Alum Intake Manifold Questions

[John_S]

OK, its cold here in NY, so idle minds tend to read, and formulate many questions <br /><br />I am planning a 2 to 4brl upgrade on my '97 5.7L mercruiser, raw water cooled. I am using the Edelbrock Performer 2104, and plan on a weber/carter/edelbrock 600cfm marine carb. I boat only in fresh water, so in general, the aluminum manifold should not be an issue. The Adirondak water where the boat is moored all summer, is rated as slightly acid. I suspect that is not a good thing for aluminum. <br /><br />I am planning to paint the exterior exposed surface of the manifold, and use an aluminum primer and black merc paint, similar to the procedure for painting outdrive. Is it worth priming and painting the internal water passages? or possibly using something else? I do have a concern if the paint peels off in large chunks, and possibly plugs passages. Probably not much more risk than rust scale or impeller chunks? Thoughts? Experience?<br /><br />My experience many years ago with cars and aluminum intake manifolds, leads me to believe that heat percolation to the carberator will/could be an issue, especially after shutdown/heat soak. I plan on using a good quality intake manifold gasket and block off the egr passages (the carb has electric choke). I will also use a spacer between the maifold and the carberator, but haven't decided between the edelbrock dual plane heat spacer or standard 4 hole square bore spacer. The water I boat in, only ever reaches high 70 degrees, air temp 80's, but ussually cooler than that. Will blocking off egr and carb spacer make things too cold, leading to rough idle? ie maybe use the restrictive egr block-off instead? <br /><br />Anyway, you see that I have too much time on my hands, and thinking way down in the weeds. :0 I'll hold off on my carb jetting/metering rod study and questions, for another cold NY weekend.

 

[Bondo]

Re: Alum Intake Manifold Questions

The Adirondack water where the boat is moored all summer, is rated as slightly acid. I suspect that is not a good thing for aluminum

Naw.... It Won't Hurt a Thing........<br />I've got a place over on Lake Bonaparte, just outside the "Blue Line" on the Northwest corner of the Adirondacks........<br />Believe Me, We boat in Very FreshWater........... <br />

I am planning to paint the exterior exposed surface of the manifold, and use an aluminum primer and black merc paint, similar to the procedure for painting outdrive. Is it worth priming and painting the internal water passages?

If you wish to paint the Outside, It's Your Choice.......<br />But, Not Necessary.......... <br />Leave the Water Passages Alone..... Really wasting your Time,+ Money Here.....<br />

My experience many years ago with cars and aluminum intake manifolds, leads me to believe that heat percolation to the carberator will/could be an issue, especially after shutdown/heat soak. I plan on using a good quality intake manifold gasket and block off the egr passages (the carb has electric choke). I will also use a spacer between the maifold and the carberator, but haven't decided between the edelbrock dual plane heat spacer or standard 4 hole square bore spacer. The water I boat in, only ever reaches high 70 degrees, air temp 80's, but ussually cooler than that. Will blocking off egr and carb spacer make things too cold, leading to rough idle? ie maybe use the restrictive egr block-off instead?

Bad ideas here Too......<br />Mount it as Specified, with Quality Gaskets, Exactly like the 1s you Remove......<br />Your motor Won't Ever get Hot enough to worry about percolation.....<br />With Raw Water Cooling, you Should have the 145* T-stat........ It's Already Too Cold for Efficiency.........<br /><br />For the Next Cold Weekend,<br />Wander over to Here,+ Click on Carburetors..... <br />On that page, Click on Edelbrock Performer Series (EPS) Carburetor Owner's Manual................<br />This will get you to the Greatest Carb Manual for the above mentioned carb. I've been Able to Find..........

 

[John_S]

Re: Alum Intake Manifold Questions

Bondo,<br /><br /> I was planning to paint the outside of the intake for that stock look. Doing the water passages would not be much more work. My bigger concern is how well the paint will hold up. Outdrive paint/primer seems to hold up well. Does the paint hold up with the heating/cooling cycles of the engine? The last thing I want to end up with is bunch of peeling paint. I had a wood deck like that, that a prior owner painted, instead of staining. Maybe I have to reconsider that aluminum look.<br /><br />My engine uses a 160 degree thermostat, but I do know the older engines used 140. Boat gauge reads 170-175. Dennis Moore recommended blocking off the egr passage, in his book. Sounds like it will make things too cold. <br /><br />Thanks for the pointer to the tuning guide. I have read that (found due to one of your prior posts), along with Dennis's tuning recommendations, and Merc's rebuild section of the manual. Overall, it seems to be very straight forward carb and relatively easy to work on. I also compared the jets/metering rods of Merc to what the stock edelbrock 1409 has. The 1409 is suppose to be set-up out of the box for sbc, but the secondary jets are much richer than most of the merc set-ups. The LX and 350 mag run 0.092, while the 1409 has 0.101. The LX and 350 mag are three stages leaner on secondaries! The primaries somewhat compare after comparing the different metering rods. Began to think that the edelbrock was slightly different than the weber, but then noticed the edelbrock 4.3 kit, uses the exact jets/rods as merc. <br /><br />OK, now I'm going to have to read some more for next weekend ;-)<br /><br />BTW, I remember seeing a post about a small block stroker engine you were working on. Wouldn't mind reading some details on that.

 

[TilliamWe]

Re: Alum Intake Manifold Questions

John I understand why you want to paint the outside, and I say go for it! I would use "engine" paint. It's made to hold up to high heat. They sell it at Wal-Mart (at least the last time I looked they did)<br />You answered your own question in your original post about painting the water passages. The paint wouldn't hold up & it would flake off. Why risk anything getting into the water passages, when you don't have to? I say leave the inside of that maifold alone

 

[Bondo]

Re: Alum Intake Manifold Questions

Like I said, The Painting thing is Up to You........<br />I painted my 4.3LX with the Prettiest Cat Yellow Tractor Paint(Just because I was painting a dozer) when I put it together about 5 or 6 years ago..........<br />It's holding up Just Fine.......<br />If you decide to paint the Insides, <br />Even if it Peels... It'll Pass the system Much Easier than the rust scale or impeller chunks, gasket pieces,+ chunks of silicone sealer.....<br /><br />If Dennis says to block off the cross-over, then that's what I'd do..... I like Him,+ Use his book as a Bible............... <br /><br />For that Carb., You've Got to go find yourself a Carter Strip Kit, part# 10-201..........Lot's of Needles,+ Jets,+ Springs,+ Etc.....UnBelieveable Tuneability...... <br />Most of the HotRod catalogs have them.... <br />Best $40. or $50. I Ever Spent......<br />I leaned my idle,+ fattened the top end.......Still got a tiny mid-range stumble, but I think the next step of springs is going to do it........<br /><br />Yaaaa, The Bored & Stroked 327 is at the MachineShop......... <br />I Wish I had the numbers right here for that motor, But I don't....<br />It's a 1968 327 virgin block, big journals......Cast steel crank, in the 3 3/4" stroke..... powered metal 5.7" rods... Vortec, 906 casting heads... Kodiack Marine Aluminum high-rise intake,+ Alum. runner exhaust manifolds...<br />And, Of Course a Carter/Merc./Weber/Edlebrock Carb.............

 

[jimmythekid]

Re: Alum Intake Manifold Questions

do they build a manifold without the EGR passages for marine app??<br /><br />bondo: did you mean forged steel crank? or cast iron? ive never heard of a cast steel crank before.<br />327ci was my first engine build ever. those things would rev like no tomorrow

 

[John_S]

Re: Alum Intake Manifold Questions

It's a 1968 327 virgin block, big journals......

A 37 year ole virgin??? Now, that is some find! <br /><br />What kinda boat you putting her in? Drive?

 

[John_S]

Re: Alum Intake Manifold Questions

Jimmy,<br /><br />Good point. I have been saying EGR, when I meant to say exhaust crossover passage. <br /><br />

327ci was my first engine build ever. those things would rev like no tomorrow

I think the chevy 302 had it beat! Been a very long time since I sat in one of those cameros.

 

[Northern Eclipse]

Re: Alum Intake Manifold Questions

John, I noticed you mentioned that your motor is a 97 is this not a Vortec engine if so then the 2104 Edelbrock Intake will not fit, small blocks went to Vortec heads in 96, but thats not to say your carbed 350 is a Vortec, since any of the Vortec blocks I'v seen have been fuel injected but thought I would just mention this so has you can be sure on the correct intake, Maybe Bondo or somebody knows for sure if carbed sbc for that year had Vortec heads or not, Oh ya one other thing I painted the exterior of my intake with Dupli-colors high heat ceramic engine paint in aluminum color, looks like shiny aluminum and is very durable I also paintend my manifolds and riser in black dupli-color it still looks has if I painted them yesterday. Exhaust cross-over can be blocked off since carb is an electric choke.

 

[John_S]

Re: Alum Intake Manifold Questions

Northern,<br /><br />I wish I had vortec heads, but I don't, and I've looked. In '97 you could get them if ordering a gen+ engine. Not 100% sure, but believe in '98 all sbc mercs went vortec.

 

[Bondo]

Re: Alum Intake Manifold Questions

Jimmy,<br />Depending on Who's Catalog you're looking at,<br />Nodular Iron, Or Cast Steel Cranks are just 1 step Better than a factory Cast Iron Crank........<br />No It's Not Forged...Wish it Was......<br />The rotating assembly has Already been Balanced, So I Won't be going to Forged in This motor..............<br /><br />John,<br />Ayuh, She's a Virgin, in that it Hasn't seen a Machine Tool yet.....<br />But, I'm Sure it was run Plenty Hard when it was in the Station Wagon it came from the factory in............<br /><br />It's "New Home" is a 1973 Old Town Atlantis.... Built by Old Town Canoe Co.......<br />Old Town has been building Canoes for over 100 years.... They built Wooden boats during the late 40s, into the early 60s.....At that time Leo Gilman took the company into the Fiberglass boat business(I grew up in Old Town, This is where my 1st memories of the factory come from)...<br />Around the late 70s, Sam, S.C. Johnson bought the company..... <br />He decided that Old Town was a Canoe Company... Not a Boat Builder....<br />So, the boats were dropped from the line,+ They went on to become the Worlds Premier Canoe Company.........<br /><br />After 5 Years of Searching, I ended up with the Corporate owned(Old Town Canoe Co.) 25' Atlantis..... My Hull came out of the Mold the Same year I graduated from Old Town High School... We're Both from the Old Town, Class of 73........ I managed to find 4 other Atlantis's...1 outside Bar Harbor Me., It had been refitted with a Mercruiser 7.3l Diesel,+ a Bravo III..... Another right here in My backyard, It's been refitted with a Volvo 4cyl. Diesel,+ has since been moved down to the Islands in the Caribbean....Another is from the Boston area, It has been refitted with a Mercruiser 350Mag,+ Bravo III.... And, the last 1 is setting in a field in Georgia, Stripped,+ Rotting away... I'm tempted to go get that 1.....(As if I Need Another Project)<br /><br />BTW, The Atlantis was the Flagship of the line..... 25', Built for the Ocean off the coast of Maine.........<br />I'm Hoping that She'll handle the chop on Lake Ontario with Ease......<br />At the moment, She's on blocks in the yard, getting a Total Refit......<br />No More OMC.... It'll be an Alpha 1 for the time being......Ya, I Know it'll be the Weak Link, But I'm thinking I can keep my hand in Control, on the Throttle.........<br />The "Trickest" part of the refit is, I'm moving the engine forward 2',+ it'll run thru a jackshaft to the outdrive.....<br />That'll give me Full Access to All of the Transom, for Fishing purposes......

 

[John_S]

Re: Alum Intake Manifold Questions

Bondo,<br /><br />I never would have guessed that Old Town made 25' fiberglass boats. As you said, famous for canoes. Any pictures?

 

[Scaaty]

Re: Alum Intake Manifold Questions

Jeezzz...from manifolds, to carbs, to paint, to heads, to cranks, to boats..WHOA. Back to the question.......<br /> No one mentioned Pencil Zinc's. I have a Salt/Raw 96GM350, Aluminum Edelbrock Man, Edelbrock (love it) 600cfm carb, zero spacers, blocks...just what it called for (simple gaskets). Heat not a problem. <br /> On the top/front on the manifold should be 3/4 pipe fittings for sensors (Temp Guage). Use replaceable pencil zincs that screw into the brass top nut/plug sold at any boat shop. On mine I use the 5/8ths size cut down to 1 1/2 inch. Replace yearly in salt. <br />Ps. If I had a 327, I would chrome, chevy orange, "roots", pedestal, and stare at it!

 

[Bondo]

Re: Alum Intake Manifold Questions

Ayuh..... I guess we got a little off topic........<br /><br />John,<br />No Photos..... Haven't learned how to FTP yet.....<br />And, The only 1 I've seen on the web is Gone.....<br />

If I had a 327, I would chrome, chevy orange, "roots", pedestal, and stare at it!

Well, I haven't decided on the color of the block yet,......Leaning towards Mack Gold......<br />But,<br />I've got Polished Aluminum Valve Covers, Polished Aluminum Oil Pan, Aluminum Manifolds,+ Aluminum Intake.........<br />All I'm Lacking is an old original Chevy aircleaner "327/350hp" sticker to put on the Flame Arrester.................. <br /><br />Now, Back to the Topic,.....<br />The Pencil Zinc Isn't a Bad Idea, <br />But, <br />The water we boat in really doesn't require it.... <br />Really Cheap Insurance, none the less...........