Warning - Hi-tek Marine Stainless Manifolds - please learn from my expensive lesson
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#25
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HI-TEK Manifolds will **** themselves
"Hello all from slow boater land. I just wanted to post my experience with Hi-Tek Marine Manifolds out of Australia. I purchased these for my small block 5.7 GXI Volvo hoping to add a bit more HP to my boat. The purchase process wasn't too bad, but the claims that are made about the product are pretty far fetched. Allen the owner was very quick to call when I had questions, but of course he wanted my $2300. Nevertheless, I am a bit of a novice but with his direction, I was able to get them installed. Allen told me that I would love these manifolds and that he had a customer that installed these with my same motor and gained 400 rpms.
Well, to make it short, the manifolds no performance gain whatsoever for my 5.7 VP Gxi small block. I did seem to pick up a bit on the low end, but I also changed out the original sparkplugs for NGK Iridiums, so I give them the credit for that really. It sounds good, even from the stock exhaust, but that is it really. I even thought that it might need to be tuned (although Allen said that was not necessary), but there is no way to get an AF wideband sensor to the exhaust as there is no port for them. Needless to say but I think that the improvement numbers for the manifolds that Hi-Tek claims are not entirely accurate.
In short, they look pretty, but that is about it. For my application they were a total waste of money. Probably should have known that."
Well, to make it short, the manifolds no performance gain whatsoever for my 5.7 VP Gxi small block. I did seem to pick up a bit on the low end, but I also changed out the original sparkplugs for NGK Iridiums, so I give them the credit for that really. It sounds good, even from the stock exhaust, but that is it really. I even thought that it might need to be tuned (although Allen said that was not necessary), but there is no way to get an AF wideband sensor to the exhaust as there is no port for them. Needless to say but I think that the improvement numbers for the manifolds that Hi-Tek claims are not entirely accurate.
In short, they look pretty, but that is about it. For my application they were a total waste of money. Probably should have known that."
I have a set of HI-TEK manifolds for my 5.7 mercruiser as i had to replace the origioal cast iron junkers (They leaked salt water and hydraulic my motor so i had to rebuild it) I bought them for $2500 and they were relitavely easy to install [B]when the motor is out of the boat.[B] I have had them on my engine for around 18 months and i had no probllems. Right up until around 2 months ago. I was taking the boat out to an island just for a quick 1 hour blast. I was cruising at around 20 knots (Usually cruise at around 25), or about 3600 revs for around 10-15 minutes. When we got to the island we slowed back to idle to throw out a couple of lures. We atarted to troll at just above idle. The motor sputtered a little then shut off. We thought it was just a little dummy spit so i tried to fire it back up. Only to hear the sound of a munching ring gear and no V8. The motor would not turn over at all. We took the spark plugs out of cylinders 2, 4, 6 and 8. Salt water gushed out of the cylinders. They were completely filled with salt water!! We let it dry, put some WD40 down the carbie and in the cylinders. put the plugs back in after 1 and a half hours and tried to start it. It started after half an hour of trying, as long as we kept the revs up it would run.
Long story short we took the motor apart cleaned the salt water out of it and then ran it on the ground for 10 minutes with medium revs and sure enough salt water came out of the pipes. They did not leak cold though. We stuck a camera up inside the HI-TEK manifolds. UNBELIEVABLE!!! There was parts of the pipe were someone had nicked the pipe with a angle grinder and unbelievably ****ty MIG welds inside the supposedly all stainless and all TIG welded manifolds. The MIG welds looked like they were done with carbon steel and there was no penetration AT ALL. My 15 year old son can weld better than that. No joke!! We sent them back to him as they were under warranty.
We rang the HI-TEK guy up 'Alan' and he told us that we had over heated them and that is why they failed. But they had worked fine on 2 1/2 hour trips to the reef. We hadn't over heated them at all. We would frequently check them on boat trips and they were WELL in the green temperature zone. Long story short we had a huge drama getting new manifolds.
THIS IS A WARNING TO ANYONE WHO IS THINKING OF HI-TEK MANIFOLDS. I AM NOT SAYING DONT BUY THEM. I AM NOT AYING THEM OUT. I AM SIMPLY TELLING AS MANY PEOPLE AS I CAN ABOUT THESE MANIFOLDS. THEY FAILED AND LEAKED WATER INTO MY MOTOR!!
#26
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My question is I'm need at inboards is the hi-tek manifold are good I want to get rid of my stoke manifold I just want my motor to be save I don't want more hp I just want to besavewhat do you guy recommend me
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Hi-tek manifolds
Hi mate. After the huge debackle trying to get 'Allen' to get us replacement manifolds, we did finally get them and honestly so far we have had no problems with the replacement ones, (I think 'Allen' wanted to make sure there was NOTHING wrong with the replacement ones 😂. Like a lot of people have said before, we have found no hp or rev increase at all since installing them. But so far no problems, (as long as you check and replace the anodes in the manifold periodically). We bought them for the same reason you need them because our stock cast mercruiser ones failed and we hyrdrauliced the motor and sheered the starter motor bolt. They are NOT worth the price, but we havnt had any problems since the replacement of the failed stainless ones so i think mabye we got a bad pair. If you get them they will save your motor from salt water but will not save your wallet. Mabye shop around a little bit and see what else there is first. I think America would have a few different kinds easy and if not or they look suspiciously cheap, jump at the hi-tek's.
#29
Hello all from slow boater land. I just wanted to post my experience with Hi-Tek Marine Manifolds out of Australia. I purchased these for my small block 5.7 GXI Volvo hoping to add a bit more HP to my boat. The purchase process wasn't too bad, but the claims that are made about the product are pretty far fetched. Allen the owner was very quick to call when I had questions, but of course he wanted my $2300. Nevertheless, I am a bit of a novice but with his direction, I was able to get them installed. Allen told me that I would love these manifolds and that he had a customer that installed these with my same motor and gained 400 rpms.
Well, to make it short, the manifolds no performance gain whatsoever for my 5.7 VP Gxi small block. I did seem to pick up a bit on the low end, but I also changed out the original sparkplugs for NGK Iridiums, so I give them the credit for that really. It sounds good, even from the stock exhaust, but that is it really. I even thought that it might need to be tuned (although Allen said that was not necessary), but there is no way to get an AF wideband sensor to the exhaust as there is no port for them. Needless to say but I think that the improvement numbers for the manifolds that Hi-Tek claims are not entirely accurate.
In short, they look pretty, but that is about it. For my application they were a total waste of money. Probably should have known that.
Well, to make it short, the manifolds no performance gain whatsoever for my 5.7 VP Gxi small block. I did seem to pick up a bit on the low end, but I also changed out the original sparkplugs for NGK Iridiums, so I give them the credit for that really. It sounds good, even from the stock exhaust, but that is it really. I even thought that it might need to be tuned (although Allen said that was not necessary), but there is no way to get an AF wideband sensor to the exhaust as there is no port for them. Needless to say but I think that the improvement numbers for the manifolds that Hi-Tek claims are not entirely accurate.
In short, they look pretty, but that is about it. For my application they were a total waste of money. Probably should have known that.
again Just MY OPINION feel free to chime in!!!
#30
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I bought these 2 years ago and gained 400 rpm on a 502 mpi engine. For me was it a good buy. But it was a hazzle to mount them. Little space and angle for the 8 squere bolts that came with the headers. All in all, thumbs up👍