Riser To Manifold Torque w/Sierra gasket

[cyauch]

I seriously hate having to ask this. Spent the better part of a day and a half trying to find an answer that wasn't immediately contradicted by someone else....who doesn't own, nor ever owned, an I/O . I also feel I'm starting to believe this place is becoming my second home too.....which may not be a bad thing.

But here's the deal: I'm finally getting some sea trials out of the way in prep for the season (and some major repairs following an underwater strike). On the last trial, i noticed water weep from the Port riser to manifold area. Maybe a drop or two, but water none the less. I have a set of VP OEM gaskets on the way, but this weekend coming up is the only time I'll really have time to do more short trial runs to check other things out. I picked up circ pump gaskets and the marine shop gave me a set of Sierra manifold / riser gaskets because they kept getting wrong circ gaskets from their supplier before getting the correct VP one.

So the Sierra's are grey, seem pretty think, and appear to be a graphite type gasket. Do i use the same VP torque spec for the VP OEM's? All other threads and post on the interweb seem to dive into 'green paper gaskets are bad' and i'm dumbfounded how that even came up since that usually wasn't the OP's question anyway. But here we are.
So yea, this won't be a long term fix, but i'm nervous about what I'm gonna find since I'm sure these are the original manifolds and risers (15 years old). And yes, i will replace them asap no matter due to the issues with overheating (seems resolved but want to take it on trials and do some more tests) and condition of the RWP i just replaced. I just need this to work for this weekend only so i can check the repairs and maintenance done on other things the past few months. Then, during the two weeks that follow, tear things down, order the replacement parts, and get ready for another set of trials for those parts in 2 - 3 weeks. I just wanna order as much as i can in one shot vs order, wait, order, wait, etc.

I tried to also find a Sierra site that might help with torque specs but either i'm a loser or it doesn't exist

THanks

 

[bruceb58]

12-18 ftlb

I sent you some links to manuals. Older than your model but will help with most stuff like this

 

[enginesilo]

Have you tried to tighten down the bolts a bit on the existing setup? I’d be cautious with taking apart an riser that old, once they get disturbed they don’t always handle it well. See if just a little extra turn on the existing bolts help stop the weep. Or if you can just ride it out as is until you are ready to do the job and change them out. If you do swap in the new gasket be sure to check out your manual as they will sometimes specify to re torque after a heat up/cool down cycles.

 

[Lou C]

Do they look like these? These came with my Barr exhaust kit, they sealed well, installed about 3.5 years ago.
you could try torqueing the bolts that hold the exhaust elbows on, (people call them risers but the are elbows, a riser is a spacer between the manifold and the elbow). Try 25 ft lbs, if they are looser than that you can get leaks.
I put the late OMC/Volvo style exhaust on my engine then during a top end overhaul (reman heads etc) because the old one piece OMC V6 manifolds were long since NLA. The Barr exhaust fit well and the machining was very good.

 

[cyauch]

Do they look like these? These came with my Barr exhaust kit, they sealed well, installed about 3.5 years ago.
you could try torqueing the bolts that hold the exhaust elbows on, (people call them risers but the are elbows, a riser is a spacer between the manifold and the elbow). Try 25 ft lbs, if they are looser than that you can get leaks.
I put the late OMC/Volvo style exhaust on my engine then during a top end overhaul (reman heads etc) because the old one piece OMC V6 manifolds were long since NLA. The Barr exhaust fit well and the machining was very good.

yep. thats what they look like

 

[cyauch]

12-18 ftlb

I sent you some links to manuals. Older than your model but will help with most stuff like this

as always, thanks! you've more than helpful and i appreciate the guidance and info

 

[cyauch]

enginesilo: well, i wish i read ur post before i took the port riser off. lol. but the suspense was killing me on what these things look like in the water passages. prior to pulling though i did hit heads with a torque wrench. all 4 turned at least a quarter turn before i got a click. paranoia then set in as the worry if water seeping into the exhaust materialized.

but to surprise, considering these are probably the 15 year old originals, i think they look pretty good. again, all things considered. some rust and scale build up that probably affects some coolling capability, but the passages look wide open and i saw no growth. im starting to feel much better about the water passages internal to the engine now. and i saw no signs of water leaking into manifold

still, i do plan to replace but i think can make it through this season and make this a winter job? for now also, i think ill re torque the stbd riser even though its not weeping any water....yet but not disturb it just yet.

my pressing issue is a pop in the arrestor that seems to have shown itself again following a fuel cell (pump) replacement. LP went out and HP was singing a nice toon before i replaced that. but i suspect the RWP was the root cause due to overheating issues resolved (i hope for good) with RWP replacement. i need to get a pressure gauge on this thing this weekend so i can pressures under load. ran great on first two trials but random popping again after RWP replaced. not related im sure, but aggrivating none the less.

pre and post clean pics attached

 

[Lou C]

15 years? you must be in fresh water because in 15 years I'd have changed the exhaust at least 2x if not 3x lol. So, I would probably want to run a belt sander on those to make sure there are no pits or slightly corroded areas if you want to reuse them. What we do is usually replace the elbow at 5 years, because the outlet will have the most corrosion since its exposed to hot exhaust gases and salt water and then exposed to air when the engine is shut off. The manifolds can last longer. We take them off the engine and fill the water passage with acetone which has less surface tension than water, if any wetness appears in the exhaust ports that line up with the cyl head they are junk.
After running them on the belt sander use a straight edge to see if a feeler blade will fit between the sealing surface and the straight edge. A .003" or a .002" should not fit, my new ones wouldn't even allow a .001" to slide in.
I'm going to attach the Volvo service bulletin for the exhaust system....

 

[Bondo]

So the Sierra's are grey, seem pretty think, and appear to be a graphite type gasket. Do i use the same VP torque spec for the VP OEM's? All other threads and post on the interweb seem to dive into 'green paper gaskets are bad'

Ayuh,..... Sierra dropped the green paper gaskets, 'n now carries the ones you have, which are just as good as the Oem gaskets, 'n yes, torque to the same values if ya wanta torque 'em,......

I just wrench 'em down to good, 'n snug, with my calibrated elbow, myself,....

 

[cyauch]

thanks guys. yea, im assuming 15 years. its a 15 year 1 prior owner boat i bought last year out if Louisanna south of new orleans. they told me previous owner moved from south carolina and never saw salt, so traded for a center console. i took that with a grain of salt (pun intended). ive always like Regals. since low hrs, hull and hardware great shape, and bilge / engine area were damn near spotless, pulled the trigger. sold our pontoon quicker than we thought so needed something. hated the quick decision but understand this will need some TLC for bit then should be ok....we hope anyway

 

[bruceb58]

They look good.

Confirm flatness with a straight edge.

Always use a torque wrench

Use the instructions with the gaskets I mailed you...went out today.

 

[bruceb58]

I'm going to attach the Volvo service bulletin for the exhaust system....

Out of curiosity, where did you find those torque specs? Sure doesn't say that in my Volvo service manual.

 

[Lou C]

I did it 4 years ago so I can't remember exactly where I got em but I think it was from the TSB that seems to have disappeared. Those are the specs I used, using the Barr gaskets and no leaks at all, salt water use. But the Volvo updated gaskets are different, so if I was using those, I'd follow what comes with the instructions, hopefully they do list torque specs and not just refer you back to the manual because those are updated, changed after the manuals came out.

 

[cyauch]

thanks! for now, i only did the port riser but did check torque on stbd. it was good. as for the port riser, i did set a metal ruler. couldnt find my feeler gauges (and of course the kids and wife have sudden and selective amnesia) so by eyeball it 'looked' ok; no major gaps visible. but there is some small pitting. i dont have a belt sander so used a little emory cloth in long passes so as to not put dips in. and, i know i'll prolly get yelled at, but used a light coat of permatex in the gasket and torqued things down.

i know i know. i hate doing it this way but they are going to get replaced so this isnt permanent. as i said prior, i really want to try and get some fuel pressures in the short window i have this weekend in hopes i can figure out the sudden and random popping in arrestor following fuel pump replacement. willing to bet trash made it to injectors. uggh. regulator screen looked meh so who knows

so ya, hated to do that riser like this but i promise, it aint staying this way for long

 

[cyauch]

another round if seal trials done. pop in arrestor never reared its ugly head. maybe a little trapped air is all it was. run today was an hour long up the river and back to launch. no leaks at riser....for now. and engine temps seemed good.

keep in mind my rpm gauge doesnt work ( another thing ti address) so im basing rpms on past mph when gauge did work

gauge at cruise speed

engine at cruise speed

idle speed in gear after 30 min or so run

view aft at cruise speed

 

[cyauch]

but i now have a power steering leak that appears to be near the transom. at least it looks like its running down from there. two hoses on left side of ram are dry so i dunno. pump has obvious foaming and noise progressed as run went on. bilge around pump and hose that runs under engine showed no dripping or flow. didnt have a leak at all last year so undoubtably i nicked an o ring or screwed something up when i pulled everything due to transom seal leak. somewhat easy to get back there and do a better inspection but i need to look at some diagrams also. may be starting a new thread on that

but thanks again to everyone who chimed in and offered help on the overheat and this riser leak issue. despite the PS leak, im feeling good about the engine and her reliabilty after some major work this winter