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Discussion Starter · #1 ·
as i look at short deck 9.8 dart blocks they say 4.625 max bore 4.500 max stroke 565 max cid that does not all add up.

i was told by some people that i can get 598 short deck motor others say i need a tall deck. some say they would not run a 4.500 stroke in a short deck. others say 4.357 stroke and 4.600 bore 582 is max what does everyone here say?
 

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I'd have to agree that a 4.5" stroke / 598 should use a tall deck and longer rod.
582 is a VERY popular combo right now with the 4.375" stroke and
about as much as I'd use in a short deck. Big bore long stroke engines have
and issue with side loading the piston in the bore.

One of my personal favorites is still a 4.6" bore and 4.25" stroke.
565, ..

Curtis
 

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I agree with Curtis 100% (who wouldn't?).
I have seen guys run 4.50 stroke in a 9.8 deck block and the skirts of the pistons get beat up really bad from side loading. Going from a 9.8 block to a 10.2 block might not sound like alot but it makes a world of differance.
I think the other thing anyone needs to keep in mind is what you plan on doing with that combo, n/a, turbo, spray, and if you have the heads and hardward to go along with it.
 

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I'm on my 3rd, 3/8th stroke short deck engine. Nice combination, 1/2" is too much as mentioned.

.
 

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Discussion Starter · #5 ·
talked to the builder he said since this is a street car max rpm is going to be in the 5500 range and he was going to use .400 long rods that side loading would not be a problem. thoughts on that? for my combo i need to stay with a short deck motor.

nice to get some more info before we build thanks guys. so a 582 would be the best combo for me?
 

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No expert, I just write the checks. Not sure you can get a 400 rod in a 582".
All three of mine use a custom 270 rod to get the ratio the builder wanted?? Good luck.

.
 

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Check my math
deck height - (stock rod length + .400) - 1/2 stroke = piston compression height
9.800 - 6.535 - 2.250 = 1.015
That doesn't leave much room for the ring stack even with the oil ring going across the wrist pin and NO spray on that bad boy for sure.
If I was building a big street motor I would stick with a 4.625 bore max x 4.250 stroke. I think you will save money, not be loosing that much Hp and will hold up better.
 

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Discussion Starter · #8 ·
Check my math
deck height - (stock rod length + .400) - 1/2 stroke = piston compression height
9.800 - 6.535 - 2.250 = 1.015
That doesn't leave much room for the ring stack even with the oil ring going across the wrist pin and NO spray on that bad boy for sure.
If I was building a big street motor I would stick with a 4.625 bore max x 4.250 stroke. I think you will save money, not be loosing that much Hp and will hold up better.
yeah one guy i was talking to was talking about compression heights and said it really did not matter much if it was a 540 or a 598 the pin was going to be in the oil ring either way. so you would build the 565 over a 582 just because of rod angle and side load? there for making it have a longer life?

thanks for all the help and teaching.
 

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I personally would build a 565 over a 582. I like the longer piston skirts, the compression height down around 1.27ish and not worring about everything clearing. True the oil ring will still need a support ring depending on where the ring stack is but there is more room above the pin. I am not saying a 582 would not work I would bet there is a great number of guys on here with that combo and they run great, just not my choice.
One thing I would do is talk to cylinder head guys like Curtis or Mike and see what they recommend for heads, intake and cam. If you want a kick ass motor it needs to be the total package not just big cubes.
 

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Discussion Starter · #10 ·
I personally would build a 565 over a 582. I like the longer piston skirts, the compression height down around 1.27ish and not worring about everything clearing. True the oil ring will still need a support ring depending on where the ring stack is but there is more room above the pin. I am not saying a 582 would not work I would bet there is a great number of guys on here with that combo and they run great, just not my choice.
One thing I would do is talk to cylinder head guys like Curtis or Mike and see what they recommend for heads, intake and cam. If you want a kick ass motor it needs to be the total package not just big cubes.

that is the thing i know i'm going to give up some hp for what i want to run but.... here is what i have a set of 310 pro-1's and a corvette tri-power. my car is a 69 vette i need a short deck and low intake. the intake and heads will be done by a guy namde gary that did all our pullling truck stuff did busch car and nascar heads too. he worked at a place called kippley performance. the owner rick kippley now sold his shop and works for KB and builds greg andersons motors. rick still says gary is one of the best head porters. but i would still like to hear curtis and mikes thoughts as i may be inclined to sell my heads and get something different.
 

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Sounds like a bitchin` project right there....................


For simplicity sake,and packaging,i`d probably tell you to do a 540-565 and keep it simple........

Still make lots of power....good pin ht. and room for nos, if the motor won`t get you where you want to be....
 

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Discussion Starter · #13 ·
Sounds like a bitchin` project right there....................


For simplicity sake,and packaging,i`d probably tell you to do a 540-565 and keep it simple........

Still make lots of power....good pin ht. and room for nos, if the motor won`t get you where you want to be....

the more i look into it the more i'm liking that route. i already have the tri-power plates and the rest of wlison system off a different car. the vette now has a 4 link and a nine inch and sits on a pair of 325 50 15 bfg drag radials. the rear is a stragne fab housing, s housing and upgraded locker with 35 spline axles. behind the motor is a tremec and a spec 3+clutch. ( i love to shift) it will be mostly a street car but want that little something.
 

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just look at what the some of the bigger builders have for combos online reher morrison/schmidt/schaffirof.never seen them offer a short deck 598.im sure they would if it was a good combo?.
 
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