383 Vs 355
01-20-2008, 10:09 PM
#43
I have to ask just becouse of the nature of this tread if you had to choose all over again if you would go 383 or 355 or something different? also what did it run you to do the 355? what is your compression ? also I no longer have a trans am i now own a z28 and the pic is not my car btw its a nother members but mine looked exactly the same but had white racint stripes on it it was bad
01-20-2008, 10:17 PM
#44
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Just know that as soon as you move a car away from factory, the gas mileage WILL BE AFFECTED, most of the time in a bad way. If you're worried abot gas mileage in anyway do not mod your car. Now, CAI's coils and plug wires can improve gas mileage and performance so those mods are not neccisarily a bad idea. My 96 Z was a forged 355 with a hotcam and LT's and it got terrible gas mileage, why? Because i messed with the motor, just a warning that you might want to think about.
01-20-2008, 10:21 PM
#45
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I have to ask just becouse of the nature of this tread if you had to choose all over again if you would go 383 or 355 or something different? also what did it run you to do the 355? what is your compression ? also I no longer have a trans am i now own a z28 and the pic is not my car btw its a nother members but mine looked exactly the same but had white racint stripes on it it was bad
01-20-2008, 10:43 PM
#46
i still get a kick outta you guys fretting over gas mileage in these fuel injected cars. guess i'm still stuck in carburator world. any way, a larger engine will always be more streetable then a smaller engine given the horsepower is the same, since the larger will make the horsepower at lower rpm. not to mention the torque (the fun part) will be lower in the rpm range as well. the trade off in mileage between a 355, 358, 370, 383, 388 will be almost negligable given a proper tune. not to mention, YOU ARE FUEL INJECTED! i still giggle at my mileage in my '97 M6 T/A compared to my 462cubed, 3200stalled '65 Pontiac LeMans. sorry, i guess gas mileage is realitive.
01-20-2008, 10:58 PM
#47
it also depends on what youre aiming for.. this car is my daily, and im rather content with my decision. it all really depends.. sure, 383 is more cubes, but is it really necessary? if i could go back and do it all over again, id probably do the same thing i did now, but do heads/cam as well.. being that im a broke college student, im doing the best i can. its all up to your intentions and the abuse your wallet can take
01-20-2008, 11:43 PM
#48
it also depends on what youre aiming for.. this car is my daily, and im rather content with my decision. it all really depends.. sure, 383 is more cubes, but is it really necessary? if i could go back and do it all over again, id probably do the same thing i did now, but do heads/cam as well.. being that im a broke college student, im doing the best i can. its all up to your intentions and the abuse your wallet can take
01-21-2008, 12:44 AM
#49
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Id go with the 383 mainly because of the Torque. But thats me. But for your case a simple rebuild to stock specs would be an all around good engine. These LT1s obtain pretty good #s stock.
01-21-2008, 04:41 AM
#50
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Very Well Said Here is my 2 cents, FLAME SUIT now on.
Many people who have V8 powered daily drivers are very concerned with MPG, I just paid 3.49 a gallon (premium) to fill up my Z28. Many guys however are not obsessed enough to go V6 or Honda Civic, they just want to build a new engine with some compromise in mind. What is wrong with that?
With gas expected to approach $4.00 a gallon, many of the folks who say screw gas mileage are going to have a change of heart, and some will continue to say screw the gas mileage.
You need to ask yourself if MPG is important and build around that. You need to have a realistic goal in mind for the power you are wanting. You need to have an idea of what your budget is.
Bottom line a 383 will have worse gas mileage compared to the 355 due to more displacement, what the exact difference is hard to calculate. The 383 will make more torque across the curve compared to the 355. The ironic thing is the two motors normally make about the same HP but the 355 has to rev higher to accomplish this.
IMHO the thing that sends gas mileage straight to hell is the size and aggressiveness of the camshaft and rear ring & pinion ratio. Also driving style comes into play, who would of thunk that.
The 355 is going to be cheaper to do cause you can reuse your crank and port your stock heads. Many people believe that to build a good 383 you have to use aftermarket heads like AFR or LT4 to get get flow. Heavily ported stock LT1 heads are on the thin line for being "big" enough to feed a hungry 383. Keep this in mind, these heads ain't cheap.
I do care to some degree about MPG purely from an economical point of view, thats why I chose the setup shown in my signiture. Guess I am not "hardcore man enough" to say screw the MPG's. There has been a very noticable impact to the mileage I get with my new engine compared to the stock LT1 and stock gears, I am glad its not any worse.
Many people who have V8 powered daily drivers are very concerned with MPG, I just paid 3.49 a gallon (premium) to fill up my Z28. Many guys however are not obsessed enough to go V6 or Honda Civic, they just want to build a new engine with some compromise in mind. What is wrong with that?
With gas expected to approach $4.00 a gallon, many of the folks who say screw gas mileage are going to have a change of heart, and some will continue to say screw the gas mileage.
You need to ask yourself if MPG is important and build around that. You need to have a realistic goal in mind for the power you are wanting. You need to have an idea of what your budget is.
Bottom line a 383 will have worse gas mileage compared to the 355 due to more displacement, what the exact difference is hard to calculate. The 383 will make more torque across the curve compared to the 355. The ironic thing is the two motors normally make about the same HP but the 355 has to rev higher to accomplish this.
IMHO the thing that sends gas mileage straight to hell is the size and aggressiveness of the camshaft and rear ring & pinion ratio. Also driving style comes into play, who would of thunk that.
The 355 is going to be cheaper to do cause you can reuse your crank and port your stock heads. Many people believe that to build a good 383 you have to use aftermarket heads like AFR or LT4 to get get flow. Heavily ported stock LT1 heads are on the thin line for being "big" enough to feed a hungry 383. Keep this in mind, these heads ain't cheap.
I do care to some degree about MPG purely from an economical point of view, thats why I chose the setup shown in my signiture. Guess I am not "hardcore man enough" to say screw the MPG's. There has been a very noticable impact to the mileage I get with my new engine compared to the stock LT1 and stock gears, I am glad its not any worse.
I have been wrestling with 355 or 383 for a while now.
This post got straight to the point and has helped me decide on my build (when I finally kill this motor).
I pay the equivalent of $11.00 a gallon, so factoring the above for me it's got to be a 355 for my DD & weekend warrior.
As I've read in other posts, decide where you want to go with your car first and plan it out - great advice...
Rob
01-21-2008, 07:09 AM
#51
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The car has recently put down 337.. you can believe what you want. get that **** out of your ***
01-21-2008, 07:33 AM
#54
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For economy and long-term reliablility I'd pick the 355LT1.
A popular and economical 355 build is one where the stock crankshaft is re-used and you buy a nice set of 6" rods and the premium Mahle pistons.
New stock oil pump, new stock timing chain...rebuild it yourself of find a reliable shop.
I've seen 3 or 4 builds like that here in LS1Tech.com in member signatures. Thumbs up to that idea.
Karl Ellwein
A popular and economical 355 build is one where the stock crankshaft is re-used and you buy a nice set of 6" rods and the premium Mahle pistons.
New stock oil pump, new stock timing chain...rebuild it yourself of find a reliable shop.
I've seen 3 or 4 builds like that here in LS1Tech.com in member signatures. Thumbs up to that idea.
Karl Ellwein
01-21-2008, 08:12 AM
#55
There are several things I do not understand on this forum.
The two that bother me most are these:
A.) Not EVERY car is built strictly for the dragstrip.
B.) Bigger is not always better!
I do agree that homework has to be done. I would search for days and read everyting you can get your hands on. I would define the goals you want to set for your car and then I would find someone on this or any other board that has a setup similar to what you want and have then give you a ride! Trust me when I say this, there is nothing like experiencing the feel for yourself. We can all talk the benchtop racing all we want, but in a street motor you want reliability, driveability and yes decent mileage!
In your goals for the car you should include if and how often it will see a track. What rpm range it will be driven the most in. Traffic conditions such as highway cruising to city driving and budget.
I have found in my experiences that no matter what the application the best insurance you can do is to use a complete forged assembly. The cost is not that much more, but the benfits are. You can throw whatever modifications you want after you base out the bottom with no worries.
Some other noteable interests should be 5.7 or 6" rod, piston compression heigth, quench and compresion ratio. Most everyone will say 6" rod, but utilizing a 6" rod can get you into trouble if the other factors are not within spec. Regardless of the name brand these are the things you should most be concerened with for an efficient and powerful engine, and yes that can be used in the same sentence!
The two that bother me most are these:
A.) Not EVERY car is built strictly for the dragstrip.
B.) Bigger is not always better!
I do agree that homework has to be done. I would search for days and read everyting you can get your hands on. I would define the goals you want to set for your car and then I would find someone on this or any other board that has a setup similar to what you want and have then give you a ride! Trust me when I say this, there is nothing like experiencing the feel for yourself. We can all talk the benchtop racing all we want, but in a street motor you want reliability, driveability and yes decent mileage!
In your goals for the car you should include if and how often it will see a track. What rpm range it will be driven the most in. Traffic conditions such as highway cruising to city driving and budget.
I have found in my experiences that no matter what the application the best insurance you can do is to use a complete forged assembly. The cost is not that much more, but the benfits are. You can throw whatever modifications you want after you base out the bottom with no worries.
Some other noteable interests should be 5.7 or 6" rod, piston compression heigth, quench and compresion ratio. Most everyone will say 6" rod, but utilizing a 6" rod can get you into trouble if the other factors are not within spec. Regardless of the name brand these are the things you should most be concerened with for an efficient and powerful engine, and yes that can be used in the same sentence!
01-21-2008, 08:25 AM
#56
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Build your car however you want - spend 500 dollars on an 88-91 EF civic hatch or something of those natures with a single cam D series motor in it that doesn't go over 80 mph so you dont go back into the future. save gas - makes insurance cheaper they pretty much dont fall apart if you just service and dont mess with them (has honda friends). Build Camaro be happy with cheaper insurance - screw MPG and enjoy modding worrie free.
That's just my 2. cents.
That's just my 2. cents.
01-21-2008, 08:43 AM
#58
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the cc306 isn't a bad cam from what i've seen I know you had bad luck with it in your 383 build but dont let it sturr you away from it still . . . . you can always get a custom grind cam for about the same price as any of these mass marketed cams.
01-21-2008, 09:49 AM
#59
As suggested, do a lot of research, I see dozens of motors with after market Rods when stock rods with ARP bolts would of been fine. Same with cranks, Today's nodular cranks are stronger than the old cast cranks. Even pistons, The LS7 has Hyper pistons and look at the horsepower it produces. Bottom line if you just want a fairly healthy motor, not radical, no power adders then yes even the stock pistons will suffice. People on a budget can still have a fun vehicle, spend your money wisely on porting the heads, exhaust, drive train and suspension work. One of my customers had a BONE STOCK LT1 sans Headders, He had a lot of suspension work, a mild stall and ran 13.00 Flat, He threw in a 100 shot and ran 12.02 on a STOCK motor, He ran this until he was ready to build a better motor. Never had any problems..
01-21-2008, 11:59 AM
#60
