3.7/488 help

[searcyfarms]

so this has turned into a 3 yr project, family stuff, life, etc.....wrote on here before regarding my debacle with the bad snout on cam and eating seals - SO i get my engine apart - and am i missing something here, i am trying to find a replacement cam and none have teh same snout on the end of the cam like mine, mine has ground opposing flat spots to turn the water pump impellar the ones i see online are totally round and look to also be shorter in the snout? Do I have some rare version of the 3.7 and they dont make replacement cams for it? Mines out in the boat so i found one like this online. Are they available anywhere?

 

[Bondo]

and they dont make replacement cams for it?

Nope,.... It's been outa production for What,..?? 30 years,..??

If the only problem with yer's is the seal area, put a speedi-sleeve on it,.....

 

[Bt Doctur]

There are two versions depending on serial number,impeller is stud mounted or bolt mounted
tons are on ebay

 

[searcyfarms]

well i have done the speedi sleeve, got me 2 yrs - they are junk hate them, difficult to install also and getin right spot - anyway - there are none on ebay with the newer style slotted type snout for the impellar drive fyi

 

[Scott Danforth]

send your cam in to a cam re-grinder, have the snout welded up, hardened, then re-ground.

a few cam grinders:

https://www.howardscams.com/
https://www.camcraftcams.com/
https://effingham-regrinding.com/
http://www.kamsinc.com/

 

[searcyfarms]

well its going to cost the same to grind as new mercruiser one? is the metal in the new cranks better than teh original?

 

[Scott Danforth]

no, the cam nose is still not hardened from Mercruiser. unless you send it out to get the nose hardened, it will suffer the same fate.

 

[Bondo]

as new mercruiser one?

Ayuh,..... Isn't the part number for the new Mercruiser 470 cam, NLA,..??..??

The usual killer of that spot on those cams is rust, not wear,.....

 

[Scott Danforth]

however the nose isnt hardened, so the seal starts to wear a groove in it. only the lobes were hardened

 

[searcyfarms]

so were the old style impellars driven by the keyway that the cam gear drives from ? my impellar has no key way and is driven by the flat spots on the end of the cam snout - was there a design change in the cam style snouts and drive of teh impellar?

 

[Scott Danforth]

the circulating impeller has a double-D hole that is driven by the extended cam snout or there is the threaded version. you need your engine serial number to break it down.

none were driven by the cam keyway.

 

[searcyfarms]

so per mercruiser, just got off phone the ONLY cam number that were extended/ground Drive for impellar were the original 8479A1 cams, those changed to the 9410 and A1 versions and in there were the stud and impellar that changed also

SOooooo i have the rare bird style with the D/Ground drive cam - and will have to search for a different impellar and stud so mine can be modified - shouldnt be hard to find on ebay or salvage i wouldnt think - i wish there was an easy way to change to a different engine the boat is just too nice to scrap honestly going from an inline 4 to v6 isnt easily done - my insurance is paid up maybe the stupid thing will catch on fire lol

 

[searcyfarms]

maybe i can squeeze a 5.9 cummins in there adn roll some coal!!!

 

[Rick Stephens]

Find a rotted out donor boat with a 4.3L V6 and go to building motor mounts. Transfer everything from the donor boat, sell all your 3.7L parts and pieces. I broke even doing that from 3.0L to 4.3L and the 3.0L is dirt common and cheap compared to selling off the 3.7 as parts.

 

[searcyfarms]

my bottom/transom/hull would have to be totally butchered adn cut out, im not that kind of a fabricator those 4.3 are stocky - mine sits out in front of the transom and not down in/recessed in the back it would take out that back seats also to make one fit. It looks like there are lots of cams of the newer version with the thread on impellar and different snout on the cam. I wonder if the after markets are better metal on the snout for wearing/rusting than the original mercruisers?

 

[Rick Stephens]

my bottom/transom/hull would have to be totally butchered adn cut out, im not that kind of a fabricator those 4.3 are stocky - mine sits out in front of the transom and not down in/recessed in the back it would take out that back seats also to make one fit. It looks like there are lots of cams of the newer version with the thread on impellar and different snout on the cam. I wonder if the after markets are better metal on the snout for wearing/rusting than the original mercruisers?

Uh, a v-6 will be a little bit less lengthy, and a teeny bit wider. It would sit in front of your transom nearly identical and heigth also nearly identical. Not sure what your issues would be. But OK.

 

[Scott Danforth]

so per mercruiser, just got off phone the ONLY cam number that were extended/ground Drive for impellar were the original 8479A1 cams, those changed to the 9410 and A1 versions and in there were the stud and impellar that changed also

SOooooo i have the rare bird style with the D/Ground drive cam - and will have to search for a different impellar and stud so mine can be modified - shouldnt be hard to find on ebay or salvage i wouldnt think - i wish there was an easy way to change to a different engine the boat is just too nice to scrap honestly going from an inline 4 to v6 isnt easily done - my insurance is paid up maybe the stupid thing will catch on fire lol

there are a lot of the double D cams and water pump impellers on ebay right now.

swapping to a V6 is easy

 

[searcyfarms]

Uh, a v-6 will be a little bit less lengthy, and a teeny bit wider. It would sit in front of your transom nearly identical and heigth also nearly identical. Not sure what your issues would be. But OK.

hmmmmm maybe i could try that in the future - my dad has a 4.3 v6 in his Tahoe - its a 190hp i think seems to be pretty reliable - just seems wider but his is down in a hole vs mine - mine is in an AMF Crestliner Nordic i have not done exact measurements on his to see the difference, i did see his has near if not exactly the same gear ratio in the lower unit ironically

 

[searcyfarms]

i have the impellar, the only double D shafts i see on ebay are of USED cams that need the same things my double D shaft needs - either reground or replaced due to bad snout rust/grooves

 

[Rick Stephens]

Here's the 4.3L installation drawings that will let you know exactly how big an 4.3L is. I've never seen drawings for the 3.7L, so you'll have to compare while sitting in your boat. I think it will surprise you haw little size difference there is.

Rick