Offshoreonly.com - Enginetech Stellite Exhaust Valves?

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Quote:

Originally Posted by Mr Maine (Post 4476733)

The 1.6 rockers will give you .033 more valve lift, and that same amount less in retainer to valve seal clearance with all else being equal. That bit of extra lift will slightly increase over the nose spring pressure since the spring will be compressed a bit more. Retainer to valve seal clearance and how close you are to coil bind should be checked. The springs should be in the recommended seat pressures for opened and closed, I don't think a touch more lift would require different springs, and you can make adjustments with installed heights too.

With more lift and more rpms, the press in studs become a weak point. Screw in studs are the way to go to avoid that issue. Collared ones will require machining the bosses down, but you can get collarless screw in replacements that don't require milling the bosses. Only tapping the existing rocker stud hole. Summit sells a guide that makes this easy. Also, the pushrod hole in the head has to be drilled out because the pushrod will hit with a 1.6 rocker.

I did consider the screw ins with collar but that, plus machine work or bit to cut bosses, plus 3 angle seat grind, plus magnaflux, plus new valves, plus new rockers, plus maybe new springs, maybe machine work or bit to cut seats, and probably new valve covers to clear the taller poly locks = damn near a set of decent aluminum heads after selling the vortecs.

I was just going to pin the stock studs. Stock pressed in is supposed to be good for up to 350 lb. open pressure without pinning. I'm not running that radical a cam so the pinned should be strong enough even with 1.6 rockers? Or go with the Mr. Gasket collarless?

Quote:

Originally Posted by Gannz (Post 4476764)

Haha, I hear ya. You have to draw the line somewhere. Pinning them should be fine. I have seen them pull out on stock engines so with more spring pressure it's a good thing to do.

Edit in:
I believe the intakes are back cut already and if the seats are in good shape maybe just have them touched with a stone and forgo the 3 angle. Really for a moderate marine engine probably not gonna make a huge difference

Just wondering, what influence if any would adding a stud girdle have? Seems like it should help, no?

Quote:

Originally Posted by Mr Maine (Post 4476801)

They seem to be in good shape to me. No rust, no pitting. Just a little roughness on 3 of the 4 exhaust seats on the middle cut. Not sure what it is but it should clean up with a stone like you said. Then I'll lap em. This is a rebuilt long block that's less than 2 years old and the builder did the 3 angle and 30 degree back cut at that time. I was thinking the back cut wasn't wide enough but looking at some more photos they seem about right. Close enough anyway. First post shows one of my intake valves and third post shows seats.

Quote:

Originally Posted by GLENAMY 242SS (Post 4476819)

Just wondering, what influence if any would adding a stud girdle have? Seems like it should help, no?

I don't think they would do anything at the RPM's we run and hydraulic rollers. They're more for 6000+ with solid rollers to maintain stability.

Quote:

Originally Posted by GLENAMY 242SS (Post 4476819)

Just wondering, what influence if any would adding a stud girdle have? Seems like it should help, no?

Screw in studs, better pushrods, and better rockers would be more worth it...in order. But, if the cam is that mild in this motor,,,you can just say fuk it to those too. Lol.

SB understood I was thinking for budget sake used girdles can be had fairly cheap and with the pressed studs adding rigidity by tying everything together. Not asking for the normal high RPM reason, it was just a thought.
The OP was talking budget. I personally have nightmares about 2 things boating, 1) Valve-train failure, 2) Water incursion.

Switched to a fine stainless wire wheel on the dremel an cleaned up the roughness on those exhaust seats. I'm guessing it was just carbon. It was shiny so that kind of threw me but I probably just polished the carbon with that brass wheel. The stainless didn't take any extra material off. Not even a light scratching on the seats. Again, I'm pretty sure they're inconel seats.

So, I'll have them checked for cracks, get new exhaust valves, finish cleaning them up, and lap the valves. Probably should have checked for cracks first but they were just magnafluxed 2 seasons ago so I'm optimistic.

Thanks for all the help and advise. I'll probably start a budget 383 build thread soon because I'm sure I'll have more questions soon. LOL