Replaced risers, manifolds and PS cooler - one lingering question

jtm3

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So, I did it (with a lot of help from a crusty old boat mechanic in northern NY) – replaced the risers and manifolds on my 2001 Pursuit 2860 with VP 7.4L GSI. Did it in the shed with a propane heater and 17 degrees outside temp….nothing like holding heavy cast iron parts on a cold day, while climbing around the engine compartment….I used OEM for both the manifold and riser. My crusty old mechanic (ode to Mr. S. Danforth) was less concerned with riser to manifold connection then folks on this board, sanded them but wasn’t, how shall I say super anal about it. The VP instructions were clear that no sealant should be used with the “new” style gaskets…Fingers crossed come spring.

To back up, this was a used boat from FLA, that still had original exhaust (two things I said I would never do, buy a boat from saltwater and Florida….oh well) I had it brought up last spring to Lake Champlain and used it over the summer, to sort of shake it down. During the summer replaced the sea water pump, thermostat and oil cooler. She ran well, after the pump and t-stat replacement, temps stayed consistent, but knew this was job #1 going forward. The manifolds looked very good, the risers on the other hand were toast, the water jackets were somewhat compromised, but the nipple/discharge going into the rubber hose broke apart under the slightest pressure. Cast iron is brittle and that was perfect example. The boat was kept on a spring fed river for a number of years and had a flushing connection so for a raw water-cooled engine the water jackets were pretty clear all things considered.

I also replaced the power steering cooler with an eye towards replacing as much as I could of anything exposed to salt. I couldn’t keep power steering fluid in the pump, since the oil cooler was bad, I figured I should replace this cooler as well. Of course, the old PS cooler was fine, it was a leak from the hose connection. I hope I didn’t burn up the PS pump, since I stopped adding fluid at the end of the season because it felt like I was just dumping PS fluid in the bilge….

So, this isn’t a completely self-congratulatory post, we ran in to one issue. There is one small hose that comes from the fuel pump to the port riser with a little threaded brass elbow – yet another cooling line. Well of course we missed it when we put the plugs in and mounted the port riser (tapped on the engine side). So, since we didn’t want to take it all apart again, we installed the elbow on the starboard riser. I figured I would ask here if this is an issue. The brass elbow was clogged (we cleaned it) but all I could think not much cooling taking place there.

I did find a used thermostat housing that is in much better shape than the current one, probably swap it out in the spring when it is warmer. Thanks for any insight folks can provide. The information I gain on this site is really helpful. Happy New Year!
 

alldodge

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There is one small hose that comes from the fuel pump to the port riser with a little threaded brass elbow – yet another cooling line. Well of course we missed it when we put the plugs in and mounted the port riser (tapped on the engine side). So, since we didn’t want to take it all apart again, we installed the elbow on the starboard riser. I figured I would ask here if this is an issue. The brass elbow was clogged (we cleaned it) but all I could think not much cooling taking place there.

The should not be for cooling nor go to the riser, this is the fuel pump diaphragm rupture tube. It should go to the carb, so if the pump ruptures, it dumps the excess gas into the carb
 

jtm3

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Now you made me dig into my shop manual some more, based on the attached image - I don't think it matters which riser it goes to. It is fuel injected so no carb to go to. But it pretty clearly shows the cooling water from the t-stat housing to fuel pump then to the riser.
 

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BRICH1260

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I thought VP modified its original instructions to add a copper based gasket material spray on the riser and manifold mating surfaces prior to installing the gaskets.

It may not be needed in your case, but I distinctly remember reading that somewhere. I say this because this is a job that I will be doing in the next few weeks.
 

Lou C

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look here
 

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jtm3

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Interesting - I'll have to get the instruction that came with the risers. It was very clear to NOT to use anything - it says that they sent out new instructions with every set of risers since they are using a new gasket. Of course everything is on the boat and not handy so I'll have to see if I can find the copy. I read the thing a number of times and I would have not gone any further had it said that. Lou C has been very helpful to me personnally, but that is a different set of instructions then what came with mine.
 
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Bt Doctur

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No engine has ever gone bad using PermaTex Aviation sealant on anything.You also should run a flat file across the surfaces new or used Now if you have those new thin metal gaskets I would change them to composition ones
 

jtm3

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This is what the installation instructions said
 

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Lou C

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The one I posted is from a while back; if your gaskets came with those instructions I’d follow what you got. When I did my new Barr exhaust I emailed their tech support and they advised that I use Permatex Aviation with the Barr gaskets. Different gaskets require different procedures.
 
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