elisowski

I just built a 455 0.30 over with 9.6:1 forged aluminum pistons, (0.003-0.0035 piston to bore clearance as per Mondello, Edelbrock heads, comp cam with .475/.480 lift and 218/224 duration @0.50, degreed straight up. Total advance is 36 degrees @ 3500 rpm. Right now it has a 600 cfm holley double pumper and edelbrock intake. Brand new plug wires on an HEI distributer with an accell super coil.

It won't idle below 1200 rpm, and runs better with more advance. Will cycle the thermostat one time @ 195 degrees then heats up to 210-220 in about 6-8 minutes and never returns.

Tonight I noticed that the headers were bright red after about two minutes of running, and the temp climbed to 215 after cycling the thermostat one time before I shut her down. This motor is barely broken in and I have no clue how to tune it or stop it from overheating. I have installed the biggest electrical fan on the market.

It will not start at all after it reaches the 210 degree mark. The solenoid is mounted on the fenderwall to try to prevent hot starts. I am about to replace the starter with a high torque model.

I performed a compression test and the results showed 180 lbs. on 1-7, 2-4-6-8 and 165 lbs. on 3 & 5. Could this be a blown head gasket? There's no anti-freeze smell in the tailpipe, nor is there any white smoke. May be a little pressure in the radiator, not sure.

I need some help with basic timing, tuning and carb adjustment.

Any suggestions?

70ragtop

Wow, where to start.....

With your advance numbers, 35deg BTDC @ 3500 RPM, I would bet it won't start after 210 deg. Thats a little too much advance for a stock starter to overcome at that temp.

Three ways you can overcome this: 1) Heat up the car (to 210 presumabily) and back off timing until car starts freely (OK timing range for a daily driver) 2) Install a switch on the ignition coil to disable it while starting. Then after engine is rotating freely enable coil. 3) Install a high torque starter and leave the advance at 35 deg.

I am not a big fan of Holley Carbs at all, so I am of little help here.

Lets talk a little about Olds motors and temp here. It is not uncommon for ALL Olds motors to run hot. My 70 Convertible with a 350 runs on average between 210-220 on a good day with a 185 deg thermostat, flex fan, and 4 row radiator. I have had it as high as 240 on the highway pulling a trailer. In my opinion if you are running only electric fans you WILL have cooling problems with an Olds. Run a good shroud, a 4 row radiator, a corrisponding flex or high quality clutch fan, and put the electric fan in the front as pusher fans for the heavy work.

If you are worried about head gasket failure, start the car with the rad cap off. If water shoots out of the radiator, then you have a problem, otherwise lets look at other factors first.

The glowing at the headers leads me to think you may have a lean condition going on. This can also atribute to the idle problems.

Tell me a little about how you broke in the motor and adjusted the valves.

elisowski

A lot has happened since I posted the question.

Changed the head gasket. Brand new Edelbrock heads were O.006" off between the center cylinders. Had them resurfaced and and put the motor back together with a new speed demon 750 cfm carb with vacuum secondaries and a new pertronix hei distributor and a new high-torque starter.

Headers apparently red hot because of the ignition being retarded.

Car runs 195-205 degrees on a 185 thermostat without a fan blade and using a 2350 cfm electric "pusher" fan on the outside of a 4-row radiator in traffic. Seems to be working well.

But, I'm still a little puzzled about the timing.
Without vacuum, it needs 25 degrees BTDC to idle @ 1000 rpm. The vacuum gage reads 17-18 inches at this advance. To get 20 inches, I need to give it about 29 degrees advance. But its hard to re-start.

If I give it 35 degrees total advance @ 3500, it seems to be slightly retarded. It really wants to have about 42 degrees @ btdc with vacuum to run well. But I'm afraid to let it get there. I have been told that under load that reading will retard, and should be ok.

But I don't feel like grenading another motor.

I degreed in the cam and it met all of the opening and closing events on four different cylinders so I feel it was installed correctly and straight up.

I have been told to advance the cam 4 degrees by Mondello. I really don't understand how this will help.

Any suggestions?

Thanks for your time!!!

crown14

Timing.

70ragtop

have you checked the harmonic balancer to see if it sliped or is on true TDC when the mark reads 0? At close to 45deg total advance the headers should not be glowing. I think your initial reading is more like 16 degrees and your total advance is somwhere around 27 deg. Check your balancer and the weights in the distributor.