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Help with my combo... need some ideas #213617 02/04/09 02:59 AM 02/04/09 02:59 AM
Joined: Feb 2005 Posts: 5,207 Menomonee Falls DemonDust OP master
DemonDust OP master Joined: Feb 2005 Posts: 5,207 Menomonee Falls	Would like to get an idea of which way I should go. Since my XR block will be done soon. I need to know what is the best way to build it. 3.800 stroke 4.185 bore 9.600 deck P7 heads flow over 400 cfm 93 octane or E-85 not sure 12:1-13:1 comp? Going in the duster. Manual, 4.56, it will weigh about 3100 lbs when complete. What cam, carb, rod length, comp ratio? Will be street and strip. let me know what you guys think? I think you have all the info. SDG Motorsports Hellcat Demon and Redeye Supercharger CNC Porting https://www.sdgmotorsports.com/

Re: Help with my combo... need some ideas [Re: DemonDust] #213618 02/04/09 03:33 AM 02/04/09 03:33 AM
Joined: Dec 2006 Posts: 4,647 aotearoa rebel master
rebel master Joined: Dec 2006 Posts: 4,647 aotearoa	how fast are you intending to run this beast?

Re: Help with my combo... need some ideas [Re: rebel] #213619 02/04/09 03:37 AM 02/04/09 03:37 AM
Joined: Feb 2005 Posts: 5,207 Menomonee Falls DemonDust OP master
DemonDust OP master Joined: Feb 2005 Posts: 5,207 Menomonee Falls	Well, I'm thinking this will make 650 hp easily. So I'm thinking low 10's high 9's.. SDG Motorsports Hellcat Demon and Redeye Supercharger CNC Porting https://www.sdgmotorsports.com/

Re: Help with my combo... need some ideas [Re: DemonDust] #213620 02/04/09 01:22 PM 02/04/09 01:22 PM
Joined: Jan 2003 Posts: 5,484 SoCal Brian Hafliger master
Brian Hafliger master Joined: Jan 2003 Posts: 5,484 SoCal	Quote: Would like to get an idea of which way I should go. Since my XR block will be done soon. I need to know what is the best way to build it. 3.800 stroke 4.185 bore 9.600 deck P7 heads flow over 400 cfm 93 octane or E-85 not sure 12:1-13:1 comp? Going in the duster. Manual, 4.56, it will weigh about 3100 lbs when complete. What cam, carb, rod length, comp ratio? Will be street and strip. let me know what you guys think? I think you have all the info. Why 3.8 stroke?? Those heads will want alot of piston speed so you will need RPM or STROKE to achieve this. You also NEED to decide for sure which fuel you WANT to run, since that will have a major impact on the build. Why not do a larger cid engine, like 440 cubes and up, and shoot for a 7500rpm cap? That's what I would do using those heads. Brian Brian Hafliger

Re: Help with my combo... need some ideas [Re: Brian Hafliger] #213621 02/04/09 03:39 PM 02/04/09 03:39 PM
Joined: Feb 2005 Posts: 5,207 Menomonee Falls DemonDust OP master
DemonDust OP master Joined: Feb 2005 Posts: 5,207 Menomonee Falls	I have the 3.800 crank. But I can go 4.000. Thats why I put this post up to see what you guys thought. Was thinking maybe 13:1 then the aluminum heads would bring it back down to about 12:1. I could easily run e-85. Or the other option would be 12:1 and pump fuel. I just wanted to know which one would be the better combo. SDG Motorsports Hellcat Demon and Redeye Supercharger CNC Porting https://www.sdgmotorsports.com/

Re: Help with my combo... need some ideas [Re: DemonDust] #213622 02/04/09 03:57 PM 02/04/09 03:57 PM
Joined: Jan 2003 Posts: 5,484 SoCal Brian Hafliger master
Brian Hafliger master Joined: Jan 2003 Posts: 5,484 SoCal	Quote: I have the 3.800 crank. But I can go 4.000. Thats why I put this post up to see what you guys thought. Was thinking maybe 13:1 then the aluminum heads would bring it back down to about 12:1. I could easily run e-85. Or the other option would be 12:1 and pump fuel. I just wanted to know which one would be the better combo. I guarantee you if you try to run 12:1 on pump gas it will detonate!! Aluminum heads dissipate heat better than cast iron, but not a point worth! I'd run 13:1 on E-85 if you can get it easily. True pump gas (91) octane, will only work with about 11:1 max. Unless you are at elevation (above 3500ft). With pump gas you are likely to get less than fresh gas, and maybe a little water too so the MAGAZINE pump gas (93 octane from a sealed drum) engines you read about are very misleading. That's my . I would go 4" or 4.100 stroke and 4.155 bore and have fun. Brian Brian Hafliger

Re: Help with my combo... need some ideas [Re: Brian Hafliger] #213623 02/04/09 04:51 PM 02/04/09 04:51 PM
Joined: Feb 2005 Posts: 5,207 Menomonee Falls DemonDust OP master
DemonDust OP master Joined: Feb 2005 Posts: 5,207 Menomonee Falls	E-85 is at almost every gas station around here, so that is no problem. Is 4.155 a common bore? I was gonna go 4.185 just because rings can be bought off the shelf. Why do you suggest 4.155? Another question you could maybe answer, which is better a longer rod or more comp height on the piston? SDG Motorsports Hellcat Demon and Redeye Supercharger CNC Porting https://www.sdgmotorsports.com/

Re: Help with my combo... need some ideas [Re: DemonDust] #213624 02/04/09 05:32 PM 02/04/09 05:32 PM
Joined: Feb 2005 Posts: 5,207 Menomonee Falls DemonDust OP master
DemonDust OP master Joined: Feb 2005 Posts: 5,207 Menomonee Falls	Another question, What size carb do you think it would like? SDG Motorsports Hellcat Demon and Redeye Supercharger CNC Porting https://www.sdgmotorsports.com/

Re: Help with my combo... need some ideas [Re: DemonDust] #213625 02/04/09 07:50 PM 02/04/09 07:50 PM
Joined: Jan 2003 Posts: 5,484 SoCal Brian Hafliger master
Brian Hafliger master Joined: Jan 2003 Posts: 5,484 SoCal	Quote: E-85 is at almost every gas station around here, so that is no problem. Is 4.155 a common bore? I was gonna go 4.185 just because rings can be bought off the shelf. Why do you suggest 4.155? Another question you could maybe answer, which is better a longer rod or more comp height on the piston? 4.155 bore is a .030 overbore for the sb chevy, just as 4.185 is .060 over. I suggest that because it will give you a good bore size and it will leave the cylinders nice and thick. On the rod, just use a typical sb mopar length.

Re: Help with my combo... need some ideas [Re: DemonDust] #213626 02/04/09 07:52 PM 02/04/09 07:52 PM
Joined: Jan 2003 Posts: 5,484 SoCal Brian Hafliger master
Brian Hafliger master Joined: Jan 2003 Posts: 5,484 SoCal	Quote: Another question, What size carb do you think it would like? I would use a 1050 dominator, and have the idle circuits cleaned up. You could use a 1000HP carb if it's easier, they should be within 15HP of one another, maybe closer. Brian

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