Iron block 427 6.0
02-16-2010, 05:19 PM
#21
From similar scenarios I've seen in the streetcar stuff, where someone is trying to run too much compression for pump gas, it's usually advantageous to run a lower compression ratio, rather than to band aid the tune (or cam timing) to avoid detonation/preignition. It's not uncommon to see an engine make more power with 11:1 than it did with 12:1 on pump fuel. Adding fuel to cool the charge and pulling timing to delay the peak cylinder pressure is wasteful, and generally results in lower IMEP, BSFC's, and higher EGT/coolant temps. The difference between an iron block and an aluminum block in a streetcar probably is negligable though.
However, the racecar scene may be different. To expand further into "the big picture", the iron block's inability to dissipate heat as well as an aluminum block, puts more demand on the cooling system. I think it was either the RO7 or FR9 NASCAR engine that was so much more efficient at cooling the engine than it's predecessor, that the team found a large aerodynamic advantage sealing up the front of the car since the radiator was smaller and required less frontal area in the bumper.
Basically, what I'm trying to say is that too much heat can be a bad thing.
But so can too little.
However, the racecar scene may be different. To expand further into "the big picture", the iron block's inability to dissipate heat as well as an aluminum block, puts more demand on the cooling system. I think it was either the RO7 or FR9 NASCAR engine that was so much more efficient at cooling the engine than it's predecessor, that the team found a large aerodynamic advantage sealing up the front of the car since the radiator was smaller and required less frontal area in the bumper.
Basically, what I'm trying to say is that too much heat can be a bad thing.
But so can too little.
my experience with these cars, your always going to be tuning around something wether it be detonation or the never ending fuel trims on a CLSD tune or something as little as getting the O2's to last with LT's. lol
02-16-2010, 06:51 PM
#23
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Man wow. I just saw some companies selling these 427 made out of iron blocks and havent heard of that at all. Heck my just take my 370 re ring it and but more spray to it.
02-16-2010, 08:50 PM
#28
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They will run at the temp. the thermostat allows them to run. However the (hold on this is an important word here..) *RATE* at which the engine dissipates the heat will change. If it didn't you wouldn't need a 'stat, you could calculate flow and thermal exchange and just run a specific sized restrictor.
Its not MY theory bud. Output is dependent upon thermal efficiency. You live where its cold, don't you ever see diesel trucks cover their radiators in the winter? You had better tell them they don't know what they are doing!!
Its not MY theory bud. Output is dependent upon thermal efficiency. You live where its cold, don't you ever see diesel trucks cover their radiators in the winter? You had better tell them they don't know what they are doing!!
all the new trucks, do not need them. they get up to operating temp no prob
and comparing it to diesel truck is really not fair.
diesels do not use spark to ignite fuel, they do it with compression and by warming up the intake charge in form of bypassing the interccoler, glow plugs, and some warm up fuel.
yes heat/ fire makes power in the motor but after the fuel is ignited and burned and the piston is at bottom dead center you do not need the heat to stay there, the faster you can get the heat out of there the better. the reason for this is when the engine is cooler the fuel will be less prone to pre ignite, so i really do not see the advantage of keeping the extra heat in the block.
02-16-2010, 09:10 PM
#29
actually, the only guys that do that are the ones with the 80's mack trucks
all the new trucks, do not need them. they get up to operating temp no prob
and comparing it to diesel truck is really not fair.
diesels do not use spark to ignite fuel, they do it with compression and by warming up the intake charge in form of bypassing the interccoler, glow plugs, and some warm up fuel.
yes heat/ fire makes power in the motor but after the fuel is ignited and burned and the piston is at bottom dead center you do not need the heat to stay there, the faster you can get the heat out of there the better. the reason for this is when the engine is cooler the fuel will be less prone to pre ignite, so i really do not see the advantage of keeping the extra heat in the block.
all the new trucks, do not need them. they get up to operating temp no prob
and comparing it to diesel truck is really not fair.
diesels do not use spark to ignite fuel, they do it with compression and by warming up the intake charge in form of bypassing the interccoler, glow plugs, and some warm up fuel.
yes heat/ fire makes power in the motor but after the fuel is ignited and burned and the piston is at bottom dead center you do not need the heat to stay there, the faster you can get the heat out of there the better. the reason for this is when the engine is cooler the fuel will be less prone to pre ignite, so i really do not see the advantage of keeping the extra heat in the block.
new diesel trucks (rams, 2500/3500 chevys, F-250's etc...) take FOREVER to get to operating temp. me and my buddy could cruise around town for an hour in his 2500 Durajunk '07 and it would barely move off 160, then when we hit 40mph for any lengthy (read 1 minute or more) amount of time it would drop. same with my other friends 24v cummins...the blocks and heads are so thick for durability and insane boost that it takes forever for the heat to leave the chamber/cylinder and enter the coolant. take a look around next time your out on a cold *** day and tell me how many newer diesels you see with bras over their radiator, or incase of the real rednecks or broke guys, a piece of cardboard.
and, to your last statement....diesels need cylinder heat and pressure to ignite the charge. thats why they have block heaters and if you forget to plug it in, it wont start in the morning because the cylinders themselves are so cold, even compression wont fire it.
some of the newer trucks like the Dirtymax and Powerchoke have grid heaters on the fuel rail, so they dont need block heaters.
02-16-2010, 10:32 PM
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i have to disagree...
new diesel trucks (rams, 2500/3500 chevys, F-250's etc...) take FOREVER to get to operating temp. me and my buddy could cruise around town for an hour in his 2500 Durajunk '07 and it would barely move off 160, then when we hit 40mph for any lengthy (read 1 minute or more) amount of time it would drop. same with my other friends 24v cummins...the blocks and heads are so thick for durability and insane boost that it takes forever for the heat to leave the chamber/cylinder and enter the coolant. take a look around next time your out on a cold *** day and tell me how many newer diesels you see with bras over their radiator, or incase of the real rednecks or broke guys, a piece of cardboard.
and, to your last statement....diesels need cylinder heat and pressure to ignite the charge. thats why they have block heaters and if you forget to plug it in, it wont start in the morning because the cylinders themselves are so cold, even compression wont fire it.
some of the newer trucks like the Dirtymax and Powerchoke have grid heaters on the fuel rail, so they dont need block heaters.
new diesel trucks (rams, 2500/3500 chevys, F-250's etc...) take FOREVER to get to operating temp. me and my buddy could cruise around town for an hour in his 2500 Durajunk '07 and it would barely move off 160, then when we hit 40mph for any lengthy (read 1 minute or more) amount of time it would drop. same with my other friends 24v cummins...the blocks and heads are so thick for durability and insane boost that it takes forever for the heat to leave the chamber/cylinder and enter the coolant. take a look around next time your out on a cold *** day and tell me how many newer diesels you see with bras over their radiator, or incase of the real rednecks or broke guys, a piece of cardboard.
and, to your last statement....diesels need cylinder heat and pressure to ignite the charge. thats why they have block heaters and if you forget to plug it in, it wont start in the morning because the cylinders themselves are so cold, even compression wont fire it.
some of the newer trucks like the Dirtymax and Powerchoke have grid heaters on the fuel rail, so they dont need block heaters.
we did not have a single customer this year with a cardboard in front of the rad.
i think we are getting a little of track here
my argument is why do you need the block to retain the heat after the piston has reached bottom dead center, all of the energy is absorbed at that point by the stroke, so please give me an argument against that so i can go to sleep
02-17-2010, 12:01 AM
#34
if you have seen an LS7 piston, it has a short skirt compared to any other LS piston. i imagine for this reason.
i think a mod needs to clean up and move this thread to the advanced section, i bet we get more responses there.
cause, if a 6.150 rod was used, that would give us another .025 of cylinder wall for the rings to travel before they started rocking....
however, that poses another problem...
the LS engines stock have a -.006 to -.008 deck height. if you use a .025 longer rod, your going to have -.031 to -.033 deck height, so you would have to use at least a .060 gasket to keep your .030 quench in the chamber....also, when you move the piston up in the bore, you have to watch that the top ring stays in the hole.
to me this is like trying to fit 10 lbs of **** into a 9.99 lb bag.
02-17-2010, 12:16 AM
#35
if a 6.150 rod will clear....
here is my thought
im going to take all my measurements for compression depth on the piston using a 6.125 rod, and leaving a +.020 deck clearence.
so....
deck height on my 6.0 block is 9.25
half the stroke is 2
rod length is 6.125
so to acheive a 0 deck i will need a 1.125 CD piston....
but i want to leave myself +.020 deck clearence (piston in the hole .020)
so...
ill order a 1.123 CD piston. now i have the piston in the hole .020
now, with a 4 inch crank, and a 6.125 rod, and a 1.123 piston i have the piston in the hole .020
heres where the longer rod comes into play...
4 inch crank, 6.150 rod and a 1.123 piston puts the piston .005 out of the hole and hopefully more clearence at the bottom of the cylinder.....
as you can see from my random thinking here, its late. someone read this and tell me if its feasable, or im just overthinking it.
here is my thought
im going to take all my measurements for compression depth on the piston using a 6.125 rod, and leaving a +.020 deck clearence.
so....
deck height on my 6.0 block is 9.25
half the stroke is 2
rod length is 6.125
so to acheive a 0 deck i will need a 1.125 CD piston....
but i want to leave myself +.020 deck clearence (piston in the hole .020)
so...
ill order a 1.123 CD piston. now i have the piston in the hole .020
now, with a 4 inch crank, and a 6.125 rod, and a 1.123 piston i have the piston in the hole .020
heres where the longer rod comes into play...
4 inch crank, 6.150 rod and a 1.123 piston puts the piston .005 out of the hole and hopefully more clearence at the bottom of the cylinder.....
as you can see from my random thinking here, its late. someone read this and tell me if its feasable, or im just overthinking it.
02-17-2010, 05:08 PM
#37
if a 6.150 rod will clear....
here is my thought
im going to take all my measurements for compression depth on the piston using a 6.125 rod, and leaving a +.020 deck clearence.
so....
deck height on my 6.0 block is 9.25
half the stroke is 2
rod length is 6.125
so to acheive a 0 deck i will need a 1.125 CD piston....
but i want to leave myself +.020 deck clearence (piston in the hole .020)
so...
ill order a 1.123 CD piston. now i have the piston in the hole .020
now, with a 4 inch crank, and a 6.125 rod, and a 1.123 piston i have the piston in the hole .020
heres where the longer rod comes into play...
4 inch crank, 6.150 rod and a 1.123 piston puts the piston .005 out of the hole and hopefully more clearence at the bottom of the cylinder.....
as you can see from my random thinking here, its late. someone read this and tell me if its feasable, or im just overthinking it.
here is my thought
im going to take all my measurements for compression depth on the piston using a 6.125 rod, and leaving a +.020 deck clearence.
so....
deck height on my 6.0 block is 9.25
half the stroke is 2
rod length is 6.125
so to acheive a 0 deck i will need a 1.125 CD piston....
but i want to leave myself +.020 deck clearence (piston in the hole .020)
so...
ill order a 1.123 CD piston. now i have the piston in the hole .020
now, with a 4 inch crank, and a 6.125 rod, and a 1.123 piston i have the piston in the hole .020
heres where the longer rod comes into play...
4 inch crank, 6.150 rod and a 1.123 piston puts the piston .005 out of the hole and hopefully more clearence at the bottom of the cylinder.....
as you can see from my random thinking here, its late. someone read this and tell me if its feasable, or im just overthinking it.
If I understand this concept clearly enough, this is basically what the piston designers do with these long stroke combinations. The pistons have a barrel profile, where the widest part is what supports the piston along the cylinder wall. In stock stroke combos, this isn't a big deal as there is plenty of room, but with these long strokes, they have to move this support area higher up the piston so they don't poke out of the bottom of the cylinder. When they do, they're forced to move up/shrink the ring pack, which isn't optimal for large hits of nitrous or boost, since the rings are closer to the heat and that can be bad juju.
