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.

 

No and yes.

Norm

 

Yes.

Yes

Not factors.

If the machine work was done right, the fan and shroud is in place, and your fuel mixture/timing is close, it should work. If not, you will know soon enough.

Not a problem.

What are Mag Rods, Mag Lifters, and Mag Rockers?

Norm

 

Thanks Norm, the more I think about it I'm convinicing myself that I've got it timed ATDC a bit and that's contributing. Either that or my starter is dragging as it takes all I can give it to get it to turn over (I've tried two old starters). It really lugs as if it's vapor locked (if that makes any sense) in the begining then after a couple revolutions it seems to pick up and fire. Also drains a brand new 750 cranking Amp battery to the bone. Either that or the starter just isn't enough for the newly rebuilt engine. Let me know if any of that makes sense? Probably both (starter and timing).

In answer to your question, it's Comp Cams upgraded version over their entry line replacement for Olds. The lifters are High Energy Hydraulic (855-16), Rocker Arms are Magnum Roller Rockers (1442-16) which required a conversion to studs, the Push Rods are Magnum Pushrods (7582-16) which means they are hardened for use with guide plates.

Let me know if there is anything else you or anyone can think of in order to bring the temp down. I'd hate to get this thing together only to find I've got an issue somewhere but it sounds like I'm OK. As you probably know the engine wouldn't just drop in with the headers on and was a royal pain getting them on with the motor installed. The drivers side went OK once we pulled the front of the motor up as it gave enough clearance but the passenger side was a challange. We finally removed the oil filter and bracket, secured the motor mount on the drivers side then pivoted the motor up towards the drivers side in order to get the clearance and angle in order to bolt them on. Once on, they fit like a glove (that will never come off!!). She really sounds good with the cam and open headers. Neighbors thought I bought a Harley

PS: don't know if this has any value but when I degreed the cam I did advance it one click (on a Cloyes I think that's about 4 degrees) in order to compensate for timing chain stretch etc.

 

I remember I was on pins and needles when I first started the 455 after being rebuilt. I had the same concerns about heat build up. It would really help out if you installed a good water temperature gauge so you could actually KNOW how hot the engine was. You might bump up the timing a little and see if it starts easier and runs a little cooler. What really concerns me and I don't have an answer is the part about it almost killing the starter and battery to get the engine running. I don't remember having that trouble....

 

Unless you used an accurate timing light, there is no way you can know where your timing is.

Have it tested by your local auto parts supplier.

It doesn't. Vapor lock causes a lack of fuel to the carb, and it would act as if it were out of gas.

When it is hot, the cause could be too much advance. On cold a startup, timing wouldn't make any difference.

Have it tested at the same time you test your starter.

Now, here is a good place to look. If the rebuild was done properly, the starter/battery would be the problem. If it was not? Wasn't there a discussion earlier, about you shops competence?

Remove the plugs and crank it with the starter. How did it react?

Using the appropriate socket, and a breaker bar/torquewrench, rotate the crank clockwise. How much torque was needed to get it started? How much to keep it going?

Anything under 200° is no problem. How hot did your gauge show it to be?

It's very possible, something was damaged because you did not put it back together.

You probably overcompensated by 7x or so. Other than that, you moved your power band down a few hundred RPM. For your application, it will work OK.

Norm

 

A fresh engine is tighter so a good/new high torque started is recommended. At 2000 RPM there is not enough cooling air to cool things properly standing still. The radiator is questionable....It should at least have 3 rows of fins. If its not new look for a new 442 radiator. Timing is important....get a timing light and set the timing.

 

Thanks guys, I was out of the country for a couple days but back. I did pick up a timing light and will check everything out this weekend.

Another question though, on the back of the intake there's a short hose that leads to the heater coil. The hose hooks to the intake on a 5/8" (guessing) fitting/nipple. The nipple on the 330 was a plain standard nipple (no restriction). The 5/8" nipple on the 425 has a machined restriction hole in the bottom (about 1/4"). I used the 425's restricted nipple but am thinking it would be better to have increased flow. Is there any reason the flow would need to be restricted to the heater coil? Would it be better to eliminate it by replacing it with a standard one?

Also, I did use the starter without plugs installed and it turned over with no problem, also used a small breaker bar when establishing TDC without too much effort. I'll use the torque wrench to get a better idea but old starters/battery sounds like the likely issue. I'm also going to change the power cable to the starter, while it looks good it seems like the right thing to do for a couple bucks.

The combination of not having the radiator/cowling in place, the fuel mixture dialed in and the timing set seems as the likely culprets to the temp issue. Also, if there's anything to this restriction hole in the nipple to the heater coil?? I've bought a new radiator cap as well and did pick up a temp gauge to look at accurate readings this time.

 

Hi. I had the same issue with a 73 I did years ago. No front clip, just a rad and hoses. Fresh 350 running for the first time after rebuild. Checking timing, and oil pressure, etc... then poof, rad cap blew open. In the end, having the fan shroud on would have saved the boil over. Without it, the fan doesn't even draw air through the rad. Hope this helps, and best of luck on the ride.
Jim.

 

About the heater core hose. That is a return from the core, to the engine (via the inlet on the intake). The water is pumped from the water pump, through the hose on the passenger side into the core, from the core to the back of the engine, through the engine back up to the pump. Most cars have the heater core flow control valve on that hose you are referring to so that it can stop the flow of heated coolant, thereby controlling how hot the core will get. Of course, the coolant will also flow through the block itself as well. I don't know if having a smaller ID nipple on that inlet will reduce flow or just increase the pressure of the coolant entering the back of the block.

About the overheating issue. It seems as though you are getting a handle on it, let us know what transpires, alright?

 

I read an article about the restricted nipple. I dont remember the source but it said the restriction was there to reduce pressure in the heater core that may cause rupture if not restricted. I really didnt see the sense behind that idea but the article went into detail with pressure gages and how the guy had to replace 3 heater cores. I have used just a plain nipple on many of my Oldsmobiles and never had a problem. If you have the correct nipple though I would use it.

 

Thanks guys, I couldn't wait for the weekend so dug in again last night. I picked up a new radiator cap as I read something where that could aide in the problem and followed the great advice offered in all of the posts.

First I pulled the plugs, put the tourque wrench on it and turned over very easy (set at 80 lbs of tourque and didn't break or strain), then I turned it over with the starter which again was easy, pulled the #1 to TDC and rechecked the rotor alignment in the distributor. This was an issue as it was retarded quit a bit. I realigned the rotor and then advanced it just a bit. Reinstalled the plugs, pulled the temp sensor valve and replaced it with an accurate temp gauge, hooked up all of the electrical and prayed ..... fired right off with little problem.

Next I played with the carb adjustment in order to get it as smooth as possible, double checked all the vac. lines for signs of leakage then work on bringing the idle down as far as I could. Got it down to about 900 RPM's without killing, worked on the carb a little more then loosened the distributor and turned it until I got it running really smooth. Once I got it purring, worked the carb a bit more then started to retard it slowly until I got a nic harder rumble. The temp ran up to about 220 but keep in mind I still don't have the cowling or radiator installed permanently and it really isn't drawing much air through it. Put the timing light on it and fined tuned a bit more but kept it a bit on the hard idle side.

The car was running good, started immediately and seemed to be running a lot cooler (although still a little hot). All in all I probably had it running for 30 minutes or more and the temp crept up to the 230 range but seems to me it will be fine once I bolt everything up and get it dialed in a bit more?

As a side note, I'm running AC Delco 45S plugs which I think is on the hotter side of the band (according to Mondello's Tech manuel should run 43 - 45 with AC's)?

In any event I think I'm out of the woods but will know for sure this weekend when I put the front end back together. Please provide any additional advice or thoughts as this has been an education and fun. I realize I'm probably a pain but you have no idea how much you've helped someone who has NEVER done this before.