Starting the build/mods

The thermostat we have already has a small hole in it. It has a little brass kinda check valve that flutters back and forth...it does not seal one way or the other.

Any way the "balance line" at the back of the engine could have had something to do with this?

Hope Haydn has a closer look at it tonight.

 

We used LUCAS Hot Rod & Classic high zinc 10w40 oil, with a quart of actual LUCAS Break-in oil. (Only used 4 quarts out of five of the 10w40)
We dumped the oil the next day, because we thought it got hot, but the temperature gun proved otherwise. (And we picked up another Autometer temperature sender.)

This is gonna be the second oil change, but it's better to be safe, than sorry.
The electric fans worked great before, and I turned the setting down to the minimum for the new engine.
No air come out of the temperature sender hole, when I pulled it out to replace it.

A lot is running through my head, as to what it could be...but I keep coming back to the thermostat.
Either that, or we got the wrong head gaskets maybe??? idk

 

That temp sender may not be compatible with your gage. I went thru that on my boat this spring. Had to put a resister in-line on the sender(VDO), to calibrate the gage(AC delco) reading. Got it perfect with boiling water on stove, and meat thermometer, but installed, it still reads 10 degrees off. I can live with that.

Something I've noticed: 70 & later blocks/heads need these 3/16" burp holes. 68-69 gaskets don't have them. Black arrows. I sold Sean a couple sets of the 68 style steel gaskets, and told him to drill the holes. I don't think having the holes interferes with the older style blocks/heads either.

 

I did see you had a thermostat with a hole in it so that should be ok. The line at the back of the intake could be the problem.

I did an entire post on this and the consensus was Not to hook up any line from the back to the front. I see you connected the two sides together.

The water travels thru the heads to the back then goes thru the heads to the front of the engine. The water needs to go thru the heads to cool them off and now I feel the line at the back or connecting this in any way to the front could and probably does Disrupt the water flow thru the heads. This could be why you have air in the engine and could be the problem with the overheating issue. I would plug those two lines and start over.

I even feel hooking up the line at the back of the engine to the heater core is not a good idea either since this may stop the flow thru the head on that side to the front. The line was put at the front to the heater core for a reason at the factory.

 

Things we will try when I get home:

-pull thermostat, and test it to see if it's NFG.
-remove the rear tube that connects the rear coolant ports on the intake.
-change to a colder set of plugs. (Asked Haydn to pull plugs and check them, and send me a picture.)
-look at the initial timing. Presently at 10-12* BTDC, I believe.
-try to lift front of car even higher when refilling coolant.
-dump oil out, and refill. Replace oil filter as well.

***The sender we bought, an Autometer, was the correct replacement sender for the Autometer gauge.***

 

Tested the thermostat tonight...works perfect. Starts to open at 180*F, fully open by 200*F.
Changed the gap on the plugs from 0.040" down to 0.032"
They are a range 7. (Stock is a range 5) NGK are backwards, so the higher the number, the colder the plug.
Removed the rear balance line from the intake manifold.
Removed the little brass "check valve" from the thermostat.
Will be filling it up again tomorrow morning to see if I can get the air out of it.....

 

Don't know much abt the NGK's, I run A/C R45TSX's gapped @ .060

The MSD fires them very well.

 

I asked the same questions about the gap of the plugs.
They said "Of course the MSD can fire it at 45, or even 65 thou gap...but for the compression you got, it will fire a stronger spark when gapped at 32 thou.

These guys are racers. Father and son both race their race cars, not their daily drivers...the father has worked in speed shops all his life, and finally opened up his own shop.
His son is a high performance junkie, fully licensed mechanic, who got awards at some kind of engine building competition.

I gotta at least try what they suggest.

I also appreciate all the help everyone is giving us here as well. Without this forum, and its members, this entire engine would not have come to exsist at all.

We had one of the biggest car shows here a couple weeks ago...just over 270 cars and trucks....not one Buick, and not one 69-72 GMC/Chevy truck!
Harry, one of the members here, has the rankest GSX clone I have ever seen. I was very disappointed that he never brought it out. (He works a lot though)

These are very rare cars, and everyone who stops to see Haydn's car, starts by saying, "I remember my best friends dad had one of these cars...."

I am almost 100% sure it was just air locked.
Haydn finally told me the REAL story of what happened last night over 6 lbs of wings, and beers.

He was visiting an old co-worker at Tim Hortons.
After the visit, he came out to find his friend had just finished work, and was waiting for him at his car. (Parked beside him)
Haydn asked him if he was ready to go for a ride, and of course his friend's reply was, YES!
So they drove to a spot in town that is not busy with traffic at all, going 35-40mph. (70 Km/hr) and Haydn just drops the hammer down....
The car broke the tires loose, and spun, throwing the car into a nice slide for about 40 or 50 feet.
That's when he heard a bang of some kind, and he pulled over.
That's when he found that the plastic ring gear cover had melted, and was dragging on the ground.

So it was basically a wot run, on a 37*C day...(98.6*F)

30mph is 1500 rpm with the 3.73's and 295 x 50's.

I'm impressed....doing a rolling burnout at 35-40 mph... This thing has torque!

Anyways...Haydn has now started his courses at the College for becoming a Power Engineer, so I'm gonna put the thermostat in this morning, and try filling the block through the holes in the intake manifold, which are at the back of the block...where the balance line was.
Going to fill it extremely slow, and maybe even not put the thermostat in until I see coolant at the front of the engine...just to help get the air out of the block better.

Wish me luck!

 

Well...I think the temperature gauge is NFG.
We removed the fittings at the back of the intake manifold.
We left them open, so I could fill the block with coolant on the passenger side hole, while Haydn watched the drivers side, as well as the thermostat housing. (We left the thermostat housing off as well while filling.
Block took a jug of coolant before it reached the top of the holes at the back of the block. That's when we installed the plugs into the intake manifold. (Where the balance line was.)
Next we removed the top heater hose, and back filled the heater core. Watching air get pushed back through the radiator cap opening all the while.
Didn't take long at all, and we had coolant at the thermostat housing, and had to put the thermostat back in. (With the bypass hose.)
We kept filling through the heater hose, until we had coolant right to the top of the heater hose fitting on the intake manifold.
I lowered the hose to check to make sure the level was the same at the rad, as the block fitting, and the heater hose in my hand...it was not, so I knew there was a bit of air somewhere.
Lifting the heater hoses off the fenderwell, and squishing the hoses by hand, we eventually got the levels all the same.
Connected the heater hose to the intake, and continued to fill through the radiator.
Once the coolant was about 2" from the top of the radiator, we started the car, and let it heat up.
Once it was good and warm, we could see the flow coming through the radiator, we could tell when the thermostat was opening, and closing...so we dialled up the fans, so it would let the coolant get hotter.
Once the coolant was a continuos flow, we knew the engine was at 180-200*F
Playing with the hoses, we were still getting a small amount of air, so we kept on doing the same thing.

All this was done while the car was lifted as high as possible with our floor jack, lifting the entire front of the car.

All the air is out.

Filled the rad to the top, and revved it to about 1500rpm...coolant went down a bit, so we topped it up again, and put the cap on.

Last thing we did was dial the fan thermostat down, so the fans would come on at 140*F. (Lowest setting)

 

Man i m not being all whatever but that's entirely to much hassle , all you have to do is fill the rad letting the water settle each time till it's full takes about 30min then crank with the cap off and finish filling after the stat opens and the level drops. Never once on any car have I needed to remove hoses, thermostats, drill holes in thermostats ,Jack the car up or anything like that. Ive probaly installed at least 500 radiators. You've got it full that's good, so this is more for anyone else reading this I suppose. If you really want to get serious you can use one of the 12 water ports on the Sp3 and put a burp valve off a late model car in there

 

X2, seems going overboard to me also.

 

Well I guess it's just me not wanting to ruin a new engine over something stupid...

Sorry for the step-by-step...

 

Engines are tougher than alot of people think, little heat not going to hurt it man, I understand it's $$$, but stressing over it takes the fun out of it I promise.

 

With all that money invested, I'd be careful too.

Aluminum is less forgiving than iron.

I appreciate reading about all the little details.

Keep up the good work!

 

Ended up buying a new temperature gauge with sender included.
Didn't even need to use the new gauge...just swapped the sender out, and temperature was perfect.

Difference in the quality is very apparent between the replacement senders, and the ones that come with the gauges.

Good to know the engine was never overheated.

 

Yep, must be touchy calibration.
Great feeling to know it's a bad sender or gauge.

How's the break-in going? That cam should perform well.

 

Well Haydn took me for a scoot after verifying no leaks.
Temperature got up to 180, and he found a nice quiet back road....
This thing is gonna lose races every time....off the line wheel spin right to 2nd gear, through 2nd till it grabs traction, and then downshifts back to first.
......needs drag radials......and disc brakes.
Temperature never got over 180, even after the full throttle burst.
Turned onto the highway, and lett'r buck!.....thing goes like the streets are wet....frickin nuts!

 

For a driver do the LS brake conversion you can buy everything new from Rock auto for around $150/200 MUCH better stopping power and you don't have to change the spindles, as you uses your drum Spindle hub setup