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| V8 vs V6 (Page 9/9) |
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ericjon262
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JUN 03, 09:26 PM
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there's so many more variables to a car than the engine. Saying a 302 will be out of room to run by the time it comes into power is foolish, gearing, tires, vehicle weight, suspension, and parameters well beyond the vehicle will determine how the vehicle responds under track conditions, and none of these factors are relevant to the discussion of the performance of the engine itself, they are specific to the vehicle being moved, and the place it's being moved through.
if we really want to get down to what makes power, it's airflow and fuel. however you make it happen, it takes some amount of air and fuel to make a given amount of power, displacement and RPM determine the maximum possible airflow, and friction, valvetrain, and ports(extending to the top of an air horn to the tip of the exhaust) determine how close an engine can get to that maximum, within the confines of the materials used for the rotating and reciprocating components.
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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
cognita semper
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La fiera
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JUN 05, 09:39 PM
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| quote | Originally posted by ericjon262:
Saying a 302 will be out of room to run by the time it comes into power is foolish,
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Red= GM 305 TPI (3.736 x 3.48) all stock
Blue= Ford 302 EFI (4.0 x 3.0) all stock
As you can see the longer stroke 5.0L GM has more power from low to mid, and the short stroke Ford 5.0L has a little advantage on top.
That means they have different airflow requirements in NA configuration.
If these 2 engines are boosted then the NA airflow requirement does not matter because by altering the atmospheric pressure with a turbo/supercharger all is left is to match that airflow with fuel and the power of these 2 different 5.0L will be pretty equal.
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ericjon262
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JUN 06, 01:26 PM
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those two engines have different cams, different heads, different intakes, different exhausts, ect, so the dyno doesn't compare the difference of the bore and stroke combinations. also by the nature of those differences, they will have different area under the curve, it's also worth mentioning that the 305 TPI went into a third generation camaro/firebird, and the EFI 302 went into the fox mustang, the fox mustang covered the 1/4 mile faster, which according to the dyno you posted isn't likely to happen due to the massive area under the curve of the 305, and even the peak numbers for the 305 are higher...
the engine's airflow requirement is not determined by the induction, it's determined by the displacement and RPM the engine turns. the heads, cam, intake, and exhaust determines how much of that demand is met.
boost is irrelevant, as performance under boost is a reflection of performance N/A. add boost to two engines, the engine that performed better N/A will perform better under boost, assuming the same boost mechanism is employed on both engines, and the same amount of airmass is added.
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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
cognita semper
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La fiera
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JUN 08, 09:57 PM
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| quote | Originally posted by ericjon262:
those two engines have different cams, different heads, different intakes, different exhausts, ect, so the dyno doesn't compare the difference of the bore and stroke combinations. also by the nature of those differences, they will have different area under the curve, it's also worth mentioning that the 305 TPI went into a third generation camaro/firebird, and the EFI 302 went into the fox mustang, the fox mustang covered the 1/4 mile faster, which according to the dyno you posted isn't likely to happen due to the massive area under the curve of the 305, and even the peak numbers for the 305 are higher...
the engine's airflow requirement is not determined by the induction, it's determined by the displacement and RPM the engine turns. the heads, cam, intake, and exhaust determines how much of that demand is met.
boost is irrelevant, as performance under boost is a reflection of performance N/A. add boost to two engines, the engine that performed better N/A will perform better under boost, assuming the same boost mechanism is employed on both engines, and the same amount of airmass is added.
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1500cc producing 1300hp boosted . So since boost is irrelevant and airflow requirement is determined by displacement and RPM, How much boost and RPM that little 1.5L must have to reach 1300HP, or better said how much displacement, altered atmospheres and RPMs should it have in your book? This 1.5L was 1985-86 Renault F1 qualifying engines.
Of course the 305 and 302 have different intakes, heads and other things. They are from different manufactures. They have to compensate were their system is lacking and that what makes them unique in their own terms. But for individuals that can't make power NA there's always the turbo way.
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Trinten
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JUN 09, 12:30 AM
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Wow, I don't think I saw the OP post anywhere on the second page. lol
You all ran him off his own thread. 
To throw a grenade into the conversation, tying back to the first page, as I am using a transmission that was found in Cadillac's (and other cars), I've done a lot of reading on what can go wrong with them. As others stated, it doesn't take much for the transmission to go into 'limp home' mode. One guy (Caddy, not a swap), had an issue where his transmission would not move to first when put into drive, always started in second. Turned out to be some sensor issue.
I had a stick, the F23. Did I have fun with it? ... I guess.
Was I good at driving it? Hell no.
Was it aggravating and stressful in stop-and-go, inner-city, or have-to-stop-on-an-incline driving? Oh most definitely. Most of if that was because I'm not good at driving a manual, I'm sure.
If you are not skilled with a manual, consider solving the auto-transmission issue. If the transmission came out of a Caddy, check out their forums, search by the year/make that transmission was found in (sometimes you get better results than searching by designation code).
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BillS
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JUN 09, 12:21 PM
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Another engine swap possibility occurs to me. The engines that I like the sound of the most are straight 6 and V12s. Not many have installed a straight 6 transversely, but Volvo did, in their T series sedans. It would take some creativity, but splicing that engine/gearbox into a Fiero would go very well (up to 600 bhp turboed) and look great. (the pic is of an in line installation in an older Volva sedan)
 [This message has been edited by BillS (edited 06-09-2022).]
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ericjon262
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JUN 11, 09:56 PM
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| quote | Originally posted by La fiera:
1500cc producing 1300hp boosted . So since boost is irrelevant and airflow requirement is determined by displacement and RPM, How much boost and RPM that little 1.5L must have to reach 1300HP, or better said how much displacement, altered atmospheres and RPMs should it have in your book? This 1.5L was 1985-86 Renault F1 qualifying engines.
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yes, we all understand that increasing the charge density increases the output of the engine, the point of my remark was boost isn't relevant to the discussion of big bore/short stroke Vs small bore/big stroke.
| quote | Originally posted by La fiera:
Of course the 305 and 302 have different intakes, heads and other things. They are from different manufactures. They have to compensate were their system is lacking and that what makes them unique in their own terms. But for individuals that can't make power NA there's always the turbo way. |
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my point was that there is no isolated variable between the two engines, so their comparison is more or less useless for the discussion at hand, the only thing they have in common is the approximate 5.0 liter displacement. if one were to get a Gen II LT1, and L99, swap the cranks, and install the same cam in both engines, that would make for a more accurate representation of the effect of bore/stroke in the same displacement.
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"I am not what you so glibly call to be a civilized man. I have broken with society for reasons which I alone am able to appreciate. I am therefore not subject to it's stupid laws, and I ask you to never allude to them in my presence again."
cognita semper
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sanderson231
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JUN 13, 01:38 PM
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Back to the OPs question if it is still an issue. It sounds like the 4.9 is in "limp home " mode. I had a 4.9 PCM reprogrammed to remove the Pass Key and change the fan setting. Something happened in the process and the car run in limp home. Down on power and as I recall the transmission started in second gear. Sinister Performance burned another chip and car runs normally.
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sanderson231
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JUN 13, 01:39 PM
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Back to the OPs question if it is still an issue. It sounds like the 4.9 is in "limp home " mode. I had a 4.9 PCM reprogrammed to remove the Pass Key and change the fan setting. Something happened in the process and the car run in limp home. Down on power and as I recall the transmission started in second gear. Sinister Performance burned another chip and car runs normally.
Sorry about the double post[This message has been edited by sanderson231 (edited 06-13-2022).]
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