Camshaft Replacement on Vortec 4.3L 262

[Kita05]

Greetings one and all.

I recently started a project in my downtime of rebuilding a free 1999 vortec Mercruiser 4.3L 262 2 barrel carb engine that came with almost everything except the crankshaft and the camshaft. My friend told me that he bought the used engine for those parts only and now has no use for the rest of the engine.

Looking at replacing the camshaft (part number 431-803186), I see these go anywhere from $500 - $800, and I think that's pretty expensive.

Before buying this cam at the best price I can find, are there any other marine cams that would work just as well that aren't OEM that would cost half as much?

Don't get me wrong, I'll spend the money on quality - just looking for verification before pressing the buy button on a cam that obscenely expensive.

Marine Parts Express

Marine Parts Express is one of the largest retailers of marine engine parts in North America. We specialize in Volvo Penta engines, outdrives, and more.

www.marinepartsexpress.com

Thanks gang!

 

[Scott Danforth]

It's just a GM truck cam. You could get a crane cam or comp cam

 

[Kita05]

It's just a GM truck cam. You could get a crane cam or comp cam

Hey thanks a ton for the quick reply. I thought that marine cams have a much harder grind to them because they don't sit at idle as much as a car or truck.

From what I've read, you definitely can use a truck cam, but it wont have that get-up, high RPM power that's useful getting on plane and going full-throttle cruising from point a to b. Basically, it'll run, but not well unless you have the truck cam reground or are using an actual marine cam.

 

[itsathepete]

Melling MC1315 from Rockauto is a decent stock replacement and cheap. Without knowing what valve lift your heads are capable of, can't make any further suggestions

 

[itsathepete]

Hey thanks a ton for the quick reply. I thought that marine cams have a much harder grind to them because they don't sit at idle as much as a car or truck.

From what I've read, you definitely can use a truck cam, but it wont have that get-up, high RPM power that's useful getting on plane and going full-throttle cruising from point a to b. Basically, it'll run, but not well unless you have the truck cam reground or are using an actual marine cam.

You might lose a few horsepower but it's typically not noticeable especially since you only have a 2 barrel carb

 

[Kita05]

Melling MC1315 from Rockauto is a decent stock replacement and cheap. Without knowing what valve lift your heads are capable of, can't make any further suggestions

Hey thanks, the valve heads are vortec that came stock with the engine that I linked in the mercruiser schematics in the original post. Part number 938-827178 I believe.

You might lose a few horsepower but it's typically not noticeable especially since you only have a 2 barrel carb

Good to know - so if I swapped out the intake manifold and used Edelbrock 1409 4 bbl/4bbl manifold, it would be more noticeable?

 

[Bondo]

Hey thanks a ton for the quick reply. I thought that marine cams have a much harder grind to them because they don't sit at idle as much as a car or truck.

From what I've read, you definitely can use a truck cam, but it wont have that get-up, high RPM power that's useful getting on plane and going full-throttle cruising from point a to b. Basically, it'll run, but not well unless you have the truck cam reground or are using an actual marine cam.

Ayuh,.... You need a cam that makes power from idle to 5,000rpms,....

Any bigger cam than that, yer gonna have reversion issues, gettin' water sucked into the cylinders,.....
'n it won't make enough power down low, to get onto plane,......

 

[Kita05]

Ayuh,.... You need a cam that makes power from idle to 5,000rpms,....

Any bigger cam than that, yer gonna have reversion issues, gettin' water sucked into the cylinders,.....
'n it won't make enough power down low, to get onto plane,......

Great info Bondo, and all the others, I appreciate the help. This has been really useful. GM truck cam sounds good to me - or grinding MC1315 from RockAuto. Both make great alternatives.

Heard good things about this forum, and I'm happy to see it lives up to the hype - excellent info in the matter of a couple hours. Rock on, boaters

 

[Scott Danforth]

4.3 GM marine cam part number is suspiciously the same as the GM Silverado/S-10 truck cam

Hey thanks a ton for the quick reply. I thought that marine cams have a much harder grind to them because they don't sit at idle as much as a car or truck.

From what I've read, you definitely can use a truck cam, but it wont have that get-up, high RPM power that's useful getting on plane and going full-throttle cruising from point a to b. Basically, it'll run, but not well unless you have the truck cam reground or are using an actual marine cam.

Not sure where you are getting your info.

Other than the core plugs, water pump and the head gaskets (early on) the 4.3 coming down the Tonawanda line didnt know if it was a truck motor, a forklift motor or a boat motors. After a point, head gaskets and core plugs became the same

Remember any cam you go with, make sure there is no valve overlap in a wet exhaust marine application

 

[Lou C]

Was going to add that, make sure the cam overlap won’t cause reversion. When they went to the Vortec heads in ‘96, the 4.3s were seen as more susceptible to reversion (not sure if it’s the head design or cam, Scott do you know?). V/P made a few changes to off set this, they added one way check valves to the elbows to break the vacuum that can develop in the exhaust stream, & they also changed the shape/angle of the 90* down pipes that connect the elbows to the Y pipe. I learned this when I had to upgrade from the old one piece batwings to the 2 piece exhaust used on later OMCs & Volvos (in fact Volvo used this right up to the cat converter exhaust). Not sure if Merc did anything to their exhaust to reduce the chance of reversion on their Vortec 4.3s. They had their batwings from 96-99 had a lot of problems and then went back to the conventional 2 piece units.

 

[nola mike]

After a point, head gaskets and core plugs became the same

Glad to see you've finally accepted that

 

[Lou C]

You can tell if your engine came off that line because the GM serial # in the front starboard side of the block will have a T for Tonawanda in the serial #…
Mine did & definitely had the stainless head gaskets when I took it apart…

 

[Kita05]

4.3 GM marine cam part number is suspiciously the same as the GM Silverado/S-10 truck cam


Not sure where you are getting your info.

Other than the core plugs, water pump and the head gaskets (early on) the 4.3 coming down the Tonawanda line didnt know if it was a truck motor, a forklift motor or a boat motors. After a point, head gaskets and core plugs became the same

Remember any cam you go with, make sure there is no valve overlap in a wet exhaust marine application

Heya Scott

Great, thanks!

The part number came off of the mercruiser engine schematics I linked in the original inquiry. I've used it and cross-referenced it with the official mercruiser schematic site and they both seem to use the same part numbers. Should I use a different site?

Here is the link again

Marine Parts Express

Marine Parts Express is one of the largest retailers of marine engine parts in North America. We specialize in Volvo Penta engines, outdrives, and more.

www.marinepartsexpress.com

matics page and they seemed to be the same. Is there a different one I should use?

 

[Kita05]

Was going to add that, make sure the cam overlap won’t cause reversion. When they went to the Vortec heads in ‘96, the 4.3s were seen as more susceptible to reversion (not sure if it’s the head design or cam, Scott do you know?). V/P made a few changes to off set this, they added one way check valves to the elbows to break the vacuum that can develop in the exhaust stream, & they also changed the shape/angle of the 90* down pipes that connect the elbows to the Y pipe. I learned this when I had to upgrade from the old one piece batwings to the 2 piece exhaust used on later OMCs & Volvos (in fact Volvo used this right up to the cat converter exhaust). Not sure if Merc did anything to their exhaust to reduce the chance of reversion on their Vortec 4.3s. They had their batwings from 96-99 had a lot of problems and then went back to the conventional 2 piece units.

This is really good info to know, thank you Lou

 

[Scott06]

Melling 22119 Camshaft for a Chevy 4.3 Marine for sale online | eBay

Find many great new & used options and get the best deals for Melling 22119 Camshaft for a Chevy 4.3 Marine at the best online prices at eBay! Free shipping for many products!

www.ebay.com

 

[Kita05]

Melling 22119 Camshaft for a Chevy 4.3 Marine for sale online | eBay

Find many great new & used options and get the best deals for Melling 22119 Camshaft for a Chevy 4.3 Marine at the best online prices at eBay! Free shipping for many products!

www.ebay.com

Now that's a price that sounds reasonable - thank you, Scott!

 

[itsathepete]

FWIW the Melling 22119 cam is spec for a non-balance shaft (pre 1992) 4.3
The Melling marine cam for balance shaft equipped 4.3 is #22222
I have no idea what the difference is

https://www.melling.com/wp-content/uploads/2018/02/ag-marine-catalog.pdf

page 38
This is, of course, assuming that the original cam was a hydraulic roller and you have a good, full set of roller lifters as well as the antirotation links, hold down plate, and the cam retaining plate.

Oddly, Summit lists this as a flat tappet cam. This I assume is an error as Melling's literature, O'Reilly, and Rockauto all list it as hydraulic roller

 

[Scott Danforth]

Should I use a different site?

Not sure why you are looking up GM parts on the Mercruiser site. 500% markup

I use a few GM industrial sites to get GM part numbers.

However if rebuilding, my local machine shop

 

[Kita05]

Not sure why you are looking up GM parts on the Mercruiser site. 500% markup

I'm not. The existence of this very post serves as proof that's exactly NOT what I'm doing, since it's purpose is to find a cheaper alternative.... lol

Again, I use both the site I linked, and the official Mercruiser site, for part numbers. Not for prices. I guess we do things differently. I prefer to use schematics that contains all the different components of the engine when looking for a replacement - and then seeing if there are alternatives based on whether the prices are outrageous or not.

They are the official Mercruiser part numbers. This is according to both the official Mercruiser website, and 3rd party schematic websites.

Here is the official Mercruiser site. Again, as I said before, same cam part number....

https://public-mercurymarine.sysonline.com/Default.aspx?sysname=NorthAmerica&company=Guest&NA_KEY=NA_KEY_VALUE&langIF=eng&langDB=eng

Google Search Results..

 

[Kita05]

FWIW the Melling 22119 cam is spec for a non-balance shaft (pre 1992) 4.3
The Melling marine cam for balance shaft equipped 4.3 is #22222
I have no idea what the difference is

https://www.melling.com/wp-content/uploads/2018/02/ag-marine-catalog.pdf

page 38
This is, of course, assuming that the original cam was a hydraulic roller and you have a good, full set of roller lifters as well as the antirotation links, hold down plate, and the cam retaining plate.

Oddly, Summit lists this as a flat tappet cam. This I assume is an error as Melling's literature, O'Reilly, and Rockauto all list it as hydraulic roller

Good to know, thank you!