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Hi, I have a 83 trans am with a 305 crossfire injection with clutch fan, I am trying to find out what the sensor is on the passenger side head, been told that it is a fan switch but that can't be right as I don't have an electric fan, does anyone have any idea what is for?
Sorry I don't know, I took the car on part way through a restoration, the engine is in pieces and I'm replacing everything that is worn or out of spec, I only have a Haynes manual at the moment which is a bit crap when it comes to details, I know the coolant switch for the ecu is on the manifold and the temp sensor for the gauge is on the drivers side head, knock sensor is on the block, oil sensor for ecu on rear of manifold and oil sensor for gauge is by oil filter, so I ain't got a clue what the other sensor is, I am new to American v8s, with me living in England I have only ever worked with 4 cylinder European engines, and British v8s are slightly different in configuration,
OK as soon as I get into the garage in the morning I will post some photos, I think they are original though because the crossfire injection manifold has a different bolt alignment to the heads compared to other years as far as the literature I have read states, the block is original as the engine number is a match to the vin number
You could be right on the heads, when I purchased the car the previous owner said that the guy he brought it from had the timing chain snap on him, the engine looks like it has been worked on, new valves n springs, new timing chain and sprocket, newish pistons which are 030 over, but colour of block and heads were exactly the same, which makes me think the heads were worked on and not replaced, I will write down the casting numbers on the heads so we can try and find out if they are original or not, does anyone know what is the correct casting number for 83 305 crossfire heads
the crossfire injection manifold has a different bolt alignment to the heads compared to other years as far as the literature I have read states
Then you've been reading the wrong "literature". That's not true.
AFAIK that motor came with the same casting # heads as most of the other 305s at the time did, 416.
Whether they are that casting # or not, it sounds like either they simply came off of another car, that had an electric fan switch; or, they came off of 2 other cars, and you have 2 driver's side heads and therefore 2 temp gauge sending units but they didn't turn the one they put on the pass side into a pass side one by removing the sending unit and putting in a pipe plug. A photo will tell which kind of part it is.
Meanwhile, you can do exactly that yourself... just go to HD or some such and get a pipe plug and replace it. The hole should be 3/8" NPT if the heads are 416, which is about ¾" in diameter.
colour of block and heads were exactly the same
The paint probably just came out of the same can. Hardly diagnostic for "identifying" anything about a "rebuilt" motor.
Looks like you are correct about the heads, one looks older than the other, 2mm difference in height they are both 416's but one is different, oil galleries are different a little, date stamp is different I don't have any idea by how much as I don't know
at the dots work out to, check out the pictures
This is the passenger side head Drivers side You can see the difference between the oil hole on this head compared to the next pic
Looks like you are correct about the heads one looks older than the other one in the picture you can see the difference in the oil passages as well as the older looking head is 2mm higher in deck height than the other, they have the dots to date them but I don't know what they mean, check out the pictures
As you can see they are both 416's but oil passages are different
They look the same height to me. Really, pretty much identical in every way, subject to typical production-line variation. Neither looks "older".
Not sure what you mean about "oil passages"; there are no oil passages in small block Chevy heads.
The casting date is only clear in one of the photos: it's L202. That stands for the 20th day of month L (the 12th, Dec: A is Jan, B Feb, etc.), in a year ending in 2. Therefore that one was cast on Dec 20 1982. So it, at least, is not original to the car; 82 vehicle production would have ended in early July 82 so that the first 83 cars could be built, shipped, and stocked in dealer showrooms on Labor Day weekend. Engine castings for the 82 model year would have been completed by around April 82 so they would have time to "season" aka sit around outside in the rain and sun for acoupla weeks, then be machined, then shipped to an engine plant and built into a motor, then shipped to a vehicle assy plant, then installed in a 82 car by early July 82. The other one I think ends in 3 but it's really hard to tell because that part of the photo is out of focus, so if that's true, then obviously it's not from 82 either.
They look like different colors to me; the one looks Chevy red-orange, the other Chrysler red, although they might have been the same at one time and just have faded differently since then. Neither color is original to the car. Heads and block should probably have been a medium dull slightly greenish blue. Although they might have switched to black by then. The color changed from red-orange to "corporate blue" in about 77 or so, then Chevy introduced their own blue in about 80, then they went to black in about 82 or 83. I know my 83 was black but I can't recall what 82s were.
The connector with the blade is the temp gauge sending unit. The one with the round, sort of coaxial looking, connector is a fan switch. The temp gauge sending unit belongs in the driver's side head, so if you don't want that other just ... being there ... anymore, replace it with a 3/8" pipe plug. The heads themselves are the same on both sides so it doesn't matter which one goes back where.
You're welcome.
Last edited by sofakingdom; May 12, 2018 at 11:26 AM.
