ClassicOldsmobile.com - View Single Post

Oldsproject · 06-11-2007, 05:58 PM

I'd like to start off by thanking everyone on this site and for the gracious help and advice offered. Today was a big day! My 16 year old son and I have been working on a complete rebuild of a 425 to put into his "65" Cutlass. Our hard work paid off as the beast fired and ran for the first time. I was able to maintain a good 2000 rpm run for about 15 minutes before we had to shut her down as it started to overheat. I'm pretty sure we got a good break in on the cam and everything souds really great! The concerning point is that it's running really hot though. I don't have any of the electrical hooked up yet as I wanted to be sure the engine would run and get it broke in first so I don't know how hot but it did start to release (so it's really hot). To the point that it's making me a bit nervous. It could simply be the condition it's in but looking for some expert thoughts. Here's what I've got:

The specs on the motor as are as follows:
Crank - Steel Forged and Balanced
Pistons - Egge 10.25:1
Rings - Federal Mogul Sealed Power (file gapped)
Heads - C with valve job but no porting
Valve Train and springs - Comp Cams Mag Rods, Mag Lifters, Mag Rockers, Guide Plates, BeeHive Springs
Cam - Mondello JM 20-22
Intake - Edelbock Performer
Carb - Edelbrock 750 CFM
Exhaust Manifold - Hooker Comp Headers

I don't know anything about timing so what I did for initial startup was to find TDC on #1 in the compression stroke, pulled the distributor and reset it so that the rotor was pointing as close to the #1 cylinder as possible, made alignment marks on the intake in line with the center of the rotor and the direction it pointed, placed the cap on and advanced it (clockwise) about 1/4". It fired, started and sounds pretty good. If I'm not dead on or advanced too far or retarded too far will the engine run hotter?

Another thing is that I have the entire front end off the car (fenders included). So in order to fire it I strapped the radiator onto the bottom mount but it's not sitting completely vertical and since there is no cowling around it it's likely that little air is passing through it. Is this contributing?

Also I'm running just water in the radiator and using a low temp thermostat. Does this help or hurt?

Finally, the car had a 330. I used the existing radiator as it fits but isn't as wide as the one that was in the 67 dynamic that the motor came from. I also used the water pump from the 330 as it's discharge was on the drivers side (same as the radiator) whereby the discharge on the 427 was t the passenger side. I don't think this would be an issue but maybe?

Is there anything to worry about here or will it get better once I get the front end on and the engine better timed? Sorry for being so long winded but I thought the detail might help.

06-11-2007, 05:58 PM	#1 (permalink)
Oldsproject Member Join Date: Mar 2007 Posts: 55	Engine Temperature Issues?? I'd like to start off by thanking everyone on this site and for the gracious help and advice offered. Today was a big day! My 16 year old son and I have been working on a complete rebuild of a 425 to put into his "65" Cutlass. Our hard work paid off as the beast fired and ran for the first time. I was able to maintain a good 2000 rpm run for about 15 minutes before we had to shut her down as it started to overheat. I'm pretty sure we got a good break in on the cam and everything souds really great! The concerning point is that it's running really hot though. I don't have any of the electrical hooked up yet as I wanted to be sure the engine would run and get it broke in first so I don't know how hot but it did start to release (so it's really hot). To the point that it's making me a bit nervous. It could simply be the condition it's in but looking for some expert thoughts. Here's what I've got: The specs on the motor as are as follows: Crank - Steel Forged and Balanced Pistons - Egge 10.25:1 Rings - Federal Mogul Sealed Power (file gapped) Heads - C with valve job but no porting Valve Train and springs - Comp Cams Mag Rods, Mag Lifters, Mag Rockers, Guide Plates, BeeHive Springs Cam - Mondello JM 20-22 Intake - Edelbock Performer Carb - Edelbrock 750 CFM Exhaust Manifold - Hooker Comp Headers I don't know anything about timing so what I did for initial startup was to find TDC on #1 in the compression stroke, pulled the distributor and reset it so that the rotor was pointing as close to the #1 cylinder as possible, made alignment marks on the intake in line with the center of the rotor and the direction it pointed, placed the cap on and advanced it (clockwise) about 1/4". It fired, started and sounds pretty good. If I'm not dead on or advanced too far or retarded too far will the engine run hotter? Another thing is that I have the entire front end off the car (fenders included). So in order to fire it I strapped the radiator onto the bottom mount but it's not sitting completely vertical and since there is no cowling around it it's likely that little air is passing through it. Is this contributing? Also I'm running just water in the radiator and using a low temp thermostat. Does this help or hurt? Finally, the car had a 330. I used the existing radiator as it fits but isn't as wide as the one that was in the 67 dynamic that the motor came from. I also used the water pump from the 330 as it's discharge was on the drivers side (same as the radiator) whereby the discharge on the 427 was t the passenger side. I don't think this would be an issue but maybe? Is there anything to worry about here or will it get better once I get the front end on and the engine better timed? Sorry for being so long winded but I thought the detail might help.