How can I tell 400ci or 455ci?
04-16-2008, 12:55 PM
#1
Teching In
Thread Starter
Join Date: Apr 2008
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
How can I tell 400ci or 455ci? Hey guys, today Im going to check out a 1981 Trans Am.
The owner days she runs like a bat outta hell!
The owner said someone had installed a 455 in her before he purchased it.
What all engine options did they have for 1981 Trans Ams?
How do I tell its a 455ci and not a 400ci.
The owner builds hotrods but I just wanna make sure it is indeed a 455!
The owner days she runs like a bat outta hell!
The owner said someone had installed a 455 in her before he purchased it.
What all engine options did they have for 1981 Trans Ams?
How do I tell its a 455ci and not a 400ci.
The owner builds hotrods but I just wanna make sure it is indeed a 455!
04-16-2008, 01:02 PM
#2
TECH Enthusiast
Well it's actually really hard to tell. The block sizes are the same.
IF it is a 455 block, then it will be stamped as such, you'll have to go under the car and take a look. It will look like this
That's on the drivers side, behind the fuel pump.
BUT because 455 blocks are getting rare, a lot of people are building 455's out of 400 blocks. In that case, if it's a stroked and bored 400 block, you can't tell by looking at it.
IF it is a 455 block, then it will be stamped as such, you'll have to go under the car and take a look. It will look like this
That's on the drivers side, behind the fuel pump.
BUT because 455 blocks are getting rare, a lot of people are building 455's out of 400 blocks. In that case, if it's a stroked and bored 400 block, you can't tell by looking at it.
04-16-2008, 07:04 PM
#4
TECH Addict
iTrader: (3)
Join Date: Oct 2005
Location: SE VA
Posts: 2,255
Likes: 0
Received 0 Likes
on
0 Posts
FYI, theres no way a 400 or 455 was offered in 81, which i hope you already knew. like iron said, theres very little way to tell what kind of pontiac motor it is, if it is indeed a pontiac motor. the best but most time comsuming would be to run the vin on the motor itself. it will at least give you the year and size of the block. besides that, youll have to take the builders word for it until you tear it down yourself.
04-16-2008, 07:12 PM
#5
Staging Lane
iTrader: (1)
Join Date: Jul 2007
Location: Columbus Ga.
Posts: 70
Likes: 0
Received 0 Likes
on
0 Posts
Hey guys, today Im going to check out a 1981 Trans Am.
The owner days she runs like a bat outta hell!
The owner said someone had installed a 455 in her before he purchased it.
What all engine options did they have for 1981 Trans Ams?
How do I tell its a 455ci and not a 400ci.
The owner builds hotrods but I just wanna make sure it is indeed a 455!
The owner days she runs like a bat outta hell!
The owner said someone had installed a 455 in her before he purchased it.
What all engine options did they have for 1981 Trans Ams?
How do I tell its a 455ci and not a 400ci.
The owner builds hotrods but I just wanna make sure it is indeed a 455!
FYI, theres no way a 400 or 455 was offered in 81, which i hope you already knew. like iron said, theres very little way to tell what kind of pontiac motor it is, if it is indeed a pontiac motor. the best but most time comsuming would be to run the vin on the motor itself. it will at least give you the year and size of the block. besides that, youll have to take the builders word for it until you tear it down yourself.
04-16-2008, 09:15 PM
#6
TECH Senior Member
iTrader: (3)
Join Date: Oct 2006
Location: Decatur, TN (N-W of Athens)
Posts: 7,564
Likes: 0
Received 3 Likes
on
3 Posts
Very few options were offered back in 81 (last of the 2nd gen cars), and all were low HP and slow. Which is why someone would've swapped in a bigger motor. But if someone swapped in a motor, it wouldn't matter what was offered.
Basically (To my knowledge) It was a 301 (horribly slow), 301 Turbo (horribly less slow), and a Chev 305. The 301s were Ponchos though. 301 was standard equipment.
Basically (To my knowledge) It was a 301 (horribly slow), 301 Turbo (horribly less slow), and a Chev 305. The 301s were Ponchos though. 301 was standard equipment.
04-16-2008, 11:54 PM
#7
Teching In
Thread Starter
Join Date: Apr 2008
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
Okay guys I picked the car up today and man is it nice..the car hauls *** and even gets very good gas mileage!
Ill check the block tommorow morning when its light outside..
I think it is a its definitly a 455 or atleast a built hot 400..
Pics coming soon
Ill check the block tommorow morning when its light outside..
I think it is a its definitly a 455 or atleast a built hot 400..
Pics coming soon
Trending Topics
04-17-2008, 12:23 AM
#8
TECH Enthusiast
Congrad's man... I love my LS1, don't get me wrong... but driving around in an old school big cube Firebird is somethin else. I wouldn't get too happy about fuel mileage though! I noticed, that even back then, the first half of the tank takes twice as long to go down as the second half?
What type of mods does the thing have? What head casting? You can get the casting number at the center of each head, on the side, above the middle two exhaust ports. It'll say something like "6X".
What type of mods does the thing have? What head casting? You can get the casting number at the center of each head, on the side, above the middle two exhaust ports. It'll say something like "6X".
04-17-2008, 03:31 PM
#10
TECH Enthusiast
Oh, I was gona add here bro, if you want to know more about your car but don't know much about Pontiac V8's. Just take some pics of the engine, and heads.. etc.. and I'll fill ya in best I can.
Last edited by IRONFIST; 04-17-2008 at 03:42 PM.
04-17-2008, 09:51 PM
#11
Teching In
Thread Starter
Join Date: Apr 2008
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
Ive been driving her all day long...WOT=Pure Sex!
This car will absolutely devour my 2000 Z28 Camaro!
I dont know the specs on the engine...but for some reason the top end power on this baby is insane it just wants to keep pulling and pulling!
These are some phone pics for now..tommorow I will actually look for that 455 stamp on the block!
I have a feeling it is a 455.
Im gonna give her a good tuneup this Saturday.
He also gave me a spare set of T Tops I may put up for sale!
This car will absolutely devour my 2000 Z28 Camaro!
I dont know the specs on the engine...but for some reason the top end power on this baby is insane it just wants to keep pulling and pulling!
These are some phone pics for now..tommorow I will actually look for that 455 stamp on the block!
I have a feeling it is a 455.
Im gonna give her a good tuneup this Saturday.
He also gave me a spare set of T Tops I may put up for sale!
Last edited by kevamg; 04-17-2008 at 10:15 PM.
NICE CAR MAN..
04-18-2008, 12:53 AM
#16
TECH Enthusiast
Don't worry about the interior, that's easy to fix. Look's like a cast iron intake and cast iron heads. That doesn't make them bad though, I'm running cast iron heads on my 400, and I'm making awesome power on 87 octane! Now someone could swap in a 455 and then put 400 decals on it, I would for the sleeper look, but the 6.6L stickers are deffinetly not original.
Well, it's deffinetly either a 400 or a 455 from what you described as the power its making. Both engines are very respectable..
Well, it's deffinetly either a 400 or a 455 from what you described as the power its making. Both engines are very respectable..
04-18-2008, 08:48 AM
#17
Teching In
Thread Starter
Join Date: Apr 2008
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
Lol..naw man..this baby is just a weekend toy..I have no plans on restoring the interior nor body...Its a rough rugid no A/C no luxury fire breathing street monster!THATS IT!
All the money and work will go into the drivetrain only! I bought this car just to tear up the streets and cruise! I can care less about car shows,restoration or collecting.
04-19-2008, 02:39 PM
#19
TECH Enthusiast
Knocking already? That doesn't make sense. Well, if the cam isn't stock, whoever swapped it probably went with adjustable rockers. Pull the rocker covers, and re-lash.
If they arent adjustable, I hope you didn't rev that stock short block too high? Cause a crank bearing would be much harder to fix.
If they arent adjustable, I hope you didn't rev that stock short block too high? Cause a crank bearing would be much harder to fix.
04-19-2008, 02:54 PM
#20
Teching In
Thread Starter
Join Date: Apr 2008
Posts: 30
Likes: 0
Received 0 Likes
on
0 Posts
Knocking already? That doesn't make sense. Well, if the cam isn't stock, whoever swapped it probably went with adjustable rockers. Pull the rocker covers, and re-lash.
If they arent adjustable, I hope you didn't rev that stock short block too high? Cause a crank bearing would be much harder to fix.
If they arent adjustable, I hope you didn't rev that stock short block too high? Cause a crank bearing would be much harder to fix.
I dont get it either! I can tell if the clacking is coming from the right or left valvetrain!
It was running like a champ yesterday!
Im so pissed!