[Blued and Painted]

Generaly speaking running hot in stop and go driving is normally a fan or air flow problem.
Overheating while cruising would be restricted radiator or poor coolant flow for one reason or another.

I would run manifold vacuum to the hei.
Has the Mechanical advance curve been checked.

[indymanjoe]

I would Degree the cam and start from there.Adding anything or changing stuff is a bandaid or crutch.First things first,degree the cam and KNOW its done right.

[General Z]

Right on. I'm just debating buying, borrowing, renting, the kit and learning the skill on this fresh engine that I can't afford to screw up, or paying a shop to do it.

[indymanjoe]

There is alot of folks here who will point you in the right direction.Start to finish.And yes,do this yourself and learn.

[RamAirIV28]

3'73's, unknown converter. those can do it

also cams with too much overlap.

whats your gas milage?

[Old Goat 67]

Do you have any pictures of the water pump impeller and plates you put in?

[General Z]

Update:

I haven't degreed the cam, but I did do a few other things.

1. I changed the total timing to 32 instead of the 36 I had it at.

2. I pulled the 180 balanced thermostat that was in it and instead used a standard thermostat with the guts ripped out of it, so it's just a restrictor disc.

3. I removed my 13 lb. thermocap and put a new 16 lb standard cap on the radiator.

4. I added a bottle of purple ice.

I have 16 inches of vacuum at the lowest idle I can get. I like the car a lot better with the vacuum advance on manifold vacuum. I didn't have the time to do a compression test.

I went for a long drive. Prior to this, the engine was only broken in and had about 10 miles on it. While driving on normal roads and on the freeway, the car ran at 190. Heck, on the freeway, it was down to 180. I drove about 30 miles. When I got off the freeway, I kept an eye on the coolant temp. It never went over 202. I even pulled over and sat in one spot idling, with the car in gear and it never went over 202. I put my foot into it a few times and I like the cam better than I initially did. I still say my 99 Z28 would kill this car though.

That being said, the ambient temps were 15-20 degrees colder than they were the other day, so I won't go so far as to say anything is fixed.

I'm probably still going to find someone local with a cam degree kit and the experience with it to help me degree the cam.

[General Z]

Old Goat 67, the water pump has a cast impeller. I don't have pics though. The divider plate is the factory one I think.

[Old Goat 67]

There are many badly shaped cast impellers out there!

Here is a good one. NOS.

[General Z]

I believe my impeller looks like the one in your picture and my clearance may be even tighter. I had the plate basically touching without a gasket.

[mchell]

Originally Posted by General Z

Update:

I haven't degreed the cam, but I did do a few other things.

1. I changed the total timing to 32 instead of the 36 I had it at.

2. I pulled the 180 balanced thermostat that was in it and instead used a standard thermostat with the guts ripped out of it, so it's just a restrictor disc.

3. I removed my 13 lb. thermocap and put a new 16 lb standard cap on the radiator.

4. I added a bottle of purple ice.

I have 16 inches of vacuum at the lowest idle I can get. I like the car a lot better with the vacuum advance on manifold vacuum. I didn't have the time to do a compression test.

I went for a long drive. Prior to this, the engine was only broken in and had about 10 miles on it. While driving on normal roads and on the freeway, the car ran at 190. Heck, on the freeway, it was down to 180. I drove about 30 miles. When I got off the freeway, I kept an eye on the coolant temp. It never went over 202. I even pulled over and sat in one spot idling, with the car in gear and it never went over 202. I put my foot into it a few times and I like the cam better than I initially did. I still say my 99 Z28 would kill this car though.

That being said, the ambient temps were 15-20 degrees colder than they were the other day, so I won't go so far as to say anything is fixed.

I'm probably still going to find someone local with a cam degree kit and the experience with it to help me degree the cam.

You lined your cam up dot to dot?.......what makes you think it's the cam causing your issues?.... Put plenty in without degreeing and never had an issue....degreed plenty and have not found one I've had to adjust yet....must be lucky I guess

New engine?......drive it some.... You might be surprised to find temps ease up a bit

[General Z]

mchell: Yes, the engine is newly rebuilt. Heck, my knowledge is limited enough that it wasn't my call that the cam was retarded. Other board members came up with that one.

It will be 84 on Sunday, so that will be a good test to see if these new steps truly made an improvement.

Thanks

[[email protected]]

I just went thru 2 sending units that read wrong.
I checked to make sure when the thermostat open on the stove. I then put it back in the car and waited with my temp gun for the hot water to go thru the upper hose. the thermostat housing, upper hose and inlet of the radiator were all around 180. gauge read 210. went to a different store and problem fixed.

Kevin

[General Z]

I'll be swinging by Harbor Freight to pick up a temp gun in the next few days. Been on the list for a while, but never got one yet.

Thanks

[General Z]

Got it running great now. Put a 16 lb cap on, changed to a Superstant 180 instead of the balanced flow. Adjusted spark timing and idle mixture. I can drive around at 190 or less and the hottest it is getting when stopped for a while after driving is 202.

[Tom Vaught]

Did you make ANY mods to the 3310 Holley carb during this whole exercise?
or was this a new carb?

Tom Vaught

[General Z]

Tom,

I messed with the mixture screws and kept trying to decide on ported or manifold vacuum. Shortly after it was new, I upgraded the accelerator pump, because I wasn't getting a big enough shot for the size of the engine. The only other thing I did was flip the carb over and reset the secondary set screw. It was too open, too much slot was exposed. Before doing that, I could run the car without the main idle screw even being engaged.

[Tom Vaught]

Think you really need to open up the Idle Feed Restrictions on the Primary Metering Block. Stock 3310 Vacuum Secondary carb has pretty small ones. With any kind of a camshaft the engine needs more Idle Fuel/Transition fuel to not run really hot.

Here is a link to a picture showing the location of the Idle Feed Restrictions.

https://www.google.com/search?q=Holl...bs%3B600%3B399

The picture shows putting a wire in the restriction hole, we want to actually open up the hole size.

With a 455 engine, I would make those .038" in size vs the size that they are now.

They can easily be opened up with a "Pin Vice" and a .038" drill bit by hand. The brass restriction drills very easily.

If you can't do it yourself, PM me and we can work out me making the mod for you.

Tom Vaught

[General Z]

Thanks Tom. I could certainly handle doing the job, but I'm so thrilled with the way the car is running right now, I'll probably leave well enough alone for the time being. I will keep it in mind on the "future plans" list though. Thanks again. I've never heard of this modification.

[Tom Vaught]

Touch base with Shaker455 or Cliff Ruggles to confirm what I have posted (if you want)
A VERY COMMON carb mod for a Holley Carburetor.

Tom V.