Edelbrock heads engine overheating steam vent question

jerthemost · May 28, 2011

I have a 68 mustang coupe with automatic and 289 engine, a/c, ps.pb. I just had the heads changed out. I had edelbrock e-street heads with the 1.9 valves installed. I used comp cams aluminum roller rockers. I also had edelbrock cam installed at the same time along with new high performance water pump, edelbrock timing set. I gave the mechanic a new premium 180 deg. Thermostat to install which I later found out he did not do. Instead he put in an orifice with 5/8” hole. The car never ran hot before the head and cam change but now I cannot drive it because the temp shoots up very fast and will overheat if I don’t shut it down. I let it get to 230 then shut down. I tried putting water on the front of radiator as a test to see if that would bring the temp down much indicating that the radiator is too small. The temp only dropped less than 10 degs. The rad is oversized by the way 22”. The mechanic told me I had to buy a monster radiator with elec fans for about $1600 plus install.

I called edelbrock and discussed it with them. The first thing the guy said was did you drill the steam vent holes. I checked with the mechanic and he did not drill the holes. Edelbrock says it should not be running any hotter than before the new heads if installed correctly and that the steam vent holes not being drilled will definitely cause overheating.

Does anyone have any experience along this line? And how much difference in temp do you think it would make? Do i need holes and new radiator? All comments appreciated.

rbohm · May 28, 2011

if you read the instructions regarding the installation of the edelbrock heads, you will find that with the heads going on a 289 block that there are steam holes that need to be drilled in the block. you can use the head gasket as a template to drill the needed holes. here is a detail of the e head install instructions;

http://www.edelbrock.com/automotive_new/misc/tech_center/install/5000/5025.pdf

jerthemost · May 28, 2011

i have the instructions

i have the instructions and i even brought it to the attention of the mechanic and his service manager before the changeout. i am looking to see if anyone has hadd experience with tthis issue and if it makes a lot of difference in temp and if so how much. thanks

2+2GT · May 28, 2011

I would not drill the "steam holes". The coolant should enter the cylinder block, travel all the way to the rear of the engine, then up through the large coolant holes at the rear of the head, forward to the front of the head, and into the intake manifold. Drilling the holes allows coolant to bypass the rear of the engine, which keeps the front nice and cool but allows the rear half of the engine to permanently overheat.

You should also be using a genuine Ford 190° thermostat, which is what the engine was designed for. Use the Ford, I have seen too many aftermarket units run erratically.

The arrow points to the front, which has no coolant passages, the large holes at the rear are for that.

jerthemost · May 28, 2011

very interesting

sounds like you know what you are talking about. this is a very interesting point about cooling bypass but what you say does make sense. i am going to run this one by edelbrock and see how they justify the bypassing of coolant. i will post their answer next week. will also get a ford tstat. i am in hot houston texas climate do you think 190 is right for this area?

2+2GT · May 28, 2011

190° is right for the engine. If you have an overheating problem, putting the wrong thermostat in won't help.

stangman67 · May 28, 2011

I installed 60229 i believe, about 6 years back, and did drill the block. I see the logic of 2+2 but they must know something that we do not. If i understand correctly, you now have a plate with a 5/8" hole in place of the tstat? If so i would try a tstat first, and then if it doesnt help, drill those holes. Also, sounds like maybe you need a new shop. $1600 seems like an awful lot for any of the fancy units installed.

iskwezm · May 28, 2011

2+2 is not correct. You MUST drill the steam holes. I had the same issue. Asked my buddy that works for Edelbrock and he gets a lot of calls from people what know more and will not drill them and chase the overheating every which way.The heads are made for newer blocks and by drilling, they can be used on older blocks

Loup-garou · May 29, 2011

2+2GT said:
I would not drill the "steam holes". The coolant should enter the cylinder block, travel all the way to the rear of the engine, then up through the large coolant holes at the rear of the head, forward to the front of the head, and into the intake manifold. Drilling the holes allows coolant to bypass the rear of the engine, which keeps the front nice and cool but allows the rear half of the engine to permanently overheat.

You should also be using a genuine Ford 190° thermostat, which is what the engine was designed for. Use the Ford, I have seen too many aftermarket units run erratically.
(snip)

The "steam holes" are misnamed; all they do is allow trapped air to be purged from the uppermost portion of the block's cooling jacket. They are not large enough to disrupt the primary flow of coolant.

Aluminum heads conduct heat away from the combustion chambers more rapidly than cast iron heads do; that is why the overheating problem is seen after the installation of such aftermarket heads (not just Edelbrock) where no problem was evident when running the iron factory heads.

2+2GT · May 29, 2011

Seriously? The 1/4" diameter so-called steam holes in this stock 289 block aren't big enough? Sounds like a real good reason to avoid using aftermarket heads, to me.

jerthemost · May 29, 2011

radiator suggestions?

thanks for all the comments. i think i will ask the mechanic to drill the holes since it is recommended by edelbrock and cannot do any harm anyway. i will also have him take out restrictor and put in thermostat. then will see what we have. but can someone reccomend a radiator size, type brand etc? i cannot go any wider than what i have now without moving the battery.

65ShelbyClone · May 29, 2011

If the mechanic can't follow even simple directions like using the thermostat you provided, I wouldn't put it past them to have installed the head gaskets backward, which will also cause overheating.

2+2GT · May 29, 2011

65ShelbyClone said:
If the mechanic can't follow even simple directions like using the thermostat you provided, I wouldn't put it past them to have installed the head gaskets backward, which will also cause overheating.

I agree. Anyone who uses a restrictor plate on a street-driven car (especially against the express instructions of the car's owner) is not to be trusted.

As for Edelbrocks' instructions, I fail to see how drilling a 1/8" hole, lower down than the 1/4" factory hole will accomplish anything at all.

And even if you want to do it, do you really trust Bubba to drill the right size? After all, he screwed up the thermostat part, which as far as I'm concerned is 100% of your overheating problem. Now he want's to sell you a $1600 cooling system? He's not just incompetent, he's a thief. Put a new thermostat in yourself, and avoid this yokel. I'm betting you could cure this problem for $10 and an hour of your time.

65ShelbyClone · May 29, 2011

2+2GT said:
As for Edelbrocks' instructions, I fail to see how drilling a 1/8" hole, lower down than the 1/4" factory hole will accomplish anything at all.

If the E-Street head is machined like a Performer, then this is why:

There's nothing for the original hole in the block to line up with.

2+2GT · May 29, 2011

I guess they figure a poorly-placed vent hole is better than none.

65ShelbyClone · May 29, 2011

Yeah, it's really been a problem since Ford completely omitted that 12:00 coolant hole in the early '80s.

Oh, wait...

2+2GT · May 30, 2011

65ShelbyClone said:
Yeah, it's really been a problem since Ford completely omitted that 12:00 coolant hole in the early '80s.

Oh, wait...

Hmmm… That would mean about a spazillion SB Ford engines don't have these holes, such as my '97 5.0, which is in a truck, and and never overheats (or even goes above normal) even in heavy traffic, on 98° days, with the AC pumping out ice cold air… I see your point.

65fastbackresto · May 31, 2011

Per Edelbrock the steam hole is...

To prevent a hotspot from forming in that part of the head, being as aluminum shrinks and contracts at a different rate than iron, it only becomes a problem when your using aluminum heads on the iron block. I went thru the same thing about 4 years ago.

danledford · Jun 4, 2011

So, is there any way to tell whether you have a "new" or "old" block that requires drilling? My'68 is running hot and I can't remember whether I checked or not before installing the heads. I'd hate to have to tear down the engine to find out if this is my problem.....

2+2GT · Jun 4, 2011

danledford said:
So, is there any way to tell whether you have a "new" or "old" block that requires drilling? My'68 is running hot and I can't remember whether I checked or not before installing the heads. I'd hate to have to tear down the engine to find out if this is my problem.....

Sure- Is it the 68 block?

Edelbrock heads engine overheating steam vent question

jerthemost

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