I have a 1975 "Smog" 455 in my 1982 Cutlass, I can not figure out why is is getting hot. I'm new to Oldsmobile's I have tried a couple things, Its getting good coolent flow and the clutch fan works good. It seems to now overheat white at idle, I'm pretty sure it has a fuel or timing problem it looses all power at mid throttle. It runs and sounds great at idle.

My car had a good running 1970 455 in it, Bottom end didn't hold up.

Now has that smog engine in it while I'm building another 455, Pretty stock besides 750 Edelbrock Th350 8.5 373 Posi

I do not know what the timing is set at, I'm still learning about the 455

 

I'd say timing is to high. Remember Olds distributors spin ccw so turning clockwise will advance timing no retard it.

 

Thanks for the reply, I'm going to try to mess with the timing tomorrow, the harmonic balancer does not have anything on it to check the timing.

 

Huh?

 

There should be a line on the harmonic balancer and a timing tab attached to the timing cover. Let us know what your timing and idle rpm are set to. Also what distributor are you running?

Generally an overheat condition at idle and not at cruise can be an air flow issue through the radiator, and/or timing, carb set to lean, etc...

What temp is it running at idle, and at cruise?

 

It overheats while driving not usually at idle, There is no timing tab on this block and no timing sticker on the balencer.

 

I went off of this comment.

You need to find a timing tab and install it, or find tdc and make a mark so you can set your timing. Somewhere on your harmonic balancer it has a scribed mark for timing.

What temps are you running at idle and at cruise?

 

you can use your vacuum gauge to get decent timimg without the marks for now

 

Classic symptoms of a marginal radiator, not conclusive proof though.
Just because a radiator flows well that doesn't mean it dissipates heat properly if the core has built up a layer of scale.

You still need to sort out some accurate timing marks to give yourself a reference point to tune the engine properly.

Roger.

 

Another thing that it could be it if this was just a pluck and drop is there could be scale built up in the cooling passages of the block and heads restricting coolant flow. This is very possibly the case and no matter what you do with the cooling system it will still overheat.

$.02

 

Thanks Guys

I've washed the block out over 10 times and every time the water comes out a nasty brown. Inside my radiator looks nasty, I've tried two thermostats and the radiator hoses always get very tight.

The fuel problem I posted about has to do with my secondary's not opening i'm petty sure. When I push the petal in the trans kicks down the rpm's go up but it has NO power, kinda reminds me of a valve floating sound.

 

I had something similar to this happen with a Quardajet years ago. It had something to do with the choke rods and a latch that doesn't allow the secondary top plate to open when the choke is engaged getting stuck.

Old carbs tend to have issues.

 

Retarded timing generally leads to overheating
Without timing marks, of course... that's harder to evaluate.
Time for good high vacuum if no timing marks are available.
Excess advance leads to pinging- assuming you can hear it.

How about a pic of each sided of your carb.

 

I tried to retard the timing because I thought it would run cooler with lower timing. I'll attach pic of the carb.

 

Base timing needs to be in the 20° range to start with.

 

I'm not an Edelbrock fan, I ordered a Holley 750cfm carb yesterday.

I tried opening the throttle while the car was running and not running and the secondary's did not open.