glowing exhaust manifold
Thread Starter
Instructor
Joined: Oct 2001
Posts: 169
Likes: 2
From: Glen Aubrey NY
glowing exhaust manifold
I recently installed cam, and chambered exhaust on my 77 L48. Now after running for a while the whole engine seems really hot, although temp guage
is normal. Engine gets so hot one exhaust manifold turns red. Any ideas on what the cause is are appreciated.
is normal. Engine gets so hot one exhaust manifold turns red. Any ideas on what the cause is are appreciated.
Drifting
Joined: Jul 2001
Posts: 1,418
Likes: 1
Re: glowing exhaust manifold (EarnIt)
Probable intake manifold leak on that bank.Spray WD 40 in the area to see if idle picks up.If a dual plane manifold is used there might be a restriction in the carb on that side as well although unlikely
The timing being retarded grossly can be a cause but not for one bank of cylinders.
[Modified by mountainmotor, 8:48 AM 2/2/2002]
The timing being retarded grossly can be a cause but not for one bank of cylinders.
[Modified by mountainmotor, 8:48 AM 2/2/2002]
Drifting
Joined: Oct 2000
Posts: 1,825
Likes: 56
From: Shawano WI
Re: glowing exhaust manifold (EarnIt)
A tight exhaust valve lash, retarded timing, or extremly rich or extremly lean condition will cause the exhaust to turn red. You said that you just put in a cam so i would recheck the valve settings and timing. If they are OK, then possibly the combination of cam/better exhaust has caused a lean condition so you may have to rejet the carb.
Burning Brakes
Joined: Mar 2001
Posts: 1,211
Likes: 5
From: Nashville TN
Re: glowing exhaust manifold (EarnIt)
You are probably going to have to re-jet the carb to account for the decrease in exhaust backpressure and the cam shaft change. It sounds like you are running to lean.
Team Owner
Joined: Jul 1999
Posts: 65,492
Likes: 230
From: Orange Park Florida
Re: glowing exhaust manifold (EarnIt)
ONe thing you should look for.....blocked heat riser flapper valve on the pass side....if it's partly closed or even shut...exhaust is forced over the intake to other side, as if warming engine....constantly.....so see that it's open or opening all the way....
IMO...take the damn thing out entirely....about useless...use an electric choke if not allready....
GENE
IMO...take the damn thing out entirely....about useless...use an electric choke if not allready....
GENE
