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Discussion Starter · #1 ·
hi guys; i have an 350 chevy engine with an 4bl. edelbrock intake and i noticed a small amount of antifreeze around most intake bolts so does this mean the gaskets are bad and if so what type is best for alum. intakes? also with this leaking gaskets perhaps this has been causing my car to run at high temp 200-220 degrees in traffic jams idling? Help and thanks
 

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489 Lemans
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don't do anything drastic

The intake bolts screw into the heads which overhang the lifter valley. If you do not put thread sealer on these bolts oil may bleed up through them but not antifreeze. My guess would be you have a leak around the thermo housing or hose (maybe even rad) and the fan is blowing it back across the intake and settling around the bolts. Try to find the leak before pulling the intake off.

Doesn't matter where the leak is. Low antifreeze will cause high temp.
 

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check the simple first to leak test

wrong radiator psi cap = to much pressure forcing a leak (and the opposite, use a higher psi cap to test for leaks)

stuck thermostat or not fully opening = start the car motor cold, cap off, let it warm up, should be a "river" of coolant flowing when the thermostat is open across the top of radiator

leaking radiator/hoses/pump etc = fill the radiator to the correct level, clean and dry all the possible culprits, warm up the motor, turn it off and sprinkle baby powder/talc on all, put newspaper on the floor, let it sit over night

weird but cooling system hose clamps do loosen themselves and do it "whenever" they want to
 

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I have an Edelbrock intake also and had the same problem.

Standing at the front of the car, looking at the engine, the second bolt on the intake(both sides) runs thru the water jacket for your thermostat. If you do not use a bolt sealer these will leak and run to the back of the intake.

Dry off the intake and when the engine is cold pull the bolts seal them and then warm the engine to operating temp. Then check the bolts for correct toque and your leak should be cured. You should check the apposing bolts at the rear of the intake also.

Top off your radiator and you should be good to go.

Pappy
 

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If pappy is right....

If you do re-seal the bolts, 10-12ft/lbs should be enough!

It's very easy to snap a bolt or break the manifold with to much torque!

Won't seal with 12, probably didn't clean enough when you mounted it, remove and clean some more
 

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489 Lemans
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front 2 bolts

I have never had the front bolts on a sb leak. I have had a leak in my bb but it ran down the front of the block. I always put sealer around the water ports on the heads and intake before installing. I wasn't aware that the front 2 bolts go into the water jacket. I have a brand new set of alum heads in the garage. Will have to check it out.
 

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Re: front 2 bolts

bracketeer said:
I have never had the front bolts on a sb leak. I have had a leak in my bb but it ran down the front of the block. I always put sealer around the water ports on the heads and intake before installing. I wasn't aware that the front 2 bolts go into the water jacket. I have a brand new set of alum heads in the garage. Will have to check it out.
My Darts dont go into the water jackets.

Chris
 

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pappy 32

I have never seen a small block Chevy manifold from Edelbrock or anyone else where any of the manifold bolts pass through a water jacketed area of the manifold. Nor do they go into a water jacketed area of the cylinder heads. There should be no need to coat the manifold bolt threads with a sealant. My company is in the intake manifold business so I am pretty familiar with their design and construction.

To the original poster, as mentioned by someone else, the only way coolant could be collecting around your intake manifold bolts is if the coolant was coming from somewhere else like the thermostat housing, radiator hose, or radiator and blowing back over the engine and collecting by those bolts. One other possible source of a leak is if there is some porosity in the casting in the area of the manifold water jacket and coolant is seeping from there. You should be able to see this however.
 

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i recently had the same thing happen to me.first time in my life.i also recently watch horse power t.v. and saw them change an intake and again for the first time ever hearing anyone mention it;they specifically said to put sealer or silacone on the bolt threads to prevent oil and antifreeze from coming up the threads.i'm pretty sure they use silacone which i know you won't often see.if you use silacone go easy on it cause its hell to clean when the time comes.
 

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It is possible for oil to come up since eight of the twelve bolts holding the sb manifold onto the heads are tapped through to the valley chamber. The four corner bolts go into blind holes. However, I have been running small block Chevys since the mid-fifties and don't recall ever seeing any oil coming up under bolt heads and I never used any kind of sealant on them. And some of my engines were spinning up around 10,000 rpm.

However unless your block or heads are cracked and coolant is leaking into the valley chamber, I don't see how it is possible to ever get coolant coming up under a manifold bolt head.
 

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Discussion Starter · #12 ·
thanks all of you, i will try the sealant on bolts this weekend and what can anyone tell me about vacuum readings like my car idling at 800 rpm's has a reading 10 to 12 inches back and forth. should it be a steady reading and what should it be?
 

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rick,

now you have listed 3 problems, a leak, runs hot, low vacuum.

all we know from what you have written so far is that you have a 4V on a 350......

no info=no answer possible
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Don't do Chevy's, but from the knowledgeable people who posted, I doubt sealing the bolt will work.

A small block Ford can leak around the intake and I wonder if Pappy 32 missed that it is a Chevy

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If the heater hoses are next to the carb, good chance that is the leak. The motor cooks and destroys those hoses
 

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By chance do you have the thermostat housing with the O-Ring style gasket? On my Edelberock Performer RPM,I had to set it about three different times to get it to seal correctley.
 

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It would seem that I have caused a lot of conversation about this bolt leakage. After rereading and some researching This is what I have concluded:

I said in my first post:

"Standing at the front of the car, looking at the engine, the second bolt on the intake(both sides) runs thru the water jacket for your thermostat. If you do not use a bolt sealer these will leak and run to the back of the intake."

At the point of looking at the second bolt on the intake, I should have said that the bolt runs by, NOT THRU the water jacket and may leak if not properly torqued.

If this statement has caused more problems I'm truly sorry for my mis-spoken statement. It was not meant to mis-inform. So when I get up to get another cup of coffee I will at that time .....
Stand Corrected!

I did some researching and found this on the Edlebrock site:

Edelbrock Installation Tips

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Edelbrock Performer Intake Manifolds

1. The following Edelbrock Performer intake manifolds require the use of our #2732 square-bore adapter when using an Edelbrock or other square-bore carburetor: 2104, 2151, 2156, 2161, 2730, 3706, 3761, and 5486. The #2732 is an 1/16" thick steel plate with a gasket and ensures you will not have a vacuum leak between the intake manifold and the carburetor base. The #2101 Performer manifold does not require a #2732 adapter when using an Edelbrock Performer Series carburetor. When using a Holley carburetor on a #2101 Performer manifold, a #2732 adapter is required.
2. DO NOT use the Fel-Pro Permatorque/Blue intake gaskets. Because of their very hard, non-pliable construction, they don't compress well when used with an aluminum intake manifold. Instead, use a Fel-Pro Printoseal or Mr. Gasket UltraSeal gasket. The factory composition-type embossed gasket also works satisfactorily.

3. Be sure to bolt down the intake following the specific sequence noted in the manifold's instruction sheet. Failure to follow this sequence can result in a "warped" intake. DO NOT over-torque manifold bolts as this may cause damage to the manifold. The manifold bolts need to be torqued down to 25 ft/lbs in most cases, but be sure to check the instruction sheet for clarification.

4. All Edelbrock small-block Ford Windsor intake manifolds feature a 12-bolt intake manifold pattern, but they can be used on 1974 and earlier small-block Ford Windsor heads having a 16-bolt pattern. When using a 12-bolt manifold on 16-bolt heads, you have to use a 16-bolt intake gasket to ensure proper sealing around the water ports on the heads.

5. On 1962-72 Windsor Fords you have to be extremely careful when tightening down the front and rear-most intake manifold bolts/studs. Because these heads lack sufficient material at these corners for full support, overtightening will crack the manifold casting at each "ear." Such abuse is not covered by warranty. Torque these bolts/studs hand tight per the instruction sheet.EDELBROCK

Again I apologize for my statement in error.

Pappy
 

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I don't know about the typing but I hate it when my mind goes faster than my fat, slow fingers.

Besides I want to give out correct information, not garbage. When I get going I make mistakes. On my stuff, well I pay. On someone else's it is just unacceptable!

I guess it's time I go a little slower.

Two finger typing ....... ah yea ....that's the ticket!

Pappy
 
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