overheating problem

[TriodeLuvr]

Nope, Head gaskets and heads went on great.

ok, I think I found something. Was just out putting the plug in and I noticed on the ground below the starter about 7-10 drops of oil.
I looked up behind the head and I see a little puddle of oil.
Could that be it? vacuum and oil leak from the back of the manifold.

That oil on the ground could have been there before, but with all the anti. thats been on the ground and cleaning that up I've most likly over looked it.

That sounds like the rear manifold oil seal has slipped out of place.

Jack

 

[oino]

I used rtv. Looks like it's the corners.
I just sprayed brake cleaner in one of the corners while the car was running and it changed the way it was running.

 

[TriodeLuvr]

I used rtv. Looks like it's the corners.
I just sprayed brake cleaner in one of the corners while the car was running and it changed the way it was running.

There are as many opinions on gasket cement as there are mechanics. IMO RTV isn't the right stuff. Bear in mind it's been 30-odd years, but I always used the 3M yellow weatherstrip cement. They used to sell it at all the speed shops and parts stores, but I don't know if that's still the case.

I'm not familiar with the aftermarket EFI systems. Is there an air path from the crankcase to the intake, such as PCV? If so, you're simply injecting the carb cleaner into the air/fuel mixture. It might not mean anything in terms of diagnostics.

 

[oino]

There are as many opinions on gasket cement as there are mechanics. IMO RTV isn't the right stuff. Bear in mind it's been 30-odd years, but I always used the 3M yellow weatherstrip cement. They used to sell it at all the speed shops and parts stores, but I don't know if that's still the case.

I'm not familiar with the aftermarket EFI systems. Is there an air path from the crankcase to the intake, such as PCV? If so, you're simply injecting the carb cleaner into the air/fuel mixture. It might not mean anything in terms of diagnostics.

I use the black rtv. It's what I've always used. I wasn't really feeling the manilfold gaskets I put on. They where thick ones from fel-pro. Kinda odd.
29.99 at speedway. It looked like it went togother all ok, but guess not.

You bring up a point. When I spray the brake cleaner in the corner of the manifold the idle drops and the car gets slugish. But how. There is no air/fuel there. Right?
hmmm. I'll pull it apart, and that should show me whats up...

Can the heads leak oil?
I know that the oil comes up the push rods and the back down the oil holes in heads. Is that the only place a head has oil running through it?

Sucks, looks like I can't get manifold gaskets til Tuesday at speedway.
None of part stores carry the gaskets the work with a carb manifold and vortec heads.

 

[TriodeLuvr]

When I spray the brake cleaner in the corner of the manifold the idle drops and the car gets slugish. But how. There is no air/fuel there. Right?

If crankcase volume is being pulled into the intake system through PCV or other attachment, then the carb cleaner you're spraying under the manifold will also be pulled in.

Does this car overheat just idling? Is the outside temperature hotter than before you changed the heads and intake? Did you fill the radiator and engine block separately, then connect the top hose? Just thinking out loud...

 

[oino]

I hate my car. Crank bolt stipt out. awwww.

 

[Screaming Metal]

Yep, you got a manifold leak. Remember, I asked to check the manifold by spraying cleaner around the injectors and all around the intake? Thats what we were looking for. A intake leak, coupled with a EFI's ability to adjust itself on the spot within a millisecond, can wreak havok with the motors tuning.

Now, next time you go back together with the intake manifold, leave the manifold end gaskets off, and just run a big thick bead of silicone on the front and rear, with the std. intake manifold gaskets on the manifolds sealing face where it bolts to the heads. I've always had the end gaskets interfer with a good manifold seal, I just toss them in my toolbox, I use them to layout holes or for a pattern if I'm doing custom intake work, after I use them once, I toss them. Just run a big, thick bead of silicone at the ends.

After the motor has run hot like that, I'd, if it were me, pull the heads anyway, and make sure its all as it should be! Correct lined up gaskets on the head decks, make sure all the holes are uncovered, have the heads checked for cracks, have them straight edged, then straight edge the block your self. All you need is a precision machinists ruler and a .002 feeler gauge to check it.
Then, go back together with it. While your doing that, look at all the cooling passages and into the waterjacket, look for rust, obstructions, anything that can impede waterflow.

That way your sure all is as it should be. I don't take chances with motors. If it were me also, its only a 15 minute job, I'd yank that waterpump also, since its a main part of your cooling system, I'd put a new gasket on it also, just to check out the impellar and the bearing.

Just take your time and redo the gaskets and all. Your gonna be a great mechanic!

 

[Screaming Metal]

If you don't feel the love.... go by Fastenal, Loctite makes a thread strip repair that will work on the crankshaft bolt. used it many times myself on Drag cars.... just follow the directions to the letter, exactly....
I do this for a living, work on High Performance Engines. (Everybody take note, I say engines, very seldom!) Its only as hard as you make it. All you gotta be is mechanically inclined! Smile, make it a learning experience and enjoy it. Your only young once! Enjoy Your HotRod!
-----If it were easy, everyone would have one!-----

 

[Mike]

I used rtv. Looks like it's the corners.
I just sprayed brake cleaner in one of the corners while the car was running and it changed the way it was running.

Which it can quite easily do, if you were spraying around the front corner of the head, because the fan will move the cleaner back where the carb can start 'seeing' it. Does the idle speed change when you spray at the rear of the head?

If you are testing for a vacuum leak in this manner, get a piece of cardboard between where you are spraying and the carb or air cleaner. Actually, you would be better off using carb cleaner, rather than brake cleaner, as the carb cleaner won't have as much flashing vapor as the brake cleaner. People never think of it, but water will accomplish the same end, without any worry about flammable vapor.

You're not going to be able to reliably read your spark plugs, what with all the idle time you have on them. So I wouldn't count on them being any real source of information.

 

[RPM]

Does the computer controlled EFI give a vacuum reading off of a sensor? If you have a vacuum leak a gauge will tell you this pretty quick.

 

[Mike J]

If you don't feel the love.... go by Fastenal, Loctite makes a thread strip repair that will work on the crankshaft bolt. used it many times myself on Drag cars.... just follow the directions to the letter, exactly....
I do this for a living, work on High Performance Engines. (Everybody take note, I say engines, very seldom!) Its only as hard as you make it. All you gotta be is mechanically inclined! Smile, make it a learning experience and enjoy it. Your only young once! Enjoy Your HotRod!
-----If it were easy, everyone would have one!-----

we are not politicly correct here. How about " my Mill is running fine"

 

[2old2fast]

Had a crank bolt strip a while back , ran a tap in , checked the depth & was able to go w/ a longer bolt , snugged up just fine
dave

 

[oino]

Had a crank bolt strip a while back , ran a tap in , checked the depth & was able to go w/ a longer bolt , snugged up just fine
dave

Ya, I checked the depth of the hole last night. I can use a longer one.

Back at work today. I'll get it all pulled apart tonight. Have to wait until Tuesday for intake gaskets. So I'll just be ready for them when I get them.

 

[2old2fast]

I've used mr. gasket a few times , worked fine ,available at the "chain" auto parts store , just a thought ..

dave
about $12 ,IIRC

 

[oino]

I've used mr. gasket a few times , worked fine ,available at the "chain" auto parts store , just a thought ..

dave
about $12 ,IIRC

Not for vortec heads. I've checked.

 

[TriodeLuvr]

Not for vortec heads. I've checked.

The best end gaskets I ever used were made from cork. Unlike the vinyl/rubber versions, they can be glued to the block with 3M and won't slip out from under the manifold. I don't remember who used to supply those in their gasket set, but there's always the option of getting sheet cork about 3/16" - 1/4" and cutting to fit. Several of the auto supply houses where I live sell gasket punches to make this easier.

 

[2old2fast]

Sorry , forgot you had the vortecs & I'd never ever ever use anything but silicone or "the right stuff" on the china walls of a sbc ever ever again !! It's just too easy & foolproof !!!
dave

 

[2old2fast]

Did some searching & found some discussion about vortec needing an external by-pass in order to cool properly ???? don't know if this applies to the heads or the newer vortec blocks ??
dave

 

[Duke]

I have Vortec heads on my bucket sbc and have no cooling problem at all. I also have an aluminum radiator. I have to run a thermostat or the engine wouldn't get over 140. I have no external bypass.

 

[Screaming Metal]

Well, to be perfectly honest here, this thread is one that ought to make folks think about this certain scenario.
This man had a running Bucket Motor, SBC 350.
He not only changes the intake manifold, but he changes his heads which are gonna probably flow better, and have more compression. Then on top of this, he's throwing in a EFI system and trying to adjust it out.

I do this on a daily basis. If you throw too many variables into the stew pot, stur it up some, if you start having troubles, its hard to find out what is causing what.
The ideal solution would have been to put the heads on, and the intake, but running a carb, adjust it out, run it for a few days or a week, seeing how the power was, tuning it accordingly. Let the valves get seated and all. After the motor ran some, then switch out the carb for the EFI.
But, with enough experience a person learns what does what when certain things start acting up.

The bad part of any swap out like this, is 85% of the time, the EFI will not start right off the bat and run good, because there are too many adjustments that are being left to sensors and computers. Just installing the EFI on a already running and tuned motor isn't as hard for that computer to adjust to.
I often have a big hi-horse motor that I have to run in on a dyno and it has EFI, sometimes it takes me the better part of 3 hrs. to get it running in top form. Sometimes, I hit it within 30 minutes. Every motor and every system is different.

Regardless of how well that motor ran last week before all this, this is a completely different and new engine. All of its characteristics have been changed. Whatever performance cam he had is going to be diff., because the head is going to flow differently, and the EFI is going to fuel it completely diff. from the carb that was on it. And we haven't even mentioned the intakes rpm range.

Like I told this customer last month, guessing don't cut it. Because a motor will start and idle great don't mean jack. If you can't drive it down the road, shut it down, go for a burger, come back out fire it up and go home....its completely worthless as a dependable car. He also had just installed a EFI system....