which is more streetable-comp cam?

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rbdart

rbdart

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Well here I go again changing stuff around...got 440 .030 forged flattops .150 down in the hole with 77cc ported 906's 2.14/1.81 valves comp 925 springs with comp special grind solid 562-300 [email protected] balanced assembly, etc....m-1 intake 800dp..2'' fendwewell headers...ran extremely well in 69 dart 4.10 gear 4spd car.....now going to transplant into a 71 dart street car lightened 2 3050lbs without my lard *** [195] has narrowed 8 3/4 back braced aftermarket axles rear with 3.73 gears and a detroit locker...and a 727 auto with dynamic 9.5 convertor shift kit etc..frame tied welded custom built...ss springs...relocated to frame rails..comp adj shocks....etc..etc......Now as best a s I can figure the compression works out to a 8.7...ran great on pump gas in 69dart and pulled hard from dead stop to 7grand with no bog or any signs of slowing down...ran I'm guessing 11.90's--12.00 easily with stock wore out suspension in 69....I just rebuilt the engine[which really was no need as everything was ok] resized the ly rods installed new arp rod bolts, new rings- brgs -gaskets-pump etc...heads fresh...Its hard 2 believe it ran as good as it did with the low-comp and for the size of cam...being that I'm going to auto car with higher gears should I mill heads down to 72cc to get comp up to compensate?? I'm thinking that a 9-9.4 area would be better and still b pump gas friendly....maybe 2 much cam for combo on the street?? do have another comp cam solid xe290s-10 is a little smaller...540-558lift..290-298dur and [email protected] rockers are 1.6 stainless steel adj rollers...which makes the lift closer to 600lift..and my carb is a stigmeyer 930cfm [mod holley] street tires are 28x10...need some input from u guru's
 
Just wanted to say that I wont be wrapping 7grand...lol... prob in 63-6600 rpm range...
 
I think the cam is way too big for your compression. Just my opinion. I think somethin like the Comp 268 solid would benefit you greatly.
 
I will be using one of the 2 cams listed above, I know they work...a 268 or 270 aint gonna cut it, this has convinced me that u can run a larger cam with lower comp contrare to what we've been told and still perform well, I am not blowing smoke on how well this engine ran and performed and I think with either cam and 9-1 comp would be capable of mid to low 11's easily for both cams have have ran mid 10.60's -10.90's in 440 with 10.9comp and 11.3 comp but with steeper gears-slicks-fuel-etc with iron heads in 32-3400lb cars at the track....being that I will be tagging and insuring the 71 dart for the street I want to be able to run pump gas and drive it and for it to perform well as it did in 69 dart..the Frank Lupo Dynamic convertor aint no punk with a stahl rating of 25-5500 rpm and the suspension is far superior and weight is lighter and it is a 440 so torque isnt an issue...as for the 906's whoever ported them knew what they were doing for I believe this is the real key to why this 8.7 comp engine worked so well....unless I've miscalculated the compression...it was a nasty lil'beast for comp ratio, and the 562-300-265 comp solid cam callls for 10+ and up comp...steeper gears..good convertor..etc..I am not being defensive or disputing anyones opinions or advice or recomendations as for I have asked u all what ur input or thoughts are cause I am suprised as to the performance level of this 440 with this large of cam [562-300]and lower [8.7] compression but it worked great in wore out 69 dart..was it the 4spd...4.10 gear...good heads...or the combo and my concern in the transplant to the 71 with the 3.73s and automatic was and is the comp ratio which I can bump up to 9-9.4 fairly easily and still run pump gas and would the slightly smaller cam work better for the street or stay with the 562-300??? bring on the comments and dont think I'm defensive for I am not meaning to be just wouldnt have thought this combo shouldve performed this well...thanx....Ken
 
i think you should use the smaller cam, but how are you going to get the compression up 7 tenths of a point , i dont see how you can do this easily. even head milling and the shim gasket might get you an lncrease of only .5 i believe.
 
rbdart said:
........with a stahl rating of 25-5500 rpm
Click to expand...
Stahl rating? you mean stall rating.

NOT to criticize you (by far not the only one), but there is
no such thing as a "STAHL" converter!

I don't know where this got started but.........

Jere Stahl was a hell of a racer. He made a lot of products
including his famous STAHL brand custom exhaust headers
and his STAHL brand tall skinny frontrunner drag tires.

But Jere Stahl NEVER made torque converters. This is a common
misconception.

The correct term is a high STALL speed converter; as in, at what
rpm will it stall? (cease to slip); having a higher stall speed.....and
made by any number of manufacturers.

Excuse me but I slip a gear whenever I see a common aftermarket
high stall speed torque converter (ATI, Turbo-Action, Coan, B&M,
Fairbanks, A-1 what have you...) referred to as a "STAHL" converter.

I swear, you cannot open a "Car Trader" magazine anywhere in this
country without seeing this error repeated!
 
First, you posted a question asking opinions. then you came back and said basically, "tough ****, I don't care what yall think, I'm gonna run what I'm gonna run." Then run it. But you could be faster with a better matched cam. The reason the car was so fast is because it's a small car with a big motor. You have to make some pretty stupid mistakes sho nuff to make it slow right from the start. It can be faster yet with a properly matched camshaft. If you think otherwise, then that's all the more reason for you to listen to opinions rather than disregard them.
 
Well 1/2 point is prob all I will get which is more than I have now, which should be 9.2....and I've seen stall/stahl spelled both ways...which is neither here nor there....talked to a couple diff old heads that have seen this before in their experiences some say could be combo of good flowing heads and a little looser motor....balanced well...luck... so figure flatop piston .o30[bore is 4.350] standard 3.75 stroke...rods 6.76'' length...heads 77cc 2.14-1.81 valve...piston is .150 down......then figure with a 72cc head...??????
 
The United Engine web site calculator says 8.546:1 using a 72cc head. You will be grossly overcammed. Have at it.
 
As good as it ran....and I don't doubt it....it could be so much better.

Big cams, at least duration-wise, bleed off cylinder pressure and you won't
have much to start with.

No wonder it was never finicky about pump gas.
 
Strokerscamp...not saying tough ****, just which of 2 cams that I have and have a history of working in this motor should I use and was asking for input of why this worked...not trying to pick a fight or ruffle feathers as I explained in above post I am not being defensive or confrontational and maybe someone could enlighten me...no need to piss anyone off when we are supposedly trying to help each other here...I aint new to this by no means been playing with mopars for 38 yrs off and on and this puzzled me cause they normally dont perform this good....so sorry if anyone takes offense is not the intent.........
 
We're tryin real hard to tell you. Camshafts with a large amount of duration are not what you need. They bleed off gobs of cylinder pressure. You need a camshaft with no more than 236* @.050" at the VERY MOST....and smaller than that would be better. My God. It's a 440 in a Dart. Kinda hard for that not to be fast no matter how badly the parts are mismatched.
 
Then again I may have to use my other shortblk 440 std bore flat-top .042 in hole with 77cc head but was afraid of too much comp for pump gas...????
 
If you have to one of those two, use the second one, 252 at .050 and install it at 100-102 ICL.
 
rbdart said:
Then again I may have to use my other shortblk 440 std bore flat-top .042 in hole with 77cc head but was afraid of too much comp for pump gas...????
Click to expand...

You could run that with either of the other cams. That combo comes up with 10.264:1.
 
Stroker...I hear ya and I understand the concept and I agree with it to a point...but this really worked well for reasons I am not sure of...ripped out of gate like it was shot out of a cannon and pulled hard all the way thru like there was no end to it, Ive seen and drove a bunch of smblks and bblks alike and this was unbelievable performance for whatever it is....no bog no sputtering smooth clear to 7g[not me driving at time] but now that I own it was trying to duplicate it as close as possible in 71 and run pump gas and work....maybe not...maybe wishful thinking...sure sounded good...maybe Im gettin senile at 51
 
Just asking, but common deck heights for B-motors seem to range
from .000 to -.025.

Do yours measure -.150 and -.042 or -.0150 and -.0042?
 
hell I cam up with 10.9 with 2nd shtblk with .020 shim gasket and 10.4 with .039 gasket....pump gas here is 91 oct....93 pretty much extinct...trying to stay away from mixing fuel for better octane
 
Cracked back ur video may cause me bodily harm...wife caught me gawking at it and said...'so what kinda compression u lookin for' lol
 
rbdart said:
- .042 and -.150 down in hole so minus it is
Click to expand...

No. When figuring compression it's a positive number. Negative indicates an above deck piston. Honestly, I think you can improve on this combo. I don't really care how fast you thought it was back in the day, it was horribly mismatched. It was fast cause it was a flippin 440 in a dart.
 
Plik said:
rbdart, you should buy my cam :D
Click to expand...

Indeed....I thought about that. It is still a touch big, but would be so much better than either of his choices.
 
Yes I understand the minus- positive in figuring comp ,was just explaining that minus was referring to 'down in the hole' ......not above deck....thanks for all ur input...my figures for comp r slightly higher than urs maybe the calculator site I'm using differs....still aint sure what I'll do yet but I'm sure I'll get more replies and input along the way....I get the impression that I'm not making any believers in this combo but this same engine in a 70charger 4spd-4.10 geared full weight ran 12.40's with the 562-300 cam but it did...and in the day was in last 2 yrs....same exactblk heads cam/pistons...????????????????????????????????????????????????????
 
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