Guest Anonymous Posted October 20, 2002 Share Posted October 20, 2002 i was just wondering what would the main difference be between a 3.2 litre V8 and say 4.0 litre V8? Quote Link to comment Share on other sites More sharing options...
jeromio Posted October 20, 2002 Share Posted October 20, 2002 That'd be 0.8 liters. Quote Link to comment Share on other sites More sharing options...
Guest greimann Posted October 20, 2002 Share Posted October 20, 2002 If both motors were built to make about 1 hp per cubic inch (61.4 hp per liter) then the smaller motor would be less powerful by 49.12 H.P. Quote Link to comment Share on other sites More sharing options...
RPMS Posted October 20, 2002 Share Posted October 20, 2002 Heya, bub. My thoughts, for what they're worth, are thus. All other things being equal, I'd think that a smaller V8 would spool up faster than a bigger one, and would produce less HP and torque. Comparing a small V8 with an inline 6 of similar displacement, I think the 8 would produce more torque down low than the 6, but would have a lower redline, and would probably generate less horsepower. My observations stem from back when BMW put a small (3.0 liter) V8 in the e34 530i. My 535i (inline 6) would just about run away from one on a racetrack, but the V8 had the advantage off the line. A 528 didn't seem to have the low end grunt of the 530, although the horsepower ratings were in the same ballpark. All things NOT being equal, I think a small displacement 8 that was built to rev to 6-7k rpm would be a heck of a fun engine in the Z. Keep everything lightweight and not change the character of the car too much. That's MY opinion. Your mileage may vary. Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 20, 2002 Share Posted October 20, 2002 Depends on the stroke/bore ratio of each motor as to which would spool up quicker. For example, a long stroke smaller motor with a smaller bore would not rev as quick as a short stroke big bore motor. All things being equal, theres no reason to give up .8 litre if you don't have to, a turbo may be a equalizer, but .8 litre + turbo is even better, why leave that on the table unless its monetarily cheaper to use the smaller motor. IMHO, run the biggest displacement you can afford, anything less is, well just less. Regards, Lone Quote Link to comment Share on other sites More sharing options...
David K Posted October 20, 2002 Share Posted October 20, 2002 id have to disagree Lone. it may be smaller, and less powerful, n/a wise. If you took the smaller v8, since it is smaller in size, you do have signifigant room in the engine bay to twin turbo that puppy with ease. Quote Link to comment Share on other sites More sharing options...
yo2001 Posted October 20, 2002 Share Posted October 20, 2002 I saw a guy with V8 283? (it was chevy) in a 280zx. He ran 15.8 sec So my guess is if you are not doing 350ci or more V8, (except 327's) not going to be too happy with the result. Quote Link to comment Share on other sites More sharing options...
David K Posted October 21, 2002 Share Posted October 21, 2002 small displacement twin turbo....yummmm Quote Link to comment Share on other sites More sharing options...
DavyZ Posted October 21, 2002 Share Posted October 21, 2002 This thread just begs the question: "Does a smaller, 'lighter' V8 spool faster (pull faster) under load?" And the royal answer to that when it comes to accelleration from the drag racing point of view. I'm pretty sure I'm correct since the faster drag racing cars usually bigger motors. So I would think that a 350 SBC would better than a 283, and a 406 SBC would be better than a 350, all things being equal. Spank me if I'm way off here, but I don't think so. Davy Quote Link to comment Share on other sites More sharing options...
David K Posted October 21, 2002 Share Posted October 21, 2002 why did matt leave an empty post? Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 21, 2002 Share Posted October 21, 2002 Glitch.. same thing happened to me a few days ago. Quote Link to comment Share on other sites More sharing options...
David K Posted October 21, 2002 Share Posted October 21, 2002 man sometimes that happens to me on other sites. i spend an hour typing a reply and then i click submit and it goes to a cannot be found type page. i click back to try again, but my post is gone. makes me want to hit my monitor with my forehead and keep banging. Quote Link to comment Share on other sites More sharing options...
CruxGNZ Posted October 21, 2002 Share Posted October 21, 2002 No glitch... I decided to retract my post. It wasn't very "me" to say the least. !M! Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 21, 2002 Share Posted October 21, 2002 i was thinking about a maserati 3.2litre biturbo engine from 3200 GT. i've seen a tuned version of the engine having round about 500bhp and 600Nm. stock runs 370bhp and 500Nm. Maserati have revently released a new V8 N/A which runs couple of digits lower then the one above. So i was thinking about putting the twin-turbo V8 into my 240Z. Although they aint cheap at all! )) Quote Link to comment Share on other sites More sharing options...
Guest Anonymous Posted October 21, 2002 Share Posted October 21, 2002 the new N/A V8 has got a higher redline at 7500rpm! but the compresion ratio is definetly out of turbo freindly range at 11.1:1. the twin-turbo setup on one of those would cost a fortune. so, what do you guys think about a 3.2 twin-turbo V8? Quote Link to comment Share on other sites More sharing options...
RPMS Posted October 21, 2002 Share Posted October 21, 2002 Originally posted by DavyZ:This thread just begs the question: "Does a smaller, 'lighter' V8 spool faster (pull faster) under load?" And the royal answer to that when it comes to accelleration from the drag racing point of view. I'm pretty sure I'm correct since the faster drag racing cars usually bigger motors. That's not necessarily true of engines in general, because you're comparing apples to oranges. A 1000 hp dragster has a bit more torque to get the crankshaft moving than does a 300 hp street machine! All things being equal (the key phrase) a lighter (smaller) reciprocating assembly will want to spool up faster than a heavier one. Like Lone says though, a lot depends on geometry. That's why the massively oversquare engines in F1 cars can spin up to 12,000 rpm in the blink of an eye. It's easier to move the piston 2 inches than it is to move it 4 inches in the same span of time. Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 21, 2002 Share Posted October 21, 2002 Scott, I agree on the over square thing. The area of the piston multilpies the instantaneous cylinder pressure. And going from a 350 to a 400 means 6.3% more area. Nothing to sneeze at. Add to that better valve unshrouding and you see more gains in the pressure. Multiply those gains together (Force = pressure * area) and you get a bigger push on the connecting rod. The above has to do with instantaneous and average con rod downward force. Rod/stroke ratio will play here too. Grumpyvette has explained this here before. Rod length affects the angle at which the rod's downward force is imparted to the crank pin, and it's relation to the pressure history above the piston. The actual reciprocating and rotating mass is not insignificant to how fast and engine will rev under load, but it can pale in comparison to the force imparted by combustion. Going to a short stroke to gain some kind of rev-ability is noble for F1, but in drag racing with a low rpm stall converter and certainly on the street, it can be a losing proposition. Yes, I'm planning a 406 at the moment. For many of the reasons stated above. Maybe I'm all wet. Quote Link to comment Share on other sites More sharing options...
JohnG Posted October 21, 2002 Share Posted October 21, 2002 Pete, I'd encourage you to stick with your 406 idea -- you'll love the torque! Don't use the short (stock 400) rods though -- go with the longer 5.7 or even 6.0 rods with compensated forged aluminum pistons. When are you coming up to Butler? --JohnG Quote Link to comment Share on other sites More sharing options...
pparaska Posted October 21, 2002 Share Posted October 21, 2002 Bulter - Summer of 2003 I'm doing a 6" Eagle SIR I beam rod, 11:1 with Hyper pistons. I've been a forged piston fan for years, but I've been swayed that I'll be fine with Hyper. I'm going budge here. I have a quote from a good builder friend in Arkansas who will start with HIS 400 std 2 bolt block, add a SCAT 9000 crank, the Eagle rods, King bearings, cast iron rings, and KB pistons. $1300 BALANCED, blueprinted with file-fit rings. Most likely that will be internally balanced, for that price, if three slugs of mallory metal are enough, or I pay for extra slugs. I expect shipping to eat up a few hundred bucks. The cam will be first the same Comp Cams 12-677-4 I have in the 327 with a 63 deg ABDC intake closing. With 11:1, the cranking pressure is still 180psi or less, a dynamic compression ratio of 8.3 or so. That should be fine for pump gas. I am going with .040" quench height to help with detonation resistance. Ultimately, I'll probably go with a Crane 118451 mechanical roller cam with similar opening and closing points, (crane 118541) but more lift and area under the curve. If driving with the Comp 12-677-4 in the 406 is really mild at low rpm, I'll do the 118551 roller instead. Someday, I'll move away from my ported 461 heads to a Canfield 200cc mostlikely. Cubes with compression and a slightly agressive cam. Grumpy has convinced me this is the way to go! I try to be a good student . Quote Link to comment Share on other sites More sharing options...
SBC_400 Posted October 21, 2002 Share Posted October 21, 2002 personaly I am big fan of the smaller displacement v8, reguardless of the fact that I have a 400 in my datsun. But if you do a small dispalcement v8 , you have to do it right, dont mess around with 265, or any other standard small block. My obsession is with the olds and buick all aluminum block 215 from the early 60's. This engine was the topic of heavy research in the 70's and 80's an did make it into the f1 program with decent results. The rights of this engine has been picked up by Rover as of late. they have built it up to a 4.6 L in recent years with a very good fuel injection system. there is an engine builder in almont MI, who build these engines only, I forget the name of the company at the moment, But i will get the website and post it for thoes who are interested, he ran a vette in the 60's with a 215, and I believe he was running somthing in the 8's on the quarter mile. these engines can be pushed extremely far too, as they are mainly built for road racing. A standard 215 block can be bored and stroked to nearly 5.0L, and run with a compression ratio of 13.5 to one with relative ease, the company builds extra large valve body heads, and an intake to run quad down draft webber 45dcoe and will run around a road course at an average of 6k rpm's You can run 300-500 hp in an engine that is substatialy lighter than an iron block 350. and as we all know horse power is just a number to brag about, but it is the hp-weight ratio that makes cars fast. the main reason I did not go this way is that i am poor and it coast about double what it does the build a standard small block. just my thoughts. Quote Link to comment Share on other sites More sharing options...
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