What would be the power difference between these two engines?

MOTOR 1 .1987 460, 8 to 1 compression ratio, stock lower end, has a comp cam 34-235-4 (duration @50 218/226... valve lift .514 / .524 on 111 lobe separation., stock 1987 heads, stock valve terrain, c8 cast iron intake manifold with 1 in spacer and holly 750 carb. and headers. Ran Great! pulled good vacuum. Any Idea what Kind of Power this motor makes???




Motor 2.    DIVE block , stock crank, stock rods with arp bolts, and some KB137-.060 flat top pistons , Stock C8VE heads milled .010 with screw in studs and guide plates maybe cheap set of roller rockers., should be right around 12 to 1 compression. Looking at Comp Cam 34-239-4 , (duration @50 226/234, valve lift .554/.574 lobe separation 111)( If it would pull 15 Vacuum at 900 rpm.  Don't know what intake manifold to use , still have 750 holly carb.

What Kind of Power would each of these motors make?

Thanks.

Duration figures are not at 0.050" for either cam you listed. 218, 226 @ 0.050" for the first cam and 226 and 234 for the second cam.

Engine #1 who knows what power - maybe 275 hp? 450 ft lbs torque?

Engine #2, The 12:1 CR engine will require a very high octane fuel as cylinder pressures will be sky high with the short duration cam. 226 and 234 duration @0.050" is a very small cam for a 460 and 12:1 CR.

motor needs to pull 15 inch of vacuum at 900 rpm... thats y cam choice is where it is.

Is this for a racing class? What do the heads flow?
A custom camshaft designed for the engine (heads etc..) will be far, far better than a shelf cam.

its just a street stock LOW budget racing class. just for fun. the heads are bone stock C8VE heads... not going crazy.. just was wondering what i would gain for power vs the first motor i have listed because that what i am running.

You may get less power if you can't get a fuel that will work with the high CR.
Can you run E85?

Door #2 FTW it will make a bunch more power.

Have somebody grind you a custom cam, they aren't much more than the shelf stuff

no e85... all other gas is easy to get... we have 110 at the bp at the pump... that will be perfect for this motor... Could i expect 100 hp and 100 tq more ??

There are still a lot of question marks about the combo for the questions you are asking; it is pretty hard to get the numbers when you haven't decided on the intake, given the intake you choose, and the cam configuration you are wondering about, are you set on the 750 carb, are you looking for bottom end (torque) for shorter straights, or more RPM for longer straights, gearing, trans, tire size, weight??? Motor #2 has more potential but there are too many variables to say whether it will perform better or fall on its face....the 110 Octane should be fine for 12:1 ... is it power brakes that are the vacuum concern, because that can be addressed separately too.

Agree with Dfree,

Custom cam is the only way to go with high compression and a vacuum rule.
One can certainly use much more duration with a much wider LSA to keep vacuum up.
Jones Cam Designs has done custom vacuum rule cams before.
Lem Evans may have done some vacuum rule stuff as well.

intake and carb i was looking for your advice ... Motor is going in this blue mud truck that comes up every time i post.. 38 in tires, c6, 208f tcase ran in low range ., 3:55 gears.

I know you guys are right on the custom grind cams...

I was just trying to build a simple quick motor that would have more power than the one in it....

Randy Malick is a good choice for the cam too, he build slot of engines like your wanting to do.

what cam and intake would you guys run on the second motor????

dfree383 wrote:Randy Malick is a good choice for the cam too, he build slot of engines like your wanting to do.

^^^^^^^^^^^^^^^^^^^^^^^^^^^^^This contact Randy, tell him what you are looking for and what you want out of it when you order your cam and he will fill in the blanks...I for one cannot give any other advise on this as you only answered half of my questions. DP intake 850+ carb for torque, SGL plane 1050+ for HP.

After torque... max rpm 5500... about 7 second wide open run time... I am going to run the cam that i posted...(no custom ground. It is what it is... Please give advice on what i am working with... ) Thanks...

racinghabbit wrote:After torque... max rpm 5500... about 7 second wide open run time...  I am going to run the cam that i posted...(no custom ground. It is what it is... Please give advice on what i am working with... ) Thanks...

You already have the cam? Or you're just to damn stubborn to get one ground? Which is it?

If you already have it..... It is what it is.... How are our suggestions going to make it different? You asked us what cam and I've given you the suggestion.... Get one ground specifically for the goals don't use a shelf cam.

As for an intake get an Eddy RPM or a weiand stealth an be merry.

Have I told you what you want to hear yet?

With the RPM will he get a large hooterd blond to rub his ass after he realizes he could have had his cake and ate it too?????

kim wrote:With the RPM will he get a large hooterd blond to rub his ass after he realizes he could have had his cake and ate it too?????

Depends on the lobe seperation and how well degreed the centerline intake axis is......

racingrabbit, you want Advice. know what it means when you said "it is what it is".   How does any member change that fact?

Guys, I love this site but sometimes when i ask a question I get some good advice and some attitude... Sorry if you don't understand me..

I have the Cam already. This is a budget build to have fun. and be a little competitive...

The main question was what kind of power difference could i expect from the 2 motors i posted about..

then on the second motor i was looking for the best intake and carb combo to make better torque...

Yes all of my question are answered..

Thanks for the help ... I'm here to learn and not piss off people or have people piss me off..

With the 2nd engine,c8 heads,  D0VE cast iron intake< (YOU WERENT SURE OF WHICH INTAKE),and cast iron ehx manifolds and a diff cam, It made over 500 to the crank

If you use stock c8 heads on no1 engine it wont be  8 TO 1