Re: 915 HP heads on low-compression 400 low deck??
[Re: caseyjones]
#247650
03/09/09 06:51 AM
03/09/09 06:51 AM
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Joined: Mar 2005
Posts: 3,141
Central NC
gch
master
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master
Joined: Mar 2005
Posts: 3,141
Central NC
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 Sounds like a cool project.Love the intake.However it probably won't perform well with that cam,low compression,and small c.i. The carbs are a bit much on a stockish 400 but can be made to work.Probably not going to have a lot of bottom end.Plan on some gears. Nothing wrong with the heads.As suggested I would mill them accordingly and try to get your compression up to 9.0-1 or 9.5-1 would be even better. BTW the cast crank will be fine for what you are doing.Buy a weighted flexplate and spend the money elsewhere. 1 7/8 headers are a tad big for a street driven 400(1 3/4 would be better for low end and mid range).That being said they will work. I would pick a different cam for that motor.Need to know the rest of the drivetrain(stall,gear,weight of car) and intended usage(street,street/strip) to pick one that will work.
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Re: 915 HP heads on low-compression 400 low deck??
[Re: plumebody]
#247651
03/09/09 08:49 AM
03/09/09 08:49 AM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
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Quote:
You may have a problem with using that cam and the low compression. Your slugs are going to be .090-.110 in the hole, so piston to valve clearance shouldn't be a problem. Use a thin head gasket and mill the heads as much as you can. If new pistons are and option, that's what I would do. Those are cast pistons and won't hold up to that paxton you want to put on 
Or you could go with a little less duration, or degree it in 4* like on a 110 center line.
sure they will...as long as you keep gas fed to them. I used stock 9:1 Speed Pros on my S/C'd 440. I did burn up #3 once when I forgot to turn on the electric fuel pump, but I had at least 100 runs on those cast pistons.
the 915's will help. If you have the engine apart why not have the block cut down?? and why a 383 crank anyway?
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Re: 915 HP heads on low-compression 400 low deck??
[Re: Mr.Yuck]
#247652
03/09/09 09:44 AM
03/09/09 09:44 AM
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Joined: Jan 2003
Posts: 75,005
U.S.S.A.
JohnRR
I Win
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I Win
Joined: Jan 2003
Posts: 75,005
U.S.S.A.
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Quote:
Quote:
You may have a problem with using that cam and the low compression. Your slugs are going to be .090-.110 in the hole, so piston to valve clearance shouldn't be a problem. Use a thin head gasket and mill the heads as much as you can. If new pistons are and option, that's what I would do. Those are cast pistons and won't hold up to that paxton you want to put on
Or you could go with a little less duration, or degree it in 4* like on a 110 center line.
sure they will...as long as you keep gas fed to them. I used stock 9:1 Speed Pros on my S/C'd 440. I did burn up #3 once when I forgot to turn on the electric fuel pump, but I had at least 100 runs on those cast pistons.
the 915's will help. If you have the engine apart why not have the block cut down?? and why a 383 crank anyway?
Cutting the block down is not a good idea , escecially that much .
the motor is apart ... BUY NEW PISTONS ....
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Re: 915 HP heads on low-compression 400 low deck??
[Re: Mr.Yuck]
#247655
03/09/09 10:36 AM
03/09/09 10:36 AM
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Joined: Jan 2003
Posts: 1,075
rochester,new york
plumebody
super stock
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super stock
Joined: Jan 2003
Posts: 1,075
rochester,new york
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Quote:
Quote:
You may have a problem with using that cam and the low compression. Your slugs are going to be .090-.110 in the hole, so piston to valve clearance shouldn't be a problem. Use a thin head gasket and mill the heads as much as you can. If new pistons are and option, that's what I would do. Those are cast pistons and won't hold up to that paxton you want to put on
Or you could go with a little less duration, or degree it in 4* like on a 110 center line.
If you think 100 runs is good, god bless ya. I would not recommend cast pisons on a s/c or NOS motor. Will it work, yes for a while(as in your case). A forged piston motor with good rod bolts and studs will last forever(well, you know what I mean)
sure they will...as long as you keep gas fed to them. I used stock 9:1 Speed Pros on my S/C'd 440. I did burn up #3 once when I forgot to turn on the electric fuel pump, but I had at least 100 runs on those cast pistons.
the 915's will help. If you have the engine apart why not have the block cut down?? and why a 383 crank anyway?
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Re: 915 HP heads on low-compression 400 low deck??
[Re: plumebody]
#247656
03/09/09 10:37 AM
03/09/09 10:37 AM
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Joined: Jan 2003
Posts: 24,562
Brookeville, Md
Mr.Yuck
Not enough dumb comments...yet
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Not enough dumb comments...yet
Joined: Jan 2003
Posts: 24,562
Brookeville, Md
|
Quote:
Quote:
Quote:
You may have a problem with using that cam and the low compression. Your slugs are going to be .090-.110 in the hole, so piston to valve clearance shouldn't be a problem. Use a thin head gasket and mill the heads as much as you can. If new pistons are and option, that's what I would do. Those are cast pistons and won't hold up to that paxton you want to put on
Or you could go with a little less duration, or degree it in 4* like on a 110 center line.
If you think 100 runs is good, god bless ya. I would not recommend cast pisons on a s/c or NOS motor. Will it work, yes for a while(as in your case). A forged piston motor with good rod bolts and studs will last forever(well, you know what I mean)
sure they will...as long as you keep gas fed to them. I used stock 9:1 Speed Pros on my S/C'd 440. I did burn up #3 once when I forgot to turn on the electric fuel pump, but I had at least 100 runs on those cast pistons.
the 915's will help. If you have the engine apart why not have the block cut down?? and why a 383 crank anyway?
I sold the car..I'm sure I could have gotten many many more out of it.
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Re: 915 HP heads on low-compression 400 low deck??
[Re: caseyjones]
#247657
03/09/09 11:13 AM
03/09/09 11:13 AM
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Joined: Feb 2003
Posts: 1,095
Bloomington, Illernoise
cptn60
super stock
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super stock
Joined: Feb 2003
Posts: 1,095
Bloomington, Illernoise
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Quote:
I'm building up a 400 low deck block for my '65 Dodge Coronet. It's a new old stock block that I found with stock flat-top pistons, crank, rods, etc.. I plan on using a forged 383 crank in place of the cast one that's in it now (As soon as I can find one that is!). I'm using an Edelbrock STR-15 crossram manifold and will be using a set of 625 cfm Carter AFB's. Using 1 7/8" headers and a Lunati bracket master II cam w/ advertised Duration (Int/Exh): 292/292 Gross Valve Lift (Int/Exh): .480/.480, RPM Range: 2500-6000. I just bought a set of 915 HP closed chamber heads with the larger 1.74" exhaust valves. My question is this: has anybody used a set of these 915 heads on one of these low compression motors? Does anybody know what compression this is going to give me using the stock flat-tops? Any advice on how to make this combo work for me would really be appreciated? This is going to be a street driven car.
After reading your post, it reminds me Chrysler built PACKAGE cars. Just seems like a mishmash of parts. Stroke the motor, if you are gonna change the crank, lets pump it up. A new set of pistons, and you are at 451 or more. Get with Rapid340 for a cam recommendation, call John Cope for a torque converter and set your rear axle up with a nice sure grip and proper gearing for how you roll. Make sure you have good brakes,(disc it!) and rebuild the front suspension, and rear while you are at it. And have fun! 65 'Nets are beautiful cars, as you already know. 
This space available for rent
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