Question about rebuilding the 4.6
#11
01-20-2020, 03:10 PM
So I got with the machine shop today and discussed things with the new block. They were telling me that this new block is in better shape than my old one (cylinders are worn down less and the deck is in better shape and the casting of the block is better). This new block was also not involved with a overheating or engine failure so it should still be in good shape. The reason why they want to bore it out is because there is pitting in a couple cylinders. Their plan is to bore it out .020 of a inch and get bigger pistons (they found some for about 750 dollars I think they were telling me). If I were to go this route, I am for sure upgrade the cooling system to lower the temp for sure. I am just not certain if I still want to bore out the engine since these liners are already a major failure with these engines. If I had enough money i'd go with RPI and get their blocks but it's just not affordable for me right now (being a poor college student is fun). Tomorrow I will talk with some professors at my college that have been in high performance automotive racing for 30+ years and get their ideas. Thank you guys for all the help!
Basically, the cylinder wall will be 2 1/2 sheets of paper thinner(paper being .004, and going around an I.D).
Will it be ok? Should be, but might crack tomorrow...kind of just like a stock engine.
The idea of making cylinder walls thinner on a engine that is prone to cracking blocks, slipping liners, and head gasket issues, just seems like a much bigger gamble.
Vs getting another block.
#12
01-20-2020, 03:12 PM
Camel Trophy
@Freedom38 The liners themselves are not an issue for cracking and are never a direct source of leaks. There is a lot of confused and contradictory information around on these engines.
1st off is poor quality control casting of the engine block at the end of the production run - the can leak to weak spots in the water jacket
Next an engine running at higher temps for emissions reasons without an actual temperature gauge - what we have is an idiot light
Liners move a result of significant overheat -not a little bit, but a lot. No major overheat it is unlikely your liners will move in any significant way.
Block cracks generally develop the same way, a very hot engine likely running at the top end of the safe temp range then cooling then heating over 1000's of KM and hours. This is coupled with poor castings.
Early Head Gasket failure I can not figure out but they do go over time - it may be an aluminum head/block issue with incorrectly set TTY bolts. My gut says the head and block are not clamping the gasket correctly or cheap gaskets that are not right for the application are being used.
I would ask the machine shop if they think a hone would clean up the problem rather than over boring
1st off is poor quality control casting of the engine block at the end of the production run - the can leak to weak spots in the water jacket
Next an engine running at higher temps for emissions reasons without an actual temperature gauge - what we have is an idiot light
Liners move a result of significant overheat -not a little bit, but a lot. No major overheat it is unlikely your liners will move in any significant way.
Block cracks generally develop the same way, a very hot engine likely running at the top end of the safe temp range then cooling then heating over 1000's of KM and hours. This is coupled with poor castings.
Early Head Gasket failure I can not figure out but they do go over time - it may be an aluminum head/block issue with incorrectly set TTY bolts. My gut says the head and block are not clamping the gasket correctly or cheap gaskets that are not right for the application are being used.
I would ask the machine shop if they think a hone would clean up the problem rather than over boring
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Sixpack577 (01-20-2020)
#13
01-20-2020, 03:18 PM
Correct on the blockc cracking, not the liner itself.
However, after making the liner thinner, it is still absorbing the same amount of heat.
That same heat can then further damage the thinner liner, and cause a weak spot to let go, in terms of the block then cracking, liner slipping, or liner itself sustaining damage.
However, after making the liner thinner, it is still absorbing the same amount of heat.
That same heat can then further damage the thinner liner, and cause a weak spot to let go, in terms of the block then cracking, liner slipping, or liner itself sustaining damage.
The following users liked this post:
Richard Gallant (01-20-2020)
#14
01-20-2020, 03:21 PM
@Freedom38 The liners themselves are not an issue for cracking and are never a direct source of leaks. There is a lot of confused and contradictory information around on these engines.
1st off is poor quality control casting of the engine block at the end of the production run - the can leak to weak spots in the water jacket
Next an engine running at higher temps for emissions reasons without an actual temperature gauge - what we have is an idiot light
Liners move a result of significant overheat -not a little bit, but a lot. No major overheat it is unlikely your liners will move in any significant way.
Block cracks generally develop the same way, a very hot engine likely running at the top end of the safe temp range then cooling then heating over 1000's of KM and hours. This is coupled with poor castings.
Early Head Gasket failure I can not figure out but they do go over time - it may be an aluminum head/block issue with incorrectly set TTY bolts. My gut says the head and block are not clamping the gasket correctly or cheap gaskets that are not right for the application are being used.
I would ask the machine shop if they think a hone would clean up the problem rather than over boring
1st off is poor quality control casting of the engine block at the end of the production run - the can leak to weak spots in the water jacket
Next an engine running at higher temps for emissions reasons without an actual temperature gauge - what we have is an idiot light
Liners move a result of significant overheat -not a little bit, but a lot. No major overheat it is unlikely your liners will move in any significant way.
Block cracks generally develop the same way, a very hot engine likely running at the top end of the safe temp range then cooling then heating over 1000's of KM and hours. This is coupled with poor castings.
Early Head Gasket failure I can not figure out but they do go over time - it may be an aluminum head/block issue with incorrectly set TTY bolts. My gut says the head and block are not clamping the gasket correctly or cheap gaskets that are not right for the application are being used.
I would ask the machine shop if they think a hone would clean up the problem rather than over boring
If they want to bore .020" to clean up pitting, then those liners sat with water in them and got rusted good.
Small block Ford or Chevy, no problem.
D2 4.6, good luck.....
#15
01-20-2020, 03:30 PM
Camel Trophy
Correct on the blockc cracking, not the liner itself.
However, after making the liner thinner, it is still absorbing the same amount of heat.
That same heat can then further damage the thinner liner, and cause a weak spot to let go, in terms of the block then cracking, liner slipping, or liner itself sustaining damage.
However, after making the liner thinner, it is still absorbing the same amount of heat.
That same heat can then further damage the thinner liner, and cause a weak spot to let go, in terms of the block then cracking, liner slipping, or liner itself sustaining damage.
The following users liked this post:
Sixpack577 (01-20-2020)
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