1fastgreencar
Well-Known Member
408 stoker from blue print , going to have the eddy heads port and polished , what gain have you seen in your time slips? After head work done
What gain will I see in my time slips
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Depends on the type of porting they do...how extensive, how much they flow, if the camshaft is suited for the combo.
1fastgreencar
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1fastgreencar
Well-Known Member
I under stand thanks just looking to kinda see what others have gained
33IMP
Well-Known Member
Rough estimation (VERY rough) is two hp per cfm is possible, if everything is right. Therefore, if your porting goes from 240cfm to 270, you can theoretically pick up 60 hp. How much of that potential 60hp shows up on your timeslip is ENTIRELY dependant on how good your car is.
You can go to wallace calculators, and investigate how much power you have now, and get an educated guess as to what it might do with more.
Edit: 60 hp from just porting would be a huge increase, i wouldn't expect to see that on my junk. Still, pocket ported 906 big block heads MIGHT flow 240, edelbrock claims(repeat, claims) 290 from their big block rpms.
You can go to wallace calculators, and investigate how much power you have now, and get an educated guess as to what it might do with more.
Edit: 60 hp from just porting would be a huge increase, i wouldn't expect to see that on my junk. Still, pocket ported 906 big block heads MIGHT flow 240, edelbrock claims(repeat, claims) 290 from their big block rpms.
1fastgreencar
Well-Known Member
Ok thanks that’s gets me in the ball park
you are going from unported eddy heads to ported eddy heads?.....how fast is the car now?,,,,,,is the camshaft big enough to use the additional air flow....carb...gearing ...converter...
are ported heads going on the flow bench?
are ported heads going on the flow bench?
1fastgreencar
Well-Known Member
Yes on the heads no on a flow bench ,it a Dodge Dart full interior 391 gear not sure on the cam that’s in it now I’m at work so I don’t have the spec with me I’ll put it on here when I can
1fastgreencar
Well-Known Member
Best it ever ran was a 12.40
K.O. SWINGER
Meeting in the alley since 1976
I think you have room for improvement but all things being the same I think you'll crack the 11s just to guess. Let us know.
1fastgreencar
Well-Known Member
If this helps....My Barracuda with a healthy 360 (OOTB Edelbrocks, MP 509 cam, Air-gap) ran 12.5. I rebuilt that engine with a stroker kit (410 cubes), 10.7:1 compression, fully ported the Edelbrocks, and ran a small "street" solid roller (248/254 duration @ 0.05 0.576/0.584 lift). First pass on that engine was ~11.4, but it went 10.89 after tuning. Swapped to a Victor intake and it went ~10.7 normally, with a best of 10.57 in great air. (and a tail wind, lol). The stroker ran well considering I was not taking advantage of all the port work of the heads....
....Fast forward to now, current motor with the same heads/intake (408 cubes) with 13:1 compression and a healthy solid flat tappet cam (264/268 @ 0.05 ~0.630 lift) runs 10.3-10.2 in the heat, current best is 10.1.....big difference just taking advantage of the flow of the heads.
famous bob
mopar misfit
that still aint worth a crap compared to a big block chevy tho , think about it .
1fastgreencar
Well-Known Member
Thanks yes that help a lot so it sounds like I’ll be happy I doing it
1fastgreencar
Well-Known Member
This is the cam I’ll be running with a 1.6 ricker
@1fastgreencar The above is agreed with BUT....
If your current cam isn’t lifting the valve up high enough to take advantage of the porting & the air flow gains, then the chances are your not going to see a whole lot.
If your porting work goes from 240 to 270 like 33IMP said, that’s a nice gain, but where is the gain? Like the top end of the flow chart. Where the valve is opened up a lot. If the major gains are above .500 or .550 lift and your only lifting the valve to say, .509, then the performance gain in full will not be realized.
You’ll have to look at the flow differences in the lift area. At .509 lift, it’s all valve job and work in the bowl. Normally, not a huge gain, but important nonetheless. And yes, that should power that you can easily feel. As far as time slip goes, this is a good question that no one can answer for you on your car since there is zero information on it. But what others have achieved should be interesting none the less. I’m looking forward to it!
1fastgreencar
Well-Known Member
Yes I agree and also that’s kinda what I wanted to see , what gains have other achieved from there head work they have done and thank you for your response
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furrystump
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Not apples to apples but I went from unported eddies to seriously ported x’s and picked up 3-4 10ths. Would have picked up more but had to take a step backwards in the intake dept.
Dont have em polished
That’s right!
Only the chamber.
1fastgreencar
Well-Known Member
View attachment 1715752010 so Just a up date I pick up 4 tenth of a second my best before the head porting and can swap was I believe a 12.6 . I only mad one pas that day because I found out my sure grip is not working lol one wheel peal
B3422w5
Well-Known Member
Its most definately down on power somewhere. Only going 107 with a healthy cam, ported heads and a stroker crank.
What convertor are you using?
What convertor are you using?
1fastgreencar
Well-Known Member
3500 stall company called freak show converters out of Texas I’m running a 26x10 m/t
B3422w5
Well-Known Member
Convertor is definately contributing to the numbers being what they are. Good 8 inch would really improve the numbers a bunch, for starters.
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