rob6773

My lightning headers on my 454 were putting out steam especially at low speed last time out. The oil cooler and headers were getting hot. I found the plastic impeller housing to be coming apart instead of the impeller. I retrived the pieces of plastic from the cooler and got it running again. I still have steam out of one header. What I found was huge flow out of one side and a dribble out of the other. I pulled some hoses and can't yet find the cause. My engine does not run a thermostat or engine water pump. Can the header itself get clogged? I put a garden hose to the log on the hot header and found the two back cylinders cooled quickly, but it took a while to cool the front two cylinders. When I did this there water went right in without spashing back, making it seem to have good flow.

Uncle Dave

Sure it can.

ANY water jacketed header can clog up.

You seem to already have it diagnosed pretty well.
Youll probably find heat melted plastic bits in there, but getting to them can be a real pain.


Uncle Dave

PatriYacht

I bet it could clog under just the right conditions. I'd try to back flush it using the hose that jumps to the riser.

rob6773

I have a compressor. Do you think like 120psi could clear it? If I try this should I push air through the log or try to sneak past my flaps and shoot air where the inner and outer shell of the collector are exposed. There was a very small amout of plastic lost from my pump and the honeycomb of the cooler seems really tight.

rob6773

I worked on it tonight. I first used compressed air piching off three cylinders and filling one. Nothing weird. Nothing came out. I then garden hosed it in the same fashion, each one seemed to flow the same. I them hooked the hose to each header for comparision and they flow the same. I then hooked-up the hose to my Perko and ran water with hoses off the would-be thermostat housing. One side seems very slightly favored. I then connected and ran again and had flow just out of the one header. This makes no sense at all. But then I fixed it is a super hack way accidently. I took my hose crimpers and squeezed the good side to force water out the troubled side, the hose on this side is metal reinforce so it did not fully rebound and was left with a 50% pinch. Now running or not running the headers are flowing an equal amount of water. Can I leave it this way? The headers are staying cool enough.

rob6773

Still favoring one side. I got the header really hot by running the engine and then garden hose direct to header. Still was bad so I removed the log from the bottom of the header and it appears OK. Not sure what to do next. I have a set of manifolds that I think are good. Can a header be boilded out like when re-building an engine?