Thread: mangled piston on a 454

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okay, here are some shots of the pistons. Some of the pistons say 8, and some say 6, so I guess my theory on the 00 for the bore is wrong. Anyhow here they are. I see some scuffing on piston 4 also...

Oops, forgot close up of piston 4

Pat, I want to eventually build this into a 496 stroker, but I thought I needed a different crank for that. I'm trying to get this fixed for cheap and fast, I am still finishing a 1600 sq ft addition on my house need to pay for that yet. I had hoped to bore it .060 over and buy forged pistons now, then reuse them with the stroker kit but the machine shop said that won't work. Will take different pistons for stroker kit. I guess I could just buy cheapo .060 over pistons now, then buy the good ones to install in my forged stroker kit.

Hey important is it to use a forged crank? Or could I get away with one of the cheaper cast stroker cranks? Or shouldn't I cheap out there?

Originally Posted by pat mccarthy

why not bore it to .060 over? for a 496 you just need the bock

The standard 454 crank is 4" crank right? I am planning on running this stoker combo with a weiand 177 (actually a B&M 177) blower but still want the stroker crank for the added torque.

I probably shouldn't rush this, or try to fix it cheap because I know I'll just run into problems, I'm just not ready to accept that my boating season is over so soon, and I still need to finish my addition on my house

Originally Posted by Futs

4.310 bore x 4.25 crank is a 496. we just built a 10:2-1 pump gas N/A tunnel ram (with 2 holley 600 cfm) 496 that made 710hp @ 6100 rpm.It hauls ass.

Unfortunately the fiance won't allow me to spend big $$ on the boat and leave the house like this

i did not say you could use your crank .489/ 496.. they both would need the 4.250 crank i build more 496 then 454 s the number are not over size but could be piston position i do this the i bore and hone the block and find smaller size pistons in the set or useing used pistons that need to go in that bore for size this i do by the fireing order .but they are not in any order but have seen this on many 454 from GM if they are over size they will be 060 or040 or030 them number do not mean much i would say it done for the year and i woul build it to a 489 .030 bore and 4.250 crank with a 6.375 long rod on the boat i would use at lest a 4130 crank and a srp pistons you could use a cast steel crank and I beam rods with hyper pistons but ? with the blower and in a boat you would not save much money so i would lean to better parts i have put alot of power thru the scat cranks they for the money work good in the 4.250 size i have used many

Pat, so you're saying I should just do a .030 bore, not the .060? I guess the power differance wouldn't be that much from the 489 to the 496 and I would save some cylinder material for later use...

I'll see how much the machine shop says I need to bore the cylinders...

Thanks for the comments. Oh, Pat, I should have bought the merlin heads you were selling, I ended up buying some $400 781 heads, but then needed to do $440 worth of machining to them. At least they have the 2.19/ 1.88 SS valves and hardened seats and brass guides now. Plus they have been ported and polished by previous owner so with the blower should make good power I hope.

Originally Posted by pat mccarthy

i did not say you could use your crank .489/ 496.. they both would need the 4.250 crank i build more 496 then 454 s the number are not over size but could be piston position i do this the i bore and hone the block and find smaller size pistons in the set or useing used pistons that need to go in that bore for size this i do by the fireing order .but they are not in any order but have seen this on many 454 from GM if they are over size they will be 060 or040 or030 them number do not mean much i would say it done for the year and i woul build it to a 489 .030 bore and 4.250 crank with a 6.375 long rod on the boat i would use at lest a 4130 crank and a srp pistons you could use a cast steel crank and I beam rods with hyper pistons but ? with the blower and in a boat you would not save much money so i would lean to better parts i have put alot of power thru the scat cranks they for the money work good in the 4.250 size i have used many

well you will not see any thing with a030 bigger bore less you build a 4.500 to4600 bore 4.250 crank

Okay, you lost me. I'm not a mechanic, just an amateur, but:

CID = 8(cylinders) X. 7854X 20.25(bore of 4.5 squared)X 4.25 (stroke) = 540.7. Wow, love to build that!

Originally Posted by pat mccarthy

well you will not see any thing with a030 bigger bore less you build a 4.500 to4600 bore 4.250 crank

Originally Posted by AdamB

Okay, you lost me. I'm not a mechanic, just an amateur, but:

CID = 8(cylinders) X. 7854X 20.25(bore of 4.5 squared)X 4.25 (stroke) = 540.7. Wow, love to build that!

well try this 4600.with a 4.750 crank all alum donovan block it will run on pump gas i will be selling it soon

Probably as expensive as my addition too

Actually I wish I could use the weight saving benefits of an aluminum block (and heads for that matter), but the salt water would eat right thru it. I don't want to bother with a closed cooling system, which would add more weight and trouble in the long run. Oh well, have to stay with this 454 block, or maybe switch to a 502 if I could find one real cheap.

With that in mind, what is the difference between a 454 block and a 502 block. I assume different crank and bore sizes, but can a 454 block be made into a 502? Probably a dumb question but....

Originally Posted by pat mccarthy

well try this 4600.with a 4.750 crank all alum donovan block it will run on pump gas i will be selling it soon

i have built the short deck with a 4.3/8 crank . the 502 is a 4.470 a bigger bore you can not really bore a stock 454 out that far. i do find the world blocks and darts .bowtie blocks used some times they need to be sleeved one or two hole s i fix them and some times need nothing

Originally Posted by pat mccarthy

well try this 4600.with a 4.750 crank all alum donovan block it will run on pump gas i will be selling it soon

Is this the mysterious and elusive 707 you spoke of a while back?

Oh, was just wondering since they used the same exhaust, cranks etc. Makes sense though.

The machine shop said I could get away with a cast steel crank?? What's the difference between cast steel, and regular cast? Just different type of metal I guess??

Originally Posted by pat mccarthy

i have built the short deck with a 4.3/8 crank . the 502 is a 4.470 a bigger bore you can not really bore a stock 454 out that far. i do find the world blocks and darts .bowtie blocks used some times they need to be sleeved one or two hole s i fix them and some times need nothing

Originally Posted by 4speedTerror

Is this the mysterious and elusive 707 you spoke of a while back?

what ? this would be a 632? i am working on my 730 that a 11.500 HC donovan with a4.600 bore with 5.500 crank that still getting machine by callies there is nothing mysterious about it i still am waiting on the crank they said it would be done at the end of june ?i have 90% of the parts for this engine in some time i may or not post some photos