Re: 498 cid 440 stroker build formula
[Re: ahy]
#1258623
06/27/12 11:30 PM
06/27/12 11:30 PM
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Dcuda69
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Quote:
There are lots of variables in figuring compression and more in estimating detonation potential... but in your case I'd say no way on pump gas.
With 80'ish cc heads and 4.15+ stroke you will just about always need a decent size dish piston for pump gas. As a guess, you are around 11.5 CR with the flat top. With a smaller performance cam, you should be at 10 or maybe less depending on quench for pump gas.
I'd send it back and get the dish piston. If you have measurements on your engine - deck height, rod length - and know the piston specs - compression height and dish or valve relief volume - CR can be calculated more accuratly.
Bottom line, flat top on a stroker is normally a race gas only setup.
I have a dish in my Diamonds in a 470"(low deck) with Eddy heads at 84cc...puts me at 10.2:1 which works great on pump swill.
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Re: 498 cid 440 stroker build formula
[Re: moparmojo]
#1258626
06/27/12 11:38 PM
06/27/12 11:38 PM
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Dcuda69
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"Is 11:1 too high with aluminium heads?" I think that depends on what your plans are. I wanted to make sure I can ALWAYS be able to buy fuel so I went pretty conservative(mine runs fine on 89, found that out by an oops )If your plans are always being able to run race gas or premium fuel(or any type of combo)you can be more aggressive. I have no idea what pump swill will be in the years to come, so I stayed conservative.
Last edited by Dcuda69; 06/27/12 11:39 PM.
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Re: 498 cid 440 stroker build formula
[Re: 300by500]
#1258628
06/28/12 12:19 AM
06/28/12 12:19 AM
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Quote:
My 4.15 crank / .040 over 498 RB has relieved pistons at zero deck, and it will be about 11:1 with 84cc Edelbrocks. It has a Hughes 246/250 duration hydraulic cam (.614 / .610 lift with the 1.6 Harland Sharps)
If you have 80cc heads and your pistons are near the top of the bore, I'd guess you'll be over 11:1 compression, which is about as high as you want to go with 93 octane.
The 440source stealth heads claim to have 80cc heads, I hope not. If they dont that will help my issue.
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Re: 498 cid 440 stroker build formula
[Re: DaytonaTurbo]
#1258629
06/28/12 12:23 AM
06/28/12 12:23 AM
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I ran the 60303, it's not an aggressive cam for a 440. Tiny for a 493. I'd be looking more at the 60305.
Will that 60305 cam give me a smooth idle with lots of low end torque?
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Re: 498 cid 440 stroker build formula
[Re: ahy]
#1258630
06/28/12 12:30 AM
06/28/12 12:30 AM
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Quote:
There are lots of variables in figuring compression and more in estimating detonation potential... but in your case I'd say no way on pump gas.
With 80'ish cc heads and 4.15+ stroke you will just about always need a decent size dish piston for pump gas. As a guess, you are around 11.5 CR with the flat top. With a smaller performance cam, you should be at 10 or maybe less depending on quench for pump gas.
I'd send it back and get the dish piston. If you have measurements on your engine - deck height, rod length - and know the piston specs - compression height and dish or valve relief volume - CR can be calculated more accuratly.
Bottom line, flat top on a stroker is normally a race gas only setup.
The machine shop is going to measure out everything and see where we are at. After that I will make a decision. I am upset about the extra cost because he sent me the wrong stuff. This really sucks.
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Re: 498 cid 440 stroker build formula
[Re: 2fast4yourBrain]
#1258632
06/28/12 01:35 AM
06/28/12 01:35 AM
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Quote:
Stupid question, but can you install a super thick head gasket to lower compression ratio? Or will that screw up quench?
Im not sure but I think your correct. Thats what my buddy told me.
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Re: 498 cid 440 stroker build formula
[Re: torqueaddict]
#1258633
06/28/12 04:23 AM
06/28/12 04:23 AM
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Joined: Sep 2008
Posts: 42 Nelson-New Zealand
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Hi Anthony. That cam is far too small for those cubes. I have a 493ci Stroker. I use "Diamond Piston" part#52415 which has an effective dish of -12:5cc. I have a deck clearence of 2 thou; & using Comp Cams 294S which is 248@050" & with the cam installed straight-up, has a cranking pressure of 185 lbs. On pump gas this is close to as much pressure that you want to go. I use Stealth Heads(standard)it idles at 800rpm & with 2:75 gears in an Aussie Charger with myself & fuel weighs in at near 4000lbs, with 4-speed New-Process does 12:00-12:30@ 117-118mph in the 1/4 & 92mph at the 1/8 mile mark. I also get 17mpg Imperial(approx 15US). 2260 revs @ 62mph. I believe you will have regrets with a cam that small. It is even small in a 440 so it will just starve a 493ci. Mike in New Zealand
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Re: 498 cid 440 stroker build formula
[Re: BIG-MIKE-500 ci]
#1258634
06/28/12 07:35 AM
06/28/12 07:35 AM
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Posts: 2,886 Bowling Green KY / Nashville, ...
300by500
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Quote:
Hi Anthony. That cam is far too small for those cubes. I have a 493ci Stroker. I use "Diamond Piston" part#52415 which has an effective dish of -12:5cc. I have a deck clearence of 2 thou; & using Comp Cams 294S which is [Email]248@050"[/Email] & with the cam installed straight-up, has a cranking pressure of 185 lbs. On pump gas this is close to as much pressure that you want to go. I use Stealth Heads(standard)it idles at 800rpm & with 2:75 gears in an Aussie Charger with myself & fuel weighs in at near 4000lbs, with 4-speed New-Process does 12:00-12:30@ 117-118mph in the 1/4 & 92mph at the 1/8 mile mark. I also get 17mpg Imperial(approx 15US). 2260 revs @ 62mph. I believe you will have regrets with a cam that small. It is even small in a 440 so it will just starve a 493ci. Mike in New Zealand
12 flat quarters in a 4000 lb car with 2.75 gears! THAT is why I love strokers!
You're right about the cam...
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Re: 498 cid 440 stroker build formula
[Re: BIG-MIKE-500 ci]
#1258636
06/28/12 11:09 AM
06/28/12 11:09 AM
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Joined: Aug 2010
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Quote:
Hi Anthony. That cam is far too small for those cubes. I have a 493ci Stroker. I use "Diamond Piston" part#52415 which has an effective dish of -12:5cc. I have a deck clearence of 2 thou; & using Comp Cams 294S which is [Email]248@050"[/Email] & with the cam installed straight-up, has a cranking pressure of 185 lbs. On pump gas this is close to as much pressure that you want to go. I use Stealth Heads(standard)it idles at 800rpm & with 2:75 gears in an Aussie Charger with myself & fuel weighs in at near 4000lbs, with 4-speed New-Process does 12:00-12:30@ 117-118mph in the 1/4 & 92mph at the 1/8 mile mark. I also get 17mpg Imperial(approx 15US). 2260 revs @ 62mph. I believe you will have regrets with a cam that small. It is even small in a 440 so it will just starve a 493ci. Mike in New Zealand
One of the members from cuda challenger uses that cam. He says he really likes the cam. I changed it and went a step up just to be safe. He said my compression would be too high even if I bring it below 11:1. So I went with the next one up. I am not sure where the piston sits in the hole however I think I am just going to send them back and get the dished pistons.
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Re: 498 cid 440 stroker build formula
[Re: torqueaddict]
#1258637
06/28/12 02:01 PM
06/28/12 02:01 PM
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Joined: Feb 2003
Posts: 18,582 Rust Belt, SW PA
Silver70
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I had a 499, edelbrock heads, mp 590 cam, 11 to 1 compression and it ran fine on 93 octance.
68 Road Runner, 69 Belvedere, 71 Challenger Vert 340 barracuda, 01 Ram CTD, 95 Ram, 04 Ram, 85 Daytona turbo Z 66 GTO, 06 Magnum RT AWD. 07 Ram CTD, 07 Ram
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Re: 498 cid 440 stroker build formula
[Re: torqueaddict]
#1258640
06/28/12 04:16 PM
06/28/12 04:16 PM
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72blubird
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Big Mike what kind of vacuum pressure do you have?
Also does anyone know what the stealth head CCs really are? Tried to measure them but the syringe used was not the best and am not sure.
You can definitely use different thickness of head gaskets for compression change.
What was I thinking....
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