Stainless Steel Manifolds

JR VIC, have you called Allen about this heat issue? He has been very receptive to any questions and issues I have had so far,I don't think there should be a difference in the two ,same water,same distance=same temp.......boat dr
Jim as far as the conversation was a pleasure here also. My keystrokes leave a lot to be desired, but i talk real well.There are a lot of neat people I have met here,and hope to add to my list,its cool to put a voice with a name..........billy

Yes they have drain plugs...one on each side. The boat in the water sounds just like it did before with the stock OEM manifolds...no difference in sound in my opinion.

Thanks!

I will do a search again here in the forum but it seems as though I either read it here, talked to Vince at DIM, or one of the tech guys at PCM in North Carolina told me that it was normal to have the starboard side manifolds on my 92 351W to be hotter than the port side but not sure by how much. As M3Fan mentioned, it could have been doing this before but because I was never really paying attention to the stock manifolds it went unoticed. This may sound strange but the stock OEM heavy cast iron manifolds are very thick as most of you know and you don't hear much exhaust sound around the manifold when it is running. I say this because in the past if I was tuning the carb with the engine running on the trailer and bent down leaning over the engine with my ear close to the stock OEM manifold you don't hear much exhaust sound. After I changed to the Hi-Tek headers and in the same situation of bent down and leaning over the header to adjust the carb while the engine was running on the trailer, I noticed you could hear an exhaust note at the header...not a ticking exhaust leak just an exhaust note. As I leaned my ear right up almost touching the header you can hear alot of exhaust sound unlike before. Don't get me wrong, it is nothing that is real loud and you would not notice with the engine cover closed because in that sitaution it sounds just like stock. My point is that if I leaned over to the header very close you can hear so much more exhaust sound than before leading me to beleive that the walls surrouding the headers appear to be very high quality yet much thinner than the stock, thick, cast iron manifolds. Make sense? If you lay your hand on the side if the headers you can almost slightly feel the exhaust pulses. Maybe because of this design you just can hear a little more and you also feel more tempature as well. One other note...the engine temp is perfect and running a touch cooler than before and when I ran my hand over the water spitting out the rear of the boat while idling on the trailer it does not seem any hotter than before. Also...most of this higher temp on the starboard side is behind the header at the rubber exhaust hose that connects it to the muffler and not so much on the header itself. Any more ideas?

Some difference in mani temps is normal as far as I know. Looking at the Tstat housing it would appear that the easiest route for the water to flow is straight over to the port side manifold. It's probably just more noticeable with the stainless steel vs. the cast which will take longer to show swings in temp. Just a theory for conversation's sake.

depends on the quality of the exhaust too. If there is a difference in the jackets that create the water cavity so that one side can hold a large amount of water vs. the otherside then one would be hotter than the other. I would think they se a jig so that they are the same but I have never seen there manifacturing process and if they are all done by hand then you will see a difference from one to another and could create this very problem. Double check the routing and hose sizes for something to create a restriction on the side that is getting hotter. 5-10 degrees I wouldn't get excited about but 20-30 difference side to side isn't right.

sounds like a water flow problem, water takes its easiest path especially at idle, its possibly that there may be corrosion in the risers or some where else, fire the boat on the trailer and see if there is a difference at the exhaust in volume of water. if it was a carb or thermostat it would heat both sides and the problem disappears at wot, because now the water is under higher pressures and possibly is making its way through the restrticted area and allowing it to cool

if that side is lean then it would run hotter and down the road would cause problems. The hy-tek's aren't causing the problem that's for sure.

Boat Doc, I a$$ume youre including me in your SBF count. I do not want any paint or powder on them- Id prefer them bare. I plan to have them jet-hot coated once I get them.

Not sure if that changes the price or not.

I have been very happy with the Hi-Tek headers so far. As mentioned in a previous thread they bolted up almost as easy as the OEM ones with the exception that the way the headers come out and turn up I was only able to get a socket on about half of the bolts but again I don't have a vast selection of specialty sockets etc. The remaining bolts had to be tightened with an end wrench and with about 10 hours of use none have losened up so far. Absolutely no clearance issues at all anywhere on my 92 SNCB. Did not have to adjust the carb settings with the exception raising the idle about 100 RPM. Took it to the lake and picked up 4.0 MPH. I have also added the new style DUI HEI style distibutor and a Weiand intake as well. Also changed to a rear billet metering block and upped the jet sizes and the boat is now running about 52.5 MPH with 14 degrees of timing which I have been very happy considering these are only bolt on mods. I mentioned to Boat Dr. that the last few times out I am still having the starboard side run hotter than the port side by about 70 degrees (140 port to 210 starboard) only at idle but seems to normlize under way. Hope this helps.

Thanks!

$1687.00 was said earlier.

boat dr...how much are the polished ones??

79, you don't need to go back to school,it's my math that is suspect. Total weight of 2 manifolds is 62lbs.2 Risers weigh 42 lbs. this adds up to 104 lbs. subract 12 lbs per manifold and you only lose 80 lbs.
My digital scales, i hope,will show the weight of the Hi Teks as Allen advertised them.Sorry for the wrong info.........boat dr

Yes, those sounds like BBC w/ 4" riser numbers.

Reid, a picture's worth a thousand words:



Since automotive headers swing down and marine headers swing up, we have no fitment problems. Plug angle is actually much improved over the stock heads.

Boat Dr, Ill give you a call today.

And Tim, no problem with these and the P heads as there is with automotive headers? I was hoping that since they curve up that it wouldn't be an issue compared to auto headers going out and down. Just checking.