[oldbogie]

Originally Posted by rude 72

what heads at the most can i use , to make it run like a beast .

I'd like the details of this engine as in type of crank, rods, pistons? Also your thoughts on why you choose building it this way. I kind a cogitated on this last night, it was that or watch the circus in DC on TV. Overall I came to the conclusion that you may have thrown everybody for a loop with a somewhat unconventional approach that will work if you've got a stiff enough gears in the car.

I'm not done being concerned about your bottom end but some deeper details especially about the piston shape could ease my mind.

Bogie

[barnym17]

Just as example to ease your mind about stock cast pistons, my first year of hobbystock around 1993 or 4 dead broke just married, gotta do what ya gotta do.Engine was a 100,000 mile short block out of a 74 pickup, new 19.99 timing chain, elgin claimer solid cam .536, .557 lift. 186 casting heads.Ran that sucker 20 nights before a piston broke and needed replaced.I turned well past 8,000 every lap because I didn't know any better but it lasted just fine. Again as I said i wouldn't recomend much over 6500 continuously but the ocassional blast no big deal.With a stock uncut deck and 49 cc heads and normal composition gasket at .040 you will be close to 10 or 10.5 comp which the cam will like.

[oldbogie]

Originally Posted by barnym17

Just as example to ease your mind about stock cast pistons, my first year of hobbystock around 1993 or 4 dead broke just married, gotta do what ya gotta do.Engine was a 100,000 mile short block out of a 74 pickup, new 19.99 timing chain, elgin claimer solid cam .536, .557 lift. 186 casting heads.Ran that sucker 20 nights before a piston broke and needed replaced.I turned well past 8,000 every lap because I didn't know any better but it lasted just fine. Again as I said i wouldn't recomend much over 6500 continuously but the ocassional blast no big deal.With a stock uncut deck and 49 cc heads and normal composition gasket at .040 you will be close to 10 or 10.5 comp which the cam will like.

I think that when you "don't know better" the racing gods let you get away with things. Once you "know better" your grace period expires.

That may confirm why, "ignorance is bliss", cause you can get away with things that are other wise impossible.

Bogie

[j.d.brown.042964]

Not to beat this dead horse any further into submission, but here I go.

I have done what you describe before, not recommended but it can work. I put a set of heads with 49cc chambers on a stock bottom end. Two bolt main, castcrank, stock rods with silv-o-lite hypereuthetic pistons. Did not deck the block, ran a 0.026" thick gasket. Installed a isky flat tappet 259 degrees @0.050" with0.550" lift.Mine needed 100 octane fuel, ran real strong for a couple of years to 7000 RPM till a starter bolt hole cracked. It's really a gamble, might run for a couple of years, might break tomorrow. Run it into autoignition and it will break real soon.

my first year of hobbystock around 1993 or 4 dead broke just married, gotta do what ya gotta do.Engine was a 100,000 mile short block out of a 74 pickup, new 19.99 timing chain, elgin claimer solid cam .536, .557 lift. 186 casting heads.Ran that sucker 20 nights before a piston broke and needed replaced.I turned well past 8,000 every lap because I didn't know any better but it lasted just fine

-I still stand by what I said in my earlier replies due to the fact that he clearly stated,and I quote:

i want this to be a street car , but like to take to the track a couple times also.

That would lead one (at least ME) to believe that this vehicle's gonna see considerable street time and might need to have "street manners", (in case Aunt Edna needs to borrow it when her mint '66 Bonneville is in for a repair! ). I deduce that reliability and a REASONABLE level of economy would be expected to be parts of the equation of this build if it's gonna see mostly street time. The other scenarios mentioned were more "race-dedicated" usages and aren't currently getting one back/forth to work lately, are they? Not tryin' to rain on anyone's parade, but for a "daily-driver" I'd stay with the K.I.S.S. theory and stay uncomplicated for drivability sake. -Jim

[barnym17]

I would suggest selling the Darts this should get you more than enough for a set of vortecs and vortec intake.Go with the performer rpm version, also as a street car your cam will work however it will idle very rough and have low vacuum it is a circle track design with tight lobe centers great midrange tourque but bad manners at idle.If you can live with the idle and low speed bad manners it is a good cam, if not back off a little to say a comp 268h or something similar and you will have a good streetable engine.

[j.d.brown.042964]

I truly believe that you'd be much happier with the lower-rpm characteristics of the Comp286 or something similar, (as opposed to what you have now), simply due to the fact that the poor combustion characteristics at lower rpms (of a long duration cam) would probably render a very inefficient engine below 2500-3000 range, which is where the majority of it's time will be spent while being street-driven. At $4 a gallon these days, we need all the help we can get. Not to mention that what is not getting combusted is aiding in washing-down the cylinder walls of oilfilm and helping to prematurely foul the plugs. Remember that on the lift you can regain a bit with 1.6 rockers as opposed to 1.5 ratio. Even though vortec heads have great low-rpm flow, why not EMPHASIZE IT with a cam having 215-230* duration, as opposed to using that characteristic to band-aid a cam of much longer duration that prefers 2500/3000 - 7000? Save that Elgin cam/lifter set (keeping everything location-matched, of course) for when you build that 7500 rpm "screamer". You'll be much happier in the long run. -Jim