1968FormulaS340
Well-Known Member
After reading this thread I went in the bathroom and punched myself in the face for 20 minutes.
adjusting my vac
- Thread starter SRT_DSTRHOLC
- Start date
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Johnny Dart
Well-Known Member
You should be talking to your builder than. Plain and simple.
Hold him accountable.
If this is following the instructions of a "Pro" I would hate to see an amateur.
You WILL go up^ in HP with A SMALLER CAM. and i think you need a better or different compression gauge.
Have a hard time believing that compression unless your static compression it closer to 11 then 10.........................................
What altitude did you say you live at............
SRT_DSTRHOLC
"There is never enough horsepower...."
static is 11.0-10.9 and dynamic is 8.222 and what cam do you think will make more HP with this setup and with the stroker?
You have the cam card or company and grind.
A cam with 240-245 at .050 would make more power throughout the range than the one you currently have. A stroker could possibly use the cam you have.
Longgone
John/68 Barracuda & Dart
As someone mentioned earlier, maybe try setting the lash in your valves real slack (like .040) and although it may be noisy, see if that helps tame the cam some. I agree with using a vacuum advance, it`s much more street friendly when you`re in and out of the throttle. If you primarily want to drive the car on the street it would behave better with a smaller cam and a dual plane intake.
SRT_DSTRHOLC
"There is never enough horsepower...."
ya my cam is a comp 360s magnum, I told him I want something that I can leave in there in case I want to go to a stroker...Im moving to orange county...30 min from Pomona..I will be at that track more then less...I want to get into a small class, so the car will be both street and strip
You mean 306S?
You won't be racing at Pomona! maybe Irwindale, Barona or Fontana
306s has an intake closing event in the 85* area IIRC. The card says 79* at .015. Using that, 79*, you only have a ratio of 7.60:1, at 85* it's 7.11:1, If it's higher than 85*, it's even lower.
If you don't have a 4K stall and deep gears, it's going to be tough.
If you don't have a 4K stall and deep gears, it's going to be tough.
SRT_DSTRHOLC
"There is never enough horsepower...."
oh pomona doesn't let people on? only pro drags?
w2360Duster
No Patience
And your cylinder pressure in reality is probably 90 to 110 PSI , the bright side is ,is you don't have to worry about hi-octane fuel, also you can probably also use stock skinny radial tires because it won't be mustering any bottom end torgue. Your 60 foots will be an estimated 2.2 also. Well id be saving up for the big CID kit soon to get er out of the 14s.
SRT_DSTRHOLC
"There is never enough horsepower...."
your talking about dynamic compression? I have a 3600 stall and 4.10 gears not that deep but it seems to run well
SRT_DSTRHOLC
"There is never enough horsepower...."
I highly doubt that the pressure is that low.....The builder has the top engine programs and put all the info in and came out with 8.222 dynamic compression not 7
SRT_DSTRHOLC
"There is never enough horsepower...."
it says it has 56 at .050 and 79 seat to seat or the IVC
SRT_DSTRHOLC
"There is never enough horsepower...."
ok...For once I did Research for myself...I used the KB website with their calculator...It says I have 10.959 static compression and 8.263 dynamic compression...they used the IVC at 50 plus 15 which is 71
SRT_DSTRHOLC
"There is never enough horsepower...."
thanks....I want to know why he said I wont be able to race there?
The 15 degrees is a guideline to add to you .050 number. If the tappet valve is still off the base circle .015 at 79*, how can your closing number be 71? See the problem there?
I believe you need to use the 79 number because that's where the lash ramp will be. .015*1.5= ~.022 which is your lash.
You have 7.6:1 compression right now, using a 10.9:1 number.
Try it here which is what you already found in your research. Rod length is 6.123
http://kb-silvolite.com/calc.php?action=comp2
I believe you need to use the 79 number because that's where the lash ramp will be. .015*1.5= ~.022 which is your lash.
You have 7.6:1 compression right now, using a 10.9:1 number.
Try it here which is what you already found in your research. Rod length is 6.123
http://kb-silvolite.com/calc.php?action=comp2
SRT_DSTRHOLC
"There is never enough horsepower...."
ya that calculator ask for at 50 plus 15 its 8.221 same thing the builder said doing it with the .56 plus 15 that is
But that's WRONG... it closes later than that by 8 degrees.
SRT_DSTRHOLC
"There is never enough horsepower...."
whats the effect of the lower dynamic compression? This site http://www.empirenet.com/pkelley2/DynamicCR.html says It appears that most gas engines make the best power with a DCR between 7.5 and 8.5 on 91 or better octane. so does this mean im fine and that I can use lower octane?
What you currently have! It will suffer from lack of end torque.
Think how a late model 360 runs compared to an earlier 340's. That's why a cam with 20* less duration at .050 would work better for you now. You've really got no compression in the thing. It will run on regular is my guess.
You'd be better off pulling that cam and spending $200 on a new cam/lifters. Then you won't have to lock out the timing and could actually get a mech curve in the thing.
Sorry man, the builder did you no favors.
SRT_DSTRHOLC
"There is never enough horsepower...."
what cam should I put in that will do well for this setup and for when I go stoker?
Put a XS282S in it. That will raise the effective comp to about 8.5:1
The cam you have will work fine in a good stroker. It's fairly close to the one Mad_Dart had in his duration wise. His cam had much more lift. Maybe toss it in a bit advanced.
SRT_DSTRHOLC
"There is never enough horsepower...."
ok is this one too much? http://www.summitracing.com/parts/DCC-4120655/
prolly is...Im thinking if I really want to tear it down for the cam or just save and stroke it...
prolly is...Im thinking if I really want to tear it down for the cam or just save and stroke it...
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