High compression in 1 cylinder - 7.4 carb

[ScottinAZ]

Sierra part was basically same price shipped to West Marine so ordered the intake gasket. If I need Cam, I can just order cam shaft kit from auto parts store, right? Nothing "marine" about the cam or internal parts?

a marine cam is usually what would be referred to as a "truck" or an "RV" cam. A bit spicier than a regular cam, but not one with overlap, or you can suck water into the engine through the exhaust from reversion.

Others here, such as Scott Danforth can elaborate a bit more on this point, but it has been generally recognized that if you are swapping an automotive engine into a boat, you need the "truck" cam for the job.

 

[Kola16]

Like Scottin said, the cam is actually way different. Marine cams are built with all low end torque in mind, similar to what a truck is. A cam from NAPA would leave you with a gutless boat engine. You need a marine cam and they are more $$$.

Additionally, depending on where your engine is mounted, you will need to raise the engine to get the cam out. If you have a few feet of access in front of your water pump; however, you can leave the engine in the boat to get the cam out.

 

[jimmbo]

Marine, RV/Truck are not the same Cams. Most trucks just use the regular Auto Engine so no "Truck Cam". RV cams, are still different than a Marine Grind. "Close" is really only Valid, with Horseshoes, Grenades, and Nuclear Weapons. If you need a Cam, get one from Mercrusier, a few extra bucks can save a lot of Headaches, when the "close to" Cam isn't quite right

 

[Lou C]

The problem with cam design is overlap in addition to the torque curve. Too much overlap results in exhaust reversion.
If the BBC is just like the SBC, to get the timing cover off the engine oil pan has to come off or at least get lowered.

 

[snowbrd84]

Found this set on ebay - 64 sold and seller has good reviews. Any thoughts? I am a bit of a loss at how to find what cam kit to buy if I end up needing it.

Chevy 7.4 454 Marine HYD Cam Camshaft+Lifters Kit STD Mercruiser 22216/E1589S | eBay

Chevy 7.4 454 Marine HYD Cam Camshaft+Lifters Kit STD Mercruiser.

www.ebay.com

 

[nola mike]

Marine, RV/Truck are not the same Cams. Most trucks just use the regular Auto Engine so no "Truck Cam". RV cams, are still different than a Marine Grind. "Close" is really only Valid, with Horseshoes, Grenades, and Nuclear Weapons. If you need a Cam, get one from Mercrusier, a few extra bucks can save a lot of Headaches, when the "close to" Cam isn't quite right

yes, that normal 7.4L auto cam is probably totally different than the truck version.

 

[04fxdwgi25]

Found this set on ebay - 64 sold and seller has good reviews. Any thoughts? I am a bit of a loss at how to find what cam kit to buy if I end up needing it.

Chevy 7.4 454 Marine HYD Cam Camshaft+Lifters Kit STD Mercruiser 22216/E1589S | eBay

Chevy 7.4 454 Marine HYD Cam Camshaft+Lifters Kit STD Mercruiser.

www.ebay.com

If it were me, I would get the Mercruiser, but that setup looks to be viable.... IF it is USA made, not Chinesium. Fleabay ad does not state where it's made.

Contact the seller to find out it's origin.

 

[snowbrd84]

Was able to confirm I can get a USA made Marine camshaft made by Elgin with a set of lifters for about $350.

Still need to get out to pull the intake to confirm its camshaft and not just the lifter, but that will have to wait till after Sunday since we're using boat this weekend.

Luckily it looks like I can drain and unbolt the water tank and slide it out of the way, then remove a deck support post to get about 3' of clearance directly in front of camshaft for removal if needed.

 

[kenny nunez]

You need to read up on the procedure for breaking in the new cam and the zink rich oil that is needed otherwise you will be replacing the cam again.

 

[snowbrd84]

Cam lobe seems to be confirmed. Put a dial indicator on the no. 8 intake push rod and only got 0.176 in of lift. No. 2 intake rod got .310.

Time to order a camshaft.

Thanks all for the help. I'm sure I'll be back soon.