360 w/8.4:1=?power

[lead69]

that's a cool car lead69

Thanks,it was supposed to be a primer and drive for the summer for sale project that turned into a three month,poor mans overhaulin project!.Complete paint/built 360,drivetrain freshened,it was start to finish in three months in my driveway weather permitting lol,still have some sublime paint stains in the concrete from painting the jambs.Im not sure if I could pull it off a second time or even if I would want to.

 

[JoeDust451]

That gives me promise then, hopeing i can pull off some low 13s with my 71 dart with a 360 magnum, bolt-ons, 3.73 gears, & a 2500 stall.

 

[74scamp360]

Thanks,it was supposed to be a primer and drive for the summer for sale project that turned into a three month,poor mans overhaulin project!.Complete paint/built 360,drivetrain freshened,it was start to finish in three months in my driveway weather permitting lol,still have some sublime paint stains in the concrete from painting the jambs.Im not sure if I could pull it off a second time or even if I would want to.

wow sounds like you were really into it! More power to ya though man, i don't know anyone that would take on restoring a car in their driveway!! props man, it looks great!

 

[rumblefish360]

Rumble, Awsome figures there.
If I were to use those pistons and came up with lower figures than yours.
This would point directly to my deck being taller than average for whatever reason. (and not the pistons)

If I knew the center line of crank to deck meas.
or
knew the center of piston pin to top of piston

This could also help prove the reason for such crappy quench on my motor
(.1092")


Thanks from "not so sunny" Modesto, California

No problem, there for the most part, ball park, real close, not dead on exact, but close enuff for this general talk. If you mic up everything and your figures differ, I would not be surprised. I have built a 360 with the KB-107-(.030) pistons and there height came up and landed at a zero deck height. Others here stated that they have done the same build and the pistons were below the deck.

This just shows that not all blocks are created equal and a taller than ave. deck height of a block is not exactly what you'll find or something one can say is true. They (The books) list the deck height at 9.60 while others will list it at 9.58. Same goes for crank throws, journal sizes, valve diamentions. The list goes on and on.

Taller than most blocks...not likely.

Anyway, I'd stay at a max ratio of 9.5-1 for a street vehicle and pump gas. More so likely you'll have a small cam (AKA streetable with modest additions or upgrades to the car) and you will have a need for a long lasting pump gas freindly machine. Pushing the octane limits with the ratio is a crappy game to roll dice on and could result in a less powerful engine. Of course this is build dependent. And alot to do with cam converter and gearing. However, if you end up going to far, you'll need to reduce timing and this will result in a loss of HP.

That gives me promise then, hopeing i can pull off some low 13s with my 71 dart with a 360 magnum, bolt-ons, 3.73 gears, & a 2500 stall.

Yes, it is doable, choose parts wisely grasshopper. :-D
However, I don't think you'll make mid to low 12's on a low comp mill unless you do something radical. A mad mass weight loss program would just be the beginning.

 

[moper]

My truck has a stock '87 360 engine in it. I added the 318/360 Performer, a 600 cfm Performer carb, MSD, cheapie headers, and the Comp Cams XE262 w/ 901-16 springs. Very basic. Never too the engine out of the truck. It's a low compression (in the 7s realistically I'm sure) engien but it runs well. Even in whipped form...lol. I have it in a 6800lbs truck. So I'd imagine in a 3400lbs car it would be a riot.

 

[mod5v]

I have the SP H405 in my duster and they are a nice piston and less $. The 405 has a 1.637 comp hieght thats .05 taller than stock and if you want more the 116"s have a CH of 1.67 which should put them at .01-.015 down the hole. My 78 block I messured the stock pistons at just over .100" in the hole. Stock pistons have a CH of 1.587". And a dished top.

 

[360moparjunkie]

Info supplied so far is superb.

Thanks!

Out of concern for cost (just left the balance / machine shop w/ prices) I am going to go with the crappy pistons & 8.4:1.

I can afford to balance, sleeve one hole, purchase a cam / springs to go with my new lifters.

The only way I'll change pistons now is if the machine shop gives me the "KABOSH" ottytra: on my somewhat worn cyl. walls.....then if thats the case I'll have to bore and purchase new pistons.

Trying to keep costs down to a min.

Thanks All!