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Discussion Starter #1
Hello,
I have strange observations.
My cats, without blanket, get so hot that my clutch cable melted already once. I can see the metal of the cats glowing red.

I bought a heat blanket. Now my heat blanket is deteriorating.
This is what it looked when it was new.
http://s715.photobucket.com/albums/ww153/Cees321/?action=view&current=001-11.jpg
This is what is looks now after driving 1000 miles on normal roads. Average wheather.
http://s715.photobucket.com/albums/ww153/Cees321/?action=view&current=IMG_4511.jpg
http://s715.photobucket.com/albums/ww153/Cees321/?action=view&current=IMG_4512.jpg
http://s715.photobucket.com/albums/ww153/Cees321/?action=view&current=IMG_4513.jpg
http://s715.photobucket.com/albums/ww153/Cees321/?action=view&current=IMG_4514.jpg
The problems are only on the left CAT. I bought the cats from FFR. This is a new crate 302 engine. It has PJIII system which auto adjusting but I do not trust it. Engine does not performe at maximum ability.
I also noted that I had to retighten the bolts between the cats and the shorty headers. Does this have anything to do with it?
Why is it only 1 cat?
Any suggestions?
Cees
 

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Senior Charter Member
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Likely running rich on that side, which will make the cat run very hot.
 

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Cats are supposed to run very hot. They reburn the exhaust. That's why you need the air pump, to get more air into the cat to improve combustions. But it sounds like yours are much too hot.

Like he said, if they are very hot, then you could have a rich mixture. Dumping too much fuel out the exhaust and burning it in the cat.

If the header pipes are also very hot, that usually means a lean mixture. Too much timing could do that, too.
 

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Discussion Starter #4
Thanks for you suggestions but it does not make sens to me. The PJIII is a single point injection system. So left and right hand side cylinder get equal amount off fuel.
The right hand side blanket is normal and as new.

The header pipes are also NOT very hot.

Does the cat gets very hot when he sucks false air? (if the bolts are loose between the shorty header ande the cat)

Cees
 

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Thanks for you suggestions but it does not make sens to me. The PJIII is a single point injection system. So left and right hand side cylinder get equal amount off fuel.
The right hand side blanket is normal and as new.

The header pipes are also NOT very hot.

Does the cat gets very hot when he sucks false air? (if the bolts are loose between the shorty header ande the cat)

Cees
Is there a significant temp differance between one pipe and another? If one pipe is significantly colder, that cylinder is not firing properly and is dumping fuel.
 

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Snake Farmer
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As far as I am aware, most manufactures use a metal heat shield around the cats, to deflect the heat. As mentioned they are meant to get extremely hot. You may have to fabricate a similar metal shield for them. Similar to the side pipe heat shields, you want a dead air space between the cat and the shield.

You probably re-route your clutch cable, or use a stand off bracket, and wrap the cable in DEI, or similar heat shield tape or risk complete failure..
 

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Heat Blanket

I dont know what kind of heat blanket that is but it does not look like the kind that can stand much heat. Part of it even looks melted. It actually looks like fiberglass. If the heat is normal and that heat blanket melts, then you need heat blanket such as used on turbos. It is much thicker and has a blanket material that can stand very high temperatures

On the other hand the cats should not be glowing red hot. There has to be a reason for the excess fuel on that side. Check the cylinders for misfiring as noted above. The misfiring, or not firing might be the reason that the engine does not seem to be performing. Check the cylinders and the ignition system.

.
 

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Big Kahuna
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If it is a built motor I would look more at a head problem than anything. Especially if it is on only one side.
 

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The Greek
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This info might be pertinent if you have EFI and O2 sensors.
I had the exact same issue a while back, my driver's side cat got very hot and it glowed red, like a turbo manifold!!!
It was the wiring of the O2 sensors. 2 wires had to be swapped. Just an idea.
 

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FFCobra Craftsman
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Cats glow red when fuel is burned in the cat rather than in the cylinder.Since your efi is a a single point system i am thinking you have a misfire in a cylinder on that side of the engine.When the cyl. misfires, the fuel doesn't get burned and then it burns in the cat.Most common cause would be an ignition problem, ie; plug,plug wire,distributer cap.HTH
 

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Discussion Starter #11

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FFCobra Craftsman
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The color looks great.I can't wait to see it all back together.
 

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Cats required?

Are catalytic converters required? Or is it a state-by-state, country-by-country statute? Why should I choose to run cats knowing they are restrictive and hence reduce horsepower?:confused:
 

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it you only have one 02 sensor and it is on the side that is running cooler. it could be running lean on that side and the efi system is trying to compensate causing the other side to run too rich.and this causes the cat to over heat. you need to take care of this problem. I have seen cars burned because overheated cats.
 

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Discussion Starter #15
Hi Hiprojectile,
Yes, cats are required. Regulations are very strickt here in Europe.

Hi Rocardo,
Not sure if we understand each other.
The Powerjection system is a replacementnof the carborettor. The intake manifold remains the same. There is no fuel rail with 8 injectors. The fuel is injected in the center of the intake manifold, just like a carborettor. Therefor it is very unlikely that one cylinder or one side gets more fuel than the other.
 

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Likely a miss on 1 cylinder. Plugs, wires, vacuum leak or valve adjustment could all be a concern.

If you can measure the temperature of each header tube coming out of the engine, that will help identify where to start looking.
 

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Big Kahuna
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Snake Farmer
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There is no fuel rail with 8 injectors. The fuel is injected in the center of the intake manifold, just like a carborettor. Therefor it is very unlikely that one cylinder or one side gets more fuel than the other.
That being the case, it seems very odd that one side would get hotter than the other.:confused1: You absolutely sure your plug leads are in the correct firing order on that side? If this was the case, raw gas could be injected into the cat, and also would cause the performance issues you mention.
 

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Discussion Starter #19
It is a crate engine. Build in the Usa. But I am not sure. I did not check myselve.
As soon as the car is in a desent state again, (sidepipes are back on), I will let the engine run and one by one unhook the spark plugs. Each cylinder should contribute for 1/8 st. So the rpm drop should be equal.
 

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Snake Farmer
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Keep in mind the 5.0 HO engine used a different firing order then the non-HO, if your looking for that info. Did they tell you which engine it was when you bought it?
 
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