302-351, no noticed pwer difference?
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Elder User
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From: Marysville Wa
302-351, no noticed pwer difference?
I have now had time to go through my third tank of gas with my new (70,000mile junkyard engine) in my bronco. when i swapped in the motor i also put in the dual exhaust. to be honest, i am not atall happy with how it feels, i can not seem to notice a difference in power atall. My truck seems to lugging back alittle on starts also, could i possibly be having probs with the motor? I am so amazed that i cannot notice a difference. i whent from a 302 that had 170k to a 351 that had 70k. anybody else notice the same thing? i mean according to specs, i should be noticing more torque at a slitly lower RPM, not to mention the exhaust upgrade,
does this whole thing sound funny to anyone else?
oh BTW, the motor when i got it from the recking yard it had a 155 pund compression test on most and then like 145 on the others
does this whole thing sound funny to anyone else?
oh BTW, the motor when i got it from the recking yard it had a 155 pund compression test on most and then like 145 on the others
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302-351, no noticed pwer difference?
The exhaust should make some difference, a little. I would say what you are experienceing is accurate. You probably wouldn't notice the difference until you pull or haul something. I think that is the biggest misunderstanding of the 302/351 they are similar and people think if they get the 351 their hopes and dreams will be achiveved, not always the case. However the 351 will offer a better foundation for building the hp and tq that a truck needs not to say it couldn't be done with a 302. Your compression is very good, don't count the swap as a loss your old motor was getting up there so going with something with a little less potential wear was a good thing. As far as your little problems, did you swap the 351 computer in as well? Good luck
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From: Beachville, Ontario
302-351, no noticed pwer difference?
I noticed a difference right away in my 87 when I did the 302-351 swap. Is everything hooked up properly? Is your distributor set to the proper timing? Fuel pump & filter ok?
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From: Marysville Wa
302-351, no noticed pwer difference?
I dont know about the fuel pump, but i just changed the filter. i had a gauge hooked up to the system and it had said that it had 35 psi at idle without doing anything but hook the gauge up. I had a shop set the timing and clean the intake, nad fix the the Air bypass valve, so now its idling well with just a little rumble and shake along with what feels like hesitation.
I did have the trans rebuilt at the same time, do you think it could just be slipping or smthing like that? its an AOD. Im probably just being stupid i guess
I did have the trans rebuilt at the same time, do you think it could just be slipping or smthing like that? its an AOD. Im probably just being stupid i guess
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From: Marysville Wa
302-351, no noticed pwer difference?
and yes i swapped in a computer from a 89 truck, i used my 87 wire harness. does anybody think i might notice better power or gasmilage if i put a in a new computer? like a 90 or a 91?
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From: Beachville, Ontario
302-351, no noticed pwer difference?
Newer computer might not work as well because it might be set up for sequential injector firing whereas the 87 wiring harness is set up for batch injector firing. Its possible your trans is bad. Do you have a tach? Are your cap & rotor, wires, plugs etc ok? Do you have the proper firing order?
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From: Marysville Wa
302-351, no noticed pwer difference?
yeah if i got the newer computer i would also be swapping in the newer harness also. yes i have a tach, i guess relisticly i am just pissed that the motor could not spin the tires from a stop, i have 3.55 gears and 32/11.5" worn down BFG allterains. it would just push the front tires on drive pavment. I am posotive that i have the right firing order, and had just put new 9mm plugwires, MSD coil, new plugs, and rotor and cap have been replaced. It does not really feel like its slipping, it just feels like it takes awhile to get my car up and going.
but like i said, i am probably just being stupid, i had not driven my car for over 4months and have been driving a civic around untill i got my car running, so i am probably was just exspecting more.
i let my friend drive it and he thought it felt whay more powerful than his car (90 jeep with the 4.0 and 31"s)
but like i said, i am probably just being stupid, i had not driven my car for over 4months and have been driving a civic around untill i got my car running, so i am probably was just exspecting more.
i let my friend drive it and he thought it felt whay more powerful than his car (90 jeep with the 4.0 and 31"s)
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302-351, no noticed pwer difference?
My advice is to get it on a chassis dyno and find out for sure if your power is off. The seat of the pants approach isn't too scientific. The only problem then is finding out what your set up should be putting to the wheels.
Greg
Greg
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Elder User
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From: Marysville Wa
302-351, no noticed pwer difference?
ok i feel stupid now, I told my other friend that i could not get the tires to lightup and he proved me wrong. to make things worse it barly took him any effort of the truck to do so. but he did conferm one thing and thats that the throttle reasponse really sucks!! i mean like there is still somthing wrong with it. yeah i know i should pull the codes, but at this moment it is very late and my neighbores are getting pissy. any clue what could casue it to ackt like this? it also will not warm itself up. when its a cold start i have to have my foot on the gas to keep it running. anyclues?
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From: Still under the hood in O
302-351, no noticed pwer difference?
A bad MAP sensor caused the cold problem your having on mine after the truck sat a while. I also had to replace the O2.
The computer you put in, was it for a 351 or a 302? This will make a big difference.
The computer you put in, was it for a 351 or a 302? This will make a big difference.
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From: Marysville Wa
302-351, no noticed pwer difference?
hhmm. well alright, ill check into the MAP sensor. I know the 02 censor is fine because i replaced it with the motor. thanks for the help guys.
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Elder User
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From: Marysville Wa
302-351, no noticed pwer difference?
well to be honest it is suposed to be, I bought it off ebay and it was supposed to be for a 89 f150 with a 351. I was thinking about this erlier, but does anybody think it could be a bad throttle position scensor thats making the engine feel like it has a time delay?
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From: Tower MN, Houghton MI
302-351, no noticed pwer difference?
You have some seriously problems going on.
Went I went from a efi 302 to a 351 4bbl motor I noticed a HUGE increase in power, expecialy with the 35's on it. The mileage even went up some.
Went I went from a efi 302 to a 351 4bbl motor I noticed a HUGE increase in power, expecialy with the 35's on it. The mileage even went up some.
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From: Marysville Wa
302-351, no noticed pwer difference?
Im just worried that i am being real stupid over the subject. I whent from a perfectly fine 302 to a 351 with a 100k less miles on it. the swap took me like 4months (yeah i know, i had some searious tranny probs) so i am really just trying to decide if its the motors fault or if i just got disapointed exspecting some huge power gain.
to find out i really like the idea of getting it dyno'ed. how much has that cost people?
my engine also hesitates and will not stay running cold, i do not exspect anyone to be able to answer those anyways untill i pull the codes.
to find out i really like the idea of getting it dyno'ed. how much has that cost people?
my engine also hesitates and will not stay running cold, i do not exspect anyone to be able to answer those anyways untill i pull the codes.
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From: Marysville Wa
302-351, no noticed pwer difference?
Originally posted by red_rocket
expecialy with the 35's on it. The mileage even went up some.
expecialy with the 35's on it. The mileage even went up some.