Author Topic: Piston choice for higher comp on rpm heads 440 engine  (Read 203 times)

Offline cam440

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Piston choice for higher comp on rpm heads 440 engine
« on: August 03, 2017 - 08:00:00 am »
Hey everybody need some advice I'm building a nice little 440  torq street engine and need some advice was going to do a nice little stroker but it's going to cost to much by the time I order the kit , lose money on the exchange to Aussie dollars , freight then import tax so I think a 440 should go well for what I'm looking to achieve , I'm keen to get say around 10.5 to 10.7 comp with flat top pistons and 84 cc heads just want to take advantage of the alloy heads that's all and build something with a good quench area , I'm slowly learning and really enjoying these sights and people , what's a good forged piston I can use what I can gather most come up at around 10.1 then I guess zero deck the block will give more any good suggestions for a decent piston that's 30 oversize I already have a good forged crank to use and stock rods rebuilt seem to be ok up to 6 rpm what I have read
« Last Edit: August 03, 2017 - 08:03:25 am by cam440 »




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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #1 on: August 03, 2017 - 10:51:33 am »
A flat top even at zero deck with a .041 gasket still needs a chamber smaller than 84 cc to get you to 10.5...   And most pistons are actually .015 or more in the hole at blue print deck height.... Which is probably .010-.020 lower than true deck height... 

FWIW I'd go with Ross  82008 Pistons, deck the block to 10.710, run a .040 composition gasket, assuming the rods are stock length which they won't be once they are rebuilt..that puts you at 10.3... If you need more consider shaving the Edelbrocks .015, that gets you up around 10.6....
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Offline cam440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #2 on: August 03, 2017 - 06:23:39 pm »
hi mate so you think if I only deck the block and run those pistons 10.3 should be ok , if I start to machine heads etc wont that cause dramas with push rods and manifolds or 15 thou should be ok you think if I can get around 10.5 id be happy but if you think 10.3 is going to make good power ill run with that I guess and going to run a cam around 240 ish i think  and on a 110 lobe , 110 lobe will build up alittle more comp hey I read those xe serries comp cams are good for building up comp with the tight lobe centre a power range 0f 2500 to 5500 id be happy with just a fun street car , i have a 850 dp holley , strip dominator intake , 4 speed with 3.55 , those lunati cams do sound good but want a nice muscle car lump as well not looking for smooth idle , whats your thoughts on a cam choice mate knowing my combo or can I get a taller rod that works with these ross pistons and my forged 3.75 crank , you said since being rebuilt they wont be stock height
« Last Edit: August 03, 2017 - 06:32:34 pm by cam440 »


Offline cudabob496

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #3 on: August 03, 2017 - 08:06:54 pm »
I'd have recesses in the pistons in case of future cam upgrades.
I went with zero deck reverse dish JE pistons, to get 10.5/1
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Up to 4000 RPM, Warp Speed, Up to 5000, Rediculous Speed, Up to 6000 RPM, Ludicrous Speed!

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Offline cam440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #4 on: August 03, 2017 - 08:38:03 pm »
ok so you have a dome type piston they wont work with closed chamber will they

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #5 on: August 03, 2017 - 09:44:49 pm »
I'd have recesses in the pistons in case of future cam upgrades.
I went with zero deck reverse dish JE pistons, to get 10.5/1

You have a stroker completely different situation....
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
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Offline cam440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #6 on: August 03, 2017 - 10:59:46 pm »
thought so yeah that eagle 493 kit I found worked out at 10.7 would be perfect but yeah just what the cost was at the end by the time it got here its getting up there around 3700 dollars Australia wow ohh well just work with what I have I guess not in a huge hurry

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #7 on: August 03, 2017 - 11:25:33 pm »
Ok, the right way to approach this.... Get your pistons, rings, bearings.. Get the rods resized & block bored than assemble the crank & put the piston/rods in cylinders 1, 2, 7 & 8... Now accurately measure how far the pistons are in the hole @ TDC.... It's common to find no two measurements are the same..... Now have your machinist deck the block to achieve a true zero deck height on a four corners...  And FWIW I agree, 10.3 should run great, & it gives you a safety cushion if your fuel isn't as good as it should be....  Pushrods.. Once it's decked you'll need to measure first but hydraulics are pretty forgiving & you could probably get away with stock pushrods at least to get it running & broken in while you order pushrods in the proper length to get the preload optimized....
JS27N0B 70 Challenger R/T Convertible  FJ5 Sublime, Show Poodle w/90,000 miles since resto
WS27L8G 68 Coronet R/T Convertible  PP1 Bright Red, Project
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Offline cam440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #8 on: August 04, 2017 - 02:21:41 am »
what does fwiw mean sorry lol , yes should be ok 10.3 it sounds like we have good octain fuel over here so should be ok , maybe shave alittle off the heads to wouldn't hurt by the sounds of it

Offline 73440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #9 on: August 04, 2017 - 06:51:13 am »
For what it's worth
67 440
73 Barracuda w/ 68 440
65 Plymouth Fury III , I sold ,was my Nana's car till 92 yo.
51 Ford F1 239 Flathead, flipped , new cab , stolen
59 BelAir 283 4 door original patina
01 Chevy van 380,223 miles
06 Crown Vic Police Interceptor
75 HD Ironhead converted to RH shift
73 HD Ironhead
82 HD Ironhead
74 Norton 850
80 HD Shovelhead
80 Husqvarna WR 390

Offline cam440

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Re: Piston choice for higher comp on rpm heads 440 engine
« Reply #10 on: August 04, 2017 - 07:15:40 am »
Ok thanks mate lol and also for everybody's imput really appreciate it
« Last Edit: August 04, 2017 - 07:18:36 am by cam440 »