454 rebuild with blower... Pistons and clearances.
#153
Holy sh!t... 16 pages of responses from the thread that I started! I need to catch up on my reading!
#154
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From: yorkville,il
tom,you may want to skip some of it.lol.
#156
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From: dfw texas
Ill try the summary , flog me as you see fit . On toms motor the 8-71 or 420 will make more power with less inlet temp , and resulting detonation potential .
If the day comes he decides to throw down for raised port brodix or afrs a $1.3k cam and lifters set ,4k in exhaust maybe some premium h beams and carillo crank the blower wont hold himback .
Dyno readings are not consistant from one to another
even with perfect planet alignment and and a optomistic dyno and gold plated dry headers 690 out of a 250 charged 454 headed for a boat is respectable
If the day comes he decides to throw down for raised port brodix or afrs a $1.3k cam and lifters set ,4k in exhaust maybe some premium h beams and carillo crank the blower wont hold himback .
Dyno readings are not consistant from one to another
even with perfect planet alignment and and a optomistic dyno and gold plated dry headers 690 out of a 250 charged 454 headed for a boat is respectable
#157
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From: dfw texas
But maybe tom doesnt have the room for a full size huffer either height or front wise , doesnt want to fiddle with double keyway cuts and or balancer deletes , may have a real bond with his existing outdrive also and doesnt want to launch the upper gears right through his swim platform while onlookers gasp.
but hes got this shiny 250 and knows he can make his 242 faster than it is now ..
but hes got this shiny 250 and knows he can make his 242 faster than it is now ..
#158
I'm trying to get my piston issue worked out. Actually, I'm juggling a lot of things right now, biggest being that my 5 year old daughter has had the flu something terrible! A week and a half later and she's just starting to really turn the corner toward recovery. Thankful that I've kept the other kids semi-isolated. So far so good, but I digress. My short block was in much better shape than I thought. Polish of the crank, honing of the bores, and a good cleaning was all that was needed. I had one piston that was hurt, and another three that I made the call on of being marginal (and they're out). I don't want to screw with the balance, and since everything else was good, just replacing the bad pistons..I'm sourcing a lot of stuff right now... rings, bearings, valves, springs and retainers, etc. It's all kind of grown out of control compared to the plan previous to me buying the B&M, not to mention all the stuff that the boat needs post transom and stringer rebuild. A couple of times I've thought of putting my 10-sec small block S10 up for sale to get the boat in the water (not happening). Just going to take it all slow, build it right, dyno tune the setup, and get the boat back together. If she's back in the water this summer, then good. If not, I'll be on the Cigarette for the summer (OSO member Hollowpoint.... his Bullet) not to mention that I've been boat-less since late summer of 2012 because of rot issues... waiting isn't that bad!
Crazy that this thread blew up like it did!
Last edited by TomZ; 01-24-2015 at 10:37 PM. Reason: Clarity
#159
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From: dfw texas
Im not going to lie , there was a moment where i was thinking of what i could sell to get a 8-71 for the 540 thats prob going to end up in one of my jet boats . At least for a few weekends or more .the rotating assy good for 800hp and a overdriven 8-71 wont have me worried about the front of the crank breaking off or ganking the keyway.
but then theirs these 2 teenagers im feeding prop tax bills nsx is gonna need a 2000$ clutch blah blah
so i am tuned to the flat top 7.4 with a 250 channel once again for this seasons personal forced induction fix
but then theirs these 2 teenagers im feeding prop tax bills nsx is gonna need a 2000$ clutch blah blah
so i am tuned to the flat top 7.4 with a 250 channel once again for this seasons personal forced induction fix
#160
But maybe tom doesnt have the room for a full size huffer either height or front wise , doesnt want to fiddle with double keyway cuts and or balancer deletes , may have a real bond with his existing outdrive also and doesnt want to launch the upper gears right through his swim platform while onlookers gasp.
but hes got this shiny 250 and knows he can make his 242 faster than it is now ..
but hes got this shiny 250 and knows he can make his 242 faster than it is now ..
I'm already using huge by freaking huge heads (not getting into that debate at this time but they are done up well), and the bottom end will be sound for what we're doing. All good things. If my 242 hits high 70's/80 I'll be more than pleased. It takes around 525 HP to get there... I'll be at least a hundred HP over that, and I think I can do it pretty reliably. And if The relaibility goes out the window, I'll build another one.
Last edited by TomZ; 01-24-2015 at 10:50 PM.





