How hot can aluminum heads get before they warp?

Stang_ROTY · 07-30-2001, 11:23 AM

Since I've been having cooling problems lately I thought I should ask the question. My engine was running at over 230 degrees yesterday for fewer than 5 minutes and I am concerned for the obvious reasons. The engine seems to run cooler w/out the thermostat. What are the drawbacks of removing the thermo. for good?

------------------
Finally DONE!!
93 GT, 393 stroker w/ Edlebrock Performer heads and EFI, 30lb injectors, Dynamic Roller Mite C4, 8 pt cage, Sothside Machine bars & Sub-frames, 3.73's, '69 351W block w/SCAT crank.

CRIPPLED PONY · 07-30-2001, 09:06 PM

Focus on how cool your car can run, not how hot you can get it. Just kidding, don't know any real numbers, but if it got that hot it would probably toast the motor any way.

MiracleMax · 07-30-2001, 09:32 PM

Most aftermarket aluminum heads have a pretty beefy deck on them so I would venture to say at the least they are no worse than a set of light weight factory castings and are probably better that the factory iron castings.

Have you retorqued the heads yet? After a pretty good thermal cycle like that, you might want to check the cylinder head torque on a fresh build-up? I've been told that checking torque twice should be the the bare minimum (after warming up and letting cool down) and the more the better (screw ultimate reliability I say, go for 3 times successively and maybe a 4th time at some point down the week

), losing the clamping load and letting go a gasket will warp things in a jiffy possibly leading one to think that the aluminum cylinder heads warped easily.

As for 230 degrees? the good ol' IC engine produces power right on up to 220 degrees of coolant temp after that it starts to have problems (this assuming detonation from other problems doesn't surface first). although that might be the practical limit for an all cast iron engine with a combustion chamber from about 20 years ago (all kidding aside)

Its odd that your cooling system works better without the thermostat installed, typically without the stat installed coolant circulates to quick and does not adequately absorb enough heat (or transfer out) through the cooling system typically resulting in a overheating problem.

Break down your cooling system and lets see whats going on?

Stang_ROTY · 07-30-2001, 09:34 PM

The motor ain't toasted. It started first turn this afternoon and I got 60 psi of pressure when I gave it gas. The fuel return line was leaking a little so I took of the plenum cover in attempt to change the AM fitting and I noticed some fluid like brake fluid o oil in the lip of the plenum. I'm hoping for brake fluid since the manfold is connected to the vac. tree which is connectd to the power brake booster

Stang_ROTY · 07-30-2001, 09:38 PM

MiracleMax-Thanks for the advice. FYI-I got a fluidyne raduator with a Edelbrock reverse rotation 5.0 pump, Black Magic electric fan and no coolant pipes a la stock 5.0. Maybe that's the problem?

MiracleMax · 07-30-2001, 09:52 PM

Hmmm... the radiator and water pump seems up to snuff? the pump especially, since the Edelbrock pumps increase pressure and even out coolant flow into the engine. The benefit there is higher block pressures squeeze out air pockets and raise the boiling point of coolant inside the block (funny huh, every pound of pressure you increase the system raises boiling point by 2 degrees I beleive, and since block pressures are typically higher than in the rest of the system the boiling point is even higher).

My guess (if everything is alright engine pump and radiator wise) your electric fan is letting you down

Stang_ROTY · 07-31-2001, 06:37 AM

The fan is only rated at 350HP. It could be the problem. What do you think about using a stock pulley? That would help rotate the pump quicker, right?

jimberg · 07-31-2001, 12:27 PM

I remembered reading something about old 351 blocks and water passages. This was a blurb in the installation notes for my TFS TW heads.

Quote:

Quoted from Trick Flow Twisted Wedge Installation Notes:
Note that the large coolant holes always go toward the rear of the block. If you have a pre-1972 block or a 351 SVO block, you must modify the coolant passages in the deck surface as shown in Figure 3. Using the head gasket as a template, drill into the water jacket at the locations shown with a 3/16 in. drill bit. This modification must be done to prevent overheating due to steam pockets forming in the high side of the block. Be sure to tape off or otherwise cover the deck surface and cylinder bores when you are drilling.

Did you do this?

------------------
351W 89 Mustang GT Convertible

[This message has been edited by jimberg (edited 07-31-2001).]

Stang_ROTY · 07-31-2001, 01:03 PM

No I didn't. This is not good. thanks, I need to talk to my engine builder.

MiracleMax · 08-01-2001, 01:14 AM

Quote:

Originally posted by Stang_ROTY:
The fan is only rated at 350HP. It could be the problem. What do you think about using a stock pulley? That would help rotate the pump quicker, right?

This is how I look at things

hi perf pump + UD pulley @ low rpm = stock cooling or there abouts and as engine speed increase the gap opens back up in favor of the modified pump.

Taking a look at things Jim might have the answer? especially since you indicated that the engine ran cooler with the stat out. I would venture to say that maybe if you have the early block with your heads then maybe the water is cycled through the system to fast to allow steam pockets much time to accumulate?

that wouldn't be a fix though, just some duct tape covering up a problem since you still wouldn't be getting the benefit of allowing the coolant in the block time enough to absorb heat to its capacity.

Stang_ROTY · 08-01-2001, 06:37 AM

But where was the info in my box from Summit for such a drastic modification? I spent 8 months putting this car together and I did a lot of research into what I bought. I don't mean to sound like an A$$hole but I've spent too much time on the phone with tech's from Edelbrock, Summit, and FRPP to have not heard about this. I can't imagine how many dents I'd kick in the car if I have to yank that damn engine back out for the 11th time. Basically, I've come too far to go backwards. If I need to disassemble the engine I'm done with this project. I'll sell everything.

MiracleMax · 08-01-2001, 05:40 PM

Don't get discouraged my man! I know what your going through, I built a 302 and it grenaded about 2 weeks after I fired it up, discouraged...yes. Give up! No mother freakin way! If it blows up again I'll build another one!

Anywhosit you'll never get back what you put into it money or laborwise.

whats it take to pull the motor from the car? an hour and a half start to finish (I've yanked mine in as little as 45 minutes) then you got a little bit of teardown to do?

If you want to make that a last resort, then put together a check list and work your way down from simnple to hard.

I'd start with the engines state of tune then go on to the cooling system, elminating any problems as a I worked along, checking things like part numbers and the like, maybe switching some things out? Do you have the old fan assy? If so try pulling the the electric fan and installing an engine driven fan to see if that helps?

Dude you obviously spent some time and effort putting your combo together, no point in throwing it all away even if it means you have to pull the egine (or not the way Jim seems to describe, if thats the problem? You might just have to pull the heads?)

Stang_ROTY · 08-01-2001, 11:54 PM

I ried it again without a thermostat today and the engine started to heat up after about 15 minutes. I'm really starting to think that these dudes from edelbrock lie, or the pulley's I got from MARCH are straight drag racing??
Anyway, I get home and park the car on a decline with the front end pointing down. That's how the driveway is designed. 2 minutes into shutoff I blow a brand new thermostat gasket I installed. So I remove the radiator cap with a towel protecting my hands and some hot coolant come up. THEN all of a sudden the MOROSO reservoir decides to kick in and dumps a little rad. fluid and some dirt out the release valve. This sucks. It's my b-day and I can' even enjoy my car, I'm willing to met a bet that my engine builder screwed something up with the gakets.

PWR_RYD93 · 08-02-2001, 09:20 AM

Sounds like your head gaskets might be installed backwards (i.e. coolant passage holes towards the front instead of the back).

------------------
Craig
Supercharged 93 GT
Basically stock 93 Cobra
"I drive way too fast to worry about cholesterol!"

Stang_ROTY · 08-02-2001, 10:20 AM

Try to tell my engine builder that. He keeps blaming the Waterpump and pulleys

jimberg · 08-02-2001, 01:45 PM

I have a stock water pump and BBK underdrive pulleys and don't overheat. I think it's time to find a new engine builder.

------------------
351W 89 Mustang GT Convertible

Stang_ROTY · 08-02-2001, 03:24 PM

I talked with him today and he said checked the head gaskets several times to make sure that they fit correctly and didn't block my coolant passages. I have a stock type March pulley coming tomarrow which will hopefully help me. It has to....I hope. The rep. from March said that the set of pulley's I have kill my cooling bby 20%! That's pretty significant, right? As far as getting a new engine builder, I really can't. Everyone around here is Chevy, Chevy, Chevy. He really is the most reputable builder and takes a lot of pride in his work. I have no other avenues to explore. The reason he keeps bringing up the water pump is b/c he thinks the impeller might not be turning the right way, making my pump a standard rotation pump. If it was a standard rotation and I'm driving it the wrong way how could the engine cool?

jimberg · 08-02-2001, 03:58 PM

Quote:

Originally posted by Stang_ROTY:
The reason he keeps bringing up the water pump is b/c he thinks the impeller might not be turning the right way, making my pump a standard rotation pump. If it was a standard rotation and I'm driving it the wrong way how could the engine cool?

Hmm, this is new information. What is the part number of the water pump you have? Our crank pulley turns clockwise so the water pump turns counter clockwise. Is your water pump supposed to turn clockwise or counter clockwise?

------------------
351W 89 Mustang GT Convertible

Stang_ROTY · 08-02-2001, 05:03 PM

Ihad both pumps at one time and when I realized I needed the 8840 from Edelbrock I sent back the other one for the standard rotation...I think. I called Summit to verify I sent back the standard roatation and they agreed that the one I sent back was the standard one. But how do I know for sure? They supposedly have someone on the floor that visually checks but there is no guarantee.

08-03-2001, 11:55 AM

You're not going to believe this, I very recently went through something exactly like this. My car was running hot after the new engine so I upgraded the coolings system with a griffin rad and black magic fan. It still ran hot.. even hotter than before. I changed the thermostat a couple times(aggrevating with a blower on) and I kept trying to figure it out. Long story short.. the black magic fan was blowing the wrong way!! It was wired wrong from the factory! It felt like it was blowing in the right direction when you put your hand behind it because it was blowing against the radiator and then back towards the engine. We dropped the fan and switched 2 wires and now it runs so cool... its perfect.

------------------
Rick
My 89lx(updated 7/20/2001)
My 97 Cobra

07-30-2001, 11:23 AM	#1
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	How hot can aluminum heads get before they warp? Since I've been having cooling problems lately I thought I should ask the question. My engine was running at over 230 degrees yesterday for fewer than 5 minutes and I am concerned for the obvious reasons. The engine seems to run cooler w/out the thermostat. What are the drawbacks of removing the thermo. for good? ------------------ Finally DONE!! 93 GT, 393 stroker w/ Edlebrock Performer heads and EFI, 30lb injectors, Dynamic Roller Mite C4, 8 pt cage, Sothside Machine bars & Sub-frames, 3.73's, '69 351W block w/SCAT crank.

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07-30-2001, 09:06 PM	#2
CRIPPLED PONY Registered Member Join Date: Jul 2001 Location: BURLESON, TX Posts: 14	Focus on how cool your car can run, not how hot you can get it. Just kidding, don't know any real numbers, but if it got that hot it would probably toast the motor any way.

07-30-2001, 09:32 PM	#3
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Most aftermarket aluminum heads have a pretty beefy deck on them so I would venture to say at the least they are no worse than a set of light weight factory castings and are probably better that the factory iron castings. Have you retorqued the heads yet? After a pretty good thermal cycle like that, you might want to check the cylinder head torque on a fresh build-up? I've been told that checking torque twice should be the the bare minimum (after warming up and letting cool down) and the more the better (screw ultimate reliability I say, go for 3 times successively and maybe a 4th time at some point down the week ), losing the clamping load and letting go a gasket will warp things in a jiffy possibly leading one to think that the aluminum cylinder heads warped easily. As for 230 degrees? the good ol' IC engine produces power right on up to 220 degrees of coolant temp after that it starts to have problems (this assuming detonation from other problems doesn't surface first). although that might be the practical limit for an all cast iron engine with a combustion chamber from about 20 years ago (all kidding aside) Its odd that your cooling system works better without the thermostat installed, typically without the stat installed coolant circulates to quick and does not adequately absorb enough heat (or transfer out) through the cooling system typically resulting in a overheating problem. Break down your cooling system and lets see whats going on?

07-30-2001, 09:34 PM	#4
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	The motor ain't toasted. It started first turn this afternoon and I got 60 psi of pressure when I gave it gas. The fuel return line was leaking a little so I took of the plenum cover in attempt to change the AM fitting and I noticed some fluid like brake fluid o oil in the lip of the plenum. I'm hoping for brake fluid since the manfold is connected to the vac. tree which is connectd to the power brake booster

07-30-2001, 09:38 PM	#5
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	MiracleMax-Thanks for the advice. FYI-I got a fluidyne raduator with a Edelbrock reverse rotation 5.0 pump, Black Magic electric fan and no coolant pipes a la stock 5.0. Maybe that's the problem?

07-30-2001, 09:52 PM	#6
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Hmmm... the radiator and water pump seems up to snuff? the pump especially, since the Edelbrock pumps increase pressure and even out coolant flow into the engine. The benefit there is higher block pressures squeeze out air pockets and raise the boiling point of coolant inside the block (funny huh, every pound of pressure you increase the system raises boiling point by 2 degrees I beleive, and since block pressures are typically higher than in the rest of the system the boiling point is even higher). My guess (if everything is alright engine pump and radiator wise) your electric fan is letting you down

07-31-2001, 06:37 AM	#7
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	The fan is only rated at 350HP. It could be the problem. What do you think about using a stock pulley? That would help rotate the pump quicker, right?

07-31-2001, 01:03 PM	#9
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	No I didn't. This is not good. thanks, I need to talk to my engine builder.

08-01-2001, 06:37 AM	#11
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	But where was the info in my box from Summit for such a drastic modification? I spent 8 months putting this car together and I did a lot of research into what I bought. I don't mean to sound like an A$$hole but I've spent too much time on the phone with tech's from Edelbrock, Summit, and FRPP to have not heard about this. I can't imagine how many dents I'd kick in the car if I have to yank that damn engine back out for the 11th time. Basically, I've come too far to go backwards. If I need to disassemble the engine I'm done with this project. I'll sell everything.

08-01-2001, 05:40 PM	#12
MiracleMax Registered Member Join Date: Apr 1999 Location: Hayes, Va, USA Posts: 798	Don't get discouraged my man! I know what your going through, I built a 302 and it grenaded about 2 weeks after I fired it up, discouraged...yes. Give up! No mother freakin way! If it blows up again I'll build another one! Anywhosit you'll never get back what you put into it money or laborwise. whats it take to pull the motor from the car? an hour and a half start to finish (I've yanked mine in as little as 45 minutes) then you got a little bit of teardown to do? If you want to make that a last resort, then put together a check list and work your way down from simnple to hard. I'd start with the engines state of tune then go on to the cooling system, elminating any problems as a I worked along, checking things like part numbers and the like, maybe switching some things out? Do you have the old fan assy? If so try pulling the the electric fan and installing an engine driven fan to see if that helps? Dude you obviously spent some time and effort putting your combo together, no point in throwing it all away even if it means you have to pull the egine (or not the way Jim seems to describe, if thats the problem? You might just have to pull the heads?)

08-01-2001, 11:54 PM	#13
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	I ried it again without a thermostat today and the engine started to heat up after about 15 minutes. I'm really starting to think that these dudes from edelbrock lie, or the pulley's I got from MARCH are straight drag racing?? Anyway, I get home and park the car on a decline with the front end pointing down. That's how the driveway is designed. 2 minutes into shutoff I blow a brand new thermostat gasket I installed. So I remove the radiator cap with a towel protecting my hands and some hot coolant come up. THEN all of a sudden the MOROSO reservoir decides to kick in and dumps a little rad. fluid and some dirt out the release valve. This sucks. It's my b-day and I can' even enjoy my car, I'm willing to met a bet that my engine builder screwed something up with the gakets.

08-02-2001, 09:20 AM	#14
PWR_RYD93 Registered Member Join Date: Sep 1998 Location: IL Posts: 1,155	Sounds like your head gaskets might be installed backwards (i.e. coolant passage holes towards the front instead of the back). ------------------ Craig Supercharged 93 GT Basically stock 93 Cobra "I drive way too fast to worry about cholesterol!"

08-02-2001, 10:20 AM	#15
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	Try to tell my engine builder that. He keeps blaming the Waterpump and pulleys

08-02-2001, 01:45 PM	#16
jimberg Registered Member Join Date: Oct 1998 Location: Rogers, MN Posts: 2,089	I have a stock water pump and BBK underdrive pulleys and don't overheat. I think it's time to find a new engine builder. ------------------ 351W 89 Mustang GT Convertible

08-02-2001, 03:24 PM	#17
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	I talked with him today and he said checked the head gaskets several times to make sure that they fit correctly and didn't block my coolant passages. I have a stock type March pulley coming tomarrow which will hopefully help me. It has to....I hope. The rep. from March said that the set of pulley's I have kill my cooling bby 20%! That's pretty significant, right? As far as getting a new engine builder, I really can't. Everyone around here is Chevy, Chevy, Chevy. He really is the most reputable builder and takes a lot of pride in his work. I have no other avenues to explore. The reason he keeps bringing up the water pump is b/c he thinks the impeller might not be turning the right way, making my pump a standard rotation pump. If it was a standard rotation and I'm driving it the wrong way how could the engine cool?

08-02-2001, 05:03 PM	#19
Stang_ROTY Registered Member Join Date: Feb 2001 Location: Berkshire County - Massachusetts Posts: 735	Ihad both pumps at one time and when I realized I needed the 8840 from Edelbrock I sent back the other one for the standard rotation...I think. I called Summit to verify I sent back the standard roatation and they agreed that the one I sent back was the standard one. But how do I know for sure? They supposedly have someone on the floor that visually checks but there is no guarantee.

08-03-2001, 11:55 AM	#20
rbatson Guest Posts: n/a	You're not going to believe this, I very recently went through something exactly like this. My car was running hot after the new engine so I upgraded the coolings system with a griffin rad and black magic fan. It still ran hot.. even hotter than before. I changed the thermostat a couple times(aggrevating with a blower on) and I kept trying to figure it out. Long story short.. the black magic fan was blowing the wrong way!! It was wired wrong from the factory! It felt like it was blowing in the right direction when you put your hand behind it because it was blowing against the radiator and then back towards the engine. We dropped the fan and switched 2 wires and now it runs so cool... its perfect. ------------------ Rick My 89lx(updated 7/20/2001) My 97 Cobra