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489 Lemans
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Discussion Starter · #1 · (Edited)
I was looking at this posting
http://hotrodders.com/showthread.php?s=&threadid=55084
and macx made the remark "stay away from performer air gap unless you live in florida."
I have a 79 vette and am having serious heat problems.
I have had to ceramic coat the headers, cut holes in the wiper valley for air escape, and remove the thermostat. The temp has now dropped from 220 F to about 195 F. I was going to buy a performer rpm air gap on the hopes of cooling down my charge a little more. Our summer temp here is about 80 F. I use a victor jr on my lemans, which is just a bigger air gap and am quite happy with it. What is wrong with the performer rpm air gap?
 

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He stated this in that same thread:
"About my previous remark on staying away from the air gap types unless you live in Fla, that the engines have a really tough time warming up in colder weather compared to a non-gap type intake"

Hope this helps.
 

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I dont agree with removing the thermostat. Usually it allows the water to flow too quickly. It flows through the radiator so fast it doesnt have time to remove the heat from it. I think you wont like the air gap. Its more of a race intake. The rpm performer would be better. If I was having that much of a heat problem I think I would be looking for more cores in the radiator.
 

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hot hot hot

I live near palm springs ca. and my 69 427 Corvette overheated easily, even after I had a 5 core radiator custom made for me. Then I bought a Griffin aluminum radiator and 2 electric fans-no more mechanical fan-and it is GREAT! I don't even have to turn on the fans all the time. That Griffin radiator was an easy swap and the best thing I've ever done to my car.
 

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Come Home Safe Soldier
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Bracketer,I know this is your Vette but on my Malibu I run the Performer RPM on top of my 355.Got the 180 degree thermostat in it and in the winter the thing will not get over 150.I have to put a piece of 12x8 cardboard in front of my radiator.In the summer it never gets hotter than 180.
 

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Re: rad

bracketeer said:
I bought a brand new rad. Taking the thermostat out dropped the temp 20 deg. After buying a new rad I don't think I want to put out for a new aluminum just yet. I still have a few tricks left. I'll decide then. But the airgap is looking ok to me.
By doing this, did you drive the car in all types of conditions? I.E. stop and go traffic, highway, on the hottest day? I would hate to see you take a snap shot and call that the answer for your heating problems. If so, then hey, we learn something new everyday!! :thumbup:
 

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489 Lemans
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Discussion Starter · #10 ·
answer to all

i only drive it in summer so all season is not a problem.
i have the stock fan shroud with a seven blade fan. (not clutched)
I also have a malibu with a 454 using the stock 305 rad. no heating problems with that car.
hood clearance is not a problem. measured out. using a 14" dished air cleaner with a holley dual pumper. still have 1" left. and i use neoprene mounts. there is no engine twist.
 

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I am using a Edelbrock Air Gap RPM manifold with their 600 cfm carb and electric choke on a chevy 350 tucked into a 78 Datsun 280 Z. This early winter here in GA has given me an opportunity to try it out on a couple cold (15 degree) days. Pump the pedal twice, the car starts, fast idle works great, after a few minutes it idles down and runs great. Hood clearance was an issue with this set-up on my car.

When I first got the car running I had an intermediate hot condition that I chased. I flushed the system, changed thermostats twice, finally removed a brand new Summit cast iron high flow water pump and replaced it with an Edelbrock aluminum water pump. Since then the engine runs consistently in the 170-180 range. At a long traffic light the gauge will get up to about 185 and the electric fan will kick on and keep it cool.

I would recommend trying the Edelbrock water pump & high flow thermostat if the rest of you cooling system checks out. Make sure you don't have to much antifreeze in the mix. You will need the thermostat to allow the water to heat up and take the heat from the engine, try running a high flow 180 that if it sticks it will stick in the open position. This fixed my hot problem. Then if you want the Air-Gap and it fits under the hood you can make the swap.
 

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Ditto with lluciano,

Mr. Gasket makes a high flow thermostat. It would be defeating the purpose of getting a high flow water pump with a stock type thermostat. Also if you are not running a high flow direct fan, it is defeating the purpose as well.

HERE is a real good one. It helped my cooling issues tremendously. It pulls ALOT of air at idle and low rpms.
 

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that seven blade non clutched fan should work great provided fan shrouding is really looked at.

The most important thing is that the fan can only draw air that comes through the radiator. Make sure there are no gaps in the shrouding around the rad and make sure that the fan fits the opening in the shroud. Maybe 1/2 to 1/4 in gap between blade and shroud with fan halfway into the opening. Remember you have to pull the air through the rad.

PS. I would put the thermostat back in and you should be able to with a properly working system.

Ric
 

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lluciano77,
Mark your calender we actually are about to agree on something. :thumbup:

You REALLY should run a thermostat, and I can tell you removing it did not cool your car down much if any. In the long run it will do more harm than good.

When does your car over heat? (traffic, stopped idling, highway) Do you run a fan shroud? What kind of fan/s? If it over heats at a stand still that is a sign of not enough air flow through the radiator (not enough fan or some sort of restriction). If is gets warm on the highway you don't ave enough radiator or you are running a non clutch type fan and it is becoming an air blocker once the car is up to speed. Could also be a sign of a poor flowing water pump.

The thermostat only controls the minimum heat the engine will run at, once it's open, it's open. I prefer to run the high flow type thermostats (Mr. Gasket or Robert Shaw).

What do you consider over heating? How hot is too hot for you?

As far as the Air Gap goes, they are good manifolds. You shouldn't have any issue with cold weather. I ran one for a long time and never had a problem. Truth be told I don't think it makes all that much of a difference (the air gap) under hood temps and coolant temps are going to heat up the manifold anyway. They do look nice though ;)

That's my $.02


Royce
 

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I would not run a solid mount fan.They come apart to easily at high RPM's.That cheap piece will cost too much money in the long run if it does.Radiator,hood,hoses,belts,tow bills if you are on the road when it happens.Plus it is a constant drag on your engine.Electric fans or a clutch style fan are the best routes.
 

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489 Lemans
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Discussion Starter · #16 ·
hot is hot

It use to run about 220 deg. On the hwy I believe the fan was blocking the rad. I can only make it about 8 miles over 100 mph. Then I'm off the scale. Maybe 250 deg.
Yes, I do have a fan shroud in good shape. Actually I have a spare. I even tried electric fan and it ran even hotter.

I took the thermostat out. That dropped me to about 200 deg.
On the hwy I'm right back up there again. I am now going to a five blade fan, ceramic coated headers, and holes in the wiper valley.

What i did remove was the factory cool air scoop. It wouldn't fit on a holley dual pumper so it had to go. Thats why I decided to check out the air gap. Maybe get my intake air temp down. I have to buy a new one anyway. Thought I may drop a few more degrees.

I really don't want to buy a new rad. I just bought a new stock replacement. That will be a last resort.

My question seems to have gotten off track. My question isn't about a heat problem. That I can fix with double core rad if it comes down to it. My question is; Will a Performer air gap intake make my engine run cooler?
 

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Answer to that would be NO. The intake design is to keep the air/fuel charge cooler.Youre engine will still run the same with an Air Gap,Performer or even other brands. The gap in the intake allows air to flow under the carb,Most stock intakes have an oil shield under neath designed to help keep the heated oil in the valley from being thrown onto the bottom of the intake and heating the area where the air/fuel mix enters.Same principle,just a different design in doing it.
 

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RCastle said:
I would not run a solid mount fan.They come apart to easily at high RPM's.That cheap piece will cost too much money in the long run if it does.Radiator,hood,hoses,belts,tow bills if you are on the road when it happens.Plus it is a constant drag on your engine.Electric fans or a clutch style fan are the best routes.
Yep, that is true that it will come apart, if it is an aluminum fan, not stainless steel. If you go electric, then you need to ensure your electrical system is up to snuff, and then pray that it does not go out on you in the worst possible moment. The stainless fan I suggested is a high performance version, in that after x amount of rpms, the blades start to flatten out, since you are moving anyways and do not need the extra drag robbing horsepower. There are pros and cons about using whatever solution to a problem. Not one answer is absolutely correct. I just knowwhat works for me.
 

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I dont agree with removing the thermostat. Usually it allows the water to flow too quickly. It flows through the radiator so fast it doesnt have time to remove the heat from it. I think you wont like the air gap. Its more of a race intake. The rpm performer would be better. If I was having that much of a heat problem I think I would be looking for more cores in the radiator.

The t-stat is a restriction. Rescriction add the possibilty of airation. Airation causes hot spots in the head and block.

You can't push water too fast. Water flow isn't there and then not. There is always water touching a surface no matter where in the system. It's a cycle of unrelenting contact.

Overheating? Try a GM four or five blade fan. 4000 CFM is hard to argue with. 1 to1 pulley's will also help. Fin count on the rad should be 12-14 per inch.
 

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johnsongrass1 said:
The t-stat is a restriction. Rescriction add the possibilty of airation. Airation causes hot spots in the head and block.

You can't push water too fast. Water flow isn't there and then not. There is always water touching a surface no matter where in the system. It's a cycle of unrelenting contact.

Overheating? Try a GM four or five blade fan. 4000 CFM is hard to argue with. 1 to1 pulley's will also help. Fin count on the rad should be 12-14 per inch.
Thermostats are just that, restrictions to warm up the car, and one element of the "cooling system" to maintain the desired operating temperature range.

Yes, you can push the water too fast. If it goes through the radiator too fast, then it does not have enough time to dissapate the heat, and the coolant entering the block will be too hot, adding to the temp range.

But what the hey, just run it like that, hope it works for you.
 
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