Engine codes

[bfrazee]

My car is a 69 Pontiac Firebird. I've had it for 16 years. The engine was rebuilt (bored/new pistons) about 5 years ago. I've been having trouble with it overheating since it was rebuilt. It never overheated before that. I've tried everything, electric fan, oil cooler, etc. I talked to a guy that thinks it might be improper valve adjustment. He came over to help me, and he wanted to verify that it's the original engine (350). The code stamped on the front of the block is "YE". The last number stamped under the distributor is "9". The number stamped between the 2 freeze plug is "350". What is the most reliable site to go to find this kind of information? I've seen some variations from site to site. Any help is appreciated.

[savagewolf]

did u replace the radiator at any time or the hoses, and was the block moved or left in the car during the rebuild?

[FormulaLT1]

http://www.classicfirebird.com/1969/69options.html

Check out this site but YE- is a 265 Horsepower 2Bl powerglide with 3 speed. Good Luck and I agree with your friend if sounds more like a Improper fuel mixture than cooling system problem, Most likely your running lean which would cause higher temp's and possible over heating issues. Let us know how it turns out.
John

[bfrazee]

Originally Posted by savagewolf

did u replace the radiator at any time or the hoses, and was the block moved or left in the car during the rebuild?

Yes. It has a new 4-core. I took the engine out and took it to the guy that rebuilt it.

[bfrazee]

Originally Posted by FormulaLT1

http://www.classicfirebird.com/1969/69options.html

Check out this site but YE- is a 265 Horsepower 2Bl powerglide with 3 speed. Good Luck and I agree with your friend if sounds more like a Improper fuel mixture than cooling system problem, Most likely your running lean which would cause higher temp's and possible over heating issues. Let us know how it turns out.
John

Ya, I see there is a YE code for 69. This one guy, that's supposed to be a GTO expert, keeps telling me it's not the original engine. He says it's a 400 out of a 68. I don't think so because "350" is stamped between the freeze plugs. What do you think?

[FormulaLT1]

If its stamped with a YE(which is a 350 code) and the block itself says 350 I wouldn't doubt it was a 350 out of a 69 Firebird.

[savagewolf]

lol i think hes clueless. u can tell the difference from a bigblock and a smallblock just by looking at it. (i know from experence.) and if you replaced the radiator then its prob not a cooling system problem... unless theres a clog in the hose. its tough to troubleshoot the old cars because the new ones will talk back to u and tell u whats wrong, lol. John, couldn't running rich cause it too? mine runs extreamly rich and it really gets hot in the summer. i dont think its timing because u could feel it if the timing was off. go with formula and adjust the fuel mixture. i have hunches that your clutch fan might be stuck, or if its an electric fan, there might be a short in the wire.

[FormulaLT1]

Leaner fuel mixture's generate higher temp's than richer mixture's. Most car's running rich mixture's may get horrible MPG and excess smoke but will not create a over heating issue.

[savagewolf]

lol no fair! i have no choice, the 455 wont run on a lean mixture, it has to have alot of gas in it to mix with the increased ammount of air being forced in

[bfrazee]

Originally Posted by savagewolf

lol i think hes clueless. u can tell the difference from a bigblock and a smallblock just by looking at it. (i know from experence.) and if you replaced the radiator then its prob not a cooling system problem... unless theres a clog in the hose. its tough to troubleshoot the old cars because the new ones will talk back to u and tell u whats wrong, lol. John, couldn't running rich cause it too? mine runs extreamly rich and it really gets hot in the summer. i dont think its timing because u could feel it if the timing was off. go with formula and adjust the fuel mixture. i have hunches that your clutch fan might be stuck, or if its an electric fan, there might be a short in the wire.

I know it's not the ignition timing, because I've experimented with that. I'll experiment by adjusting the 2 mixture screws (out), like you suggest. If it doesn't improve, I'll try adjusting the valves. I think it has to be that, or the guy didn't punch out some of the head gasket holes. This is not a usual kind of overheating. It runs 200+ going 80mph down the freeway. I have a flex fan. My clutch fan broke. I also have an electric fan that runs all the time. This heating problem has been going on for 5 years, but I haven't looked into it this far because I only live 3 miles from work, so the overheating isn't a daily occurence. Thank you both for replying so soon. I should have posted here earlier.

[FormulaLT1]

No Problem, Welcome to the Forum and let us know how it turns out.
John

[bfrazee]

Originally Posted by FormulaLT1

If its stamped with a YE(which is a 350 code) and the block itself says 350 I wouldn't doubt it was a 350 out of a 69 Firebird.

There are other Pontiacs with the "YE" engine code, but I agree with you that mine's probably not one of them. The two others I found with "YE" are 1968 400 and 1971 455.

[FormulaLT1]

If you want to get technical the 400 block is based off the 350 with longer stroke crank and my 350 LT1 is stamped with 327 but what would make someone believe that all the factors that you have that someone not only tried to trick you by using a 400 block but went through the trouble of trying to match engine factors. Its not very likely.

[sixt8bird]

THERE IS NO SMALL BLOCK OR BIG BLOCK PONTIAC!!!!! And yes it is a 69 350. What thermostat are you running and do you have a fan shroud? The performance early birds all had a filler panel on the radiator core support and shrouds. It is a must to run a fan shroud. I run 160 stats in all my Birds and on the hottest days ,sitting in traffic ,it never reaches over 175 degs. This even includes my 12 second Firebird.

[bfrazee]

I've tried different thermostats, and no thermostat. It doesn't make much difference. I have the original fan shroud with a flex fan. I also have an electric fan on the inside of the radiator to pull air through.