. I see a few for around the $2000
if the liner has slipped because of a cracked block its fubar and time for a new block. If your basing the fact that the block is cracked off of my comment about seasoned engines dont, that was just an example of why a "seasoned" engine is a second hand one and not just one thats gone through a stress relief process at a foundry.
Providing the liner is only slipping because of a previous over heat or age then its time for a rebuild and top hatting the liners is the way to go if you never want to have the problem again.
If you get a second hand engine that doesnt have a liner problem AND the engine is out then its worth the effort of pinning the liners as that doesnt involve removing the heads, just flipping the engine, removing the sump and doing the pinning procedure.
I generally advocate that if you are going to replace the engine just because the engine needs replacing and not for another specific reason (IE you want to goto engine type X because it has feature Y) then you are better off replacing the engine with one of the same vintage/type that was originally fitted. This is partly because a) its easier, b) theres less traps to fall into c) its legal and d) it usually works out cheaper.