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| Iron duke 172 bhp / 220 ft*lbs! (Page 2/5) |
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lou_dias
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SEP 16, 03:22 PM
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@Will
That's part of the rebuild. On my 3.5 I am - you guessed it - half-filling the block. This is not rocket-science to people who rebuild engines for performance.
3.4 -> 3.5 = .120 overbore. I don't like it when things blow up.
It took me over-revving on a wet track twice to 8000 rpm to finally blow my rings just over a year ago. How many years was I racing for?[This message has been edited by lou_dias (edited 09-16-2022).]
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La fiera
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SEP 16, 09:34 PM
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I respect what that guy did, take an engine he is not familiar with and do all those mods to "see" how far he could take it. I'm pretty sure he left a lot on the table because his valve timing was way off. I'm surprised on the cam specs he chose taking into consideration he is a professional engine builder.
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Slammed
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SEP 17, 01:13 AM
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| quote | Originally posted by Will:
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I personally half filled on recommendation from a guy who built dirt circle track racers that used built up dukes. Does it need it? I have no clue, I don't know. It's so incredibly cheap and won't hurt anything, so why not? I attest the longevity to the new crank and rods. If you can fix a weak block with $50 worth of fill, it's not worth even mentioning.
Dennis, I think you misunderstood. I was saying building a duke is dumb and only something to do if you have money to throw away. There are dozens of better ways to make 200hp and also get better MPG
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La fiera
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SEP 18, 11:03 PM
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| quote | Originally posted by Slammed:
I personally half filled on recommendation from a guy who built dirt circle track racers that used built up dukes. Does it need it? I have no clue, I don't know. It's so incredibly cheap and won't hurt anything, so why not? I attest the longevity to the new crank and rods. If you can fix a weak block with $50 worth of fill, it's not worth even mentioning.
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Filling the block is not to prevent cracking or blowing up the block. Its primary purpose is to give rigidity allowing overbored cylinders to keep their roundness while preventing shifting during the reciprocating movement of the piston/rod combo. If shifting of occurs then a loss of compression will follow during operation and the power will drop significantly.[This message has been edited by La fiera (edited 09-18-2022).]
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Will
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SEP 20, 02:28 PM
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Slammed
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SEP 21, 02:37 AM
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So, your one example is from a guy 20 years ago running 11.5:1 compression?
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Will
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SEP 21, 09:57 AM
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| quote | Originally posted by Slammed:
So, your one example is from a guy 20 years ago running 11.5:1 compression? |
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Time doesn't matter. Production Duke blocks have not gotten stronger in 20 years.
I just know what I've read... but I'm not interested in doing the research on a Duke build.
Not sure what dog you might have in this fight, since you've already filled your block.
| quote | Originally posted by La fiera:
Filling the block is not to prevent cracking or blowing up the block. Its primary purpose is to give rigidity allowing overbored cylinders to keep their roundness while preventing shifting during the reciprocating movement of the piston/rod combo. If shifting of occurs then a loss of compression will follow during operation and the power will drop significantly.
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Ok, build one without, then.
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lou_dias
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SEP 21, 08:43 PM
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@Will
...what dog you might have in this fight?
What are you fighting exactly?
A simple google search for engine block filler and you'll realize this is a common practice.
For people who just like to spend years throwing in ticking-time-bombs into their engine bays ... not so much...
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Will
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SEP 22, 10:56 AM
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| quote | Originally posted by lou_dias:
@Will
...what dog you might have in this fight?
What are you fighting exactly?
A simple google search for engine block filler and you'll realize this is a common practice.
For people who just like to spend years throwing in ticking-time-bombs into their engine bays ... not so much... |
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I know block fill is a common practice... for blocks that have a high likelihood of breaking... like I said above... yes, filling the block is common practice.
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edfiero
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SEP 22, 11:01 AM
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Cool video. I like to see people doing things with the Duke.
However it looks like that was a custom intake, a custom exhaust and unless I missed, they were a bit vague about what cam they had. So its not like many people are going to be able to replicate this.
I would love to see a video on the duke like the show Engine Masters ,where they take the duke, put on the Holly Intake and TBI and Dyno it. Then throw on one SD4 intake and/or SD 4 Head. And why not the Tri Y header too. Yes these parts are all rare, but they do come up for sale from time to time and an average guy could swap out the parts.
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