im gonna post this here too since the motor swap board is usually a ghost town

Fired up my crate 350 today. Runnign well but the engine heated up fast! Like, it entered closed loop mode in about a minute or two!!! I think that would be a new record for a cast iron block. I promptly shut it down almost rigjht after i started it. Also, the oil pressure shot up to 60 psi and stayed there. That was a bit discomferting. I watched the o2 voltage and blms from my laptop and the blms where around 140 or so and the o2 return was around .6 volts. This shows that i need to bump up the fp a bit b/c im a little toward the lean end but it doesnt seem to be running lean enough to cause it to heat up so fast like that. I know that new engines have tight clearences but the fact that the oil pressure was so high and the fact that it heated up so fast scares me. To me the high oil pressure and the high heat generated points toward an oiling problem. Any thaughts?

 

I have a rebuilt engine I did myself and when I first got it running, my oil pressure stayed up there and didn't back off. At first I thought something was wrong. I talked to a few mechanics and the one that helped me do most of the work and they all said that for a chevy V8 the pressure stays high until its warmed up then drops to normal half that at speed and when idleing is only 1/4 mark. My guage fit that description perfectly so that's my new normal. Before, I had a hard time keeping it at even 30 let alone 60. After the break in period she'll still do it, just not after the whole engine is up to proper temp. When the temp outside is warm and my engine temp is at the 140 level or close to it, she'll fire into closed loop in under a min. Under heavy load and WOT the pressure should be at around 60 for well maintained (we're talking every 3k oil change with a flush and injector cleaner) I racked up 30k miles since I rebuilt it and she runs better than when I bought it.

 

my rpoblem is that the pressure doesnt back off, even after it came up to around 180 degrees or so in a minute. It takes alot of heat to bring a quarter ton of cast iron up to 180 degrees in a minute or two. I even went bakc out there and its still quite warm after four hours of sitting. This obviously points to a tremendous amount of heat being generated, possibly from friction. I think this seems to be a bit of a problem. Any more thaughts? Please tell me im overreacting and this is normal bacause i dont feel like having to tow it to a dealer and go throuhg all the paperwork to get it replaced under warantee.

 

hey

When I first dropped in my new motor, the engine ran hot and oil pressure stayed around 60 even at idle.

Gradually within the first 1000miles the temp. went down and the oil psi. went down as well.

it now has about 18psi at idle, which shoots up to abou 40psi by 2000rpm, and gets as high as 60 or so at redline.
the engine still runs slightly hot, but only when in traffic, the hottest is ever been is about 220 with fans on, and heater blowing. Normally when not in traffic it sits around 170-190 range.

You also have to remember, that the cooling system is not set up to support high power levels.

mine was originally a 305tbi, so it was only set up to handle around 200hp, and now its around 300....power=heat.

 

hmmm..maybe your right... ill richen up the mixture tommorow to get it away from the lean end and try to do the cam breakin. Heh... the way i look at if it has an oiling problem its probably already trashed. The engine will jsut live the rest of its life as a 350 bored .060" over after the cyl. walls get wasted. As for hp, i have the stock 350 thats only good for 210 or so. Also, i have no a/c and no condensor, whcih blocks flow.

 

I'd check to visually see if water is actually circulating through the motor and radiator. Feel the rad, it should be just as warm as the motor. Pull off a valve cover to see if oil is getting to the top. Check base ignition timing. Even if you were a little lean it wouldn't heat up that fast while not under load.

 

Sounds like you may have not gotten the block full of water before starting the engine for the first time. The oil pressure is normal, mine (1k miles on new crate eng) is almost 60 on start up, then drops to 45-50 at idle while still cold, but raise the RPM's above 1k and the pressure is 60+. The warm, broken in idle pressure is 30-35 now and 60 at 2k RPM.
Other than that, your engine will warm up faster than the old one did and I have found that mine warms up faster than the 305 did when new, which is really a good thing if you think about it, you enter closed loop faster.

 

think i figured out my problem. Apparently im running leaner then i thaught, alot leaner. I must have not looked at the o2 aftert he sensor warmed up. Its fine at idle but the voltage dumps out to between 0-.15 volts as soon as i brought it up to the speed i needed to break the cam in. This explanes where all the excess heat is coming from. This is also witht the fpr as high as i can get it. The fuel actually evaporates so fast that the tbi and the imediate area is ice cold to the touch on a 85 degree day. This is kinda funny too because my old 305 ran rich all the time. The 350 only makes about 30 more hp and its absolutly starving for fuel, even under no load. Heh... maybe they shipped me a hi-po 350 by mistake. Anyhow, guess i better get some 350 injectors before i continue breakin if i dont want to burn my new engine down.

 

nother thing that i dint think about earlier. I didnt install my egr because i figured "with 8.5:1 cr who cares, my NOx emmisions will be fine and the guy who inspects my car only cares about emmisions output" This would also affect the mixture because the stock prom has the tables set to account for the intake of exaust gasses under mild loads and rpms. I would think this would serve only to lean it out further.